CN101512999A - Apparatus for estimating time offset in multiple input multiple output communication system of OFDM or ofdma and method using the same - Google Patents

Abstract

The present invention relates to an apparatus and method for estimating and compensating for a time offset and a carrier frequency offset in a Multiple Input Multiple Output (MIMO) com not munication system that supports Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiplexing Access (OFDMA). According to the present invention, a phase difference of pilot signals of the same transmitting antenna, which are received through receiving antennas, is calculated. An arc tangent operation is then carried out on the phase difference of the pilot signals to calculate a time offset linear phase and/or a carrier frequency offset linear phase. Further, a time offset compensation value and/or a carrier frequency offset compensation value are found by employing the time offset linear phase and/or the carrier frequency offset linear phase. A time offset and/or a carrier frequency offset with respect to pilots and data are compensated for by employing the time offset compensation value and/or the carrier frequency offset compensation value.

Description

Be used for estimating based on the mimo system of OFDM/OFDMA and the make-up time is offset and/or the equipment and the method for carrier shift

Technical field

The present invention relates to a kind of equipment and method of time migration and/or carrier shift being estimated and compensated in multiple-input and multiple-output (MIMO) communication system of being used for, more specifically, relate to a kind of being used for (wherein at mimo wireless communication system, use IEEE 802.16d/e, WiBro and WiMAX standard criterion and support OFDM (OFDM) or OFDM inserts (OFDMA, OFDM)) in equipment and method that time migration and/or carrier shift are estimated and compensated.

Background technology

In the wireless communication system of supporting IEEE 802.16d/e, WiBro and WiMAX standard criterion, for the smooth and easy communication between base station and the terminal, the characteristic of the channel that forms between base station and terminal must be known.For this reason, at first must between base station and terminal, set up synchronously, and the operation of oscillator also must be accurate.Yet, with regard to receiver side, (for example, the multipath characteristics between transmitter side and receiver side and along with terminal or radio wave barrier move and the time-varying characteristics that take place) and generation time skew and carrier shift because various factors.This can cause the receptivity aspect receiver side to be degenerated.Therefore, receiver side skew estimated time consistently and carrier shift and time migration and carrier shift are compensated according to estimated result.

Summary of the invention

Technical problem

Therefore, consider in the prior art the problems referred to above that exist and make the present invention, and the object of the present invention is to provide a kind of time migration estimating apparatus and method thereof that in multiple-input-multiple-output communication system, can be offset estimated value computing time.

Another object of the present invention is to provide a kind of carrier shift estimating apparatus and the method thereof that can calculate the carrier shift estimated value in multiple-input-multiple-output communication system.

Another purpose of the present invention is to provide a kind of can the use in part in multiple-input-multiple-output communication system to estimate under subchannel (PUSC) pattern and the make-up time is offset and time migration and the carrier shift compensation equipment and the method thereof of carrier shift.

Technical solution

For above purpose, according to an aspect of the present invention, a kind of equipment that is used in MIMO communication system skew estimated time of supporting OFDM or OFDMA is provided, this equipment comprises: leading (preamble) linear phase calculator is used for being included in leading in each the received signal frame of a plurality of reception antennas by employing and calculates leading linear phase; Pilot tone linear phase calculator, be used for receiving the signal that sends from a plurality of transmitting antennas that use different pilot frequency designs (pattern), and calculate the pilot tone linear phase by the pilot frequency design that adopts respectively a plurality of transmitting antennas that receive from reception antenna by a plurality of reception antennas; And the time migration arithmetic unit, be used for leading linear phase that calculates by employing and the pilot tone linear phase that calculates and come skew computing time.

According to another aspect of the present invention, be used for comprising: the phase difference arithmetic unit at the equipment of the MIMO communication system estimated frequency skew of supporting OFDM or OFDMA, be used for receiving the signal that sends from a plurality of transmitting antennas that adopt different pilot frequency designs respectively, and calculate respectively the pilot tone of pilot tone transmitting element (transmission unit) of the frame that sends from a plurality of transmitting antennas that receives from reception antenna phase difference between the pilot tone that sends from same transmitting antenna by a plurality of reception antennas; The phase difference accumulator is used for phase difference is added up to generate the phase difference accumulated value; And the frequency shift (FS) arithmetic unit, be used for the phase difference accumulated value is converted to the carrier shift estimated value.

According to another aspect of the present invention, provide a kind of equipment of time migration and carrier shift being compensated at ofdm communication system of being used for, this equipment comprises: pilot signal phase difference operation device is used for calculating according to received signal the phase difference of pilot signal; Time migration and carrier shift linear phase arithmetic unit are used for the phase place of pilot signal is carried out computing, with computing time offset linear phase place and carrier shift linear phase; And time migration and carrier shift offset arithmetic unit, be used for time migration linear phase and carrier shift linear phase are carried out computing, with computing time migration value and carrier shift offset.

According to a further aspect of the invention, a kind of method of skew estimated time in the MIMO communication system of supporting OFDM or OFDMA is provided, and this method may further comprise the steps: be included in leading in each the received signal frame in a plurality of reception antennas by employing and calculate leading linear phase; By a plurality of reception antennas, receive the signal that sends from a plurality of transmitting antennas that use different pilot frequency designs, and calculate the pilot tone linear phase by the pilot frequency design that adopts respectively a plurality of transmitting antennas that receive from reception antenna; And the leading linear phase that calculates by employing and the pilot tone linear phase that calculates are come skew computing time.

According to a further aspect of the invention, the method of estimated frequency skew may further comprise the steps in the MIMO communication system of supporting OFDM or OFDMA: receive the signal that sends from a plurality of transmitting antennas that adopt different pilot frequency designs respectively by a plurality of reception antennas, and calculate the phase difference between the pilot tone that sends from same transmitting antenna the pilot tone of the pilot tone transmitting element of the frame that sends from a plurality of transmitting antennas that receives from reception antenna respectively; Phase difference is added up to generate the phase difference accumulated value; And convert the phase difference accumulated value to the carrier shift estimated value.

In accordance with a further aspect of the present invention, provide a kind of method that in ofdm communication system time migration and carrier shift is compensated, this method may further comprise the steps: the phase difference that calculates the pilot signal in the received signal; Phase difference to pilot signal is carried out computing, with computing time offset linear phase place and carrier shift linear phase; And to time migration linear phase and carrier shift linear phase execution computing, with computing time migration value and carrier shift offset.

Beneficial effect

Can be according to the equipment that is used for estimated time skew of the present invention and method by adopting leading and pilot tone is calculated the time migration estimated value that is used to compensate pilot tone and data phase.

In multiple-input-multiple-output communication system, be used for estimating that according to of the present invention the equipment of carrier shift and method can be by adopting the phase difference between the pilot tone that the pilot tone about transmitting antenna that is received by reception antenna receives from same transmitting antenna, calculating carrier shift estimated value.

In many I/O communications system, equipment and the method that is used for make-up time skew and carrier shift according to the present invention can improve receptivity by skew of estimation and make-up time and/or carrier shift under the PUSC pattern.

Description of drawings

Fig. 1 shows can use according to time migration of the present invention/carrier shift and estimates and the diagrammatic sketch of the principle of down link 2 * 2MIMO system of compensation equipment;

Fig. 2 shows the diagrammatic sketch according to the preamble transmission structure by section of the present invention;

Fig. 3 shows that time migration according to the embodiment of the invention/carrier shift is estimated and the structure of compensation equipment;

Fig. 4 is the detailed construction of the embodiment of the time migration estimation unit shown in Fig. 3;

Fig. 5 is the detailed construction of the embodiment of the leading linear phase calculator shown in Fig. 4;

Fig. 6 is the detailed construction of the embodiment of the pilot tone linear phase calculator shown in Fig. 4;

Fig. 7 shows the diagrammatic sketch of the pilot frequency design of DL (down link) the PUSC pattern in 2 * 2MIMO;

Fig. 8 is according to the OFDMA symbol under the DL PUSC pattern of the present invention and the exemplary diagram of OFDMA subcarrier;

Fig. 9 shows the flow chart according to the time migration estimation method of the embodiment of the invention;

Figure 10 is the detailed operational flowchart of the step S130 of Fig. 9;

Figure 11 is the detailed operational flowchart of the step S140 of Fig. 9;

Figure 12 is the detailed construction of the embodiment of the carrier shift estimation unit shown in Fig. 3;

Figure 13 is the detailed construction of another embodiment of the carrier shift estimation unit shown in Fig. 3;

Figure 14 shows the flow chart according to the carrier shift method of estimation of the embodiment of the invention;

Figure 15 shows the flow chart of carrier shift method of estimation according to another embodiment of the invention;

Figure 16 shows can use according to time migration of the present invention/carrier shift and estimates and the diagrammatic sketch of the principle of up link 2 * 2MIMO system of compensation equipment;

Figure 17 shows the diagrammatic sketch of the pilot frequency design of UL (up link) the PUSC pattern in 2 * 2MIMO;

Figure 18 shows that according to another embodiment of the invention time migration/carrier shift is estimated and the structure of compensation equipment;

Figure 19 is the detailed construction of the embodiment of the skew estimation unit shown in Figure 18;

Figure 20 is the detailed construction of the embodiment of COS shown in Figure 19 and SIN arithmetic unit;

Figure 21 is the detailed construction of another embodiment of the skew estimation unit shown in Figure 18;

Figure 22 shows that time migration according to the embodiment of the invention/carrier shift is estimated and the flow chart of compensation method;

Figure 23 shows the detailed operational flowchart of the embodiment of the step S350 shown in Figure 22; And

Figure 24 shows that according to another embodiment of the invention time migration/carrier shift is estimated and the flow chart of compensation method.

Embodiment

Hereinafter, exemplary embodiment of the present invention will be described with reference to the drawings.Run through the following description and drawings, though components identical is illustrated in different accompanying drawings, components identical is still represented with identical reference number.In addition, in the following description of the present invention, when the detailed description of known function incorporated herein and configuration may make theme of the present invention not know a little, the detailed description of known function and configuration will be omitted.

Before describing in detail, employed in this manual term " communication terminal " is meant the communication terminal of supporting OFDM scheme or OFDMA scheme, preferably, be meant and in the wireless communication system that uses IEEE 802.16d/e, WiBro and WiMAX standard criterion, support PUSC, all use the communication terminal of subchannel (FUSC) and band Adaptive Modulation and Coding (AMC) channelling mode.In addition, the PUSC channelling mode has only been described in detailed description of the present invention.Yet the present invention can also be applied to FUSC and band AMC channelling mode.

In addition, employed in this manual term " wireless communication system " can be meant the system based on one of IEEE 802.16d/e standard, WiBro and WiMAX.

In addition, employed in this manual term " symbol " is meant OFDMA or OFDM symbol.

Can be applied to mimo system according to time migration of the present invention/carrier shift estimation and compensation equipment, and show 2 * 2MIMO.

With reference to figure 1, respectively, base station BS (that is, the transmitter side of wireless communication system) is leading by an antenna transmission among two transmitting antenna TxAnt0, the TxAnt1, and communication terminal MS receives the signal that receives by two reception antenna RxAnt0, RxAnt1.Simultaneously, pilot signal sends and is received by two reception antennas from two transmitting antennas respectively.

Fig. 2 is according to the present invention.As shown in Figure 2, configuration is used to reduce the protection (guard) at interval of the interference of nearby frequency bands on the right side of a plurality of subcarriers and left side, and configuration DC subcarrier (that is gap carrier wave).

In addition, in one section, the conductor carrier wave is arranged in preset distance (Fig. 2 ' 3 '), and it can be used for initial synchronisation, Cell searching, frequency shift (FS) and channel estimating.In addition, targeting signal has than data-signal and the higher signal level of pilot signal, and the signal that helps under disadvantageous channel condition obtains.

Hereinafter, will only the present invention be described with reference to 2 * 2 MIMO.For example, will the present invention be described with reference to the structure of wireless communication system (wherein, communication terminal comprises two reception antennas, and two transmitting antenna received signals from be included in the base station).Yet 2 * 2MIMO only is one embodiment of the present of invention, and the present invention is not limited to this.

