CN102404265A - Multicarrier signal processing method and device - Google Patents

Abstract

The invention discloses a multicarrier signal processing method, which comprises the following steps of: according to the requirements of different transmission data in signals to be processed for distortion tolerance, dividing subcarriers for bearing the signals to be processed into V groups, and setting corresponding distortion tolerance for each group of subcarrier; according to the distortion tolerance corresponding to each group of subcarrier, determining the distributed proportion of distortion noises corresponding to canceling functions among all groups of subcarriers of a frequency domain; according to the distributed proportion of the distortion noises among all groups of subcarriers of the frequency domain, constructing the response sequence of the initial frequency domain of the canceling functions; conducting frequency domain and time domain conversion processing for the response sequence of the frequency domain, and obtaining the canceling functions for peak value canceling; and utilizing the canceling functions to conduct the peak value canceling processing for the signals to be processed. In addition, the invention also discloses a multicarrier signal processing device. The technical scheme disclosed by the invention can protect the transmission data with requirements for canceling distortion during conducting peak value canceling.

Description

A kind of multi-carrier signal processing method and device

Technical field

The non-linear peak value that the present invention relates in OFDM (OFDM, the Orthogonal Frequency DivisionMultiplexing) system suppresses technology, relates in particular to a kind of multi-carrier signal processing method and device.

Background technology

In ofdm system, in frequency domain, given channel is divided into several independently subchannels usually, on each subchannel, use a number of sub-carrier to modulate, and each subcarrier parallel transmission.Because these a series of sub-channel signals are piled up after time domain adds up can bigger spike appear constantly at some; Be easy to cause bigger peak-to-average ratio (PAPR; Peak-to-average-power ratio), i.e. the maximum peak power of signal and average power bigger.And existing power amplifier can't carry out linear amplification to the bigger signal of amplitude range; Therefore exist the signal of higher PAPR through power amplifier the time, can produce bigger spread spectrum and serious inband distortion; Cause the phase mutual interference between subchannel, thereby influence the performance of ofdm system.

In order to reduce PAPR, before carrying out transmit operation, utilize non-linear peak value inhibition technology that pending multi-carrier signal is carried out peak value offset and handle usually through antenna.Wherein, the peak value offset process generally comprises: calculate the amplitude limit amplitude as sampled point in the time domain OFDM signal of pending signal, and generate the amplitude limit sequence; The counteracting function that utilizes the amplitude limit sequence and be provided with in advance generates offseting signal; With time domain OFDM signal and offseting signal stack, accomplish peak value offset.Wherein, Sampled point can be each sampled point of confirming according to conventional method in the time domain OFDM signal; Also can be that application number is the object sampled point that the amplitude described in the patent application of 200810170235.X is higher than preset comparison threshold, can also be the sampled point of confirming according to other method.

In above-mentioned peak value offset process, traditional counteracting function adopts the window function of frequency domain continuous distribution usually, like the sinc function, but uses this class function to offset the counteracting distortion that will on each subcarrier, introduce same degree when handling, i.e. distortion noise.And in actual ofdm system, it is different that dissimilar transmission data require the counteracting distortion on the subcarrier, promptly the distortion toleance degree on the subcarrier required different.

For example; Utilize pilot frequency sequence (pilot) to carry out the ofdm system of channel estimating for needs; Because channel estimating is relatively more responsive to the counteracting distortion of pilot frequency sequence place sub-carrier positions; Therefore the distortion toleance degree on the subcarrier of pilot frequency sequence place is lower, and utilizes the conventional window function to offset when handling owing to offset the whole frequency domain that the distortion meeting expands to receiving terminal, causes the distortion of pilot frequency sequence; Therefore can worsen the channel estimating performance of receiving terminal, and the transmission performance of system is impacted.

And for example; Ofdm system for the multi-user; Sub-carrier section also has demands of different to the performance impact that the counteracting distortion brings under the different user, makes that the distortion toleance degree of the affiliated sub-carrier section of different user is also different, and utilizes the conventional window function to offset when handling because counteracting distortion meeting expands to the whole frequency domain of receiving terminal; Cause the distortion of the data that the distortion toleance degree is lower, the transmission performance of user data is impacted.

It is thus clear that the peak value offset process that adopts tradition to offset function can't be protected offsetting the transmission data that distortion has requirement.

Summary of the invention

In view of this, on the one hand a kind of multi-carrier signal processing method is provided among the present invention, a kind of multicarrier signal processing apparatus is provided on the other hand, so that protection is to offsetting the transmission data that distortion has requirement when carrying out peak value offset.

Multi-carrier signal processing method provided by the present invention comprises:

To the requirements of distortion toleance degree, the subcarrier that will be used to carry said pending signal is divided into the V group according to different transmission data in the pending signal, and corresponding distortion toleance degree is set for every group of subcarrier; Wherein, V is the integer more than or equal to 2;

Based on the corresponding distortion toleance degree of each group subcarrier, confirm to offset the corresponding distortion noise of function and respectively organize the distribution proportion between subcarrier at frequency domain;

Respectively organize the distribution proportion between subcarrier according to said distortion noise at frequency domain, structure is offset the initial frequency domain response sequence of function;

Said frequency domain response sequence is carried out frequency domain-time domain conversion process, obtain being used for the counteracting function of peak value offset;

Utilizing said counteracting function that said pending signal is carried out peak value offset handles.

