CN105917594A - Base station, mobile station and method thereof - Google Patents

Abstract

The embodiment of the invention discloses a base station, a mobile station and a method thereof. The communication method for a mobile station which is served by a base station having at least one transmission point each equipped with multiple transmit antennas includes determining a best subset of transmit antennas for each transmission point which is selected, based on channel gains, among the multiple transmit antennas of the transmission point; and reporting to the base station quantized channel state information CSI for the transmit antennas in the best subset. The embodiments of the invention can reduce the feedback overhead.

Description

Base station, mobile station and method thereof

Technical field

The present invention relates to mobile communication technology field, and more particularly, to base station, mobile station and method thereof.

Background technology

Multiaerial system, such as extensive MIMO (multiple-input and multiple-output), is one in the communication systems such as following 5G and has The technology of development prospect, it can realize being extremely improved in spectrum efficiency and simple TX/RX (send/receive) configuration aspects. Ideally, TX antenna is the most, the benefit obtained from sky line options based on perfect CSIT (transmitting terminal channel condition information) Bigger, this can produce huge feedback overhead and cost.Additionally, the dedicated RF element of each antenna, such as A/D (analog to digital) Transducer, D/A (digital to analogy) transducer and amplifier etc., can produce significant cost.

In the multiaerial system of RF (radio frequency) chain (or referred to as RF hardware) with limited quantity, for the resource of feedback It is limited.Study therefore, it is necessary to the practice with Limited Feedback and RF chain is arranged.

Summary of the invention

The present embodiments relate to for reducing the base station of feedback overhead, mobile station and method thereof.

First aspect, it is provided that the communication means of a kind of mobile station, described mobile station is serviced by base station, and described base station has At least one transmits point, and each described transmission point is equipped with multiple transmitting antennas, and described method includes: based on channel gain, from Multiple transmitting antennas of each selected transmission point determine the best subset launching antenna for described transmission point；And to institute State quantized channel status information CSI launching antenna in best subset described in base station repeats.

In the first possible implementation of the method according to first aspect, described putting for each transmission determines transmitting The best subset of antenna includes: obtain the described channel gain of the plurality of transmitting antenna of described transmission point；And select tool There is the transmitting antenna of maximum channel gain as described best subset.

In the reality that the second according to first aspect or according to the method for the arbitrary aforementioned implementation of first aspect is possible In existing mode, described determine that the best subset launching antenna includes for each transmission point: obtain the plurality of of described transmission point Launch the described channel gain of antenna；And select the described channel gain transmitting antenna more than threshold value as described optimal son Collection.

According to first aspect or the third possible reality of the method according to the arbitrary aforementioned implementation of first aspect In existing mode, described method also includes: the index launching antenna in best subset described in described base station repeats.

According to first aspect or the 4th kind of possible reality of the method according to the arbitrary aforementioned implementation of first aspect In the mode of showing, described putting for each transmission determines that the best subset launching antenna includes: based on the instruction received from described base station Information determines described best subset, and described instruction information indicates the described best subset selected by described base station according to channel gain In launch antenna index.

According to first aspect or the 5th kind of possible reality of the method according to the arbitrary aforementioned implementation of first aspect In existing mode, described quantized channel status information CSI launching antenna in best subset described in described base station repeats includes: Utilizing code book to report described quantization CSI, the size of described code book depends on the size of described best subset.

According to first aspect or the 6th kind of possible reality of the method according to the arbitrary aforementioned implementation of first aspect In existing mode, described method also includes: receive the size information being used for indicating the size of described best subset from described base station；Or The size of described best subset is selected at described mobile station.

According to first aspect or the 7th kind of possible reality of the method according to the arbitrary aforementioned implementation of first aspect In existing mode, described method also includes: the transmitting antenna beyond transmitting antenna in best subset described in described base station repeats Quantization CSI.

Second aspect, it is provided that the communication means of a kind of base station, described base station has at least one transmission point, each described Transmission point is equipped with multiple transmitting antennas, and described method includes: receive report from mobile station, and described report is used for report based on letter The optimal son launching antenna that road gain determines for described transmission point from multiple transmitting antennas of each selected transmission point Quantized channel status information CSI of collection；And send data based on described quantization CSI.

In the first possible way of realization of the method according to second aspect, described method also includes: obtain described The described channel gain of the plurality of transmitting antenna of transmission point；And select the transmitting antenna conduct with maximum channel gain Described best subset.

In the reality that the second according to second aspect or according to the method for the arbitrary aforementioned way of realization of second aspect is possible In existing form, described method also includes: obtain the described channel gain of the plurality of transmitting antenna of described transmission point；And choosing Select the described channel gain transmitting antenna more than threshold value as described best subset.

According to second aspect or the third possible reality of the method according to the arbitrary aforementioned way of realization of second aspect In existing mode, described method also includes sending instruction information to mobile station, and described instruction information is for described to mobile station instruction The index launching antenna in best subset.

According to second aspect or the 4th kind of possible reality of the method according to the arbitrary aforementioned way of realization of second aspect In existing mode, described method also includes receiving instruction information from mobile station, and described instruction information is for indicating by described mobile station According to the index launching antenna in the described best subset that channel gain selects.

According to second aspect or the 5th kind of possible reality of the method according to the arbitrary aforementioned way of realization of second aspect In existing mode, described method also includes that the described report of described quantization CSI uses code book, and the size of described code book depends on described The size of best subset.

According to second aspect or the 6th kind of possible reality of the method according to the arbitrary aforementioned way of realization of second aspect In existing mode, receive the size information being used for indicating the size of described best subset from described mobile station；Or in described base station Select the size of described best subset.

According to second aspect or the 7th kind of possible reality of the method according to the arbitrary aforementioned way of realization of second aspect In existing mode, described method also includes receiving report from mobile station, and described report is for reporting the transmitting in described best subset The quantization CSI launching antenna beyond antenna.