Fig. 3 shows that time migration according to the embodiment of the invention/carrier shift is estimated and the structure of compensation equipment.For example, present embodiment is a kind ofly wherein to receive the signal of the DL PUSC pattern that sends from the base station and the embodiment of skew estimated time and carrier shift by communication terminal.

With reference to figure 3, comprise fast Fourier transform (FFT) unit 100, dector 200, skew estimation unit 300, offset compensating unit 400 etc. according to time migration of the present invention/carrier shift estimation and compensation equipment.

FFT unit 100 can comprise a FFT unit 110 separated from one another and the 2nd FFT unit 120.FFT is carried out by the received signal (first received signal and second received signal) of base band that first reception antenna and second reception antenna by communication terminal respectively received in the one FFT unit 110 and the 2nd FFT unit 120, and making spatial transform is frequency domain.The time-domain signal of the base band that receives by first reception antenna and second reception antenna can be transformed to frequency domain by a FFT unit 110 and the 2nd FFT unit 120 respectively, but can be transformed to frequency domain by FFT unit only.

Next received signal after the conversion comprises the separated and targeting signal that extracts, pilot signal, data-signal etc. in dector 200 respectively.In other words, leading extractor 210 extracts leading from first received signal that is converted into frequency domain and second received signal, and with the leading skew estimation unit 300 that is sent to.Pilot extractor 220 extracts pilot tone from first received signal that is converted into frequency domain and second received signal, and pilot tone is sent to skew estimation unit 300.In the case, the pilot tone that sends from two transmitting antennas that is included in the received signal has different pilot frequency designs.

Describe in detail according to time migration estimation unit of the present invention below with reference to Fig. 4 to Figure 11.

As shown in Figure 4, time migration estimation unit 310 comprises leading linear phase calculator 311, pilot tone linear phase calculator 312 and time migration arithmetic unit 313.

Leading linear phase calculator 311 leadingly calculates leading linear phase based on what extract by leading extractor 210.Pilot tone linear phase calculator 312 calculates the pilot tone linear phase by adopting from two transmitting antennas transmissions and by the pilot tone that sends from same transmitting antenna the pilot tone of pilot extractor 220 extractions.In addition, time migration arithmetic unit 313 comes computing is carried out in time migration by adopting the linear phase that is calculated by leading linear phase calculator 311 and pilot tone linear phase calculator 312.The aforesaid time migration that calculates is used for coming the phase change of pilot tone and data is compensated according to time migration at time migration compensating unit 410.

Fig. 5 is the detailed construction of the embodiment of the leading linear phase calculator shown in Fig. 4.

With reference to figure 5, leading linear phase calculator 311 comprises leading phase difference arithmetic unit 311a, leading phase difference accumulator 311b and leading linear phase arithmetic unit 311c.

Can realize leading phase difference arithmetic unit 311a by using the first leading phase difference arithmetic unit and the second leading phase difference arithmetic unit (not shown).The first leading phase difference arithmetic unit and the second leading phase difference arithmetic unit calculate the leading phase difference in the received signal that is included in conversion in a FFT unit 110 and the 2nd FFT unit 120 respectively.In the first leading phase difference arithmetic unit and the second leading phase difference arithmetic unit each all can be exported the value that makes the phase difference that calculates multiply by predetermined preambles weight (weight).Leading weight can have the different value based on each reception antenna.Below having described leading phase difference arithmetic unit 311a constitutes by calculating the first leading phase difference arithmetic unit and the second leading phase difference arithmetic unit that are included in the leading phase difference in the received signal respectively.Yet leading phase difference arithmetic unit 311a can comprise a functional unit, and this functional unit can receive two received signals and the value that is included in the leading phase difference in two received signals has been added in output.

Leading phase difference accumulator 311b can realize by using the first leading phase difference accumulator and the second leading phase difference accumulator (not shown).The first leading phase difference accumulator and the second leading phase difference accumulator are accumulated in the phase difference that calculates in the first leading phase difference arithmetic unit and the second leading phase difference arithmetic unit respectively, and phase difference is added up.Leading phase difference accumulator 311b can comprise a functional unit rather than two leading phase difference accumulators, and exports the value of having added two phase difference accumulated values.

Leading linear phase arithmetic unit 311c will convert leading linear phase to respect to the phase difference accumulated value after the adding up of each leading generation.Leading linear phase arithmetic unit 311c converts the phase difference accumulated value to leading linear phase by the phase difference accumulated value that is generated by the first leading phase difference accumulator and the second leading phase difference accumulator is respectively carried out arctangent cp cp operation.Leading linear phase arithmetic unit 311c can comprise look-up table (write down the phase difference accumulated value in this look-up table and corresponding to the leading linear phase (arc-tangent value) of this phase difference accumulated value), and can the phase difference accumulated value be transformed to leading linear phase with reference to look-up table.

The leading linear phase calculator 311 of as above being constructed can obtain leading linear phase θ by adopting (equation 1) or (equation 2) when the targeting signal that receives shown in Fig. 2 _{TO_pre}

(equation 1)

(equation 2)

Wherein, in each section, p _kBe meant leadingly, k is meant sub-carrier indices (index), and m is meant the reception antenna index, and W0 is meant predetermined leading weight.

As can be seen from (equation 1) and (equation 2), by make the leading phase difference that receives by reception antenna respectively multiply by predetermined leading weights W 0, to being that the phase difference that unit multiply by leading weight adds up, then the phase difference that adds up carried out arctangent cp cp operation with the reception antenna, obtain leading linear phase.In the case, 1/6 means and exists in the conductor carrier index six species diversity to obtain phase difference in each section.In other words, if by leading p _kAnd p _K+2Calculate phase difference, then between two leading pilot tones (preamble pilot), have six sub-carrier indices.The result multiply by 1/6 with arctangent cp cp operation, thereby produces leading linear phase.Thereby the distance that is used to obtain between the leading pilot tone of leading linear phase can change with condition, and the distance between the uncertain pilot tone.In addition, the advantage of (equation 1) is, owing to carrying out arctangent cp cp operation once about the leading phase difference accumulated value that is received by two reception antennas, so compare with (equation 2), can simplify hardware configuration.

Fig. 6 is the detailed construction of the embodiment of the pilot tone linear phase calculator shown in Fig. 4.

With reference to figure 6, pilot tone linear phase calculator 312 comprises pilot phase difference operation device 312a, pilot phase difference accumulator 312b and pilot tone linear phase arithmetic unit 312c.

Pilot phase difference operation device 312a can realize by using the first pilot phase difference operation device and the second pilot phase difference operation device (not shown).The first pilot phase difference operation device and the second pilot phase difference operation device calculate about the phase difference between the pilot tone that receives from same transmitting antenna in the pilot tone (it is included in respectively in the received signal of conversion in a FFT unit 110 and the 2nd FFT unit 120) of a plurality of transmitting antennas under the PUSC channelling mode.In other words, the first pilot phase difference operation device and the second pilot phase difference operation device calculate at phase difference between the pilot tone that receives from the first transmitting antenna TxAnt0 and the phase difference between the pilot tone that receives from the second transmitting antenna TxAnt1.Pilot phase difference operation device 312a can export the value that wherein makes the phase difference that calculates multiply by the predetermined pilot weight.The pilot tone weight can have based on each reception antenna or the different value of troop (cluster).Below describe, pilot phase difference operation device 312a is made of the first pilot phase difference operation device and the second pilot phase difference operation device, and the first pilot phase difference operation device and the second pilot phase difference operation device calculate respectively in being included in received signal and the pilot tone that receives from same transmitting antenna between phase difference.Yet pilot phase difference operation device 312a can comprise a functional unit, and this functional unit can be exported the value of having added two phase differences.Pilot phase difference accumulator 312b can realize by using the first pilot phase difference accumulator and the second pilot phase difference accumulator (not shown).The first pilot phase difference accumulator and the second pilot phase difference accumulator add up respectively to the phase difference that calculates in the first pilot phase difference operation device and the second pilot phase difference operation device, and generate the phase difference accumulated value.Pilot phase difference accumulator 312b can comprise a functional unit rather than two pilot phase difference accumulators, and exports the value of having added two phase difference accumulated values.Pilot tone linear phase arithmetic unit 312c will convert the pilot tone linear phase to from the phase difference accumulated value (that is, from the phase difference accumulated value of first pilot phase difference accumulator generation and the phase difference accumulated value that generates from the second pilot phase difference accumulator) that pilot phase difference accumulator 312b generates.Pilot tone linear phase arithmetic unit 312c converts the phase difference accumulated value to the pilot tone linear phase by the phase difference accumulated value that is generated by pilot phase difference accumulator 312b is carried out arctangent cp cp operation.Pilot tone linear phase arithmetic unit 312c can comprise and wherein write down the phase difference accumulated value and corresponding to the look-up table of the pilot tone linear phase (arc-tangent value) of phase difference accumulated value, and can the phase difference accumulated value be transformed into the pilot tone linear phase with reference to look-up table.

Fig. 7 is the embodiment of the pilot frequency design that sends from two transmitting antennas respectively.Only for reference, the pilot frequency design of Fig. 7 is under DL PUSC pattern.

With reference to figure 7, the signal that sends from each transmitting antenna comprises pilot sub-carrier, data subcarrier and gap carrier wave.As can be seen, pilot sub-carrier has different pilot frequency designs.That is, the first transmitting antenna TxAnt0 sends pilot tone p0, p3, and the gap carrier wave is positioned at the part place of pilot tone p1, the p2 that will send second transmitting antenna.The second transmitting antenna TxAnt1 sends pilot tone p1, p2, and the gap carrier wave is positioned at the part place of pilot tone p0, the p3 that will send first transmitting antenna.Thereby if send two pilot frequency designs shown in Fig. 7, the reception antenna of communication terminal receives pilot frequency design as shown in Figure 8 so.

Below, with reference to figure 8 above-mentioned pilot tone linear phase calculator 312 is described.

If receive the pilot signal of DL PUSC channelling mode as shown in Figure 8, pilot tone linear phase calculator 312 can come by adopting (equation 3) to (equation 6) to obtain pilot tone linear phase θ according to OFDMA notation index value so _{TO_pil}

In other words, in the unit of trooping when the OFDMA notation index shown in Fig. 8 is 0,1,4,5,8,9,12,13,16,17,20,21, can obtain pilot tone linear phase θ 1 by adopting (equation 3) or (equation 4) _{TO_pil}In the unit of trooping when the OFDMA notation index is 2,3,6,7,10,11,14,15,18,19,22,23, can obtain pilot tone linear phase θ 2 by adopting (equation 5) or (equation 6) _{TO_pil}

(equation 3)

${\mathrm{\θ}1}_{\mathrm{TO}\_\mathrm{pil}}=\frac{1}{4}{\tan }^{-1}\left(\frac{\mathrm{Im}\left\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}(\frac{p_0(m,c)\·p_3{(m,c)}^{*}}{|p_0(m,c)\·p_3{(m,c)}^{*}|}\·W1(m,c)+\frac{p_2(m,c)\·p_1{(m,c)}^{*}}{|p_2(m,c)\·p_1{(m,c)}^{*}|}\·W1(m,c))\right\}}{\mathrm{Re}\left\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}(\frac{p_0(m,c)\·p_3{(m,c)}^{*}}{|p_0(m,c)\·p_3{(m,c)}^{*}|}\·W1(m,c)+\frac{p_2(m,c)\·p_1{(m,c)}^{*}}{|p_2(m,c)\·p_1{(m,c)}^{*}|}\·W1(m,c))\right\}}\right)$

(equation 4)

${\mathrm{\θ}1}_{\mathrm{TO}\_\mathrm{pil}}=\frac{1}{2}[\frac{1}{4}{\tan }^{-1}\left(\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·W1(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·W1(m,c)\}}\right)+\frac{1}{4}{\tan }^{-1}\left(\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_2(m,c)\·p_1{(m,c)}^{*}\·W1(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_2(m,c)\·p_1{(m,c)}^{*}\·W1(m,c)\}}\right)]$