Multicarrier signal processing apparatus provided by the present invention comprises:

The distortion toleance degree is provided with module, is used for according to the requirements of the different transmission of pending signal data to the distortion toleance degree, and the subcarrier that will be used to carry said pending signal is divided into the V group, and corresponding distortion toleance degree is set for every group of subcarrier; Wherein, V is the integer more than or equal to 2;

Offset the function generation module, be used for confirming to offset the corresponding distortion noise of function and respectively organizing the distribution proportion between subcarrier at frequency domain according to the corresponding distortion toleance degree of each group subcarrier; Respectively organize the distribution proportion between subcarrier according to said distortion noise at frequency domain, structure is offset the initial frequency domain response sequence of function, and said initial frequency domain response sequence is carried out frequency domain-time domain conversion process, obtains being used for the counteracting function of peak value offset;

The peak value offset module, the counteracting function that is used to utilize said counteracting function generation module to generate carries out the peak value offset processing to said pending signal.

Can find out from such scheme; Transmit the requirements of data according to difference in the pending signal in the embodiment of the invention to the distortion toleance degree; The subcarrier that will be used to carry said pending signal divides into groups and corresponding distortion toleance degree is set, and then according to set distortion toleance degree, design makes the corresponding distortion noise of respectively organizing subcarrier satisfy the counteracting function of corresponding distortion toleance degree; And utilize this counteracting function to carry out peak value offset and handle; Make and when carrying out peak value offset, reduce on the basis of PAPR, can protect, reduced the interference of offseting signal this part data to offsetting the transmission data that distortion has requirement.

Description of drawings

To make clearer above-mentioned and other feature and advantage of the present invention of those of ordinary skill in the art through describe exemplary embodiment of the present invention in detail with reference to accompanying drawing below, in the accompanying drawing:

Fig. 1 is the exemplary process diagram of multi-carrier signal processing method in the embodiment of the invention;

Fig. 2 is the exemplary block diagram of multicarrier signal processing apparatus in the embodiment of the invention;

Fig. 3 is the structural representation of the counteracting function generation module in the multicarrier signal processing apparatus shown in Figure 2;

Fig. 4 is the OFDM frequency domain symbol distribution map of dressing pilot tone inserted mode;

Fig. 5 and Fig. 6 are respectively frequency domain analogous diagram and the time-domain-simulation figure that tradition is offset function;

Fig. 7 and Fig. 8 are respectively the frequency domain analogous diagram and the time-domain-simulation figure of improved counteracting function in the embodiment of the invention;

Fig. 9 is the OFDM frequency domain symbol distribution map of pilot tone inserted mode of downlink OFDMA link of 2 transmitting antennas of LTE standard;

Figure 10 and Figure 11 are respectively another frequency domain analogous diagram and the time-domain-simulation figure of improved counteracting function in the embodiment of the invention;

A PAPR rejection when Figure 12 offsets improved counteracting function in the function and the embodiment of the invention for adopting the prior art tradition respectively is analogous diagram relatively;

A channel estimating performance when Figure 13 offsets improved counteracting function in the function and the embodiment of the invention for adopting the prior art tradition respectively is analogous diagram relatively;

Another PAPR rejection when Figure 14 offsets improved counteracting function in the function and the embodiment of the invention for adopting the prior art tradition respectively is analogous diagram relatively;

Another channel estimating performance when Figure 15 offsets improved counteracting function in the function and the embodiment of the invention for adopting the prior art tradition respectively is analogous diagram relatively.

Embodiment

For making the object of the invention, technical scheme and advantage clearer, below in conjunction with embodiment and accompanying drawing, to further explain of the present invention.

Fig. 1 is the exemplary process diagram of multi-carrier signal processing method in the embodiment of the invention.As shown in Figure 1, this method comprises:

Step 101, to the requirements of distortion toleance degree, the subcarrier that will be used to carry said pending signal is divided into the V group according to different transmission data in the pending signal, and corresponding distortion toleance degree is set for every group of subcarrier.Wherein, V is the integer more than or equal to 2.

In this step; For different ofdm systems; Because data type that it transmitted and composition maybe be different; All types of transmission data also are not quite similar to the requirement of distortion toleance degree, and therefore for different ofdm systems, being provided with of the value of V and distortion toleance degree need be provided with according to actual needs.

For example; Utilize pilot frequency sequence to carry out the ofdm system of channel estimating for needs; Because pilot frequency sequence requires different with information data to the distortion toleance degree that belongs to separately on the subcarrier; It is lower to the distortion toleance degree on its place subcarrier than information data to the distortion toleance degree on its place subcarrier to be pilot frequency sequence, therefore can the subcarrier that be used to carry said information data be divided into one group, and the subcarrier that will be used to carry said pilot frequency sequence is divided into another group; For the subcarrier that carries said information data is provided with the first distortion toleance degree, be lower than the second distortion toleance degree of the said first distortion toleance degree for the subcarrier setting of carrying said pilot frequency sequence.During concrete the realization, can the second distortion toleance degree be set to 0, the first distortion toleance degree and be set to 1.

