CN103001732A - Transmission mode selection method and device and user equipment - Google Patents

Abstract

The invention discloses transmission mode selection method and device and user equipment. The method includes: acquiring channel matrix of subframes in an adaptive transmission cycle by channel estimation; calculating average channel capacity and average symbol error rate of each component carrier in the subframes in different transmission modes by the acquired channel matrix; and selecting a transmission mode combination, meeting the requirements for system transmission rate and system symbol error rate, for each component carrier according to the calculated average channel capacity and average symbol error rate. On the premise of random channels, the average channel capacity and average symbol error rate of each component carrier are traversed and calculated, the system requirements for transmission rate and symbol error rate are considered comprehensively, and accordingly user throughput is effectively increased with accurate transmission of user data guaranteed, and spectral efficiency of the user equipment is maximized.

Description

Transmission mode selection method, device and portable terminal

Technical field

The present invention relates to the LTE evolution technology, especially, relate to a kind of transmission mode selection method, device and portable terminal.

Background technology

Long Term Evolution (Long Term Evolution, LTE) system supports maximum 20MHz bandwidth, and descending peak rate can reach 100Mbit/s, and up peak rate can reach 50Mbit/s.Its follow-up evolution items (Long Term Evolution Advanced, LTE-A) system supports maximum 100MHz system bandwidth, requires descending peak rate to reach 1Gbit/s, and up peak rate reaches 500Mbit/s.For bandwidth and the peak-data rates demand that reaches the LTE-A system, and consider that existing frequency distributing mode and planning are difficult to find enough whole section frequency bands of the carrying LTE-A 100MHz of system bandwidth, 3GPP adopts carrier aggregation (Carrier Aggregation, CA) technology is with a plurality of LTE R compatible carrier waves (carrier wave of LTE-8 definition), namely, member carrier (Component Carrier, CC) connects into the transmission carrier wave of LTE-A system.

So far, 3GPP RAN1 and RAN4 group have determined the main scenes of 3 classes such as the polymerization of one-segment continuous carrier, the polymerization of one-segment discontinuous carrier, the polymerization of multiband discontinuous carrier, and corresponding member carrier is respectively discontinuous carrier in continuous carrier in the band, the band, the outer discontinuous carrier of band.Because these member carriers frequency band of living in is different, each CC, particularly the nature of radio propagation between the discontinuous carrier is widely different, if so all carrier waves of a user all adopt identical transmission mode, can cause portable terminal (User Equipment, UE) under the carrier aggregation scene to be difficult to mate the problem of the channel status of each CC.

Fig. 1 is media access control layer and physical layer interface scheme schematic diagram under the LTE-A carrier aggregation scene in the prior art.

As shown in Figure 1, transmission block is at media access control (Medium Access Control, MAC) layer cutting, independently independently mixed automatic retransfer request of transmission block correspondence of each CC (HybridAutomatic Repeat Request, HARQ) entity, and each CC independently carries out Modulation and Coding Scheme and selects, and visible UE has ready conditions channel status according to each CC in the corresponding transmission mode of each CC configuration.

Huawei once proposed the scheme of a kind of Flexible CA/MIMO configuration by name, and to satisfy the peak-data rates demand of LTE-A, two member carriers of this scheme under carrier aggregation scene use identical transmission mode.This scheme has defined the UE of three kinds of newtypes for LTE-A.The up-downgoing maximum data rate of three class UE can reach by member carrier number/number of plies that configuration is united on the upper strata.Table 1 has been listed 3 kinds of CA/MIMO configurations that the UE type is possible.

Table 1

For example, the up maximum data rate of R-10UE Class1 is the twice of R-8UE.This maximum data rate can be under the number of plies prerequisite constant with respect to R-8UE be realized by the identical member carrier polymerizations transmission of two bandwidth or in the constant prerequisite of the transmission bandwidth method that the number of plies increases to the R-8 twice of ordering, namely, can be configured to CC polymerization transmission or a two-layer CC transmission of two one decks, shown in Fig. 2 a and 2b.

Wherein, Fig. 2 a shows the situation of 2 CC polymerizations, and each CC uses independently data flow of an antenna transmission; Fig. 2 b shows the situation that 1 CC uses 2 antennas, by two of two antenna transmission data flow independently, data in each data flow all with Fig. 2 a in the data flow of each member carrier transmission in the data correspondence identical, be the twice of single transmission block among Fig. 2 a through the entrained data volume of transmission block after the baseband modulation like this.

The advantage of such scheme is that evolved Node B (eNB) can use in the table 1 a kind of in the CA/MIMO configuration according to the load of each CC and channel status and other system situation.Still take Fig. 2 as example, for the good UE of channel status, eNB can adopt the scheme shown in Fig. 2 b; And for the UE of cell edge, eNB can adopt the scheme shown in Fig. 2 a, thinks that this user distributes more frequency spectrum resource, thereby obtains higher data rate.

Yet also there is obvious deficiency in this scheme.Although this scheme has guaranteed LTE-A peak rate demand by carrier aggregation, each CC adopts identical transmission mode configuration to be difficult to mate the channel status of each CC.

Fig. 3 is LTE-A closed loop transmission schematic diagram.

As shown in Figure 3, LTE-A downlink closed-loop transmission is periodically fed back channel condition information (Channel State Information by the UE place by up channel, CSI) precoding matrix indicators that obtains (Precoding Matrix Index, PMI) and order indication (Rank Indicator, RI) realize.RI is the short-term transmission mode that UE recommends eNB.Transmission diversity among the LTE-A is corresponding to RI=1, and spatial reuse is corresponding to RI＞1 (consider transmission mode2 and the transmission mode 4 of LTE-A, do not consider the Closed-Loop Spatial Multiplexing of RI=1).In the spatial reuse situation, the RI value has further indicated the number of plies, the data fluxion of also namely transmitting.

Transmission diversity and spatial reuse utilize the weak dependence of space channel, and the selectivity on the former binding time/frequency provides more copy for the transmission of signal, to improve the reliability of signal transmission.The latter transmits different data flow at a plurality of separate space channels, and to improve the peak rate of transfer of data, its data rate size is closely related with the data fluxion of transmission.For the LTE-A system is well compromised between message transmission rate and reliability, optimum transmission mode selects always to be the focus of research.Many research institutions and company have proposed themselves selection criterion.For example, with the minimum euclid distance of receiver place planisphere as open loop multiple-input and multiple-output (Multiple Input Multiple Output, MIMO) technology (diversity and spatial reuse) switching criterion, in addition, also have on this basis the scholar to propose based on the bit error rate that generates under the different representative channel scenes (Bit Error Ratio, the switching criterion of statistics BER) or BER approximate solution in addition, can also be realized based on maximum channel capacity the switching of transmission mode.