(equation 5)

${\mathrm{\θ}2}_{\mathrm{TO}\_\mathrm{pil}}=\frac{1}{12}{\tan }^{-1}\left(\frac{\mathrm{Im}\left\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}(\frac{p_0(m,c)\·p_3{(m,c)}^{*}}{|p_0(m,c)\·p_3{(m,c)}^{*}|}\·W1(m,c)+\frac{p_2(m,c)\·p_1{(m,c)}^{*}}{|p_2(m,c)\·p_1{(m,c)}^{*}|}\·W1(m,c))\right\}}{\mathrm{Re}\left\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}(\frac{p_0(m,c)\·p_3{(m,c)}^{*}}{|p_0(m,c)\·p_3{(m,c)}^{*}|}\·W1(m,c)+\frac{p_2(m,c)\·p_1{(m,c)}^{*}}{|p_2(m,c)\·p_1{(m,c)}^{*}|}\·W1(m,c))\right\}}\right)$

(equation 6)

${\mathrm{\θ}2}_{\mathrm{TO}\_\mathrm{pil}}=\frac{1}{2}[\frac{1}{12}{\tan }^{-1}\left(\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·W1(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·W1(m,c)\}}\right)+\frac{1}{12}{\tan }^{-1}\left(\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_2(m,c)\·p_1{(m,c)}^{*}\·W1(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_2(m,c)\·p_1{(m,c)}^{*}\·W1(m,c)\}}\right)]$

Wherein, p0, p3 are meant the pilot tone that sends from the second transmitting antenna TxAnt1, and p1, p2 are meant the pilot tone that sends from the first transmitting antenna TxAnt0, m is meant the reception antenna index, c is meant clustering index, and W1 is meant predetermined pilot tone weight, and Num is meant the predetermined value by simulation.When channel condition was abominable, the Num value can be set as height, and preferably, maximum is below 720.

As from (equation 3) to (equation 6) as can be seen, can obtain pilot tone linear phase θ 1 by multiply by predetermined pilot tone weights W 1, the phase difference that the phase difference that multiply by the pilot tone weight adds up, obtains adding up then be carried out arctangent cp cp operation from pilot tone p0, p3 or the phase difference between p1, the p2 that same transmitting antenna sends based on each reception antenna _{TO_pil}Or θ 2 _{TO_pil}In (equation 3) and (equation 5), 1/4 and 1/12 means that between the pilot tone shown in Fig. 8 to have four or 12 OFDMA sub-carrier phase poor.In addition, it is evident that equally,, change the value 1/4 and 1/12 shown in (equation 4) and (equation 6) so if the difference of the OFDMA subcarrier between the pilot tone that receives from same transmitting antenna changes.Simultaneously, under the situation of (equation 3) and (equation 5), advantage is, owing to only the phase difference accumulated value about the pilot tone of the DLPUSC channelling mode that receives from two reception antennas is carried out arctangent cp cp operation once, so can simplify hardware configuration.In addition, under the situation of (equation 4) and (equation 6), advantage is, can obtain accurate linear phase values by the arctangent cp cp operation of calculating about each phase difference accumulated value.

If summarize above the description, then can express the pilot tone linear phase θ shown in Fig. 8 with (equation 7) or (equation 8) _{TO_pil}

(equation 7)

${\mathrm{\θ}}_{\mathrm{TO}\_\mathrm{pil}}=\frac{1}{b}{\tan }^{-1}\left\{\frac{\mathrm{Im}\left\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}(\frac{p_0(m,c)\·p_3{(m,c)}^{*}}{|p_0(m,c)\·p_3{(m,c)}^{*}|}\·W1(m,c)+\frac{p_2(m,c)\·p_1{(m,c)}^{*}}{|p_2(m,c)\·p_1{(m,c)}^{*}|}\·W1(m,c))\right\}}{\mathrm{Re}\left\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}(\frac{p_0(m,c)\·p_3{(m,c)}^{*}}{|p_0(m,c)\·p_3{(m,c)}^{*}|}\·W1(m,c)+\frac{p_2(m,c)\·p_1{(m,c)}^{*}}{|p_2(m,c)\·p_1{(m,c)}^{*}|}\·W1(m,c))\right\}}\right\}$

(equation 8)

${\mathrm{\θ}}_{\mathrm{TO}\_\mathrm{pil}}=\frac{1}{2}[\frac{1}{b}{\tan }^{-1}\left(\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·W1(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·W1(m,c)\}}\right)+\frac{1}{b}{\tan }^{-1}\left(\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_2(m,c)\·p_1{(m,c)}^{*}\·W1(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_2(m,c)\·p_1{(m,c)}^{*}\·W1(m,c)\}}\right)]$

Wherein, b is meant from the subcarrier distance between the pilot tone of same transmitting antenna transmission.That is, value b is the dynamic value that c on duty changes when changing.For example, value b can be 4 or 12.It can also be seen that from Fig. 8 OFDMA notation index difference is ' 1 '.OFDMA notation index difference can have the appropriate value that depends on its execution mode.

Can leading according to (equation 1) to (equation 8), only adopt pilot signal or adopt leading and pilot signal is come estimated time skew according to above time migration estimation unit of the present invention by only adopting.That is, when leading weights W 0 is set as ' 0 ', can come skew estimated time by only adopting pilot signal, and when pilot tone weights W 1 is set as ' 0 ', can be by only adopting leading next skew estimated time.In the case, the channel information that can obtain based on the leading channel information that measures from each reception antenna (for example, carrier-in-interference and noise ratio (CINR) information), from pilot measurement waits weighted value is set.

As mentioned above, if leading linear phase θ _{TO_pre}With pilot tone linear phase θ _{TO_pil}Obtain by leading linear phase calculator 311 and pilot tone linear phase calculator 312 respectively, time migration arithmetic unit 313 calculates based on these two values or skew estimated time so.

That is, as shown in (equation 9), come skew computing time according to the linear phase values Phase_TO that has added two linear phase values.

(equation 9)

Phase_TO＝θ _{TO_pre}+θ _{TO_pil}

Fig. 9 shows the flow chart according to the time migration estimation method of the embodiment of the invention, and it shows the operational flowchart of the MIMO communication terminal of supporting DL PUSC channelling mode in based on any the system among IEEE 802.16d/e standard, WiBro and the WiMAX.

With reference to figure 9, in step S110, the time-domain signal of the base band that will be received by a plurality of reception antennas that are included in the communication terminal is transformed into frequency-region signal.Can carry out the conversion of frequency-region signal by FFT.

In step S120, from the received signal that is transformed into frequency domain, extract leading and pilot tone.

In step S130, calculate leading linear phase by using in step S120, extract leading.In a similar fashion, in step S140, calculate the pilot tone linear phase by using the pilot tone that in step S120, extracts.By use from be included in received signal and the pilot tone that receives from same transmitting antenna in the pilot tone relevant with a plurality of transmitting antennas calculate the pilot tone linear phase.

In step S150, come computing is carried out in time migration based on leading linear phase that in step S130 and S140, calculates and pilot tone linear phase.Time migration is used for the variation of pilot tone and data phase is compensated.

Below describe, among above-mentioned steps, calculate the step S130 of leading linear phase and the step S140 of calculating pilot tone linear phase and carry out simultaneously.Yet, can at first carry out in two steps, next carry out in two steps another again.

Fig. 9 is the detailed operational flowchart about the embodiment of the step S130 shown in Fig. 9.

With reference to Figure 10, in step S132, calculate the phase difference be included in respectively between leading in the received signal that receives by reception antenna.In the case, can export the value that the phase difference that wherein makes between leading multiply by predetermined leading weight.Leading weight can have the different value that depends on reception antenna.Can perhaps can export whole values of having added the phase difference that calculates based on each reception antenna based on the phase difference that each reception antenna calculates and output calculates.

In step S134, the phase difference that calculates in step S132 is added up to generate the phase difference accumulated value.In other words, to respectively by reception antenna receive leading between phase difference or the value that phase difference between leading multiply by leading weight is added up, to generate the phase difference accumulated value.The phase difference accumulated value that is generated can be the value of wherein having added about the leading phase difference accumulated value that is received by all reception antennas, perhaps can generate the accumulated value about the leading phase difference that calculates based on each reception antenna.

In step S136, the phase difference accumulated value that will generate in step S134 is transformed into leading linear phase.Promptly, receive the value of wherein having added about the leading phase difference accumulated value that in step S134, calculates that receives by all reception antennas, perhaps, then it is transformed to leading linear phase based on the accumulated value of each reception antenna reception about leading phase difference.Can the phase difference accumulated value be transformed to leading linear phase by arctangent cp cp operation.With reference to wherein having write down the phase difference accumulated value and, can the phase difference accumulated value being transformed into leading linear phase by arctangent cp cp operation corresponding to the look-up table of the leading linear phase (arc-tangent value) of phase difference accumulated value.

In the leading linear phase computing that comprises above step, when the targeting signal that in 2 * 2 MIMO, receives as shown in Figure 2, can obtain leading linear phase θ by adopting (equation 1) _{TO_pre}Provide the description of (equation 1) with reference to time migration estimation unit according to the present invention, and omitted their repeat specification.

Figure 11 is the detailed operational flowchart about the embodiment of the step S140 shown in Fig. 9.

With reference to Figure 11, in step S142, calculate receive by reception antenna respectively and the pilot tone relevant with a plurality of transmitting antennas under the DL PUSC channelling mode in corresponding to the phase difference between the pilot tone of same transmitting antenna.That is, calculate from the pilot tone that a plurality of transmitting antennas send from the phase difference between the pilot tone of same transmitting antenna transmission.In the case, can export the value that the phase difference that wherein makes between the pilot tone multiply by predetermined pilot tone weight.The pilot tone weight can have based on each reception antenna or different value that each is trooped.Can then it be exported based on the phase difference that each reception antenna calculates between the pilot tone that is calculated, perhaps can export the value of wherein all having added the phase difference that calculates based on each reception antenna.

In step S144, the phase difference that calculates in step S142 is added up to generate the phase difference accumulated value.In other words, in the received signal that is included in reception antenna respectively that can add up and from the phase difference between the pilot tone that sends at a plurality of same transmitting antenna under the DL PUSC channelling mode or wherein make phase difference between the pilot tone multiply by the value of pilot tone weight, to generate the phase difference accumulated value.The phase difference accumulated value that is generated can be the value of wherein having added about the phase difference accumulated value of the pilot tone that received by all reception antennas, perhaps can generate the accumulated value about the phase difference between the pilot tone that calculates based on each reception antenna.

In step S146, it is poor that the phase difference accumulated value that will generate in step S144 is transformed into pilot phase.That is, receive the value of wherein having added the pilot phase difference accumulated value that in step S144, calculates, perhaps, then it is transformed into the pilot tone linear phase based on the accumulated value of each reception antenna reception about the phase difference between the pilot tone based on each reception antenna.Can the phase difference accumulated value be transformed into the pilot tone linear phase by arctangent cp cp operation.With reference to wherein having write down the phase difference accumulated value and, can the phase difference accumulated value being transformed into the pilot tone linear phase by arctangent cp cp operation corresponding to the look-up table of the pilot tone linear phase arc-tangent value of phase difference accumulated value.

In the pilot tone linear phase computing that comprises above step, when the pilot signal that in 2 * 2MIMO, receives shown in Fig. 8, can obtain pilot tone linear phase θ by adopting (equation 3) and (equation 5) or (equation 7) or (equation 4) and (equation 6) or (equation 8) _{TO_pil}Describe (equation 3) to (equation 8) with reference to time migration estimation unit according to the present invention, and omitted being repeated in this description of they.

Describe in detail according to carrier shift estimation unit of the present invention below with reference to Figure 12 to Figure 15.

As shown in figure 12, carrier shift estimation unit 320 comprises phase difference arithmetic unit 321, phase difference accumulator 322, arctangent cp cp operation device 323, frequency translation arithmetic unit 324 and average frequency arithmetic unit 325.