And for example; Ofdm system for the multi-user; Because different user data also has demands of different to the distortion toleance degree of sub-carrier section under it; Therefore can subcarrier under each user's data with the requirement of different distortion toleance degree be divided into respectively not on the same group, and corresponding distortion toleance degree be set to each group.For example, suppose to have three users, user A, user B and user C; Wherein user A has identical distortion toleance degree with user B; User C has than user A and the lower distortion toleance degree of user B, then can the subcarrier of the data that are used to carry user A and user B be divided into first group, and the subcarrier that will be used to carry the data of user C is divided into second group; And be first group first tolerance is set, be second group second tolerance lower than first tolerance is set.If the user is A, user B has different distortion toleance degree respectively with user C; Then can the subcarrier of the data that are used to carry user A be divided into first group; The subcarrier that will be used to carry the data of user B is divided into second group, and the subcarrier that will be used to carry the data of user C is divided into the 3rd group, and is first group first tolerance is set; Be second group second tolerance is set, be the 3rd group the 3rd tolerance is set.

In addition, can similarly divide into groups equally and the setting of distortion toleance degree, enumerate no longer one by one here for other ofdm systems.

Step 102 based on the corresponding distortion toleance degree of each group subcarrier, is confirmed to offset the corresponding distortion noise of function and is respectively organized the distribution proportion between subcarrier at frequency domain; Respectively organize the distribution proportion between subcarrier based on said distortion noise at frequency domain, structure is offset the initial frequency domain response sequence of function.Wherein, initial frequency domain response sequence reflection is the distribution situation of distortion noise at frequency domain.

In this step, based on the corresponding distortion toleance degree of each group subcarrier, confirming to offset the corresponding distortion noise of function can have multiple concrete implementation when frequency domain is respectively organized the distribution proportion between subcarrier, just list below and lift a kind of concrete way of realization.

Suppose to represent total number of subcarrier, use φ with N _v, v ∈ (0,1 ..., V-1) expression v group subcarrier is with G ' _kThe frequency domain response of function in the k number of sub-carrier offset in expression, uses μ _v, v ∈ (0,1 ..., V-1) be expressed as the distortion toleance degree that v group subcarrier is provided with, wherein, 0≤μ _v≤1, μ _vThe distortion noise that more little expression is introduced relatively is more little.Then offsetting the distribution proportion that the corresponding distortion noise of function respectively organizes between subcarrier at frequency domain can confirm by following expression formula (1).

$\frac{\underset{k\∈{\mathrm{\φ}}_v}{\mathrm{\Σ}}\left|\right|G_k^{\′}\left|\right|}{\underset{k=0}{\overset{N-1}{\mathrm{\Σ}}}{\left|\right|G_k^{\′}\left|\right|}^2}\≤{\mathrm{\μ}}_v,{\mathrm{\μ}}_{v-1}\≤{\mathrm{\μ}}_v---\left(1\right)$

Utilize pilot frequency sequence to carry out the ofdm system of channel estimating specific to needs, the distribution proportion that the distortion noise that the counteracting function is corresponding is respectively organized between subcarrier at frequency domain can be confirmed by following expression formula (2).

$\left\{\begin{array}{c}{G}_k^{\′}=0,k\∈{\mathrm{\φ}}_0\\ \frac{\underset{k\∈{\mathrm{\φ}}_1}{\mathrm{\Σ}}\left|\right|G_k^{\′}\left|\right|}{\underset{k=0}{\overset{N-1}{\mathrm{\Σ}}}{\left|\right|G_k^{\′}\left|\right|}^2}\≤1\end{array}\right.---\left(2\right)$

Wherein, N is total number of subcarrier, φ ₀For carrying the subcarrier of pilot frequency sequence, φ ₁The subcarrier of expression carry information data, G ' _kFor offsetting the frequency domain response of function in the k number of sub-carrier.

In addition, respectively organize the distribution proportion between subcarrier at frequency domain, when structure is offset function initial, can construct the minimum frequency domain response sequence of distortion noise that makes the minimum or corresponding setting group subcarrier of total distortion noise based on distortion noise.Or structure satisfies the frequency domain response sequence of other conditions.

Making the minimum frequency domain response sequence of total distortion noise with structure below is example, then the frequency domain response sequence in this step G ' _k, 0≤k≤N-1} can satisfy following expression formula (3)

$\mathrm{Min}\underset{k=0}{\overset{N-1}{\mathrm{\Σ}}}{\left|\right|G_k^{\′}\left|\right|}^2$ And $\frac{\underset{k\∈{\mathrm{\φ}}_v}{\mathrm{\Σ}}\left|\right|G_k^{\′}\left|\right|}{\underset{k=0}{\overset{N-1}{\mathrm{\Σ}}}{\left|\right|G_k^{\′}\left|\right|}^2}\≤{\mathrm{\μ}}_v,{\mathrm{\μ}}_{v-1}\≤{\mathrm{\μ}}_v---\left(3\right)$

Wherein, φ _vRepresent v group subcarrier, G ' _kFor offsetting the frequency domain response of function in the k number of sub-carrier, μ _vBe the corresponding distortion toleance degree of v group subcarrier, 0≤μ _v≤1, μ _vThe distortion noise of more little relative introducing is more little.