The third aspect, it is provided that a kind of mobile station, described mobile station is serviced by base station, and described base station has at least one and passes Defeated, each described transmission point is equipped with multiple transmitting antennas, and described mobile station comprises determining that unit, for increasing based on channel Benefit, determines the best subset launching antenna from multiple transmitting antennas of each selected transmission point for described transmission point；With And reporting unit, for quantized channel status information CSI launching antenna in best subset described in base station repeats.

In the first possible way of realization of the mobile station according to the third aspect, described determine that unit is for obtaining State the described channel gain of the plurality of transmitting antenna of transmission point, and select the transmitting antenna conduct with maximum channel gain Described best subset.

Possible at the second according to the third aspect or according to the mobile station of the arbitrary aforementioned way of realization of the third aspect In implementation, described determine unit for obtaining the described channel gain of the plurality of transmitting antenna of described transmission point, and Select the described channel gain transmitting antenna more than threshold value as described best subset.

Possible according to the third aspect or the third according to the mobile station of the arbitrary aforementioned way of realization of the third aspect In implementation, the index launching antenna that described reporting unit is additionally operable in best subset described in base station repeats.

According to the third aspect or possible according to the 4th kind of the mobile station of the arbitrary aforementioned way of realization of the third aspect In implementation, described determine unit for determining described best subset based on the instruction information received from described base station, described The index of the transmitting antenna in the described best subset that the instruction of instruction information is selected according to channel gain by described base station.

According to the third aspect or possible according to the 5th kind of the mobile station of the arbitrary aforementioned way of realization of the third aspect In implementation, described reporting unit is used for utilizing code book report to quantify CSI, and the size of described code book depends on described optimal son The size of collection.

According to the third aspect or possible according to the 6th kind of the mobile station of the arbitrary aforementioned way of realization of the third aspect In implementation, described determine unit to be additionally operable to based on the size information received from described base station to determine the big of described best subset Little, or at described mobile station, select the size of described best subset.

According to the third aspect or possible according to the 7th kind of the mobile station of the arbitrary aforementioned way of realization of the third aspect In implementation, what described reporting unit was additionally operable in best subset described in described base station repeats launches the transmitting beyond antenna The quantization CSI of antenna.

Fourth aspect, it is provided that a kind of base station, described base station has at least one transmission point, and each described transmission point is equipped with Having multiple transmitting antenna, described base station includes: receiver, and for receiving report from mobile station, described report report is based on channel The best subset launching antenna that gain determines for described transmission point from multiple transmitting antennas of each selected transmission point Quantized channel status information CSI；And transmitter, for sending data based on described quantization CSI.

In the first possible way of realization of the base station according to fourth aspect, described base station also includes processor, uses In the described channel gain of the plurality of transmitting antenna obtaining described transmission point, and select the transmitting with maximum channel gain Antenna is as described best subset.

In the reality that the second according to fourth aspect or according to the base station of the arbitrary aforementioned way of realization of fourth aspect is possible In existing form, described base station also includes processor, for obtaining the described channel of the plurality of transmitting antenna of described transmission point Gain, and select the described channel gain transmitting antenna more than threshold value as described best subset.

According to fourth aspect or the third possible reality of the base station according to the arbitrary aforementioned way of realization of fourth aspect In existing mode, described transmitter is additionally operable to send instruction information to mobile station, and described instruction information is for indicating institute to mobile station State the index launching antenna in best subset.

According to fourth aspect or the 4th kind of possible reality of the base station according to the arbitrary aforementioned way of realization of fourth aspect In existing mode, described receiver is additionally operable to receive instruction information from mobile station, and described instruction information is for indicating by described movement The index launching antenna in the described best subset that platform selects according to channel gain.

According to fourth aspect or the 5th kind of possible reality of the base station according to the arbitrary aforementioned way of realization of fourth aspect In existing mode, the described report of described quantization CSI uses code book, and the size of described code book depends on the big of described best subset Little.

According to fourth aspect or the 6th kind of possible reality of the base station according to the arbitrary aforementioned way of realization of fourth aspect In existing mode, described receiver is additionally operable to receive the size of the size for indicating described best subset from described mobile station to be believed Breath；Or described base station also includes processor, for selecting the size of described best subset in described base station.

According to fourth aspect or the 7th kind of possible reality of the base station according to the arbitrary aforementioned way of realization of fourth aspect In existing mode, described receiver is additionally operable to receive report from mobile station, and described report is for reporting sending out in described best subset Penetrate the quantization CSI launching antenna beyond antenna.

Therefore, the embodiment of the present invention selects to launch the best subset of antenna based on channel gain, and to selected subset Feed back, thus reduce feedback overhead.

Accompanying drawing explanation

In order to be illustrated more clearly that the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing In having technology to describe, the required accompanying drawing used is briefly described, it should be apparent that, the accompanying drawing in describing below is only this Some embodiments of invention, for those of ordinary skill in the art, on the premise of not paying creative work, it is also possible to according to These accompanying drawings obtain other accompanying drawing.

Fig. 1 shows the example of the extensive mimo system that can apply the present invention.

Fig. 2 shows the method for one embodiment of the invention.

Fig. 3 shows the example of the gain of sky line options according to an embodiment of the invention.

Fig. 4 shows the example of the gain of sky line options according to another embodiment of the present invention.

Fig. 5 shows the example of the gain of sky line options according to another embodiment of the present invention.

Fig. 6 shows the example of the gain of sky line options according to another embodiment of the present invention.

Fig. 7 shows the method for another embodiment of the present invention.

Fig. 8 shows the block diagram of the mobile station of one embodiment of the invention.

Fig. 9 shows the block diagram of the mobile station of another embodiment of the present invention.