MIMO pattern configurations scheme under the existing carrier aggregation scene is less, and the motion of Huawei has certain representativeness, although this motion can be satisfied transmission bandwidth and the peak rate requirement of LTE-AR-10, but still has following problem:

(1) the identical transmission mode of the upper employing of each CC in the scheme, do not consider the difference of each CC channel status, generally in the channel matrix transmission mode that (for example, full rank) adopts spatial reuse in the situation preferably, can satisfy the transmission accuracy and can improve speed again; Otherwise if residual order, spatial reuse can cause higher error rate, and at this moment general the employing sends diversity;

(2) starting point of various CA/MIMO configurations is to satisfy LTE-A peak-data rates demand in the scheme, does not consider the reliability of transfer of data, and also, each CC can't dispose corresponding transmission mode according to data-rate requirements and the target bit of UE.

Summary of the invention

The technical problem that the present invention will solve provides a kind of transmission mode selection method, device and portable terminal, can maximize the spectrum efficiency of portable terminal under the prerequisite that guarantees LTE-A downlink transfer speed and transmission accuracy.

According to an aspect of the present invention, proposed a kind of transmission mode selection method, comprised by channel estimating obtaining Adaptive Transmission channel matrix on the subframe in the cycle; Utilize the channel matrix that obtains to calculate the ergodic capacity of each member carrier under different transmission mode and average error sign ratio in the subframe; Selecting to satisfy the transmission mode that system transmissions speed and system's error sign ratio require according to the ergodic capacity that calculates and average error sign ratio for each member carrier makes up.

According to a further aspect in the invention, also proposed a kind of transmission mode selection device, comprised the channel matrix acquiring unit, be used for obtaining Adaptive Transmission channel matrix on the subframe in the cycle by channel estimating; Information process unit links to each other with the channel matrix acquiring unit, is used for utilizing the channel matrix that obtains to calculate the ergodic capacity of each member carrier under different transmission mode and average error sign ratio in the subframe; And mode selecting unit, link to each other with information process unit, be used for selecting to satisfy the transmission mode that system transmissions speed and system's error sign ratio require according to the ergodic capacity that calculates and average error sign ratio for each member carrier and make up.

According to another aspect of the invention, also proposed a kind of portable terminal, it comprises the transmission mode selection device in the previous embodiment.

Transmission mode selection method provided by the invention, device and portable terminal, traversal is calculated ergodic capacity and the average error sign ratio of each member carrier under the prerequisite of accidental channel, consider simultaneously system to the requirement of transmission rate and error sign ratio, thereby under the prerequisite that guarantees the correct transmission of user data, effectively improved user's throughput, maximized the spectrum efficiency of portable terminal.

Description of drawings

Accompanying drawing described herein is used to provide a further understanding of the present invention, consists of the application's a part.In the accompanying drawings:

Fig. 1 is media access control layer and physical layer interface scheme schematic diagram under the LTE-A carrier aggregation scene in the prior art.

Fig. 2 a shows the processing schematic diagram of 2 CC polymerizations.

Fig. 2 b shows the processing schematic diagram of 1 CC polymerization.

Fig. 3 is LTE-A closed loop transmission schematic diagram.

Fig. 4 is downlink resource grid schematic diagram.

Fig. 5 is the schematic flow sheet of an embodiment of transmission mode selection method of the present invention.

Fig. 6 is Adaptive Transmission cycle schematic diagram.

Fig. 7 is the schematic flow sheet of another embodiment of transmission mode selection method of the present invention.

Fig. 8 is UE downlink resource grid schematic diagram among the another embodiment of transmission mode selection method of the present invention.

Fig. 9 is the structural representation of an embodiment of transmission mode selection device of the present invention.

Figure 10 is the structural representation of another embodiment of transmission mode selection device of the present invention.

Figure 11 is the structural representation of the another embodiment of transmission mode selection device of the present invention.

Embodiment

With reference to the accompanying drawings the present invention is described more fully, exemplary embodiment of the present invention wherein is described.Exemplary embodiment of the present invention and explanation thereof are used for explaining the present invention, but do not consist of improper restriction of the present invention.

Below be illustrative to the description only actually of at least one exemplary embodiment, never as any restriction to the present invention and application or use.

Existing transmission mode selection criterion is divided into two classes substantially: the first kind lays particular emphasis under the prerequisite that transmission rate is determined and reduces error sign ratio; Equations of The Second Kind lays particular emphasis on maximum channel capacity under the prerequisite that guarantees transmission reliability.Channel capacity in the existing Equations of The Second Kind selection criterion mostly is to obtain determining to derive under the prerequisite of channel, but actual channel declines, and channel capacity is a stochastic variable.

When Doppler frequency shift was larger, channel was piece decline or rapid fading, and channel capacity can adopt ergodic capacity to represent.Yet ergodic capacity is to have under the ergodic prerequisite at the hypothesis channel, on the time period each channel is realized that corresponding channel capacity asks statistical average just can obtain at endless, can't realize in the real system.

Consider that the LTE-A systematic codeword encodes at a subframe duration, the transmittability of system can represent with the ergodic capacity on one or more subframes.

The present invention is directed to transmission mode collocation strategy under the existing carrier aggregation scene and do not consider the problem of each CC channel status, with average size as the transmission mode switching standards, add the constraint of average error sign ratio, proposed the Adaptive Transmission model selection strategy under the LTE-A carrier aggregation scene, this strategy can maximize the transmission rate of UE under the prerequisite that guarantees data transmission credibility.

At first, set up system model:

Suppose UE at the individual member carrier transmitting data of F (F is positive integer), each member carrier has independently RF link, and the system transmissions rate requirement is R _q, the average error sign ratio of transfer of data can not surpass δ on each member carrier ₀

Fig. 4 is downlink resource grid schematic diagram.