Utilize pilot frequency sequence to carry out the ofdm system of channel estimating specific to needs, the frequency domain response sequence G ' _k, 0≤k≤N-1} can satisfy following expression formula (4)

$\mathrm{Min}\underset{k=0}{\overset{N-1}{\mathrm{\Σ}}}{\left|\right|G_k^{\′}\left|\right|}^2,$ And $\left\{\begin{array}{c}{G}_k^{\′}=0,k\∈{\mathrm{\φ}}_0\\ \frac{\underset{k\∈{\mathrm{\φ}}_1}{\mathrm{\Σ}}\left|\right|G_k^{\′}\left|\right|}{\underset{k=0}{\overset{N-1}{\mathrm{\Σ}}}{\left|\right|G_k^{\′}\left|\right|}^2}\≤1\end{array}\right.---\left(4\right)$

Wherein, N is total number of subcarrier, φ ₀For carrying the subcarrier of pilot frequency sequence, φ ₁The subcarrier of expression carry information data, G ' _kFor offsetting the frequency domain response of function in the k number of sub-carrier.

The concrete example that above-mentioned formula (1) is just enumerated for present embodiment is described to formula (4) when specifically realizing, can also have other way of realization, enumerates no longer one by one here.

Step 103 is carried out frequency domain-time domain conversion process to said initial frequency domain response sequence, obtains being used for the counteracting function of peak value offset.

In this step, the time domain conversion process can have multiple processing method, both can adopt various processing method of the prior art, also can adopt other newly-increased processing methods, does not do qualification in the present embodiment.Be example with the frequency domain-time domain conversion process method that adopts over-sampling and time domain windowing process below, the processing procedure of this step is illustrated.

According to the pairing frequency domain response sequence of the formula that obtains in the step 102 (3) G ' _k, 0≤k≤N-1} and preset over-sampling multiple J, with the outer zero setting of frequency domain response sequence band, through invert fast fourier transformation (IFFT) obtain G ' _k, the J of 0≤k≤N-1} times of over-sampling time domain expression formula be g ' _n, 0≤n≤JN-1}, the process time-domain windowed obtains being used for the counteracting function of peak value offset at last Expression formula be:

${\hat{g}}_n=g_n^{\′}\mathrm{wind}(n,\mathrm{Ns})---\left(5\right)$

Wherein, wind (n, Ns) expression central point with g ' _n, 0≤n≤JN-1} central point alignment, length is the time domain truncated window length of Ns.

Specific to the pairing frequency domain response sequence of formula (4) G ' _k, 0≤k≤N-1} with the outer zero setting of frequency domain response sequence band, promptly adds (J-1) N zero in the centre, after fast Fourier transform (FFT), be that the rectangular window of Ns carries out time domain and blocks through length, obtains being used for the counteracting function of peak value offset Expression formula be:

${\hat{g}}_n=(g_n-\underset{k\∈{\mathrm{\φ}}_0}{\mathrm{\Σ}}\exp \left(\frac{j2\mathrm{\πkn}}{\mathrm{JN}}\right))\mathrm{wind}(n,\mathrm{Ns})$

$=\left\{\begin{array}{cc}0,& 0\≤n\≤\frac{\mathrm{JN}-\mathrm{Ns}}{2}\\ (g_n-\underset{k\∈{\mathrm{\φ}}_0}{\mathrm{\Σ}}\exp \left(\frac{j2\mathrm{\πkn}}{\mathrm{JN}}\right)),& \frac{\mathrm{JN}-\mathrm{Ns}}{2}+1\≤n\≤\frac{\mathrm{JN}+\mathrm{Ns}}{2}\\ 0,& \frac{\mathrm{JN}+\mathrm{Ns}}{2}+1\≤n\≤\mathrm{JN}-1\end{array}\right.---\left(6\right)$

Wherein, g _nThe expression conventional peak is offset function, for example sinc function

Step 104 is utilized said counteracting function that said pending signal is carried out peak value offset and is handled.

The peak value offset of this step is handled can be consistent with peak value offset processing of the prior art, promptly can comprise: calculate the amplitude limit ratio as sampled point in the time domain OFDM signal of pending signal, and generate the amplitude limit sequence; Utilize the counteracting function that obtains in amplitude limit sequence and the step 103, generate offseting signal; With time domain OFDM signal and offseting signal stack, accomplish peak value offset.

More than the multi-carrier signal processing method in the embodiment of the invention is described in detail, again the multicarrier signal processing apparatus in the embodiment of the invention is described in detail below.

Fig. 2 is the exemplary block diagram of multicarrier signal processing apparatus in the embodiment of the invention.As shown in Figure 2, this device comprises: the distortion toleance degree is provided with module, offsets function generation module and peak value offset module.

Wherein, the distortion toleance degree is provided with module and is used for based on the requirements of the different transmission of pending signal data to the distortion toleance degree, and the subcarrier that will be used to carry said pending signal is divided into the V group, and corresponding distortion toleance degree is set for every group of subcarrier.Wherein, V is the integer more than or equal to 2.