Phase difference arithmetic unit 321 calculate the pilot tone transmitting element (trooping) that from the pilot tone that pilot extractor 220 extracts, is included in frame about two transmitting antennas and the pilot tone (that is pilot tone (pilot tone)) that sends from same transmitting antenna between phase difference.Phase difference arithmetic unit 321 can be realized by using the first phase difference arithmetic unit and the second phase difference arithmetic unit (not shown).The first phase difference arithmetic unit calculate be included in first received signal and the pilot tone relevant with two reception antennas in phase difference between the pilot tone that sends from first reception antenna and the phase difference between the pilot tone that sends from second transmitting antenna.The second phase difference arithmetic unit calculate be included in second received signal and the pilot tone relevant with two transmitting antennas in phase difference between the pilot tone that sends from first transmitting antenna and the phase difference between the pilot tone that sends from second transmitting antenna.

The first phase difference arithmetic unit and the second phase difference arithmetic unit can be exported the value that makes the phase difference that calculates multiply by predefined weight.Weight can have based on each reception antenna or different value that each is trooped.In addition, can weight be set based on the CINR value.

The accumulated value that phase difference accumulator 322 generates about the phase difference that calculates in phase difference arithmetic unit 321.Phase difference accumulated value 322 can be realized by using the first phase difference accumulator and the second phase difference accumulator (not shown).The first phase difference accumulator generates the accumulated value about the phase difference that calculates in the first phase difference arithmetic unit.The second phase difference accumulator generates the accumulated value about the phase difference that calculates in the second phase difference arithmetic unit.Certainly, when making phase difference multiply by weight, generate the phase difference accumulated value that multiply by weight.

Arctangent cp cp operation device 323 converts the phase difference accumulated value that generates to linear phase values by the phase difference accumulated value is carried out arctangent cp cp operation in phase difference accumulator 322.Arctangent cp cp operation device 323 can be realized by using the first arctangent cp cp operation device and the second arctangent cp cp operation device (not shown).The first arctangent cp cp operation device will convert arc-tangent value to from the phase difference accumulated value that the first phase difference accumulator generates.The second arctangent cp cp operation device will convert arc-tangent value to from the phase difference accumulated value that the second phase difference accumulator generates.The arctangent cp cp operation device can comprise and wherein write down the phase difference accumulated value and corresponding to the look-up table of the arc-tangent value (that is linear phase values) of phase difference accumulated value.Can the phase difference accumulated value be transformed into linear phase values with reference to look-up table.

Frequency translation arithmetic unit 334 converts the linear phase values of Rad to the carrier shift estimated value of frequency (Hz) unit.Measure error for the carrier shift that prevents to occur owing to the flip-flop of channel condition etc. can dispose average frequency arithmetic unit 325 in addition.

Average frequency arithmetic unit 325 generates the mean value of the carrier shift estimated value that measures about the frame every received signal.The method that generates mean value can comprise the method for using loop filter, obtain the method etc. of the mean value of the carrier shift that measured by terminal during predetermined frame.

The carrier shift that this processing measures can be passed through the error correction of automatic frequency controller (AFC) through oscillator, thereby the receptivity that prevents communication terminal reduces.

The linear phase θ of the carrier shift that can obtain by above Structure Calculation with (equation 10) or (equation 11) expression _CFOThe linear phase values of 323 conversion of arctangent cp cp operation device (that is, by).

(equation 10)

${\mathrm{\θ}}_{\mathrm{CFO}}=\frac{1}{2}[{\tan }^{-1}\left(\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·w(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·w(m,c)\}}\right)+{\tan }^{-1}\left(\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_1(m,c)\·p_2{(m,c)}^{*}\·w(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_1(m,c)\·p_2{(m,c)}^{*}\·w(m,c)\}}\right)]$

(equation 11)

${\mathrm{\θ}}_{\mathrm{CFO}}={\tan }^{-1}\left(\frac{\mathrm{Im}\left\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}(\frac{p_0(m,c)\·p_3{(m,c)}^{*}}{|p_0(m,c)\·p_3{(m,c)}^{*}|}\·w(m,c)+\frac{p_2(m,c)\·p_1{(m,c)}^{*}}{|p_2(m,c)\·p_1{(m,c)}^{*}|}\·w(m,c))\right\}}{\mathrm{Re}\left\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}(\frac{p_0(m,c)\·p_3{(m,c)}^{*}}{|p_0(m,c)\·p_3{(m,c)}^{*}|}\·w(m,c)+\frac{p_2(m,c)\·p_1{(m,c)}^{*}}{|p_2(m,c)\·p_1{(m,c)}^{*}|}\·w(m,c))\right\}}\right)$

Wherein, p0, p3 are meant the pilot tone that sends from the first transmitting antenna TxAnt0, and p1, p2 are meant the pilot tone that sends from the second transmitting antenna TxAnt1, m is meant the reception antenna index, c is meant clustering index, and w is meant predefined weight, and Num is meant by simulating definite value.When channel condition was relatively poor, the Num value can be set as height, and preferably, maximum is below 720.

As can be seen from (equation 10) and (equation 11), can by make receive by reception antenna respectively and the pilot tone relevant with two transmitting antennas in phase difference between the pilot tone that sends from same transmitting antenna multiply by predefined weight w, add up based on each reception antenna and multiply by the phase difference of weight, carry out arctangent cp cp operation then, perhaps by making phase difference multiply by weight about the pilot tone that sends from same transmitting antenna, obtain based on each reception antenna or based on each value of the phase difference that multiply by weight of adding up of trooping, then the phase difference accumulated value about the pilot tone that sends from each transmitting antenna is carried out arctangent cp cp operation, obtain the linear phase θ of carrier shift _CFOPromptly, can be by obtaining about the accumulated value of the phase difference between the pilot tone that sends from transmitting antenna, then each phase difference accumulated value being carried out arctangent cp cp operation, perhaps the accumulated value by wherein having been added the phase difference between the pilot tone that sends from two transmitting antennas, carry out arctangent cp cp operation then, obtain the linear phase values of carrier shift.

Only for reference, the advantage of (equation 10) is, can be by the phase difference accumulated value corresponding to the pilot tone of two transmitting antennas is carried out the exact value that arctangent cp cp operation obtains linear phase.The advantage of (equation 11) is, owing to only the phase difference accumulated value being carried out arctangent cp cp operation once, so it can simplify hardware configuration.

To be transformed to the carrier shift estimated value by the linear phase that (equation 10) or (equation 11) obtain and this carrier frequency frequency estimation will be inputed to AFC by frequency translation arithmetic unit 334 and average frequency arithmetic unit 335.The carrier shift estimated value that inputs to AFC can be represented with (equation 12).

(equation 12)

f _current[Hz]＝f _previous+α·Gain·θ _CFO

Wherein, f _CurrentBe meant the carrier shift estimated value that measures at the present frame place, f _PreviousBe meant the carrier shift estimated value that average computation obtains before former frame, Gain is meant the parameter that is used for the phase value of Rad is converted to the value of cps, and α is meant the filter coefficient when loop filter is used for the mean value computing, and θ _CFOBe meant the linear phase of carrier shift.

Simultaneously, can realize that carrier shift estimation unit 320 according to the present invention is to estimate carrier shift by the pilot tone that adopts its time skew to be compensated.That is, carrier shift estimation unit 320 is configured to compensating about the time migration that sends and be included in the pilot tone the received signal from two transmitting antennas, and obtains carrier shift by the pilot tone that adopts its time skew to be compensated.

As shown in figure 13, can calculate the carrier shift estimated value by the pilot tone that has been compensated from its time skew of time migration compensating unit 410 receptions.Alternatively, as shown in Figure 3, can calculate the carrier shift estimated value by directly the time migration estimated value being compensated then from time migration estimation unit 310 time of receptions skew estimated value.

The linear phase θ that can represent the carrier shift that calculates by above structure with (equation 13) to (equation 16) _CFO(that is the linear phase values that obtains by the conversion of arctangent cp cp operation device).

(equation 13)

${\mathrm{\θ}}_{\mathrm{CFO}}={\tan }^{-1}\left\{\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·w(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·w(m,c)\}}\right\}$

(equation 14)

${\mathrm{\θ}}_{\mathrm{CFO}}={\tan }^{-1}\left\{\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_1(m,c)\·p_2{(m,c)}^{*}\·w(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_1(m,c)\·p_2{(m,c)}^{*}\·w(m,c)\}}\right\}$

(equation 15)

${\mathrm{\θ}}_{\mathrm{CFO}}={\tan }^{-1}\left\{\frac{\mathrm{Im}\left\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}(\frac{p_0(m,c)\·p_3{(m,c)}^{*}}{|p_0(m,c)\·p_3{(m,c)}^{*}|}\·w(m,c))\right\}}{\mathrm{Re}\left\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}(\frac{p_0(m,c)\·p_3{(m,c)}^{*}}{|p_0(m,c)\·p_3{(m,c)}^{*}|}\·w(m,c))\right\}}\right\}$

(equation 16)

${\mathrm{\θ}}_{\mathrm{CFO}}={\tan }^{-1}\left\{\frac{\mathrm{Im}\left\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}(\frac{p_1(m,c)\·p_2{(m,c)}^{*}}{|p_1(m,c)\·p_2{(m,c)}^{*}|}\·w(m,c))\right\}}{\mathrm{Re}\left\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}(\frac{p_1(m,c)\·p_2{(m,c)}^{*}}{|p_1(m,c)\·p_2{(m,c)}^{*}|}\·w(m,c))\right\}}\right\}$

As from (equation 13) to (equation 16) as can be seen, under to pilot tone p0, p1, p2 and the p3 state that the make-up time has been offset that sends from two transmitting antennas, can be by the phase difference accumulated value between the pilot tone that sends from a transmitting antenna be carried out the linear phase that arctangent cp cp operation obtains carrier shift.Promptly, have the make-up time skew and multiply by weight by making from the pilot tone p0 of first transmitting antenna transmission, the phase difference between the p3, and, can obtain the linear phase of carrier shift to by carrying out arctangent cp cp operation based on each reception antenna with based on each phase difference accumulated value that the phase difference that multiply by weight generates that adds up of trooping.Alternatively, have the make-up time skew and multiply by weight by making from the pilot tone p1 of second transmitting antenna transmission, the phase difference between the p3, and, can obtain the linear phase of carrier shift to by carrying out arctangent cp cp operation based on each reception antenna with based on each phase difference accumulated value that the phase difference that multiply by weight generates that adds up of trooping.

Figure 14 shows the flow chart according to the carrier shift method of estimation of the embodiment of the invention.The carrier shift method of estimation of Figure 14 is configured to by adopting the phase difference between pilot tone relevant with a plurality of transmitting antennas and that send from same transmitting antenna from the pilot tone that a plurality of reception antennas (with reference to figure 8) receive to estimate carrier shift.To describe according to carrier shift method of estimation of the present invention with respect to only 2 * 2 MIMO that in based on any the system among IEEE 802.16d/e standard, WiBro and the WiMAX, support DL PUSC pattern.Yet the present invention is not limited to 2 * 2 MIMO.

With reference to Figure 14, in step S210, the time-domain signal of the base band that first reception antenna that will be from be included in communication terminal and second reception antenna receive is transformed into frequency-region signal.Can carry out this conversion by FFT to frequency-region signal.

In step S220, calculate the phase difference between the pilot tone that from the pilot tone that first reception antenna and second reception antenna receive, sends from same transmitting antenna.That is, calculate from the phase difference between the pilot tone of first transmitting antenna transmission with from the phase difference between the pilot tone of second transmitting antenna transmission by the phase difference arithmetic unit.In the case, the phase difference that each is calculated multiply by predefined weight, and can calculate phase difference based on reception antenna.Weight can have based on each reception antenna or based on the different value of trooping, and weight can be provided with based on the CINR value.

In step S230,, thereby generate the phase difference accumulated value based on each reception antenna with based on each phase difference between the pilot tone that sends from first transmitting antenna and phase difference between the pilot tone that sends from second transmitting antenna of adding up of trooping.