Figure 10 shows the block diagram of the base station of one embodiment of the invention.

Detailed description of the invention

Below in conjunction with the accompanying drawing of these embodiments, the technical scheme in the embodiment of the present invention is carried out clearly and completely Describe.Obviously, described embodiment is only a part of embodiment of the present invention rather than whole embodiments.Based on this A little embodiments, all other embodiments that those of ordinary skill in the art are obtained under not making creative work premise, Broadly fall into the scope of protection of the invention.

The subset of antenna is switched to RF chain and can significantly improve the summation capacity of system.This indicates that, available antenna ratio RF chain is the most, and antenna subset selection gain is the biggest.Antenna is selected according to the effective searching algorithm proposed, almost real with exhaustive search Show optimal performance.But, this searching algorithm assumes that perfect CSIT, perfect CSIT particularly can not in extensive mimo system OK, because feedback overhead is the biggest, it is impossible to undertake.On the other hand, under conditions of Limited Feedback, launch antenna the most, and differ Make now more preferable and rate capability, because quantifying of poor quality.Along with the increase of number of transmission antennas, quantify CSI Quality Down, Multi-user interference will limit systematic function.

Fig. 1 shows the example of the extensive mimo system that can apply the present invention, and this system includes BS (base station), its service In K MS (mobile station): MS 1 to MS K.

This BS is equipped with large-scale antenna (N_T) and a limited number of RF chain (N_RF), i.e. N_T>=N_RF.In order to be fully understood by system Performance is the most relevant to the quantity of RF chain, it will be considered that two kinds of different situation (N_T>N_RFOr N_T=N_RF).In order to maximize system System (speed) performance, selects to launch the subset of antenna, and switches to RF chain.Selection course can be carried out at receiver side, And report corresponding CSI by limited backhaul resources.We assume that be independent same distribution (i.i.d.) Rayleigh channel.

For the situation of SU MISO (single user, multiple input single output), in order to maximize the optimization wave beam forming plan of speed It it is slightly the matched beam figuration (MBF) needing accurate CSIT.But, report that all CSI can cause with limited feedback big Quantify loss.On the other hand, higher accuracy can be realized by only feedback fraction CSI.Naturally, this idea be select and Report the strongest channel (there is maximum amplitude).Owing to the quantity of beam forming gain to selected antenna is directly proportional, so this The optimization balance quantified between quality and beam forming gain will necessarily be broken.It practice, the method can be interpreted to utilize Mixing selection/the MBF of Limited Feedback.

For the situation of MU MISO (multi-user, multiple input single output), each MS reports that most important CSI (has maximum Channel gain), the CSI not reported is considered as zero by transmitter.ZF (ZF) wave beam forming strategy is considered based on partial channel knowledge. Utilizing and launch antenna on a large scale, MS reports that the probability of mutual non-overlapping antenna subset will be high.Then, it is used for cancelling multi-user to do The ZF beamformer disturbed also is the wave beam forming of the coupling of desired signal.Really, due to the imperfection of CSI reported and The CSI not reported, also has remaining multi-user interference.But, if available feedback bit can undertake selected antenna subset Size, first factor can overcome.Owing to the channel gain of non-reporting channel is the least, so second factor can be neglected Slightly.In a word, the gain obtained when us exceedes traditional MU MISO system, and multiplexing gain can be achieved with.

Additionally, if we can eliminate a day line options expense, systematic function can be obtained by promoting further.Owing to MS needs Will be to the antenna subset selected by BS notice, so the expense caused in extensive mimo system can be the biggest.In the literature, Studied from descending (up) link to the predictability of up (descending) link in FDD system.This shows, at certain In the degree of kind, channel sequencing information (COI) is known for BS.In such a mode, all of feedback bits can be used In quantized channel.In order to disclose potential gain, the situation with/without sky line options expense will be studied by we.

It is assumed to preferred CSI (CSIR) at receiver, at each MS, has " B " individual feedback bits to use.At each moment, MS Receiver be primarily based on instantaneous CSI and select to have the strongest channel of maximum amplitude, and utilize random vector to quantify (RVQ) to BS Transmitter report select the index of combination and corresponding CSI.Feedback bits individual for " B ", tradition/reference scheme is defined as N_T=N_RF.The present invention attempts institute suggests plans when to be better than reference scheme, and how gain is along with the proportional change of NT and B Change.That is, the present invention proposes how to select to arrange under (limited feedback and RF chain) to greatest extent in reality by dynamic antenna Obtain antenna selection gain.

Fig. 2 shows the communication means of one embodiment of the invention.The method of Fig. 2 is performed by MS, such as, as shown in Figure 1 MS 1 to MS K in one, this MS is serviced by BS, this BS have at least one transmission point, each transmission point is equipped with multiple Launch antenna.

201, this MS is based on channel gain, is that this transmission point is true from multiple transmitting antennas of each selected transmission point Surely the best subset of antenna is launched.

BS can include one or more transmission point, such as aerial array, antenna sets, DA (spaced antenna) element etc..Such as Fig. 1 Shown in, each transmission point is equipped with multiple (N_T) launch antenna, wherein, for different transmission points, N_TCan be different or fixing.

202, this MS reports the quantization CSI launching antenna in this best subset to this BS.

Therefore, the embodiment of the present invention selects to launch the best subset of antenna based on channel gain, and to selected subset Feed back, thus reduce feedback overhead.

Specifically, the most significant CSI during best subset has all transmitting antennas.Other outside best subset launch sky The CSI of line can not report, such feedback overhead will reduce, and the negative effect that the most this kind of imperfections CSI report causes is also Can control an acceptable scope.

Subset selects to perform at MS.As the unrestricted scheme proposed, in step 201, MS can obtain biography The channel gain of all multiple transmitting antennas of defeated point, and select the transmitting antenna with maximum channel gain the most sub as this Collection.