Offsetting the function generation module is used for confirming to offset the corresponding distortion noise of function and respectively organizing the distribution proportion between subcarrier at frequency domain according to the corresponding distortion toleance degree of each group subcarrier; Respectively organize the distribution proportion between subcarrier according to said distortion noise at frequency domain, structure is offset the initial frequency domain response sequence of function, and said initial frequency domain response sequence is carried out frequency domain-time domain conversion process, obtains being used for the counteracting function of peak value offset.

The counteracting function that the peak value offset module is used to utilize said counteracting function generation module to generate carries out the peak value offset processing to said pending signal.

During concrete the realization, above-mentioned distortion toleance degree is provided with the concrete implementation procedure of module can be consistent with the description in the step 101, can carry out sub carrier group division and the setting of distortion toleance degree according to the actual needs of different ofdm systems.

For example; Utilize pilot frequency sequence to carry out the ofdm system of channel estimating for needs; The distortion toleance degree is provided with module can be according to pilot frequency sequence and information data in the pending signal to the requirement of distortion toleance degree; The subcarrier that will be used to carry said information data is divided into one group, and the subcarrier that will be used to carry said pilot frequency sequence is divided into another group; For the subcarrier that carries said information data is provided with the first distortion toleance degree, be lower than the second distortion toleance degree of the said first distortion toleance degree for the subcarrier setting of carrying said pilot frequency sequence.

And for example; Ofdm system for the multi-user; The distortion toleance degree is provided with module can be according to the requirement to the distortion toleance degree of the data of different user in the pending signal; The subcarrier that will be used to carry each user's data with the requirement of different distortion toleance degree is divided into respectively not on the same group, and to each group subcarrier corresponding distortion toleance degree is set.

During concrete the realization, the concrete implementation procedure of above-mentioned counteracting function generation module can be consistent with the description in step 102 and the step 103.Likewise, offset the function generation module and can construct distortion noise minimum that makes total distortion noise minimum or corresponding setting group subcarrier or the frequency domain response sequence that satisfies other condition.Afterwards, said frequency domain response sequence is carried out frequency domain-time domain conversion process, obtain being used for the counteracting function of peak value offset.Wherein, frequency domain-time domain conversion process can comprise over-sampling and time-domain windowed processing.

Further, the internal structure of offsetting the function generation module can have multiple concrete way of realization, the internal structure sketch map when Fig. 3 shows wherein a kind of concrete the realization.As shown in Figure 3, this counteracting function generation module comprises: frequency domain distribution ratio determination module, frequency domain response sequence structure module and frequency domain-time domain conversion process module.

Wherein, frequency domain distribution ratio determination module is used for confirming to offset the corresponding distortion noise of function and respectively organizing the distribution proportion between subcarrier at frequency domain according to the corresponding distortion toleance degree of each group subcarrier.

Frequency domain response sequence structure module is used for respectively organizing the distribution proportion between subcarrier according to said distortion noise at frequency domain, and structure is offset the initial frequency domain response sequence of function.During concrete the realization, this frequency domain response sequence structure module can be constructed distortion noise minimum that makes total distortion noise minimum or corresponding setting group subcarrier or the frequency domain response sequence that satisfies other condition.

Frequency domain-time domain conversion process module is used for said initial frequency domain response sequence is carried out frequency domain-time domain conversion process, obtains being used for the counteracting function of peak value offset.

During concrete the realization, the concrete implementation procedure of above-mentioned peak value offset module can be consistent with the description in the step 104.

In order to further specify the technical scheme of multi-carrier signal processing method and device in the embodiment of the invention; The ofdm system that utilizes pilot frequency sequence to carry out channel estimating with needs below is an example, provide in the prior art and the embodiment of the invention in offset the frequency domain of function and the analogous diagram of time domain.

Fig. 4 shows the OFDM frequency domain symbol distribution map of dressing pilot tone inserted mode.As shown in Figure 4, dash area is the position of pilot frequency sequence in the OFDM symbol, and other parts are the position of information data in the OFDM symbol.Thus it is clear that, the sequence of pilot symbol interval D _fNumber of sub-carrier.In this example, D _f=4, promptly in subcarrier, whenever insert a pilot frequency sequence subcarrier at a distance from 3 information data subcarriers.In addition, the simulation parameter in this example is: modulation system is 16 quadrature amplitude modulation (QAM), over-sampling multiple J=4, and number of sub carrier wave was 128 (wherein 32 number of sub-carrier are used for the pilot frequency sequence transmission, and 96 number of sub-carrier are used for information data transmission).

Based on above-mentioned simulated conditions, Fig. 5 and Fig. 6 show the frequency domain analogous diagram and the time-domain-simulation figure of tradition counteracting function sinc function in the prior art respectively.Fig. 7 and Fig. 8 show improved counteracting function in the embodiment of the invention respectively, i.e. the frequency domain analogous diagram and the time-domain-simulation figure of

.