In step S240, the phase difference accumulated value that is generated is carried out arctangent cp cp operation, so that the phase difference accumulated value is converted to the linear phase values (that is arc-tangent value) of carrier shift.The arctangent cp cp operation device can be with reference to wherein having write down the phase difference accumulated value and corresponding to the look-up table of the arc-tangent value (linear phase values) of phase difference accumulated value the phase difference accumulated value being transformed into linear phase values.

In step S250, the linear phase values that will have Rad is transformed into the carrier shift estimated value of frequency (Hz) unit.For the measure error of the carrier shift that prevents to occur owing to the flip-flop of channel condition etc., can add the processing of generation in addition about the mean value of carrier shift estimated value.

In other words, in step S260, the mean value of the carrier shift estimated value that the frame every received signal measures can be generated, carrier shift estimated value still stable under the situation that causes change by channel condition can be generated even make.Generation can comprise the method for using loop filter, obtains the method etc. of the mean value of the carrier shift that measured by terminal during predetermined frame about the method for the mean value of carrier shift estimated value.

Simultaneously, Figure 15 shows the flow chart of carrier shift method of estimation according to another embodiment of the invention.Compare with the carrier shift method of estimation of Figure 14, the carrier shift method of estimation of Figure 15 also comprises: step S215 before estimating carrier shift, compensates the time migration about pilot tone.

In other words, between step S210 and step S215, come the time migration of estimating corresponding to the pilot tone of same transmitting antenna by employing is compensated with respect to the signal that receives by first reception antenna and second reception antenna.Can carry out reference for being used for to above description to technology about estimating or compensate corresponding to the time migration of the pilot tone of same transmitting antenna.

Simultaneously, about Figure 14 and Figure 15, in implementing, can carry out estimation respectively about corresponding to the processing of the carrier shift of the pilot tone of first transmitting antenna with estimate about processing corresponding to the carrier shift of the pilot tone of second transmitting antenna according to carrier shift method of estimation of the present invention.One in the processing can be at first carried out, in the processing another can be carried out then.

Hereinafter, time migration/carrier shift of describing according to another embodiment of the invention referring to figures 16 to Figure 21 is estimated and compensation equipment.Only for reference, in the present embodiment, as shown in figure 16, wherein base station reception has been described from the signal of the UL PUSC pattern of communication terminal transmission and 2 * 2 MIMO types of skew estimated time and carrier shift.Yet present embodiment is not limited to the type of Figure 16, but can be applied to down link.

With reference to Figure 16, communication terminal MS (promptly, the transmitter side of wireless communication system) sends pilot frequency design pilot_A, pilot_B by two transmitting antenna TxAnt0, TxAnt1 with different pattern, and base station BS (that is the receiver side of wireless communication system) receives received signal by two reception antenna RxAnt0, RxAnt1.

Figure 17 shows the diagrammatic sketch of the pilot frequency design of the UL PUSC pattern in 2 * 2MIMO.Figure 17 a is the time migration in a piece (tile) and the diagrammatic sketch of carrier shift.Figure 17 b shows pilot frequency design pilot_A, the pilot_B that sends from each transmitting antenna in 2 * 2MIMO.

With reference to figure 17a, in UL PUSC piece, transverse axis is represented the notation index axle, and the longitudinal axis is represented the carrier frequency index axle.In addition, P0 to P3 represents from the pilot tone of transmitting antenna transmission, and d represents data.Therefore, such as

Carrier shift generate according to pilot tone P0 about notation index axle (transverse axis) direction, and such as

With

Time migration generate according to pilot tone P0 about carrier frequency index axle (longitudinal axis) direction.

With reference to figure 17b, the first transmitting antenna TxAnt0 of communication terminal MS sends the pilot signal pilot tone _ A with first pilot frequency design, the second transmitting antenna TxAnt1 sends the pilot signal pilot tone _ B with second pilot frequency design, and the first reception antenna RxAnt0 of base station BS and the second reception antenna RxAnt1 receive all pilot signals that send from two transmitting antennas.

Simultaneously, Figure 18 shows that according to another embodiment of the invention time migration/carrier shift is estimated and the structure of compensation equipment.

With reference to Figure 18, comprise FFT unit 100, pilot extractor 220, skew estimation unit 300, offset compensating unit 400 etc. according to time migration of the present invention/carrier shift estimation and compensation equipment.

Simply they are described.FFT unit 100 is carried out FFT by the received signal (first received signal and second received signal) of base band that first reception antenna and second reception antenna by the base station are received time domain is converted to frequency domain.Pilot extractor 220 is extracted pilot tone from first received signal that is transformed to frequency domain and second received signal, and pilot tone is sent to skew estimation unit 300.Pilot tone estimated time skew and/or the carrier shift of skew estimation unit 300 from being extracted.400 pairs of estimated time migrations of offset compensating unit and/or carrier shift compensate.

For the detailed description of composed component, can carry out reference to the description that provides with reference to figure 3.Thereby, omitted the detailed description of composed component.Another embodiment of skew estimation unit 300 is below described.Only for reference, to not have the structure that comprises time migration estimation unit 310 and carrier shift estimation unit 320 as shown in Figure 3 referring to figures 19 through the skew estimation unit 300 that Figure 21 describes, estimate relevant element but can be divided into time migration estimation and carrier shift.

With reference to Figure 19, skew estimation unit 300 according to the present invention comprises time migration and carrier shift linear phase arithmetic unit (hereinafter, being called " TO/CFO linear phase arithmetic unit ") 330 and COS and SIN arithmetic unit 340.

TO/CFO linear phase arithmetic unit 330 calculates the pilot signal of extracting from pilot extractor 220 corresponding to the phase difference between the pilot signal of same transmitting antenna, and the linear phase of skew computing time and carrier shift.For example, can carry out arctangent cp cp operation to the phase difference between the pilot signal, so as computing time the offset linear phase theta _TOWith carrier shift linear phase θ _CFO

COS and SIN arithmetic unit 340 pass through time migration linear phase θ _TOWith carrier shift linear phase θ _CFOCarry out cosine and sinusoidal computing and come migration value and carrier shift offset computing time.

Figure 20 is the detailed construction of the embodiment of COS and SIN arithmetic unit.As shown in the figure, COS and SIN arithmetic unit comprise: COS and SIN computing module 341 are used for time migration linear phase θ _TOWith carrier shift linear phase θ _CFOCarry out cosine and sinusoidal computing, to calculate very first time migration value cos (θ _TO), sin (θ _TO) and the first carrier shift offset cos (θ _CFO), sin (θ _CFO); And double angle formula computing module 342, be used for the very first time migration value and the first carrier shift offset are carried out double angle formula, to calculate the second time migration offset cos (θ _TO), sin (θ _TO) and second carrier shift offset cos (2 θ _CFO), sin (2 θ _CFO).That is, obtain at time migration linear phase θ by COS and SIN computing module 341 _TOWith carrier shift linear phase θ _CFOIn by " COS and SIN (XilinxCordic) " compensation cos (θ _TO), sin (θ _TO), cos (θ _CFO) and sin (θ _CFO), and by remaining offset cos (2 θ of double angle formula computing module 342 calculating _TO), sin (2 θ _TO), cos (2 θ _CFO), sin (2 θ _CFO), cos (3 θ _TO), sin (3 θ _TO), cos (3 θ _CFO), sin3 (θ _CFO) ....Double angle formula by 342 computings of double angle formula computing module is identical with the equation shown in (equation 17).Double angle formula is used for obtaining about times a cosine of an angle value and a sine value by the loop computation that repeats.

(equation 17)

sin(nθ _TO)＝2sin((n-1)θ _TO)cos(θ _TO)-sin((n-2)θ _TO)

cos(nθ _TO)＝2cos((n-1)θ _TO)cos(θ _TO)-cos((n-2)θ _TO)

sin(nθ _CFO)＝2sin((n-1)θ _CFO)cos(θ _CFO)-sin((n-2)θ _CFO)

cos(nθ _CFO)＝2cos((n-1)θ _CFO)cos(θ _CFO)-cos((n-2)θ _CFO)

Yet, be not limited to the above formula shown in (equation 17) by the double angle formula of double angle formula computing module 342 computings of the present invention, but can comprise the known any formula of those of ordinary skill in the art.Time migration offset that calculates and the carrier shift offset that calculates are used in offset compensating unit 400 time migration and carrier shift being compensated.

Simultaneously, Figure 21 shows another embodiment of the skew estimation unit 300 shown in Figure 18.With reference to Figure 21, skew estimation unit 300 according to the present invention comprises time migration phase difference arithmetic unit 351, carrier shift phase difference arithmetic unit 352, the first square root calculation device 353 and the second square root calculation device 354.

Time migration phase difference arithmetic unit 351 is offset phase difference computing time according to the pilot signal of being extracted by pilot extractor 220 corresponding to same transmitting antenna.In a comparable manner, carrier shift phase difference arithmetic unit 352 calculates the carrier shift phase difference according to the pilot signal of being extracted by pilot extractor 220 corresponding to same transmitting antenna.For example, under the situation of the pilot tone that adopts the UP PUSC pattern shown in Figure 17, time migration phase difference arithmetic unit 351 can be exported

(that is, the time migration phase difference), and carrier shift phase difference arithmetic unit 352 can be exported

(that is carrier shift phase difference).

In addition, be used to obtain the first square root calculation device, 353 employing trigonometric functions, 1/3rd angle formula of 1/3rd angles to the time migration phase difference

Carry out computing to obtain

Adopt trigonometric function 2 double angle formulas to resulting Carry out computing to obtain

And output valve With

In addition, be used to obtain the second square root calculation device, the 354 employing trigonometric function half-angle formulass of half-angle to the carrier shift phase difference

Carry out computing to obtain

Output valve then

Following (equation 18) shows employed formula in the first square root calculation device 353 and the second square root calculation device 354.

(equation 18)

$\cos \frac{\mathrm{\θ}}{2}=\sqrt{\frac{1+\cos \mathrm{\θ}}{2}}$ $\sin \frac{\mathrm{\θ}}{2}=\±\sqrt{\frac{1-\cos \mathrm{\θ}}{2}}$

$\cos \frac{\mathrm{\θ}}{3}=\sqrt{\frac{\cos \mathrm{\θ}+3}{4}}$ $\sin \frac{\mathrm{\θ}}{3}=\sqrt{\frac{\sin \mathrm{\θ}-3}{-4}}$

In addition, time migration offset and carrier shift offset are to calculate by the method such as newton's method, convergence method and binomial series method.These values are used in compensating offset compensating unit 400 time migration and carrier shift be compensated.Hereinafter, time migration and the carrier shift of describing according to another embodiment of the invention with reference to Figure 22 to Figure 24 is estimated and compensation method.

With reference to Figure 22, in step S310, the time-domain signal of the base band that will be received by a plurality of reception antennas that are included in communication terminal is transformed into frequency-region signal.Can carry out this conversion by FFT to frequency-region signal.In step S320, extract pilot tone respectively from the received signal that is transformed into frequency domain.

At step S330, by adopting the pilot tone that sends from same transmitting antenna in the pilot tone in step S320, extract to calculate to be used for phase difference that time migration estimates (hereinafter, be called " time migration phase difference ") and be used for the phase difference (hereinafter, being called " carrier shift phase difference ") that carrier shift is estimated.

In step S340, the time migration phase difference and the carrier shift phase difference that have calculated are carried out arctangent cp cp operation, in step S330 with computing time offset linear phase place and carrier shift linear phase.

In step S350, COS and SIN arithmetic unit are to time migration linear phase θ _TOWith carrier shift linear phase θ _CFOCarry out cosine and sinusoidal computing, with migration value C computing time _TOCos (θ _TO), sin (θ _TO), cos (2 θ _TO), sin (2 θ _TO), cos (3 θ _TO), sin (3 θ _TO) ..., and carrier shift offset CC _FOCos (θ _CFO), sin (θ _CFO), cos (2 θ _CFO), sin (2 θ _CFO), cos (3 θ _CFO), sin (3 θ _CFO) ....