As shown in Figure 4, f represents the member carrier numbering of UE institute polymerization, and each member carrier can comprise a plurality of subcarriers (wherein, each subcarrier bandwidth can be 15khz, the bandwidth of member carrier is generally 10MHz, 20MHz etc.), k is the subcarrier number in the LTE-A downlink resource grid, K _fThe total number of sub-carriers that comprises in front f the member carrier of expression, K _FExpression UE is used for the total number of sub-carriers of transfer of data, K ₀=0, K _f-K _F-1Represent the sub-carrier number that f member carrier has, l is an OFDM symbol number in the descending sub frame, and L represents the sum of OFDM symbol in the descending sub frame.

With

Represent respectively the corresponding RF link of this member carrier that number of transmit antennas, reception antenna number and the UE of the RF link that f member carrier of UE is corresponding draw by following Adaptive Transmission mode selecting method in a upper radio frames the transmission number of plies (that is, order number) and

With

All be positive integer,

The downlink transfer of k subcarrier in l OFDM symbol period can be expressed as in the downlink resource grid:

$r_{(k,l),f}=\sqrt{\frac{E_x}{M_T^f}}{H}_{(k,l),f}{W}_{(k,l),f}{x}_{(k,l),f}+n_{(k,l),f},f=1,...,F,k=K_{f-1}+1,...,K_f,l=1,...,L,---\left(1\right)$

Wherein,

The pre-coding matrix of k subcarrier in l OFDM symbol period,

Expression pre-coding matrix W _{(k, l), f}In the precoding factor, the gain factor when namely the data-mapping in b data flow is to a root transmitting antenna.

The channel matrix of k subcarrier in l OFDM symbol period,

The expression channel matrix H _{(k, l), f}In d root transmitting antenna to the channel gain between the c root reception antenna.

Pre-coding matrix W in the formula (1) _{(k, l), f}Be used for the data flow on each layer is mapped to each antenna order

Be equivalent channel matrix, then formula (1) can be expressed as:

$r_{(k,l),f}=\sqrt{\frac{E_x}{M_T^f}}{\tilde{H}}_{(k,l),f}{x}_{(k,l),f}+n_{(k,l),f}---\left(4\right)$

$x_{(k,l),f}={(x_{(k,l),\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA0000092153730000012.png,HDA0000092153730000031.png"\; state="\{\{state\}\}">f</figure-callout>}}^1,x_{(k,l),\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="HDA0000092153730000012.png,HDA0000092153730000051.png"\; state="\{\{state\}\}">f</figure-callout>}}^2,...,x_{(k,l),f}^{N_{\mathrm{RI}}^f})}^T$ Represent the data flow on each layer, E _xThe average energy of each symbol, x _{(k, l), f}Energy be

$r_{(k,l),f}={(r_{(k,l),\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA0000092153730000012.png,HDA0000092153730000031.png"\; state="\{\{state\}\}">f</figure-callout>}}^1,r_{(k,l),\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="HDA0000092153730000012.png,HDA0000092153730000051.png"\; state="\{\{state\}\}">f</figure-callout>}}^2,...,r_{(k,l),f}^{M_R^f})}^T$ The receive data vector that represents each reception antenna place,

$n_{(k,l),f}={(n_{(k,l),\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA0000092153730000012.png,HDA0000092153730000031.png"\; state="\{\{state\}\}">f</figure-callout>}}^1,n_{(k,l),\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="HDA0000092153730000012.png,HDA0000092153730000051.png"\; state="\{\{state\}\}">f</figure-callout>}}^2,...,n_{(k,l),f}^{M_R^f})}^T$ Be the independent identically distributed complex value additive white Gaussian noise vector at each reception antenna place, obey distribution

Next, technical scheme according to the present invention is introduced specific embodiment:

Fig. 5 is the schematic flow sheet of an embodiment of transmission mode selection method of the present invention.

As shown in Figure 5, this embodiment can may further comprise the steps:

S502, portable terminal by channel estimating obtain Adaptive Transmission in the cycle (for example, can be a LTE-A radio frames) channel matrix on the subframe, wherein, subframe can be the first half subframe of a radio frames in this transmission cycle, former subframes or first subframe, the number that is used for the subframe of calculating channel matrix need to be considered the operand of data, to guarantee that the transmission mode combination that self adaptation goes out can be known in base station and portable terminal before next radio frames, can adopt subframe as much as possible to participate in computing in the situation of the demand satisfying, to improve the accuracy of channel capacity and average error sign ratio;

S504 utilizes the channel matrix that obtains to calculate the ergodic capacity of each member carrier under different transmission mode and average error sign ratio in the subframe;

S506 selects to satisfy the transmission mode that system transmissions speed and system's error sign ratio require according to the ergodic capacity that calculates and average error sign ratio for each member carrier and makes up.

This embodiment travels through ergodic capacity and the average error sign ratio that calculates each member carrier under the prerequisite of accidental channel, consider simultaneously system to the requirement of transmission rate and error sign ratio, thereby under the prerequisite that guarantees the correct transmission of user data Effective Raise user's throughput, maximized the spectrum efficiency of portable terminal.

In an example, above-mentioned steps S504 can be embodied as:

Determine respectively the span of the transmission number of plies of each member carrier wherein, to equal at 1 o'clock in the transmission number of plies according to the number of transmit antennas on each member carrier and reception antenna number, the transmission mode that corresponding member carrier adopts is for sending diversity mode; Greater than 1 o'clock, the transmission mode that corresponding member carrier adopts was spatial multiplexing mode in the transmission number of plies;

In the span of the transmission number of plies of each member carrier:

Calculate the ergodic capacity of each member carrier on each OFDM symbol of its subcarrier and subframe according to channel matrix;

Calculate the scope of the output signal-to-noise ratio of each member carrier according to channel matrix;

Average error sign ratio according to each member carrier of range computation of the output signal-to-noise ratio of each member carrier.

In another example, above-mentioned steps S506 can be embodied as:

Span permutation and combination according to the transmission number of plies of each member carrier goes out various transmission modes combinations;

Judgement in the ergodic capacity sum of each member carrier under the combination of a kind of transmission mode whether more than or equal to system transmissions rate requirement and the average error sign ratio of judging each member carrier under the combination of this kind transmission mode whether all less than system's error sign ratio requirement;

If the ergodic capacity sum of each member carrier all less than system's error sign ratio requirement, then is defined as this kind transmission mode the transmission mode combination of each member carrier more than or equal to the average error sign ratio of system transmissions rate requirement and each member carrier under the combination of this kind transmission mode.