To be suggested plans and reference scheme compares below, wherein, randomly choosed N_TN in individual antenna_RFIndividual carrying out sends out Send.

SU situation 1: retrain without RF chain, have selection expense

Consider to be suggested plans, wherein from N_TSelecting M in individual antenna, average output SNR is expressed as:

Wherein,

And input SNR=P/ σ²Strengthened by wave beam forming, weakened by quantization.Beam forming gain is by two groups Becoming: previous item represents array gain, latter representative antennas selects gain.In order to have selected which sky to transmitter (BS) notice Line, while using significant bit to quantify the CSI selected, receiver (MS) uses some bit (selection expense) to send out The index of antennas subset.

Utilize N_TThe average output SNR of the reference scheme of individual antenna is expressed as:

${\mathrm{SNR}}_{ref}=\frac{P}{{\mathrm{\σ}}^2}\·N_T\·(1-2^{-\frac{B}{N_T-1}})---\left(3\right)$

It can be seen that (1)≤(3), this is suggested plans in the case of showing this does not provides gain.Utilize all N_TIndividual antenna It is preferably to select.

SU situation 2: have RF chain to retrain, have selection expense

Consider to be suggested plans, wherein from N_TN selected by individual antenna_RFIndividual, average output SNR is expressed as:

$SNR\_cand=\frac{P}{{\mathrm{\σ}}^2}\·(N_{RF}+N_{RF}\·\underset{n=N_{RF}+1}{\overset{N_T}{\Σ}}\frac{1}{n})\·(1-2^{-\frac{B_{eff}}{N_{RF}-1}})---\left(4\right)$

Wherein,

And from N_TIndividual antenna randomly chooses N_RFThe average output SNR of individual reference scheme is expressed as:

$SNR\_ref=\frac{P}{{\mathrm{\σ}}^2}\·N_{RF}\·(1-2^{-\frac{B}{N_{RF}-1}})---\left(6\right)$

It should be noted that (6) be one relative to N_RFMonotonically increasing function, a fixing point the most below reaches saturated:

$\underset{N_{RF}\→\mathrm{\∞}}{\lim }{\mathrm{SNR}}_{ref}=\frac{P}{{\mathrm{\σ}}^2}\·B\·ln\left(2\right)---\left(7\right)$

This is only the function of input SNR and B, and it shows under conditions of Limited Feedback, and we would rather utilize the most RF chain.But, RF chain increase and the marginal gains that obtains becomes more and more less.On the other hand, for fixed qty RF chain, identifying is suggested plans has B and N of gain than reference scheme_TCritical point, simultaneously the most also to gain along with B and N_TOccur Change studied.

A) fixing N_RFAnd N_T

By means of harmonic progression (harmonic series) and binomial coefficient,

$\begin{array}{c}SNR\_cand\≥SNR\_ref,\mathrm{\λ}={\log }_2\left(\left(\begin{array}{c}{N}_T\\ N_{RF}\end{array}\right)\right)/(N_{RF}-1)\\ \⇒B\≥(N_{BF}-1){\log }_2\{\[(1+\log (\frac{N_T}{N_{RF}}\left)\right)2^{\mathrm{\λ}}-1\]/\log \left(\frac{N_T}{N_{RF}}\right)\}\end{array}---\left(8\right)$

In order to realize some gains, the quantity of feedback bits should meet (4).Gain delta SNR=

The following proportional change of SNR_cand-SNR_ref

$\mathrm{\ΔSNR}~(\mathrm{\α}-2^{{-\mathrm{\γ}}^B})---\left(9\right)$

Wherein, α and γ is independently of the constant of B.When B tends to infinity,

${\mathrm{\ΔSNR}}_{dB}=10{\log }_{10}\frac{\left(4\right)}{\left(6\right)}=10{\log }_{10}\[1+log\left(\frac{N_T}{N_{RF}}\right)\]---\left(10\right)$

Such as N_T/N_RF=50, Δ SNR_dB=7dB.Gain is with log (N_T) proportional change.

B) fixing N_RFAnd B

$SNR\_cand\≥SNR\_ref\⇒x\≥2^{\frac{-B}{N_{RF}-1}}\left(\right(1+x)2^{\frac{N_{RF}}{(N_{RF}-1)log\left(2\right)}\·x+\mathrm{\μ}}-1)---\left(11\right)$

Assume N_T/N_RF≥e,

It should be noted that (8) are the sufficient condition of (7).Then, we obtain N_TCritical point

$\⇒N_{RF}\≤N_T\≤N_{RF}\·\exp \[\frac{log\left(2\right)(B-(\mathrm{\μ}+1)(N_{RF}-1))}{N_{RF}}\]---\left(13\right)$

$\mathrm{\μ}=\frac{N_{RF}}{N_{RF}-1}{\log }_2\left(e\right)-\frac{N_{RF}}{2(N_{RF}-1)}{\log }_2\left(2{\mathrm{\πN}}_{RF}\right)---\left(14\right)$

This shows that ratio is bounded, i.e. in order to be realized gain from suggesting plans of limited B, N_T/N_RF≤ρ(B,N_RF).With N_TIncrease, select expense close/exceed the quantity of available bits, and the quantity of effectively/remaining bit is the least, it is impossible to exactly Quantized channel.Compared with prior art, the quantity increasing TX antenna is not always favourable to us.When B is the least or N_TTime the biggest, Suggested plans no more than reference scheme.We by increasing B or can reduce N_TObtain gain.

C) fixing N_RF、N_TAnd B

In this case, being suggested plans may be not as good as reference scheme.Gain can be obtained by utilizing part RF chain.Logical Crossing this mode, select expense to reduce, more feedback bits can make quantization accuracy higher.Meanwhile, emission array gain becomes Obtain lower, optimization process should be taked to realize the optimum balance used between the pluses and minuses of part RF chain.