At last, in step S360, pilot tone and data computation time migration offset that obtains and the carrier shift offset that calculates are come time migration and carrier shift are compensated by reflection.

Figure 23 shows the detailed operational flowchart of the embodiment of the step S350 shown in Figure 22.

With reference to Figure 23, in step S352, COS and SIN computing module are to time migration linear phase θ _TOWith carrier shift linear phase θ _CFOCarry out cosine and sinusoidal computing respectively, with calculated value cos (θ _TO), sin (θ _TO), cos (θ _CFO) and sin (θ _CFO).

In step S354, the double angle formula computing module is by adopted value cos (θ _TO), sin (θ _TO), cos (θ _CFO) and sin (θ _CFO) come migration value C computing time _TOCos (θ _TO), sin (θ _TO), cos (2 θ _TO), sin (2 θ _TO), cos (3 θ _TO), sin (3 θ _TO) ..., and carrier shift offset C _CFOCos (θ _CFO), sin (θ _CFO), cos (2 θ _CFO), sin (2 θ _CFO), cos (3 θ _CFO), sin (3 θ _CFO) ....

Simultaneously, Figure 24 shows that according to another embodiment of the invention time migration/carrier shift is estimated and the flow chart of compensation method.

In step S410, the time-domain signal of the base band that will receive by a plurality of reception antennas that are included in the communication terminal is transformed to frequency-region signal.Can carry out this conversion by FFT to frequency-region signal.In step S420, from the received signal that is transformed into frequency domain, extract pilot tone respectively.At step S430, come to be offset computing time phase difference and carrier shift phase difference by adopting the pilot tone that sends from same transmitting antenna in the pilot tone of in step S420, extracting.In step S440, divide formula by the trigonometric function arc, come migration value C computing time based on time migration phase difference that in step S430, has calculated and carrier shift phase difference _TOWith carrier shift offset C _CFODivide formula for the arc that is applied to time migration phase difference and carrier shift phase difference respectively, can carry out reference the description that provides with reference to (equation 18).At last, in step S450, pilot tone and data computation are obtained the time migration offset and the carrier shift offset that calculates comes time migration and carrier shift are compensated by reflection.Described at present according to time migration of the present invention/carrier shift estimation and compensation equipment and method thereof.Can wait and realize by using ASIC, digital signal processor (DSP), field programmable gate array (FPGA), programmable logic array (PLA), CPLD (CPLD), GAL (GAL) according to time migration of the present invention/carrier shift estimation and compensation equipment.

Simultaneously, employed function can be used as the code that computer can read and realizes in the storage medium of embodied on computer readable in equipment that discloses in the present invention and the method.The storage medium of embodied on computer readable comprises the registering device of all kinds, and wherein, having stored can be by the data of computer system reads.The example of the storage medium of embodied on computer readable comprises ROM, RAM, CD-ROM, tape, floppy disk, photonics data memory devices etc., and comprises the things (for example, sending by the Internet) that embodies with carrier format.In addition, in the computer system that the storage medium of embodied on computer readable is distributed in network is connected.Then, in distribution scheme with the code storage of embodied on computer readable in distributed storage media, and can be in distribution scheme operation code.

Though illustrate and described the present invention with reference to exemplary embodiments more of the present invention, but it will be apparent to those skilled in the art that, under the situation that does not deviate from the spirit and scope of the present invention, can make various changes in form and details, therefore, the spirit and scope of the present invention must be can't help the described embodiment of the invention and be limited, but are limited by the equivalent of claims and claims.

Claims (88)

1. equipment that is used in skew multiple-input and multiple-output (MIMO) communication system estimated time, described multiple-input-multiple-output communication system supports OFDM (OFDM) or OFDM to insert (OFDMA), described equipment comprises:

Leading linear phase calculator is used for being included in leading in each the received signal frame of a plurality of reception antennas by employing and calculates leading linear phase;

Pilot tone linear phase calculator, be used for receiving the signal that sends from a plurality of transmitting antennas that use different pilot frequency designs, and calculate the pilot tone linear phase by the described pilot frequency design that adopts respectively the described a plurality of transmitting antennas that receive from described reception antenna by described a plurality of reception antennas; And

The time migration arithmetic unit is used for leading linear phase that calculates by employing and the pilot tone linear phase that calculates and comes skew computing time.

2. equipment according to claim 1, wherein, described leading linear phase calculator comprises:

Leading phase difference arithmetic unit is used for calculating about being included in the leading phase difference of each described received signal frame;

Leading phase difference accumulator is used for described phase difference is added up to generate the phase difference accumulated value; And

Leading linear phase arithmetic unit is used for described phase difference accumulated value is converted to leading linear phase.

3. equipment according to claim 2, wherein, described leading phase difference arithmetic unit output wherein makes the phase difference that calculates multiply by the value of predetermined preambles weight.

4. equipment according to claim 1, wherein, by each described reception antenna receive described leading be that a predetermined transmitting antenna from described a plurality of transmitting antennas receives.

5. equipment according to claim 1, wherein, described pilot tone linear phase calculator comprises:

Pilot phase difference operation device is used for calculating at the phase difference of the pilot tone that sends from described a plurality of transmitting antennas based on each pilot tone that receives from same transmitting antenna;

Pilot phase difference accumulator is used for described phase difference is added up to generate the phase difference accumulated value; And

Pilot tone linear phase arithmetic unit is used for converting described phase difference accumulated value to the pilot tone linear phase.

6. equipment according to claim 5, wherein, described pilot phase difference operation device output wherein makes the phase difference that calculates multiply by the value of predetermined pilot weight.

7. equipment according to claim 6, wherein, described pilot tone weight has based on each reception antenna or based on each different value of trooping.

8. equipment according to claim 6, wherein, described pilot tone weight is based on carrier-in-interference and noise ratio (CINR) value is provided with.

9. equipment according to claim 1, wherein, described time migration estimating apparatus is applied to 2 * 2 MIMO.

10. equipment according to claim 9, wherein, described leading linear phase calculator calculates described leading linear phase according to following (equation).

(equation)

(in each section, p _kBe meant leadingly, k is meant sub-carrier indices, and m is meant the reception antenna index, and W0 is meant the predetermined preambles weight, and 3a is meant p _kAnd p _K+aBetween subcarrier distance)

11. equipment according to claim 9, wherein, described pilot tone linear phase calculator calculates described pilot tone linear phase according to following (equation).

(equation)

(p0, p3 are meant the pilot tone that sends from the second transmitting antenna TxAnt1, p1, p2 are meant the pilot tone that sends from the first transmitting antenna TxAnt0, m is meant the reception antenna index, c is meant clustering index, W1 is meant the predetermined pilot weight, b is meant the subcarrier distance between the pilot tone that sends from same transmitting antenna that depends on c, and Num is meant by simulating predetermined value)

12. equipment according to claim 9, wherein, described pilot tone linear phase calculator calculates described pilot tone linear phase according to following (equation).

(equation)

${\mathrm{\θ}}_{\mathrm{TO}\_\mathrm{pil}}=\frac{1}{2}[\frac{1}{b}{\tan }^{-1}\left(\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·W1(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·W1(m,c)\}}\right)+\frac{1}{b}{\tan }^{-1}\left(\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_2(m,c)\·p_1{(m,c)}^{*}\·W1(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_2(m,c)\·p_1{(m,c)}^{*}\·W1(m,c)\}}\right)]$

(p0, p3 are meant the pilot tone that sends from the second transmitting antenna TxAnt1, p1, p2 are meant the pilot tone that sends from the first transmitting antenna TxAnt0, m is meant the reception antenna index, c is meant clustering index, W1 is meant the predetermined pilot weight, b is meant the subcarrier distance between the pilot tone that sends from same transmitting antenna that depends on c, and Num is meant by simulating predetermined value)

13. equipment according to claim 1, wherein;

The received signal that receives by each described reception antenna comprises baseband signal, and

Described equipment also comprises: fast Fourier transform (FFT) unit, the described baseband signal of each described reception antenna is carried out Fourier transform.

14. equipment according to claim 1, wherein, described leading linear phase calculator calculates about being included in the described leading phase difference in the described received signal frame based on reception antenna, the phase difference that calculates is added up with generation phase difference accumulated value, and the phase difference accumulated value that is generated is converted to leading linear phase.

15. equipment according to claim 1, wherein, described leading linear phase calculator calculates about being included in the described leading phase difference in the described received signal frame with respect to described a plurality of reception antennas, the phase difference that calculates is added up with generation phase difference accumulated value, and the phase difference accumulated value that is generated is converted to leading linear phase.

16. equipment according to claim 1, wherein, described pilot tone linear phase calculator calculates the pilot tone that sends from described a plurality of transmitting antennas phase difference based on each pilot tone that receives from same transmitting antenna with respect to each reception antenna, the phase difference that calculates is added up with generation phase difference accumulated value, and the phase difference accumulated value that is generated is converted to the pilot tone linear phase.

17. equipment according to claim 1, wherein, described pilot tone linear phase calculator calculates the pilot tone that sends from described a plurality of transmitting antennas phase difference based on each pilot tone that receives from same transmitting antenna with respect to described a plurality of reception antennas, the phase difference that calculates is added up with generation phase difference accumulated value, and the phase difference accumulated value that is generated is converted to the pilot tone linear phase.

18. an equipment that is used in MIMO communication system skew estimated time of supporting OFDM or OFDMA, described equipment comprises:

Leading linear phase calculator is used for being included in leading in each the received signal frame of a plurality of reception antennas by employing and calculates leading linear phase; And

The time migration arithmetic unit is used for coming skew computing time by the leading linear phase that employing calculates.

19. equipment according to claim 18, wherein, described leading linear phase calculator comprises:

Leading phase difference arithmetic unit is used for calculating about being included in the described leading phase difference of each described received signal frame;

Leading phase difference accumulator is used for described phase difference is added up to generate the phase difference accumulated value; And

Leading linear phase arithmetic unit is used for described phase difference accumulated value is converted to leading linear phase.

20. equipment according to claim 19, wherein, described leading phase difference arithmetic unit output wherein makes the phase difference that calculates multiply by the value of predetermined preambles weight.

21. an equipment that is used in MIMO communication system skew estimated time of supporting OFDM or OFDMA, described equipment comprises:

Pilot tone linear phase calculator, be used for receiving the signal that sends from a plurality of transmitting antennas that adopt different pilot frequency designs respectively, and calculate the pilot tone linear phase by the described pilot frequency design that adopts respectively the described a plurality of transmitting antennas that receive from described reception antenna by a plurality of reception antennas; And

Time migration arithmetic unit, the pilot tone linear phase that is used for calculating by employing come skew computing time.

22. equipment according to claim 21, wherein, described pilot tone linear phase calculator comprises:

Pilot phase difference operation device is used for calculating at the phase difference of the pilot tone that sends from described a plurality of transmitting antennas based on each pilot tone that sends from same transmitting antenna;

Pilot phase difference accumulator is used for described phase difference is added up to generate the phase difference accumulated value; And

Pilot tone linear phase arithmetic unit is used for described phase difference accumulated value is converted to the pilot tone linear phase.

23. equipment according to claim 22, wherein, described pilot phase difference operation device output wherein makes the phase difference that calculates multiply by the value of predetermined pilot tone weight.

24. equipment according to claim 23, wherein, described pilot tone weight has based on each reception antenna or based on each different value of trooping.

25. a method that is used in MIMO communication system skew estimated time of supporting OFDM or OFDMA said method comprising the steps of:

Be included in leading in each the received signal frame in a plurality of reception antennas by employing and calculate leading linear phase;

Receive the signal that sends from a plurality of transmitting antennas that use different pilot frequency designs by described a plurality of reception antennas, and calculate the pilot tone linear phase by the described pilot frequency design that adopts respectively the described a plurality of transmitting antennas that receive from described reception antenna; And

Come skew computing time by employing leading linear phase that calculates and the pilot tone linear phase that calculates.

26. method according to claim 25, wherein, the described leading step of calculating leading linear phase that is included in each the received signal frame in a plurality of reception antennas by employing may further comprise the steps:

Calculating is about being included in the described leading phase difference in each described received signal frame;

Described phase difference is added up to generate the phase difference accumulated value; And

Described phase difference accumulated value is converted to leading linear phase.