Further, be combined as when a plurality of in the transmission mode of each member carrier, select the transmission mode of the ergodic capacity sum maximum of each member carrier to be combined as the transmission mode combination of each member carrier.

Further, when the ergodic capacity sum that is combined as a plurality of and each member carrier in the transmission mode of each member carrier all equates, in the multiple transmission mode combination of each member carrier, select the transmission mode of maximum average error sign ratio minimum in each member carrier to be combined as the transmission mode combination of each member carrier.

Next, first subframe take subframe that be used for to calculate channel matrix as radio frames describes the specific implementation process of the above embodiment of the present invention in detail as example.

Fig. 6 is Adaptive Transmission cycle schematic diagram.

As shown in Figure 6, above-mentioned steps S502 carries out in first subframe of each radio frames, and step S504 and step S506 carry out in nine remaining subframes of this radio frames.

Fig. 7 is the schematic flow sheet of another embodiment of transmission mode selection method of the present invention.Below in conjunction with Fig. 4 and Fig. 7 this embodiment is described together.

Such as Fig. 4 and shown in Figure 7, this embodiment can may further comprise the steps:

S702, receiver obtains Adaptive Transmission channel matrix H on first subframe in the cycle by channel estimating.

Wherein, each element among the H is a channel matrix that represents certain resource particle in the downlink resource grid, its line number and columns be respectively this resource particle place member carrier reception antenna number and the number of transmit antennas of corresponding RF link.

S704 calculates ergodic capacity (wherein, channel capacity be the upper limit of transmission rate) and the average error sign ratio of each member carrier under different transmission mode in first subframe according to H.

S704a, the transmission number of plies of calculating the corresponding RF link of member carrier f in the current wireless frame is

The time, each member carrier is located corresponding channel capacity at resource grid (k, l).

The transmission number of plies

The channel capacity computing formula of pressing the spatial reuse channel capacity calculate:

$C_{(k,l),f}^{n_{\mathrm{RI}}^f}\left({\tilde{H}}_{(k,l),f}\right)={\log }_2\left(\det (I+\mathrm{\&gamma;}{\tilde{H}}_{(k,l),f}^H{\tilde{H}}_{(k,l),f})\right)---\left(6\right)$

The transmission number of plies

Channel capacity calculate by the computing formula of the channel capacity that sends diversity:

$C_{(k,l),f}^1\left(H_{(k,l),f}\right)={\log }_2(1+\mathrm{\&gamma;tr}\left(H_{(k,l),f}^H{H}_{(k,l),f}\right))---\left(7\right)$

Wherein, γ=E _x/ N ₀It is the average signal-to-noise ratio at reception antenna place.

S704b, add up each member carrier the transmission number of plies be

The time ergodic capacity.

At first, add up the ergodic capacity of each subcarrier on a subframe lengths.

${\stackrel{\&OverBar;}{C}}_{(k,~),f}^{n_{\mathrm{RI}}^f}=\frac{1}{L}\underset{l=1}{\overset{L}{\mathrm{\&Sigma;}}}{C}_{(k,l),f}^{n_{\mathrm{RI}}^f},f=1,...,F,k=K_{f-1}+1,...,K_f---\left(8\right)$

Secondly, thus the ergodic capacity summation of the subcarrier that each member carrier is comprised obtains the ergodic capacity of member carrier:

$C_f^{n_{\mathrm{RI}}^f}=\underset{k=K_{f-1}+1}{\overset{K_f}{\mathrm{\&Sigma;}}}{\stackrel{\&OverBar;}{C}}_{(k,~),f}^{n_{\mathrm{RI}}^f},f=1,...,F---\left(9\right)$

S704c asks each member carrier in the transmission number of plies to be

The time the scope of output signal-to-noise ratio.

Calculate the output signal-to-noise ratio of each resource particle (k, l) in first subframe of transmission cycle of each member carrier.

For spatial reuse, when receiving terminal adopted ZF to detect, the output signal-to-noise ratio of n layer output data adopted following formula to calculate:

${\mathrm{\&gamma;}}_{n,\mathrm{ZF}}{|}_{(k,l),f}^{n_{\mathrm{RI}}^f}=\frac{\mathrm{\&gamma;}}{M_T^f}\frac{1}{{\left[{\tilde{H}}_{(k,l),f}^H{\tilde{H}}_{(k,l),f}\right]}_{n,n}^{-1}},n=1,...,n_{\mathrm{RI}}^f---\left(10\right)$

Wherein,

Expression data flow sum.It is pointed out that in the spatial reuse situation, receiving terminal also can adopt other detection methods, corresponding output signal-to-noise ratio computing formula need to be adjusted accordingly.

For transmission diversity, when receiving terminal adopted maximum merging than reception, output signal-to-noise ratio adopted following formula to calculate:

${\mathrm{\&gamma;}}_{1,\mathrm{div}}{|}_{(k,l),\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA0000092153730000012.png,HDA0000092153730000031.png"\; state="\{\{state\}\}">f</figure-callout>}}^1=\frac{\mathrm{\&gamma;}}{M_T^f}{\left|\right|H_{(k,l),f}\left|\right|}_{\mathrm{<figure-callout\; id="2"\; label="F"\; filenames="HDA0000092153730000012.png,HDA0000092153730000051.png"\; state="\{\{state\}\}">F</figure-callout>}}^2=\frac{\mathrm{\&gamma;}}{M_T^f}\underset{i=1}{\overset{M_T^f}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{M_R^f}{\mathrm{\&Sigma;}}}{\left|H_{(k,l),f}^{(i,j)}\right|}^2---\left(11\right)$

It is pointed out that in the transmission diversity situation, receiving terminal also can adopt additive method, corresponding output signal-to-noise ratio computing formula need to be adjusted accordingly.