M is expressed as the quantity of RF chain used, finds optimum M≤N_RFAveragely export SNR to maximize, and feed back corresponding CSI subset.General optimum function is defined as:

$S_M=\arg \underset{M\∈\[1,N_{RF}\]}{\max }\underset{S_M\⋐\left\{\left(\begin{array}{c}{N}_T\\ M\end{array}\right)\right\}}{\max }f\left(SNR\right)---\left(15\right)$

This needs complicated Brute-force search algorithm to realize optimal solution.Fortunately, select with low complex degree in the case of us Method maximizes SNR.More specifically, channel is ranked up by amplitude, and report maximum those.

In the case of Gai, average output SNR be expressed as:

$SNR\_cand\left(M\right)=\frac{P}{{\mathrm{\σ}}^2}\·(M+M\·\underset{n=M+1}{\overset{N_T}{\Σ}}\frac{1}{n})\·(1-2^{-\frac{B_{eff}}{M-1}}),1\≤M\≤N_{RF}---\left(16\right)$

Due to coupling character, very difficult acquisition makes to be suggested plans the closed solutions of the M being better than reference scheme.Need 1 < M≤N_RF's Numerical optimization routines.This shows to be suggested plans and provide at least the lower bound of gain.When B is the biggest, it is optimum for utilizing all RF chains , (16) are attributed to (4).Otherwise, numerical optimization (16), and it is contrasted with reference scheme, it is then determined that B to be increased still subtracts Little N_T。

Assume that transmitter has been known a priori by channel sequencing information (COI), then can improve further and be suggested plans.For FDD system, we can be according to downlink channel prediction uplink channel, and vice versa.In short, can use exactly Frequency selective fading (energy) on Uplink/Downlink is modeled by limited rank autoregression (AR) process.Work as up/down When the relative deviation of row carrier frequency is the least, show the AR coefficient that two link sharing are common.Therefore, two links stand similar Variation tendency.To this end, the hypothesis of COI is effective at transmitter, and expense is selected to also eliminate.Potential in order to disclose Gain, we consider the both above situation without selecting expense again.

SU situation 3: retrain without RF chain, without selecting expense

Assuming to have selected M antenna, the average output SNR suggested plans is expressed as:

$\begin{array}{cc}{\mathrm{SNR}}_{cand}=\frac{P}{{\mathrm{\&sigma;}}^2}\&CenterDot;(M+M\&CenterDot;\underset{n=M+1}{\overset{N_T}{\&Sigma;}}\frac{1}{n})\&CenterDot;(1-2^{-\frac{B}{M-1}})& M\&Element;\&lsqb;1,N_T\&rsqb;\end{array}---\left(17\right)$

And reference scheme utilizes all of N_TIndividual antenna:

${\mathrm{SNR}}_{ref}=\frac{P}{{\mathrm{\&sigma;}}^2}\&CenterDot;N_T\&CenterDot;(1-2^{-\frac{B}{N_T-1}})---\left(18\right)$

Very difficult derivation makes to be suggested plans and is better than reference scheme, i.e. (17) > (18), the Guan Bi expression formula of M.But, pass through Monte Carlo (Monte-Carlo) emulation is it is easy to see that by selecting part to launch antenna, gain can be achieved with.This gain Depend on NT, NRF and B.In the example that Fig. 3 is given, existing is suggested plans is better than the lower bound of reference scheme.By CSI accuracy And the compromise between beam forming gain, realizes maximum gain at zone line.

SU situation 4: have RF chain to retrain, without selecting expense

Assuming to have selected M antenna, the average output SNR suggested plans is expressed as:

$\begin{array}{cc}{\mathrm{SNR}}_{cand}=\frac{P}{{\mathrm{\&sigma;}}^2}\&CenterDot;(M+M\&CenterDot;\underset{n=M+1}{\overset{N_T}{\&Sigma;}}\frac{1}{n})\&CenterDot;(1-2^{-\frac{B}{M-1}})& M\&Element;\&lsqb;1,N_{RF}\&rsqb;\end{array}---\left(19\right)$

And reference scheme is from N_TIndividual antenna is selected N at random_RFIndividual:

${\mathrm{SNR}}_{ref}=\frac{P}{{\mathrm{\&sigma;}}^2}\&CenterDot;N_{RF}\&CenterDot;(1-2^{-\frac{B}{N_{RF}-1}})---\left(20\right)$

Owing to the performance of reference scheme is deteriorated because of limited RF chain, so compared with SU situation 3, it is thus achieved that gain can more Many, suggested plans and reference scheme as it is shown on figure 3, wherein curve " Pro " and " Ref " are corresponding respectively.

It follows that consider Multi-users MIS O broadcast channel (BC), use zero-forcing beamforming strategy to obtain multiplexing and increase Benefit.The CSI and the CSI that do not reports of imperfections report can cause the existence of remaining multi-user interference.Suggested plans and above-mentioned SU Situation is identical, provides two reference schemes simultaneously.