27. method according to claim 26, wherein, the described step that converts described phase difference accumulated value to leading linear phase comprises: output wherein makes the phase difference that calculates multiply by the value of predetermined leading weight.

28. method according to claim 27 wherein, is provided with described leading weight based on the CINR value.

29. method according to claim 25, wherein, by each described reception antenna receive leading be that a predetermined reception antenna from described a plurality of transmitting antennas receives.

30. method according to claim 25, wherein, describedly receive the signal that sends from a plurality of transmitting antennas that use different pilot frequency designs and may further comprise the steps by the step that the described pilot frequency design that adopts respectively the described a plurality of transmitting antennas that receive from described reception antenna calculates the pilot tone linear phase by described a plurality of reception antennas:

Calculating from the pilot tone that described a plurality of transmitting antennas send based on the phase difference of each pilot tone that receives from same transmitting antenna;

Described phase difference is added up to generate the phase difference accumulated value; And

Described phase difference accumulated value is converted to the pilot tone linear phase.

31. method according to claim 30, wherein, the described step that described phase difference accumulated value is converted to the pilot tone linear phase comprises that output wherein makes the phase difference that calculates multiply by the value of predetermined pilot weight.

32. method according to claim 25, wherein, described time migration estimation method is applied to 2 * 2 MIMO.

33. method according to claim 32, wherein, the described leading step of calculating leading linear phase that is included in each the received signal frame in a plurality of reception antennas by employing comprises: calculate described leading linear phase according to following (equation).

(equation)

(in each section, p _kBe meant leadingly, k is meant sub-carrier indices, and m is meant the reception antenna index, and W0 is meant the predetermined preambles weight, and 3a is meant p _kAnd p _K+aBetween subcarrier distance)

34. method according to claim 32, wherein, describedly receive the signal that sends from a plurality of transmitting antennas that use different pilot frequency designs and comprise: calculate described pilot tone linear phase according to following (equation) by the step that the described pilot frequency design that adopts respectively the described a plurality of transmitting antennas that receive from described reception antenna calculates the pilot tone linear phase by described a plurality of reception antennas.

(equation)

${\mathrm{\θ}}_{\mathrm{TO}\_\mathrm{pil}}=\frac{1}{b}{\tan }^{-1}\left\{\frac{\mathrm{Im}\left\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}(\frac{p_0(m,c)\·p_3{(m,c)}^{*}}{|p_0(m,c)\·p_3{(m,c)}^{*}|}\·W1(m,c)+\frac{p_2(m,c)\·p_1{(m,c)}^{*}}{|p_2(m,c)\·p_1{(m,c)}^{*}|}\·W1(m,c))\right\}}{\mathrm{Re}\left\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}(\frac{p_0(m,c)\·p_3{(m,c)}^{*}}{|p_0(m,c)\·p_3{(m,c)}^{*}|}\·W1(m,c)+\frac{p_2(m,c)\·p_1{(m,c)}^{*}}{|p_2(m,c)\·p_1{(m,c)}^{*}|}\·W1(m,c))\right\}}\right\}$

(p0, p3 are meant the pilot tone that sends from the second transmitting antenna TxAnt1, p1, p2 are meant the pilot tone that sends from the first transmitting antenna TxAnt0, m is meant the reception antenna index, c is meant clustering index, W1 is meant the predetermined pilot weight, b is meant the subcarrier distance between the pilot tone that sends from same transmitting antenna that depends on c, and Num is meant by simulating predetermined value)

35. method according to claim 32, wherein, describedly receive the signal that sends from a plurality of transmitting antennas that use different pilot frequency designs and comprise: calculate described pilot tone linear phase according to following (equation) by the step that the described pilot frequency design that adopts respectively the described a plurality of transmitting antennas that receive from described reception antenna calculates the pilot tone linear phase by described a plurality of reception antennas.

(equation)

${\mathrm{\θ}}_{\mathrm{TO}\_\mathrm{pil}}=\frac{1}{2}[\frac{1}{b}{\tan }^{-1}\left(\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·W1(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·W1(m,c)\}}\right)+\frac{1}{b}{\tan }^{-1}\left(\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_2(m,c)\·p_1{(m,c)}^{*}\·W1(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_2(m,c)\·p_1{(m,c)}^{*}\·W1(m,c)\}}\right)]$

(p0, p3 are meant the pilot tone that sends from the second transmitting antenna TxAnt1, p1, p2 are meant the pilot tone that sends from the first transmitting antenna TxAnt0, m is meant the reception antenna index, c is meant clustering index, W1 is meant the predetermined pilot weight, b is meant the subcarrier distance between the pilot tone that sends from same transmitting antenna that depends on c, and Num is meant by simulating predetermined value)

36. method according to claim 25, wherein, the described leading step of calculating leading linear phase that is included in each the received signal frame in a plurality of reception antennas by employing comprises: calculate about being included in the described leading phase difference in the described received signal frame based on reception antenna, the phase difference that calculates is added up with generation phase difference accumulated value, and the phase difference accumulated value that is generated is converted to leading linear phase.

37. method according to claim 25, wherein, the described leading step of calculating leading linear phase that is included in each the received signal frame in a plurality of reception antennas by employing comprises: calculate about being included in the described leading phase difference in the described received signal frame with respect to described a plurality of reception antennas, the phase difference that calculates is added up with generation phase difference accumulated value, and the phase difference accumulated value that is generated is converted to leading linear phase.

38. method according to claim 25, wherein, describedly receive the signal that sends from a plurality of transmitting antennas that use different pilot frequency designs and comprise: calculate from the pilot tone that described a plurality of transmitting antennas send phase difference based on each pilot tone that receives from same transmitting antenna with respect to each reception antenna by the step that the described pilot frequency design that adopts respectively the described a plurality of transmitting antennas that receive from described reception antenna calculates the pilot tone linear phase by described a plurality of reception antennas, the phase difference that calculates is added up with generation phase difference accumulated value, and the phase difference accumulated value that is generated is converted to the pilot tone linear phase.

39. method according to claim 25, wherein, describedly receive the signal that sends from a plurality of transmitting antennas that use different pilot frequency designs and comprise: calculate from the pilot tone that described a plurality of transmitting antennas send phase difference based on each pilot tone that receives from same transmitting antenna with respect to described a plurality of reception antennas by the step that the described pilot frequency design that adopts respectively the described a plurality of transmitting antennas that receive from described reception antenna calculates the pilot tone linear phase by described a plurality of reception antennas, the phase difference that calculates is added up with generation phase difference accumulated value, and the phase difference accumulated value that is generated is converted to the pilot tone linear phase.

40. according to the described method of claim 39, wherein, the described leading step of calculating leading linear phase that is included in each the received signal frame in a plurality of reception antennas by employing may further comprise the steps:

Calculating is about being included in the described leading phase difference in each described received signal frame;

Described phase difference is added up to generate the phase difference accumulated value; And

Described phase difference accumulated value is converted to leading linear phase.

41. according to the described method of claim 40, wherein, the described step that described phase difference accumulated value is converted to leading linear phase comprises: output wherein makes the phase difference that calculates multiply by the value of predetermined preambles weight.

42. according to the described method of claim 41, wherein, described pilot tone weight has the different value based on each reception antenna.

43. a method that is used in MIMO communication system skew estimated time of supporting OFDM or OFDMA said method comprising the steps of:

Receive the signal that sends from a plurality of transmitting antennas that adopt different pilot frequency designs respectively by a plurality of reception antennas, and calculate the pilot tone linear phase by the described pilot frequency design that adopts respectively the described a plurality of transmitting antennas that receive from described reception antenna; And

Come skew computing time by the pilot tone linear phase that employing calculates.

44. according to the described method of claim 43, wherein, describedly receive the signal that sends from a plurality of transmitting antennas that use different pilot frequency designs respectively and may further comprise the steps by the step that the described pilot frequency design that adopts respectively the described a plurality of transmitting antennas that receive from described reception antenna calculates the pilot tone linear phase by a plurality of reception antennas:

Calculating from the pilot tone that described a plurality of transmitting antennas send based on the phase difference of each pilot tone that sends from same transmitting antenna;

Described phase difference is added up to generate the phase difference accumulated value; And

Described phase difference accumulated value is converted to the pilot tone linear phase.

45. according to the described method of claim 44, wherein, the described step that described phase difference accumulated value is converted to the pilot tone linear phase comprises: output wherein makes the phase difference that calculates multiply by the value of predetermined pilot weight.

46. according to the described method of claim 45, wherein, described pilot tone weight has based on each reception antenna or based on each different value of trooping.

47. an equipment that is used in the MIMO communication system estimated frequency skew of supporting OFDM or OFDMA, described equipment comprises:

The phase difference arithmetic unit, be used for receiving the signal that sends from a plurality of transmitting antennas that adopt different pilot frequency designs respectively, and calculate phase difference between the pilot tone that the pilot tone of the pilot tone transmitting element of the frame that sends from described a plurality of transmitting antennas that receives from described reception antenna respectively, sends from same transmitting antenna by a plurality of reception antennas;

The phase difference accumulator is used for described phase difference is added up to generate the phase difference accumulated value; And

The frequency shift (FS) arithmetic unit is used for described phase difference accumulated value is converted to the carrier shift estimated value.

48. according to the described equipment of claim 47, wherein, described frequency shift (FS) arithmetic unit comprises:

The arctangent cp cp operation device is used for by described phase difference accumulated value is carried out arctangent cp cp operation described phase difference accumulated value being converted to linear phase values; And

The frequency translation arithmetic unit is used for described linear phase values is converted to the carrier shift estimated value.

49. according to the described equipment of claim 47, also comprise: the average frequency arithmetic unit is used to generate the mean value of the carrier shift estimated value that measures about each frame based on received signal.

50. according to the described equipment of claim 47, wherein, described phase difference arithmetic unit multiply by predefined weight with the described phase difference between the described pilot tone.

51. according to the described equipment of claim 50, wherein, described weight has based on each reception antenna or based on each different value of trooping.

52. according to the described equipment of claim 50, wherein, described weight is based on that the CINR value is provided with.

53. according to the described equipment of claim 47, wherein, described carrier shift estimating apparatus is applied to 2 * 2 MIMO.

54. according to the described equipment of claim 53, wherein, based on the linear phase values θ of the described carrier shift that calculates according to following (equation) _CFOCalculate described carrier shift estimated value.

(equation)

${\mathrm{\θ}}_{\mathrm{CFO}}=\frac{1}{2}[{\tan }^{-1}\left(\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·w(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·w(m,c)\}}\right)+{\tan }^{-1}\left(\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_1(m,c)\·p_2{(m,c)}^{*}\·w(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_1(m,c)\·p_2{(m,c)}^{*}\·w(m,c)\}}\right)]$

(p0, p3 are meant the pilot tone that sends from the first transmitting antenna TxAnt0, and p1, p2 are meant the pilot tone that sends from the second transmitting antenna TxAnt1, and m is meant the reception antenna index, and c is meant clustering index, and w is meant predefined weight, and Num is meant by simulating definite value)

55. according to the described equipment of claim 53, wherein, based on the linear phase values θ of the described carrier shift that calculates according to following (equation) _CFOCalculate described carrier shift estimated value.

(equation)

${\mathrm{\θ}}_{\mathrm{CFO}}={\tan }^{-1}\left(\frac{\mathrm{Im}\left\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}(\frac{p_0(m,c)\·p_3{(m,c)}^{*}}{|p_0(m,c)\·p_3{(m,c)}^{*}|}\·w(m,c)+\frac{p_2(m,c)\·p_1{(m,c)}^{*}}{|p_2(m,c)\·p_1{(m,c)}^{*}|}\·w(m,c))\right\}}{\mathrm{Re}\left\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}(\frac{p_0(m,c)\·p_3{(m,c)}^{*}}{|p_0(m,c)\·p_3{(m,c)}^{*}|}\·w(m,c)+\frac{p_2(m,c)\·p_1{(m,c)}^{*}}{|p_2(m,c)\·p_1{(m,c)}^{*}|}\·w(m,c))\right\}}\right)$

(p0, p3 are meant the pilot tone that sends from the first transmitting antenna TxAnt0, and p1, p2 are meant the pilot tone that sends from the second transmitting antenna TxAnt1, and m is meant the reception antenna index, and c is meant clustering index, and w is meant predefined weight, and Num is meant by simulating definite value)

56. according to the described equipment of claim 47, also comprise: the time migration compensating unit is used for the time migration of the pilot tone that sends and received by described reception antenna from described a plurality of transmitting antennas is respectively compensated.