Determine that by result of calculation each member carrier in the transmission number of plies is

The time the output signal-to-noise ratio scope:

${\left[{\mathrm{\&gamma;}}_X{|}_f^{n_{\mathrm{RI}}^f}\right]}_{\min }\&le;{\mathrm{\&gamma;}}_X{|}_f^{n_{\mathrm{RI}}^f}\&le;{\left[{\mathrm{\&gamma;}}_X{|}_f^{n_{\mathrm{RI}}^f}\right]}_{\max }---\left(12\right)$

Wherein,

${\left[{\mathrm{\&gamma;}}_X{|}_f^{n_{\mathrm{RI}}^f}\right]}_{\max }=\max \left({\mathrm{\&gamma;}}_{n,X}{|}_{(k,l),f}^{n_{\mathrm{RI}}^f}\right),n=1,...,n_{\mathrm{RI}}^f---\left(13\right)$

${\left[{\mathrm{\&gamma;}}_X{|}_f^{n_{\mathrm{RI}}^f}\right]}_{\min }=\min \left({\mathrm{\&gamma;}}_{n,X}{|}_{(k,l),f}^{n_{\mathrm{RI}}^f}\right),n=1,...,n_{\mathrm{RI}}^f---\left(14\right)$

Wherein, { XF, div}, ZF represent that transmitting terminal adopts spatial reuse to X ∈, and receiving terminal adopts ZF to detect; Div represents that transmitting terminal adopts the transmission diversity, and receiving terminal adopts maximum the merging than detection.

S704d is calculated as follows each member carrier and exists

The time average error sign ratio:

$P_s{|}_f^{n_{\mathrm{RI}}^f}={\&Integral;}_{{\left[{\mathrm{\&gamma;}}_X{|}_f^{n_{\mathrm{RI}}^f}\right]}_{\min }}^{{\left[{\mathrm{\&gamma;}}_X{|}_f^{n_{\mathrm{RI}}^f}\right]}_{\max }}{P}_s\left[e\right|\left({\mathrm{\&gamma;}}_X{|}_f^{n_{\mathrm{RI}}^f}\right)]\&CenterDot;p\left({\mathrm{\&gamma;}}_X{|}_f^{n_{\mathrm{RI}}^f}\right){\mathrm{d\&gamma;}}_X{|}_f^{n_{\mathrm{RI}}^f}---\left(15\right)$

Wherein,

It is the condition error sign ratio that transmitted signal adopts certain modulation system.For rectangle M-QAM, the condition error sign ratio under the fading channel is:

$P_s\left[e\right|\left({\mathrm{\&gamma;}}_X{|}_f^{n_{\mathrm{RI}}^f}\right)]=\frac{4G}{\mathrm{\&pi;}}{\&Integral;}_0^{\frac{\mathrm{\&pi;}}{2}}\exp (-\frac{g{\mathrm{\&gamma;}}_X{|}_f^{n_{\mathrm{<figure-callout\; id="2"\; label="RI\; f\; sin"\; filenames="HDA0000092153730000012.png,HDA0000092153730000051.png"\; state="\{\{state\}\}">RI</figure-callout>}}^f}}{{\sin }^{}})\mathrm{d\&theta;}-\frac{{4\mathrm{<figure-callout\; id="2"\; label="G"\; filenames="HDA0000092153730000012.png,HDA0000092153730000051.png"\; state="\{\{state\}\}">G</figure-callout>}}^2}{\mathrm{\&pi;}}{\&Integral;}_0^{\frac{\mathrm{\&pi;}}{2}}\exp (-\frac{g{\mathrm{\&gamma;}}_X{|}_f^{n_{\mathrm{<figure-callout\; id="2"\; label="RI\; f\; sin"\; filenames="HDA0000092153730000012.png,HDA0000092153730000051.png"\; state="\{\{state\}\}">RI</figure-callout>}}^f}}{{\sin }^{}})\mathrm{d\&theta;}---\left(16\right)$

Wherein,

M is number of constellation points, Be

Probability density function, be calculated as follows:

$p\left({\mathrm{\&gamma;}}_X{|}_f^{n_{\mathrm{RI}}^f}\right)=\frac{M_T^f}{\mathrm{\&gamma;}\&CenterDot;\mathrm{\&Gamma;}\left(D_X^f\right)}{\left(\frac{M_T^f{\mathrm{\&gamma;}}_X{|}_f^{n_{\mathrm{RI}}^f}}{\mathrm{\&gamma;}}\right)}^{D_X^f-1}\exp (-\frac{M_T^f{\mathrm{\&gamma;}}_X{|}_f^{n_{\mathrm{RI}}^f}}{\mathrm{\&gamma;}})---\left(17\right)$

Wherein, I () is the Gamma function,

The order of diversity of receiver:

$D_X^f=\left\{\begin{array}{c}{M}_R^f-M_T^f+1,X=\mathrm{ZF}\\ M_R^f{M}_T^f,X=\mathrm{div}\end{array}\right.---\left(18\right)$

Formula (16), (17) substitution (15) just can be tried to achieve

Next, ergodic capacity and the average error sign ratio with each member carrier of trying to achieve deposits in the following table of comparisons:

Table 2

Wherein,

Line-up of delegates's carrier wave 1 ..., f ..., the permutation and combination of the transmission number of plies of F},

Line-up of delegates's carrier wave 1 ..., f ..., F} in the transmission number of plies is

The time error sign ratio.

S706 is for each member carrier is selected the optimum transmission mode combination.

In order to guarantee user's transmission rate requirements, the ergodic capacity sum of each member carrier must be more than or equal to the system transmissions rate requirement:

$\underset{f=1}{\overset{F}{\mathrm{\&Sigma;}}}{C}_f^{n_{\mathrm{RI}}^f}\&GreaterEqual;R_q---\left(19\right)$

In addition, in order to guarantee the reliability of user data transmission, the average error sign ratio on each member carrier all must be less than the error sign ratio constraint δ of system ₀

Having got rid of in the table of comparisons after the discontented transmission mode combination that is enough to two constraintss, in the remaining transmission mode combination of the table of comparisons, select to make the transmission mode combination of UE channel capacity maximum as the transmission mode under the carrier aggregation scene; Further, if the channel capacity of a plurality of transmission mode combination is identical, then select the transmission mode combination of maximum average error sign ratio minimum to make up as the transmission mode under the carrier aggregation scene.

Fig. 8 is UE downlink resource grid schematic diagram among the another embodiment of transmission mode selection method of the present invention.