Suggested plans: channel gain is ranked up, selects maximum M, and report index and this subset of selected subset Corresponding CSI

Reference scheme 1: the quantity of fixing MS is Nu, and reports for front M the antenna sent (equivalently, at random from N_T Individual antenna is selected M) CSI

Reference scheme 2: the quantity of fixing MS, it is equal to the quantity (Nu=M) of reported antenna, and reports for transmission Front M antenna is (equivalently, at random from N_TIndividual antenna is selected M) CSI

MU situation 1: retrain without RF chain, have selection expense

The Mean Speed suggested plans is expressed as:

$R_{cand}=M\&CenterDot;E_{H,W}\&lsqb;\log (1+\frac{P/M\&CenterDot;|h_i^H{v}_{\max ,i}{|}^2}{1+P/M\&CenterDot;\underset{j\&NotEqual;i}{\&Sigma;}|h_i^H{v}_{\max ,j}{|}^2})\&rsqb;---\left(21\right)$

Wherein, channel and RVQ code book have employed expected value.V_max,iExpression will not report that CSI is considered as zero, by part ( Big channel gain) the wave beam forming vector that calculates of CSI.Meanwhile, the Mean Speed of two reference schemes is expressed as

$R_{ref1}=N_u\&CenterDot;E_{H,W}\&lsqb;\log (1+\frac{P/N_u\&CenterDot;|h_i^H{v}_i{|}^2}{1+P/N_u\&CenterDot;\underset{j\&NotEqual;i}{\&Sigma;}|h_i^H{v}_j{|}^2})\&rsqb;---\left(22\right)$

$R_{ref2}=M\&CenterDot;E_{H,W}\&lsqb;log(1+\frac{P/M\&CenterDot;|h_i^H{v}_i{|}^2}{1+P/M\&CenterDot;\underset{j\&NotEqual;i}{\&Sigma;}|h_i^H{v}_j{|}^2})\&rsqb;---\left(23\right)$

The enclosed approximation of (22) and (23) can be derived subsequently, and closed expression remains open.But, pass through Simulation (as shown in curve 401 to 403) in Fig. 4, it will be seen that owing to selecting expense relatively big, suggested plans and cannot be carried For being better than the gain of reference scheme, especially launch in antenna system extensive.Equally, we can use COI at transmitter Eliminate this expense.

MU situation 2: retrain without RF chain, without selecting expense

In this situation, suggested plans compared with two reference schemes, indeed achieved gain, because

1) it have ignored selection expense, and obtains the CSI mass identical with reference scheme 1 and 2；

2) it is by reporting that the most significant channel maintains major part channel information；And

3) if MS selects mutual non-overlapping subsets, the wave beam forming of the simple match in the subset reported also is it The ZFBF of he MS；Owing to it comes from the channel (having relatively small channel gain) do not reported, so multi-user interference is the least.

Fig. 5 shows the gain analog result more than two reference schemes of acquisition of being suggested plans.

From curve 501 to 503 it can be seen that the M of centre achieves maximum gain.Reason is as follows: for little M, CSI's Quantifying have high-quality, the non-overlapping subsets of high probability brings high beam forming gain simultaneously.But, much do not report owing to existing The CSI accused, this then corresponds to low multiplexing gain and big multi-user interference.On the other hand, big M is (close to N_T) just with This is contrary.Therefore, middle M achieves the optimum balance between these factors.

It should be noted that gain is heavily dependent on non-overlapping subsets, this is conducive to ZF and the wave beam forming of coupling simultaneously. The quantity of part CSI reported must be comparable to N_T, otherwise multi-user interference can reduce systematic function.On the other hand, if The quantity of Nu is fixed, and the quantity of Nt increases, and we will eventually get non-overlapping subsets.But owing to not reporting the quantity of CSI more Greatly, multi-user interference can be preponderated.

But, along with N_TIncrease, and if transmitter can dynamically determine the quantity of MS, the optimal number of MS also can Increase.In this way, inter-user interference can less (we feed back sufficient amount of notable CSI).Then, we are of equal value Make Nu with SU-MISO situation suitable.For each MS, we have represented, and work as N_TWhen being gradually increased, marginal gains becomes Little.This is as can be seen from Figure 6.

When the quantity of MS is the biggest, is suggested plans and be prone to combine with multi-user diversity, i.e. selected that there is non-overlapped son The MS of collection is transmitted.The quantity of the quantity of MS and the reported CSI of each MS should be by transmitter enclosed based on total speed/near Determine like value.Given N_TAnd B, completing by maximizing integrated rate expression, this integrated rate expression is N_T, the letter of B and M Number.It is also required to MS selection algorithm.

Although finding out the suggested plans gain gain more than reference scheme by emulation, but analysis result will helping In understanding the impact on rate capability of these systematic parameters.We provide the enclosed approximation of (22) and (23) herein, and to meter Calculate closed expression (21) and guidance is provided.

$\begin{array}{c}{R}_{ref1}=Nu\&CenterDot;E_{H,W}\&lsqb;\log (1+\frac{P/Nu\&CenterDot;|H_i^H{v}_i{|}^2}{1+P/Nu\&CenterDot;\underset{j\&NotEqual;i}{\&Sigma;}|h_i^H{v}_j{|}^2})\&rsqb;\&ap;Nu\&CenterDot;\log (1+\frac{P/Nu\&CenterDot;E_{H,W}\left\{\right|h_i^H{v}_i{|}^2\}}{1+P/Nu\&CenterDot;\underset{j\&NotEqual;i}{\&Sigma;}{E}_{H,W}\left\{\right|h_i^H{v}_j{|}^2\}})\\ =Nu\&CenterDot;\log (1+\frac{\frac{P}{Nu}\&CenterDot;(M-Nu+1)}{1+\frac{P}{Nu}\&CenterDot;M\&CenterDot;\underset{j\&NotEqual;i}{\&Sigma;}\frac{1}{M-1}{2}^{\frac{-B}{M-1}}})=Nu\&CenterDot;\log (1+\frac{P\&CenterDot;(M-Nu+1)/Nu}{1+P\&CenterDot;\frac{Nu-1}{Nu}\&CenterDot;\frac{M}{M-1}\&CenterDot;2^{\frac{-B}{M-1}}})\end{array}---\left(24\right)$