57. according to the described equipment of claim 56, wherein, described frequency shift (FS) arithmetic unit will send and phase difference accumulated value with pilot tone of make-up time skew is converted to described carrier shift estimated value from transmitting antenna.

58. according to the described equipment of claim 57, wherein, based on the linear phase values θ of the described carrier shift that calculates according to following (equation) _CFOCalculate described carrier shift estimated value.

(equation)

${\mathrm{\θ}}_{\mathrm{CFO}}={\tan }^{-1}\left\{\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·w(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·w(m,c)\}}\right\}$

(p0, p3 are meant the pilot tone that sends from a described transmitting antenna and its time skew has been compensated, and m is meant the reception antenna index, and c is meant clustering index, and w is meant predefined weight, and Num is meant by simulating definite value)

59. according to the described equipment of claim 47, wherein, described phase difference arithmetic unit is based on each reception antenna, calculates the described phase difference between the pilot tone that sends from described same transmitting antenna the pilot tone of the described pilot tone transmitting element of the described frame that sends from described a plurality of transmitting antennas.

60. according to the described equipment of claim 59, wherein, described phase difference accumulator adds up to the described phase difference that calculates based on each reception antenna respectively, and generates the phase difference accumulated value based on each reception antenna.

61. according to the described equipment of claim 47, wherein, described phase difference arithmetic unit is with respect to described a plurality of reception antennas, calculates the described phase difference between the pilot tone that sends from described same transmitting antenna the pilot tone of the described pilot tone transmitting element of the described frame that sends from described a plurality of transmitting antennas.

62. the method for an estimated frequency skew in the MIMO communication system of supporting OFDM or OFDMA said method comprising the steps of:

Receive the signal that sends from a plurality of transmitting antennas that adopt different pilot frequency designs respectively by a plurality of reception antennas, and calculate the phase difference between the pilot tone that the pilot tone of the pilot tone transmitting element of the frame that sends from described a plurality of transmitting antennas that receives from described reception antenna respectively, sends from same transmitting antenna;

Described phase difference is added up to generate the phase difference accumulated value; And

Described phase difference accumulated value is converted to the carrier shift estimated value.

63. according to the described method of claim 62, wherein, the described step that described phase difference accumulated value is converted to the carrier shift estimated value may further comprise the steps:

By described phase difference accumulated value is carried out arctangent cp cp operation, described phase difference accumulated value is converted to linear phase values; And

Described linear phase values is converted to the carrier shift estimated value.

64. it is, further comprising the steps of: the mean value that generates the carrier shift estimated value that measures about each frame based on received signal according to the described method of claim 62.

65. according to the described method of claim 62, wherein, described calculating comprises from the step of the described phase difference between the pilot tone of described same transmitting antenna transmission: the described phase difference between the described pilot tone be multiply by predefined weight.

66. according to the described method of claim 62, wherein, described carrier shift method of estimation is applied to 2 * 2 MIMO.

67. according to the described method of claim 66, wherein, based on the linear phase values θ of the carrier shift that calculates according to following (equation) _CFOCalculate described carrier shift estimated value.

(equation)

${\mathrm{\θ}}_{\mathrm{CFO}}=\frac{1}{2}[{\tan }^{-1}\left(\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·w(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·w(m,c)\}}\right)+{\tan }^{-1}\left(\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_1(m,c)\·p_2{(m,c)}^{*}\·w(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_1(m,c)\·p_2{(m,c)}^{*}\·w(m,c)\}}\right)]$

(p0, p3 are meant the pilot tone that sends from the first transmitting antenna TxAnt0, and p1, p2 are meant the pilot tone that sends from the second transmitting antenna TxAnt1, and m is meant the reception antenna index, and c is meant clustering index, and w is meant predefined weight, and Num is meant by simulating definite value)

68. according to the described method of claim 66, wherein, based on the linear phase values θ of the carrier shift that calculates according to following (equation) _CFOCalculate described carrier shift estimated value.

(equation)

${\mathrm{\θ}}_{\mathrm{CFO}}={\tan }^{-1}\left(\frac{\mathrm{Im}\left\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}(\frac{p_0(m,c)\·p_3{(m,c)}^{*}}{|p_0(m,c)\·p_3{(m,c)}^{*}|}\·w(m,c)+\frac{p_2(m,c)\·p_1{(m,c)}^{*}}{|p_2(m,c)\·p_1{(m,c)}^{*}|}\·w(m,c))\right\}}{\mathrm{Re}\left\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}(\frac{p_0(m,c)\·p_3{(m,c)}^{*}}{|p_0(m,c)\·p_3{(m,c)}^{*}|}\·w(m,c)+\frac{p_2(m,c)\·p_1{(m,c)}^{*}}{|p_2(m,c)\·p_1{(m,c)}^{*}|}\·w(m,c))\right\}}\right)$

(p0, p3 are meant the pilot tone that sends from the first transmitting antenna TxAnt0, and p1, p2 are meant the pilot tone that sends from the second transmitting antenna TxAnt1, and m is meant the reception antenna index, and c is meant clustering index, and w is meant predefined weight, and Num is meant by simulating definite value)

69. according to the described method of claim 62, further comprising the steps of: the time migration to the pilot tone that sends and received by described reception antenna from described a plurality of transmitting antennas respectively compensates.

70. according to the described method of claim 69, wherein, the described step that described linear phase values is converted to the carrier shift estimated value comprises: will send and phase difference accumulated value with pilot tone of make-up time skew is converted to described carrier shift estimated value from a transmitting antenna.

71. according to the described method of claim 70, wherein, based on the linear phase values θ of the carrier shift that calculates according to following (equation) _CFOCalculate described carrier shift estimated value.

(equation)

${\mathrm{\θ}}_{\mathrm{CFO}}={\tan }^{-1}\left\{\frac{\mathrm{Im}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·w(m,c)\}}{\mathrm{Re}\{\underset{c=0}{\overset{\mathrm{Num}-1}{\mathrm{\Σ}}}\underset{m=0}{\overset{1}{\mathrm{\Σ}}}{p}_0(m,c)\·p_3{(m,c)}^{*}\·w(m,c)\}}\right\}$

(p0, p3 are meant the pilot tone that sends from a described transmitting antenna and its time skew has been compensated, and m is meant the reception antenna index, and c is meant clustering index, and w is meant predefined weight, and Num is meant by simulating definite value)

72. according to the described method of claim 62, wherein, described calculating is to carry out after the step of the received signal that receives by described a plurality of reception antennas being carried out Fourier transform from the step of the phase difference between the pilot tone of described same transmitting antenna transmission.

73. according to the described method of claim 62, wherein, the step of the phase difference between the pilot tone that described calculating sends from described same transmitting antenna comprises: based on each reception antenna, calculate the described phase difference between the pilot tone that sends from described same transmitting antenna the pilot tone of the described pilot tone transmitting element of the described frame that sends from described a plurality of transmitting antennas.

74. a method that in ofdm communication system time migration and carrier shift is compensated said method comprising the steps of:

Calculate the phase difference of the pilot signal in the received signal;

Phase difference to described pilot signal is carried out computing, with computing time offset linear phase place and carrier shift linear phase; And

Described time migration linear phase and described carrier shift linear phase are carried out computing with computing time migration value and carrier shift offset.

75. according to the described method of claim 74, wherein, described pilot signal has with up link (UL) part uses the relevant symbolic construction of subchannel (PUSC) channelling mode.

76. according to the described method of claim 74, wherein, described computing time, the step of offset linear phase place and carrier shift linear phase may further comprise the steps: described pilot signal is carried out arctangent cp cp operation, to calculate the phase difference of described pilot signal.

77. according to the described method of claim 74, wherein, described to described time migration linear phase and described carrier shift linear phase carry out computing with computing time migration value and carrier shift offset step may further comprise the steps: described time migration linear phase and described carrier shift linear phase are carried out cosine and sinusoidal computing, to calculate described time migration compensation of phase and described carrier shift offset.

78. according to the described method of claim 74, wherein, described to described time migration linear phase and described carrier shift linear phase carry out computing with computing time migration value and carrier shift offset step may further comprise the steps:

Described time migration linear phase and described carrier shift linear phase are carried out cosine and sinusoidal computing, to calculate the very first time migration value and the first carrier shift offset; And

Described very first time migration value and the described first carrier shift offset are carried out the double angle formula computing, to calculate the second time migration offset and the second carrier shift offset.

79. according to the described method of claim 78, wherein, the step of described time migration linear phase of described calculating and described carrier shift linear phase may further comprise the steps: described pilot signal is carried out arctangent cp cp operation, to calculate the phase difference of described pilot signal.

80. a method that in ofdm communication system time migration and carrier shift is compensated said method comprising the steps of:

Be offset phase difference and carrier shift phase difference computing time according to the pilot signal that receives; And

Described time migration phase difference and described carrier shift phase difference are carried out computing, with computing time migration value and carrier shift offset.

81. 0 described method according to Claim 8, wherein, described to described time migration phase difference and described carrier shift phase difference carry out computing with computing time migration value and carrier shift offset step may further comprise the steps: divide formula that described time migration phase difference and described carrier shift phase difference are carried out square root calculation by adopting the trigonometric function arc, calculate described time migration offset and described carrier shift offset.

82. one kind is used for the equipment that time migration and carrier shift compensated at ofdm communication system, described equipment comprises:

Pilot signal phase difference operation device is used for the phase difference according to received signal calculating pilot signal;

Time migration and carrier shift linear phase arithmetic unit are used for the phase place of described pilot signal is carried out computing, with computing time offset linear phase place and carrier shift linear phase; And

Time migration and carrier shift offset arithmetic unit are used for described time migration linear phase and described carrier shift linear phase are carried out computing, with computing time migration value and carrier shift offset.

83. 2 described equipment according to Claim 8, wherein, described communication system comprises based on any the system among IEEE 802.16d/e standard, WiBro and the WiMAX.

84. 3 described equipment according to Claim 8, wherein, described pilot signal has the symbolic construction relevant with the ULPUSC channelling mode.

85. 2 described equipment according to Claim 8, wherein, described time migration and carrier shift offset arithmetic unit are carried out cosine and sinusoidal computing to described time migration linear phase and described carrier shift linear phase, to calculate described time migration offset and described carrier shift offset.

86. 2 described equipment according to Claim 8, wherein, described time migration and carrier shift offset arithmetic unit comprise:

Cosine and sinusoidal computing module are used for described time migration linear phase and described carrier shift linear phase are carried out cosine and sinusoidal computing, to calculate the very first time migration value and the first carrier shift offset; And

The double angle formula computing module is used for described very first time migration value and the described first carrier shift offset are carried out the double angle formula computing, to calculate the second time migration offset and the second carrier shift offset.

87. one kind is used for the equipment that time migration and carrier shift compensated at ofdm communication system, described equipment comprises:

Time migration and carrier shift phase difference arithmetic unit are used for to be offset computing time phase difference and carrier shift phase difference according to the phase difference of the pilot signal that receives; And

Time migration and carrier shift offset arithmetic unit are used for described time migration phase difference and described carrier shift phase difference are carried out computing, with computing time migration value and carrier shift offset.

88. 7 described equipment according to Claim 8, wherein, described time migration and carrier shift offset arithmetic unit adopt the trigonometric function arc to divide formula that described time migration phase difference and described carrier shift phase difference are carried out square root calculation, to calculate described time migration offset and described carrier shift offset.

Images