As shown in Figure 8, suppose:

The polymerization transmission of (1) two member carrier, the bandwidth of two member carriers is 1.4MHz, only describes as an example of 1.4MHz example herein, and the bandwidth of each member carrier of realization carrier aggregation is generally more than 10MHz;

(2) according to the relevant configuration of LTE-A, two member carriers respectively have 72 subcarriers;

(3) adopt the conventional Cyclic Prefix that disposes, 14 OFDM symbols are arranged in the subframe;

The transmitting antenna of (4) two member carrier RF links is 2, and the reception antenna quantity of receiving terminal also is 2, that is, ${\mathrm{<figure-callout\; id="1"\; label="M\; T"\; filenames="HDA0000092153730000012.png,HDA0000092153730000031.png"\; state="\{\{state\}\}">M</figure-callout>}}_T^{}={\mathrm{<figure-callout\; id="1"\; label="M\; R"\; filenames="HDA0000092153730000012.png,HDA0000092153730000031.png"\; state="\{\{state\}\}">M</figure-callout>}}_R^{}={\mathrm{<figure-callout\; id="2"\; label="M\; T"\; filenames="HDA0000092153730000012.png,HDA0000092153730000051.png"\; state="\{\{state\}\}">M</figure-callout>}}_T^{}={\mathrm{<figure-callout\; id="2"\; label="M\; R"\; filenames="HDA0000092153730000012.png,HDA0000092153730000051.png"\; state="\{\{state\}\}">M</figure-callout>}}_R^{}=2.$

This embodiment specifically may further comprise the steps:

Step 1, receiver obtains Adaptive Transmission channel matrix H on first subframe in the cycle by channel estimating:

Wherein, each element among the H is the matrix of 2 row, 2 row, represents the channel matrix of certain resource particle in the downlink resource grid, for example, and H _{(1,1), 1}Represent the channel matrix of resource particle (1,1), this resource particle belongs to member carrier 1 at frequency domain.

Step 2 because the dual-mode antenna number average of each member carrier place transmission link is 2, so determine the span of the transmission number of plies is:

Wherein, f=1,2.

The transmission number of plies The time corresponding spatial reuse, the channel capacity that resource particle (k, l) is located is calculated according to formula (6), wherein,

W _{(k, l), f}Being pre-coding matrix, being used for the data flow on two layers is mapped to two transmit antennas, is the matrix of 2 row, 2 row, and can table look-up from the LTE-A relevant criterion obtains.

The transmission number of plies

The time the corresponding diversity that sends, the channel capacity that resource particle (k, l) is located by formula (7) is calculated.

Thus, we can obtain member carrier 1,2 is the channel capacity of subcarrier on 14 OFDM symbol periods that (the corresponding transmission number of plies is respectively 1 and 2) comprises when sending diversity and spatial reuse in transmission mode, can be as follows with four matrix notations:

Wherein, A ₁, A ₂, A ₃, A ₄The channel capacity of member carrier 1 each resource particle when the channel capacity of member carrier 1 each resource particle, spatial reuse when expression sends diversity respectively, the channel capacity of member carrier 2 each resource particle during channel capacity, the spatial reuse of member carrier 2 each resource particle when sending diversity.

Step 3, the channel capacity under different transmission mode according to aforementioned formula (8) and (9) statistics member carrier 1,2, that is, and to A ₁, A ₂, A ₃, A ₄Every row be averaging, and then each row addition summation is obtained

The ergodic capacity of member carrier 1 when the ergodic capacity of member carrier 1, spatial reuse when expression sends diversity respectively, the ergodic capacity of member carrier 2 during ergodic capacity, the spatial reuse of member carrier 2 when sending diversity.

Step 4 is calculated the output signal-to-noise ratio of resource particle (k, l) under different transmission mode that member carrier 1,2 comprises according to formula (10) and (11), same available four matrix notations:

$B_4=\left(B_4^1\right|B_4^2)$

Wherein, B ₁, B ₂, B ₃, B ₄The output signal-to-noise ratio of member carrier 1 each resource particle when the output signal-to-noise ratio of member carrier 1 each resource particle, spatial reuse when expression sends diversity respectively, the output signal-to-noise ratio of member carrier 2 each resource particle during output signal-to-noise ratio, the spatial reuse of member carrier 2 each resource particle when sending diversity.B ₂, B ₄Submatrix With Represent that respectively receiver detects the output signal-to-noise ratio on two layer data that obtain.

Step 5 finds B ₁, B ₂, B ₃, B ₄Thereby in maximum and minimum value draw member carrier 1,2 in the scope that sends the output signal-to-noise ratio separately under diversity and the space multiplexing mode, substitution formula (15) obtains again The average error sign ratio of member carrier 1 when the average error sign ratio of member carrier 1, spatial reuse when expression sends diversity respectively, the average error sign ratio of member carrier 2 during average error sign ratio, the spatial reuse of member carrier 2 when sending diversity.

Step 6, with each member carrier of trying to achieve

With

Deposit in the following UE transmission mode combination table of comparisons:

Table 3

Step 7 is got rid of the transmission mode combination of discontented pedal system transmission rate request in the above-mentioned table of comparisons, and the table of comparisons after supposing to get rid of is:

Table 4

{ 1,1} { among 2, the 1}, selects the transmission mode combination of UE channel capacity maximum in the transmission mode combination.If the channel capacity of two mode combinations is identical, relatively

With

Size, select the corresponding transmission mode combination of smaller in the two as the transmission mode in next Adaptive Transmission cycle, and by uplink feedback to eNB.

One of ordinary skill in the art will appreciate that, whole and the part steps of realization said method embodiment can be finished by the relevant hardware of program command, aforesaid program can be stored in the computing equipment read/write memory medium, this program is when carrying out, execution comprises the step of said method embodiment, and two aforesaid storage mediums can comprise the various media that can be program code stored such as ROM, RAM, magnetic disc and CD.

Fig. 9 is the structural representation of an embodiment of transmission mode selection device of the present invention.

As shown in Figure 9, the device 90 among this embodiment can comprise:

Channel matrix acquiring unit 91 is used for obtaining Adaptive Transmission channel matrix on the subframe in the cycle by channel estimating, and wherein, this subframe can be the first half of a radio frames, former subframes or first subframe;

Information process unit 92 links to each other with channel matrix acquiring unit 91, is used for utilizing the channel matrix that obtains to calculate the ergodic capacity of each member carrier under different transmission mode and average error sign ratio in the subframe; And

Mode selecting unit 93 links to each other with information process unit 92, is used for selecting to satisfy the transmission mode that system transmissions speed and system's error sign ratio require according to the ergodic capacity that calculates and average error sign ratio for each member carrier and makes up.