Be example with the pilot tone inserted mode of the downlink OFDMA link of 2 transmitting antennas of 3GPP Long Term Evolution plan (LTE, Long Term Evolution) standard more below, provide the frequency domain and the time domain analogous diagram of improved counteracting function in the embodiment of the invention.Fig. 9 is the OFDM frequency domain symbol distribution map of pilot tone inserted mode of downlink OFDMA link of 2 transmitting antennas of LTE standard.R wherein ₀And R ₁The pilot frequency sequence position of representing antenna 1 and antenna 2 correspondences respectively.In addition; Simulation parameter in this example is: number of sub carrier wave is 1024, continuous 50 Resource Block (RB of CU low-frequency range; Resource Block) (each Resource Block comprises 12 number of sub-carrier; Be continuous 600 number of sub-carrier of CU low-frequency range), modulation system is 16QAM, over-sampling multiple J=4.

Based on above-mentioned simulated conditions; Figure 10 and Figure 11 show improved counteracting function in the embodiment of the invention respectively, i.e. the frequency domain analogous diagram and the time-domain-simulation figure of .

The technical scheme of utilizing the embodiment of the invention to provide can make and when carrying out peak value offset, reduce on the basis of PAPR that protection reduces the interference of offseting signal to this part data to offsetting the transmission data that distortion has requirement.

With the pairing counteracting function of above-mentioned formula (4) is example; Through pilot frequency sequence the distortion toleance degree of corresponding subcarrier be set to 0; And structure satisfies the distortion noise frequency domain distribution of this distortion toleance degree; Thereby obtain pilot frequency sequence introduce the counteracting function of distortion noise hardly on the corresponding subcarrier, thereby reduced the interference of distortion noise to pilot frequency sequence.

The ofdm system that still utilizes pilot frequency sequence to carry out channel estimating with needs below is an example; And with the application number is that the peak value offset method of describing in the patent application of 200810170235.X is an example, provides two PAPR rejection and simulation results of channel estimating performance when adopting prior art tradition to offset improved counteracting function in the function and the embodiment of the invention respectively.

Simulation result one: the simulation result of ofdm system.

The simulation parameter of this emulation is: number of sub carrier wave is 1024, modulation system is 16QAM, over-sampling multiple J=4, frequency domain use length be 256 Chu sequence as pilot frequency sequence, adopt D _f=4 dressing pilot tone inserted mode.In addition, COST207x6 travelling carriage channel is used in emulation, and the translational speed of travelling carriage is 120km/h.Wherein, see document " D.C.Chu, " Polyphase codes with good periodic correlation properties for details about the definition of Chu sequence, " IEEE Trans.Inform.Theory, vol.18, pp.531-532, July 1972 ".

Table 1 show tradition offset function and the information data distortion of improved counteracting function under above-mentioned simulated conditions than (DDR, Data-to-Distortion Ratio) and pilot frequency sequence distortion than (PDR, Pilot-to-Distortion Ratio).

Table 1

Thus it is clear that, use improved counteracting function can obtain to offset the higher PDR gain of function than tradition.As shown in table 1, when thresholding was 6dB, the PDR that improved counteracting function is corresponding is traditional, and the counteracting function increased nearly 13dB, and at this moment, the counteracting of pilot frequency sequence place sub-carrier positions is disturbed and controlled significantly, and channel estimating performance also improves.In addition, improved counteracting function when obtaining the PDR gain, DDR about 1dB that descended, this is because improved counteracting function has been introduced a part of counteracting disturbs, and cause the cancellation level of part peak value to be strengthened to some extent, but its performance loss that causes is not high.

Figure 12 shows the PAPR rejection analogous diagram relatively when adopting prior art tradition to offset improved counteracting function in the function and the embodiment of the invention respectively.Thus it is clear that, use improved counteracting function to make the PAPR of offseting signal only slightly rise, but still keep tangible PAPR to suppress effect.

Figure 13 shows the channel estimating performance analogous diagram relatively when adopting prior art tradition to offset improved counteracting function in the function and the embodiment of the invention respectively.Shown in figure 13, improved counteracting function can well improve offsets the influence of distortion to channel estimating.When channel signal to noise ratio (SNR, Signal toNoise Ratio) when being 30dB, the mean square error (MSE, Mean Square Error) that adopts the estimation channel of improved counteracting function tradition is offset function and has been reduced 4dB.And when thresholding was 6dB, the precision of channel estimation that adopts improved counteracting function was very near undistorted desirable ofdm signal.Therefore, improve reference function and can when effectively suppressing signal PAPR, improve the channel estimating and the system transmissions performance of amplitude-limiting OFDM system.

Simulation result two: the simulation result of the OFDMA system that the LTE standard is corresponding.

The downlink OFDMA link of 2 transmitting antennas of LTE standard is adopted in emulation, is modulated to 16QAM.It is that 216 Chu sequence is pilot frequency sequence, the same LTE36.211.860 of pilot tone inserted mode that frequency domain uses length.Expansion typical urban model (ETU is used in emulation; Extended Typical Urbanmodel) channel; Definition about the ETU channel sees standard " ETSI.Communication of theEuropean communities:digital land mobile radio communication-COST207.ETSI, 1989 " for details.