$\begin{array}{c}{R}_{ref2}=M\&CenterDot;E_{H,W}\&lsqb;\log (1+\frac{P/M\&CenterDot;|h_i^H{v}_i{|}^2}{1+P/M\&CenterDot;\underset{j\&NotEqual;i}{\&Sigma;}|h_i^H{v}_j{|}^2})\&rsqb;\&ap;M\&CenterDot;\log (1+\frac{P/M\&CenterDot;E_{H,W}\left\{\right|h_i^H{v}_i{|}^2\}}{1+P/M\&CenterDot;\underset{j\&NotEqual;i}{\&Sigma;}{E}_{H,W}\left\{\right|h_i^H{v}_j{|}^2\}})\\ =M\&CenterDot;\log (1+\frac{\frac{P}{M}\&CenterDot;M\&CenterDot;\frac{1}{M}}{1+\frac{P}{M}\&CenterDot;M\&CenterDot;\underset{j\&NotEqual;i}{\&Sigma;}\frac{1}{M-1}{2}^{\frac{-B}{M-1}}})=M\&CenterDot;\log (1+\frac{P/M}{1+P\&CenterDot;2^{\frac{-B}{M-1}}})\end{array}---\left(25\right)$

$\begin{array}{c}{R}_{cand}=M\&CenterDot;E_{H,W}\&lsqb;\log (1+\frac{P/M\&CenterDot;|h_i^H{v}_{\max ,i}{|}^2}{1+P/M\&CenterDot;\underset{j\&NotEqual;i}{\&Sigma;}|h_i^H{v}_{\max ,j}{|}^2})\&rsqb;\\ \&ap;M\&CenterDot;\log (1+\frac{P/M\&CenterDot;E_{H,W}\left\{\right|h_i^H{v}_{\max ,i}{|}^2\}}{1+P/M\&CenterDot;E_{H,W}\left\{\underset{j\&NotEqual;i}{\&Sigma;}\right|h_i^H{v}_{\max ,j}{|}^2\}})\end{array}---\left(26\right)$

In order to calculate the expected value in the molecule of (26) and denominator, it would be desirable to set up probabilistic model to represent average wave beam Figuration gain (is mainly determined by the matched beam figuration gain from non-overlapping subsets).

MU situation 3: have RF chain to retrain, without selecting expense

In this case, it is important that how RF chain is switched to part and launches antenna.RF switching needs by thoroughly Lift search to be optimized at transmitter.It should be noted that MU situation 3 gives the lower bound of MU situation 2.Simulation result shows, is carried Scheme is not as good as MU situation 2, but its gain is still above the gain of reference scheme.

Alternatively, as another embodiment, substituting or in addition to selection sort based on gain, subset selection can be based on The threshold value being determined by the controller (the control function as in base station) of communication system and being configured.

Specifically, in step 201, MS can obtain the channel gain of multiple transmitting antennas of this transmission point, and selects This channel gain is more than the transmitting antenna of threshold value as best subset.

Alternatively, as another embodiment, the CSI launching antenna beyond best subset can report to BS further. That is, the partly or entirely transmitting antenna beyond best subset can form a relatively weakon collection, and MS can be that this relatively weakon is collected newspapers Accuse CSI.This can be similar to the selection of best subset compared with the selection of weakon collection, and such as, sequence based on channel gain also selects Channel gain reckling, or based on another threshold value, to select channel gain to be less than the transmitting antenna of this threshold value.Implement as another Example, this relatively weakon collection can be simply the residue antenna after selecting best subset.

Alternatively, subset selects to perform in BS side, and executive mode is similar to the above-mentioned executive mode in MS side, this In situation, in step 201, MS can determine best subset based on the instruction information received from base station, and this instruction information indicates The index launching antenna in this best subset selected according to channel gain by this base station.

Further, when MS determines best subset and/or relatively weakon collection, MS can report the transmitting in these subsets to BS The index of antenna.On the other hand, when BS determines best subset and/or relatively weakon collection, BS can indicate in these subsets to MS Launch antenna index.

Alternatively, MS can utilize code book to report described quantization CSI, and the size of this code book depends on the big of this best subset Little.

The size of best subset can be determined by BS, and in this situation, MS can receive from base station and be used for indicating this most sub The size information of the size of collection.Or the size of this best subset can be determined by MS itself, such as, MS can select this optimal The size of subset.

In a word, MS can follow following behavior:

1) if the quantity of the RF chain of BS or transmission point is equal to launch the quantity of antenna, then MS reports all transmitting antennas Quantify CSI, i.e. best subset is equal to whole available antenna group.

2) if the quantity of the RF chain of BS or transmission point is less than the quantity launching antenna, and if asking MS report size etc. In the antenna subset of the quantity of RF chain, as long as then the quantity of available feedback bit is more than certain threshold value (quantity for transmitting antenna Function with the quantity of RF chain), MS selects and report optimal antenna subset and the quantization CSI of this subset, and otherwise, this MS report is pre- The quantization CSI of the antenna sets (its quantity is equal to the quantity of RF chain) of definition.

3) if the quantity of the RF chain of BS or transmission point is less than launching the quantity of antenna, and if anti-for determined number Feedback bit, request MS report size is equal to the antenna subset of the quantity of RF chain, as long as then launching the quantity of antenna less than certain threshold Value (for the function of quantity of quantity and RF chain of feedback bits), then MS report optimal antenna subset and the quantization CSI of this subset, Otherwise, the quantization CSI of the predefined antenna sets of this MS report (its quantity is equal to the quantity of RF chain).

4) if the quantity of the RF chain of BS or transmission point is less than launching the quantity of antenna, and if MS be not limited to report arbitrary Specific antenna sub-set size, then MS selects optimal antenna subset and reports its index and quantify CSI accordingly.In this situation, sky Line sub-set size can be strictly less than the quantity of RF chain.

In a word, under limited feedback and/or RF chain retrain, by dynamic and user specific sky line options, increase The quantity of TX antenna is useful in SU/MU MISO scene.

Fig. 7 shows the communication means of another embodiment of the present invention.The method of Fig. 7 is performed by BS, BS as shown in Figure 1, This BS has at least one transmission point, and each transmission point is equipped with multiple transmitting antennas.