This embodiment travels through ergodic capacity and the average error sign ratio that calculates each member carrier under the prerequisite of accidental channel, consider simultaneously system to the requirement of transmission rate and error sign ratio, thereby under the prerequisite that guarantees the correct transmission of user data Effective Raise user's throughput, maximized the spectrum efficiency of portable terminal.

Figure 10 is the structural representation of another embodiment of transmission mode selection device of the present invention.

As shown in figure 10, compare with embodiment among Fig. 9, the information process unit 101 in the device 100 among this embodiment can comprise:

Transmission number of plies scope is determined subelement 1011, be used for determining respectively according to the number of transmit antennas on each member carrier and reception antenna number the span of the transmission number of plies of each member carrier, wherein, equal at 1 o'clock in the transmission number of plies, the transmission mode that corresponding member carrier adopts is for sending diversity mode; Greater than 1 o'clock, the transmission mode that corresponding member carrier adopts was spatial multiplexing mode in the transmission number of plies;

Ergodic capacity computation subunit 1012, determine that with the transmission number of plies scope subelement 1011 links to each other with channel matrix acquiring unit 91, be used in the span of the transmission number of plies of each member carrier, calculating the ergodic capacity of each member carrier on each OFDM symbol of its subcarrier and subframe according to channel matrix;

Output signal-to-noise ratio computation subunit 1013, determine that with the transmission number of plies scope subelement 1011 links to each other with channel matrix acquiring unit 91, be used in the span of the transmission number of plies of each member carrier, calculating the scope of the output signal-to-noise ratio of each member carrier according to channel matrix;

Average error sign ratio computation subunit 1014, determine that with the transmission number of plies scope subelement 1011 links to each other with output signal-to-noise ratio computation subunit 1013, be used in the span of the transmission number of plies of each member carrier, according to the average error sign ratio of each member carrier of range computation of the output signal-to-noise ratio of each member carrier.

Figure 11 is the structural representation of the another embodiment of transmission mode selection device of the present invention.

As shown in figure 11, compare with embodiment among Figure 10, the mode selecting unit 111 in the device 110 among this embodiment can comprise:

Combination subelement 1111 is used for going out various transmission modes combinations according to the span permutation and combination of the transmission number of plies of each member carrier;

Judgment sub-unit 1112, link to each other with combination subelement 1111, ergodic capacity sum that be used for to judge each member carrier under a kind of transmission mode combination whether more than or equal to system transmissions rate requirement and the average error sign ratio of judging each member carrier under this kind transmission mode makes up whether all less than system's error sign ratio requirement;

Determine subelement 1113, link to each other with judgment sub-unit 1112, if the ergodic capacity sum that is used for each member carrier under the combination of this kind transmission mode all less than system's error sign ratio requirement, then is defined as this kind transmission mode the transmission mode combination of each member carrier more than or equal to the average error sign ratio of system transmissions rate requirement and each member carrier.

In an example of device, determine that subelement also is used for being combined as when a plurality of in the transmission mode that each member carrier satisfies system transmissions rate requirement and error sign ratio requirement, select the transmission mode of the ergodic capacity sum maximum of each member carrier to be combined as the transmission mode combination of each member carrier.

In another example of device, determine that subelement also is used for when the ergodic capacity sum that the transmission mode that each member carrier satisfies system transmissions rate requirement and error sign ratio requirement is combined as a plurality of and each member carrier all equates, in the multiple transmission mode combination of each member carrier, select the transmission mode of maximum average error sign ratio minimum in each member carrier to be combined as the transmission mode combination of each member carrier.

In addition, transmission mode selection device in above-described embodiment can also be arranged in the portable terminal, can effectively make the Release-10 portable terminal retrain the selection of finishing adaptively the transmission mode on each member carrier according to the channel condition information of each member carrier, transmission rate and the average error sign ratio that portable terminal requires under the LTE-A carrier aggregation scene, also be the selection of RI, thereby under the prerequisite that guarantees portable terminal transmission rate and transmission accuracy, maximize the spectrum efficiency of portable terminal.

Each embodiment all adopts the mode of going forward one by one to describe in this specification, and what each embodiment stressed is and the difference of other embodiment that part identical with similar between each embodiment can cross-references.For device embodiment because itself and embodiment of the method basic simlarity, so describe fairly simple, relevant part can be referring to embodiment of the method explanation partly.

The above embodiment of the present invention transmission mode selection under the existing carrier aggregation scene is failed the problem of each member carrier channel status of Adaptive matching and is started with, consider system transmissions rate requirement and transmission reliability requirement, changed the way of calculating channel capacity under the prerequisite that existing scheme is definite channel at the supposition channel, under the prerequisite of accidental channel, calculate ergodic capacity, and add the restriction of error sign ratio, under the prerequisite that guarantees the correct transmission of user data, effectively promoted user's throughput.

Although by example specific embodiments more of the present invention are had been described in detail, it should be appreciated by those skilled in the art that above example only is in order to describe, rather than in order to limit the scope of the invention.It should be appreciated by those skilled in the art, can in situation about not departing from the scope of the present invention with spirit, above embodiment be made amendment.Scope of the present invention is limited by claims.

Claims (17)

1. a transmission mode selection method is characterized in that, comprising:

Obtain Adaptive Transmission channel matrix on the subframe in the cycle by channel estimating;

Utilize the described channel matrix that obtains to calculate the ergodic capacity of each member carrier under different transmission mode and average error sign ratio in the described subframe;

Be that described each member carrier selects to satisfy the transmission mode combination that system transmissions speed and system's error sign ratio require according to the described ergodic capacity that calculates and average error sign ratio.

2. transmission mode selection method according to claim 1 is characterized in that, the subframe in the described Adaptive Transmission cycle is the first half of a radio frames.

3. transmission mode selection method according to claim 1 is characterized in that, the step that the described channel matrix that described utilization obtains calculates the interior ergodic capacity of each member carrier under different transmission mode of described subframe and average error sign ratio comprises:

Determine respectively the span of the transmission number of plies of each member carrier according to the number of transmit antennas on each member carrier and reception antenna number;

In the span of the transmission number of plies of described each member carrier:

Calculate the ergodic capacity of described each member carrier on each OFDM symbol of its subcarrier and described subframe according to described channel matrix;

Calculate the scope of the output signal-to-noise ratio of described each member carrier according to described channel matrix;

Average error sign ratio according to described each member carrier of range computation of the output signal-to-noise ratio of described each member carrier.