Table 2 show tradition offset cubic measure under above-mentioned simulated conditions of function and improved counteracting function (Cubic Metric, CM) and signal-to-distortion ratio (Signal-to-Distortion Ratio, SDR).Wherein, CM is the normalized root-mean-square value of the amplitude cube of signal s (t):

$\mathrm{CM}=20{\log }_{10}\left\{\mathrm{rms}\right[s_{\mathrm{norm}}^3\left(t\right)\left]\right\}---\left(7\right)$

Wherein, $s_{\mathrm{Norm}}\left(t\right)=\frac{\left|s\left(t\right)\right|}{\mathrm{Rms}\left[s\left(t\right)\right]},$ $\mathrm{Rms}\left(x\right)=\sqrt{\frac{\left(x^{\′}x\right)}{N}}.$

Thresholding	CM	SDR
			3dB	2.71dB	16.34dB
4dB	3.16dB	20.43dB
			5dB	3.62dB	24.53dB
6dB	4.01dB	29.24dB

Table 2

Visible by table 2, be the original transmission signal of 4.76dB with respect to CM, adopt the peak value offset algorithm of improved counteracting function signal CM to be reduced about 0.7dB-2dB along with thresholding reduces progressively.

Figure 14 shows the PAPR rejection analogous diagram relatively when adopting prior art tradition to offset improved counteracting function in the function and the embodiment of the invention respectively.Can know by Figure 14, offset function, use the PAPR rejection of peak value offset method of improved counteracting function more excellent with respect to tradition.

Figure 15 shows the channel estimating performance analogous diagram relatively when adopting prior art tradition to offset improved counteracting function in the function and the embodiment of the invention respectively.Shown in figure 15, improved counteracting function can well improve offsets the influence of distortion to channel estimating.

It will be appreciated by those skilled in the art that accompanying drawing is the sketch map of a preferred embodiment, module in the accompanying drawing or flow process might not be that embodiment of the present invention is necessary.

It will be appreciated by those skilled in the art that the module in the device among the embodiment can be distributed in the device of embodiment according to the embodiment description, also can carry out respective change and be arranged in the one or more devices that are different from present embodiment.The module of the foregoing description can be merged into a module, also can further split into a plurality of submodules.

The invention described above embodiment sequence number is not represented the quality of embodiment just to description.

Part steps in the embodiment of the invention can utilize software to realize that corresponding software programs can be stored in the storage medium that can read, like CD or hard disk etc.

Above-described specific embodiment; The object of the invention, technical scheme and beneficial effect have been carried out further explain, and institute it should be understood that the above is merely preferred embodiment of the present invention; Be not to be used to limit protection scope of the present invention; All within spirit of the present invention and principle, any modification of being done, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (13)

1. a multi-carrier signal processing method is characterized in that, this method comprises:

To the requirements of distortion toleance degree, the subcarrier that will be used to carry said pending signal is divided into the V group according to different transmission data in the pending signal, and corresponding distortion toleance degree is set for every group of subcarrier; Wherein, V is the integer more than or equal to 2;

Based on the corresponding distortion toleance degree of each group subcarrier, confirm to offset the corresponding distortion noise of function and respectively organize the distribution proportion between subcarrier at frequency domain;

Respectively organize the distribution proportion between subcarrier according to said distortion noise at frequency domain, structure is offset the initial frequency domain response sequence of function;

Said initial frequency domain response sequence is carried out frequency domain-time domain conversion process, obtain being used for the counteracting function of peak value offset;

Utilizing said counteracting function that said pending signal is carried out peak value offset handles.

2. method according to claim 1 is characterized in that, saidly respectively organizes the distribution proportion between subcarrier according to said distortion noise at frequency domain, and the initial frequency domain response sequence that structure is offset function comprises:

Respectively organize the distribution proportion between subcarrier based on said distortion noise at frequency domain, structure makes the total distortion noise minimum or the minimum initial frequency domain response sequence of distortion noise of corresponding setting group subcarrier.

3. method according to claim 2 is characterized in that, said initial frequency domain response sequence satisfies following expression formula:

$\mathrm{Min}\underset{k=0}{\overset{N-1}{\mathrm{\Σ}}}{\left|\right|G_k^{\′}\left|\right|}^2$ And $\frac{\underset{k\∈{\mathrm{\φ}}_v}{\mathrm{\Σ}}\left|\right|G_k^{\′}\left|\right|}{\underset{k=0}{\overset{N-1}{\mathrm{\Σ}}}{\left|\right|G_k^{\′}\left|\right|}^2}\≤{\mathrm{\μ}}_v,{\mathrm{\μ}}_{v-1}\≤{\mathrm{\μ}}_v,v=0,...,V-1;$

Wherein, N is total number of subcarrier, φ _vBe v group subcarrier, G ' _kFor offsetting the frequency domain response of function in the k number of sub-carrier, μ _vBe the corresponding distortion toleance degree of v group subcarrier, 0≤μ _v≤1, μ _vThe distortion noise of more little relative introducing is more little.

4. method according to claim 1 is characterized in that, said pending signal comprises pilot frequency sequence and information data;

Said based on different transmission data in the pending signal to the requirements of distortion toleance degree, the subcarrier that will be used to carry said pending signal is divided into the V group, and comprises for every group of subcarrier is provided with corresponding distortion toleance degree:

To the requirement of distortion toleance degree, the subcarrier that will be used to carry said information data is divided into one group according to pilot frequency sequence and information data in the pending signal, and the subcarrier that will be used to carry said pilot frequency sequence is divided into another group; For the subcarrier that carries said information data is provided with the first distortion toleance degree, be lower than the second distortion toleance degree of the said first distortion toleance degree for the subcarrier setting of carrying said pilot frequency sequence.