4. transmission mode selection method according to claim 3 is characterized in that, equals at 1 o'clock in the described transmission number of plies, and the transmission mode that corresponding member carrier adopts is for sending diversity mode.

5. transmission mode selection method according to claim 3 is characterized in that, greater than 1 o'clock, the transmission mode that corresponding member carrier adopts was spatial multiplexing mode in the described transmission number of plies.

6. transmission mode selection method according to claim 3, it is characterized in that the described ergodic capacity that described basis calculates and average error sign ratio are that the step that the transmission mode combination of system transmissions speed and system's error sign ratio demand is satisfied in described each member carrier selection comprises:

Span permutation and combination according to the transmission number of plies of described each member carrier goes out various transmission modes combinations;

Judgement in the ergodic capacity sum of described each member carrier under the combination of a kind of transmission mode whether more than or equal to system transmissions rate requirement and the average error sign ratio of judging described each member carrier under the combination of this kind transmission mode whether all less than system's error sign ratio requirement;

If the ergodic capacity sum of described each member carrier all less than system's error sign ratio requirement, then is defined as this kind transmission mode the transmission mode combination of described each member carrier more than or equal to the average error sign ratio of system transmissions rate requirement and described each member carrier under the combination of this kind transmission mode.

7. transmission mode selection method according to claim 6, it is characterized in that, the transmission mode that satisfies system transmissions rate requirement and error sign ratio requirement at described each member carrier is combined as when a plurality of, selects the transmission mode of the ergodic capacity sum maximum of described each member carrier to be combined as the transmission mode combination of described each member carrier.

8. transmission mode selection method according to claim 7, it is characterized in that, when the ergodic capacity sum that the transmission mode that satisfies system transmissions rate requirement and error sign ratio requirement at described each member carrier is combined as a plurality of and described each member carrier all equates, in the multiple transmission mode combination of described each member carrier, select the transmission mode of maximum average error sign ratio minimum in described each member carrier to be combined as the transmission mode combination of described each member carrier.

9. a transmission mode selection device is characterized in that, comprising:

The channel matrix acquiring unit is used for obtaining Adaptive Transmission channel matrix on the subframe in the cycle by channel estimating;

Information process unit links to each other with described channel matrix acquiring unit, is used for utilizing the described channel matrix that obtains to calculate the ergodic capacity of each member carrier under different transmission mode and average error sign ratio in the described subframe; And

Mode selecting unit links to each other with described information process unit, and being used for according to the described ergodic capacity that calculates and average error sign ratio is that described each member carrier selects to satisfy the transmission mode combination that system transmissions speed and system's error sign ratio require.

10. transmission mode selection device according to claim 9 is characterized in that, the subframe in the described Adaptive Transmission cycle is the first half of a radio frames.

11. transmission mode selection device according to claim 9 is characterized in that, described information process unit comprises:

Transmission number of plies scope is determined subelement, is used for determining respectively according to the number of transmit antennas on each member carrier and reception antenna number the span of the transmission number of plies of each member carrier;

The ergodic capacity computation subunit, determine that with the described transmission number of plies scope subelement links to each other with described channel matrix acquiring unit, be used in the span of the transmission number of plies of described each member carrier, calculating the ergodic capacity of described each member carrier on each OFDM symbol of its subcarrier and described subframe according to described channel matrix;

The output signal-to-noise ratio computation subunit, determine that with the described transmission number of plies scope subelement links to each other with described channel matrix acquiring unit, be used in the span of the transmission number of plies of described each member carrier, calculating the scope of the output signal-to-noise ratio of described each member carrier according to described channel matrix;

Average error sign ratio computation subunit, determine that with the described transmission number of plies scope subelement links to each other with described output signal-to-noise ratio computation subunit, be used in the span of the transmission number of plies of described each member carrier, according to the average error sign ratio of described each member carrier of range computation of the output signal-to-noise ratio of described each member carrier.

12. transmission mode selection device according to claim 11 is characterized in that, equals at 1 o'clock in the described transmission number of plies, the transmission mode that corresponding member carrier adopts is for sending diversity mode.

13. transmission mode selection device according to claim 11 is characterized in that, greater than 1 o'clock, the transmission mode that corresponding member carrier adopts was spatial multiplexing mode in the described transmission number of plies.

14. transmission mode selection device according to claim 11 is characterized in that, described mode selecting unit comprises:

The combination subelement is used for going out various transmission modes combinations according to the span permutation and combination of the transmission number of plies of described each member carrier;

Judgment sub-unit, link to each other with described combination subelement, ergodic capacity sum that be used for to judge described each member carrier under a kind of transmission mode combination whether more than or equal to system transmissions rate requirement and the average error sign ratio of judging described each member carrier under the combination of this kind transmission mode whether all less than system's error sign ratio requirement;

Determine subelement, link to each other with described judgment sub-unit, if the ergodic capacity sum that is used for described each member carrier under the combination of this kind transmission mode all less than system's error sign ratio requirement, then is defined as this kind transmission mode the transmission mode combination of described each member carrier more than or equal to the average error sign ratio of system transmissions rate requirement and described each member carrier.

15. transmission mode selection device according to claim 14, it is characterized in that, described definite subelement also is used for being combined as when a plurality of in the transmission mode that described each member carrier satisfies system transmissions rate requirement and error sign ratio requirement, selects the transmission mode of the ergodic capacity sum maximum of described each member carrier to be combined as the transmission mode combination of described each member carrier.

16. transmission mode selection device according to claim 15, it is characterized in that, described definite subelement also is used for when the ergodic capacity sum that the transmission mode that described each member carrier satisfies system transmissions rate requirement and error sign ratio requirement is combined as a plurality of and described each member carrier all equates, selects the transmission mode of maximum average error sign ratio minimum in described each member carrier to be combined as the transmission mode combination of described each member carrier in the multiple transmission mode combination of described each member carrier.

17. a portable terminal is characterized in that, comprises each described transmission mode selection device among the claim 9-16.

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