5. method according to claim 4 is characterized in that, saidly respectively organizes the distribution proportion between subcarrier according to said distortion noise at frequency domain, and the initial frequency domain response sequence that structure is offset function comprises:

Respectively organize the distribution proportion between subcarrier based on said distortion noise at frequency domain, structure makes the total distortion noise minimum or the minimum initial frequency domain response sequence of distortion noise of corresponding setting group subcarrier.

6. method according to claim 5 is characterized in that, the said second distortion toleance degree is 0.

7. method according to claim 6 is characterized in that, said initial frequency domain response sequence satisfies following expression formula:

$\mathrm{Min}\underset{k=0}{\overset{N-1}{\mathrm{\Σ}}}{\left|\right|G_k^{\′}\left|\right|}^2,$ And $\left\{\begin{array}{c}{G}_k^{\′}=0,k\∈{\mathrm{\φ}}_0\\ \frac{\underset{k\∈{\mathrm{\φ}}_1}{\mathrm{\Σ}}\left|\right|G_k^{\′}\left|\right|}{\underset{k=0}{\overset{N-1}{\mathrm{\Σ}}}{\left|\right|G_k^{\′}\left|\right|}^2}\≤1\end{array}\right.;$

Wherein, N is total number of subcarrier, φ ₀For carrying the subcarrier of pilot frequency sequence, φ ₁The subcarrier of expression carry information data, G ' _kFor offsetting the frequency domain response of function in the k number of sub-carrier.

8. according to each described method of claim 1 to 3, it is characterized in that said pending signal comprises the data of different user;

Said based on different transmission data in the pending signal to the requirements of distortion toleance degree, the subcarrier that will be used to carry said pending signal is divided into the V group, and comprises for every group of subcarrier is provided with corresponding distortion toleance degree:

Based on the requirement to the distortion toleance degree of the data of different user in the pending signal, the subcarrier that will be used to carry each user's data with the requirement of different distortion toleance degree is divided into respectively not on the same group, and to each group subcarrier corresponding distortion toleance degree is set.

9. a multicarrier signal processing apparatus is characterized in that, this device comprises:

The distortion toleance degree is provided with module, is used for according to the requirements of the different transmission of pending signal data to the distortion toleance degree, and the subcarrier that will be used to carry said pending signal is divided into the V group, and corresponding distortion toleance degree is set for every group of subcarrier; Wherein, V is the integer more than or equal to 2;

Offset the function generation module, be used for confirming to offset the corresponding distortion noise of function and respectively organizing the distribution proportion between subcarrier at frequency domain according to the corresponding distortion toleance degree of each group subcarrier; Respectively organize the distribution proportion between subcarrier according to said distortion noise at frequency domain, structure is offset the initial frequency domain response sequence of function, and said initial frequency domain response sequence is carried out frequency domain-time domain conversion process, obtains being used for the counteracting function of peak value offset;

The peak value offset module, the counteracting function that is used to utilize said counteracting function generation module to generate carries out the peak value offset processing to said pending signal.

10. device according to claim 9; It is characterized in that; Said counteracting function generation module is respectively organized the distribution proportion between subcarrier according to said distortion noise at frequency domain, and structure makes the total distortion noise minimum or the minimum frequency domain response sequence of distortion noise of corresponding setting group subcarrier.

11. based on the described device of claim 9; It is characterized in that; Said counteracting function generation module comprises: frequency domain distribution ratio determination module is used for confirming to offset the corresponding distortion noise of function and respectively organizing the distribution proportion between subcarrier at frequency domain based on the corresponding distortion toleance degree of each group subcarrier;

Frequency domain response sequence structure module is used for respectively organizing the distribution proportion between subcarrier according to said distortion noise at frequency domain, and structure is offset the initial frequency domain response sequence of function;

Frequency domain-time domain conversion process module is used for said initial frequency domain response sequence is carried out frequency domain-time domain conversion process, obtains being used for the counteracting function of peak value offset.

12., it is characterized in that said pending signal comprises pilot frequency sequence and information data according to each described device in the claim 9 to 11;

Said distortion toleance degree be provided with module based on pilot frequency sequence and information data in the pending signal to the requirement of distortion toleance degree; The subcarrier that will be used to carry said information data is divided into one group, and the subcarrier that will be used to carry said pilot frequency sequence is divided into another group; For the subcarrier that carries said information data is provided with the first distortion toleance degree, be lower than the second distortion toleance degree of the said first distortion toleance degree for the subcarrier setting of carrying said pilot frequency sequence.

13., it is characterized in that said pending signal comprises the data of different user according to each described device in the claim 9 to 11;

Said distortion toleance degree is provided with module according to the requirement to the distortion toleance degree of the data of different user in the pending signal; The subcarrier that will be used to carry each user's data with the requirement of different distortion toleance degree is divided into respectively not on the same group, and to each group subcarrier corresponding distortion toleance degree is set.

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