701, this BS receives report from MS, and this report is for reporting based on channel gain from each selected transmission point Quantized channel status information CSI of the best subset launching antenna determined for this transmission point in multiple transmitting antennas.

702, this BS sends data based on this quantization CSI.

Therefore, the embodiment of the present invention selects to launch the best subset of antenna based on channel gain, and to selected subset Feed back, thus reduce feedback overhead.

The procedure of Fig. 7 is corresponding with the procedure of Fig. 2 or similar, therefore, the most no longer describes in detail.

Alternatively, subset selects to perform at BS, and in the case, in step 701, this BS can obtain transmission The channel gain of multiple transmitting antennas of point, and select there is the transmitting antenna of maximum channel gain as this best subset.

Alternatively, in step 701, this BS can obtain the channel gain of multiple transmitting antennas of transmission point, and selects Select this channel gain transmitting antenna more than threshold value as this best subset.Alternatively, as another embodiment, subset selects Can perform at MS, in the case, in step 701, this BS can receive instruction information, this instruction information from mobile station The index launching antenna in the best subset that instruction is selected according to channel gain by this mobile station.

Alternatively, as another embodiment, the CSI launching antenna beyond best subset can report to BS further. That is, the partly or entirely transmitting antenna beyond best subset can form a relatively weakon collection, and MS can be that this relatively weakon is collected newspapers Accuse CSI.This can be similar to the selection of best subset compared with the selection of weakon collection, for example, it is possible to sequence based on channel gain is also Select channel gain reckling, or based on another threshold value, to select channel gain to be less than the transmitting antenna of this threshold value.As another Embodiment, relatively weakon collection can be simply the residue antenna after selecting best subset.

Further, when MS determines best subset and/or relatively weakon collection, MS can report in these subsets to BS and launch The index of antenna.On the other hand, when BS determines best subset and/or relatively weakon collection, BS can indicate in these subsets to MS Launch the index of antenna, such as, indicate information accordingly by sending to MS.

Alternatively, MS can use code book report to quantify CSI, and the size of this code book depends on the size of best subset.

The size of best subset can be determined by BS, and in this situation, MS can receive from this base station and be used for indicating this optimal The size information of the size of subset；Or the size of this best subset can be determined by MS itself, such as, this MS can select this The size of best subset.

Fig. 8 shows the block diagram of the mobile station in one embodiment of the invention.Mobile station 80 is serviced by base station, and this base station has At least one transmits point, and this transmission point each is equipped with multiple transmitting antennas.As shown in Figure 8, this mobile station includes determining unit 81 and reporting unit 82.

Determine unit 81, for based on channel gain, for being somebody's turn to do from multiple transmitting antennas of each selected transmission point Transmission point determines the best subset launching antenna.

Reporting unit 82, for quantized channel status information CSI launching antenna in this best subset of base station repeats.

Therefore, the embodiment of the present invention selects to launch the best subset of antenna based on channel gain, and to selected subset Feed back, thus reduce feedback overhead.

The parts of mobile station 80 can realize the respective process that the MS described in embodiment based on Fig. 1 to Fig. 6 is relevant, for For the sake of simplicity, here is omitted.

Alternatively, as an embodiment, determine unit 81 for obtaining the channel gain of multiple transmitting antennas of transmission point, And select there is the transmitting antenna of maximum channel gain as this best subset.

Alternatively, as another embodiment, determine that unit 81 increases for the channel obtaining multiple transmitting antennas of transmission point Benefit, and select this channel gain transmitting antenna more than threshold value as best subset.

Alternatively, as another embodiment, reporting unit 82 is additionally operable to the transmitting sky in this best subset of base station repeats The index of line.

Alternatively, as another embodiment, determine that unit 81 is for determining most preferably based on the instruction information received from base station Subset, the index of the transmitting antenna in the best subset that the instruction of this instruction information is selected according to channel gain by this base station.

Alternatively, as another embodiment, reporting unit 82 is used for utilizing code book report to quantify CSI, the size of this code book Depend on the size of this best subset.

Alternatively, as another embodiment, determine that the size information that unit 81 is additionally operable to based on receiving from this base station determines The size of this best subset, or at this mobile station, select the size of this best subset.

Alternatively, as another embodiment, reporting unit 82 is additionally operable to the transmitting in this best subset of this base station repeats The quantization CSI launching antenna beyond antenna.

Fig. 9 shows the block diagram of the mobile station in another embodiment of the present invention.

As it is shown in figure 9, mobile station 90 includes processor 91, transmitter 92 and receiver 93.

Processor 91 is used for based on channel gain, is this transmission from multiple transmitting antennas of each selected transmission point Point determines the best subset launching antenna.

Transmitter 92 is for quantized channel status information CSI launching antenna in this best subset of this base station repeats.

Therefore, the embodiment of the present invention selects to launch the best subset of antenna based on channel gain, and to selected subset Feed back, thus reduce feedback overhead.

The parts of mobile station 90 can realize the respective process that the MS described in embodiment based on Fig. 1 to Fig. 6 is relevant, for For the sake of simplicity, here is omitted.

Alternatively, as an embodiment, processor 91 is used for obtaining the channel gain of multiple transmitting antennas of transmission point, and Select there is the transmitting antenna of maximum channel gain as this best subset.

Alternatively, as another embodiment, processor 91 is used for obtaining the channel gain of multiple transmitting antennas of transmission point, And select channel gain to be more than the transmitting antenna of threshold value as this best subset.

Alternatively, as another embodiment, transmitter 92 is additionally operable to the transmitting sky in this best subset of this base station repeats The index of line.

Alternatively, as another embodiment, processor 91 is for based on the instruction information received from base station by receiver 93 Determine best subset, this instruction information transmitting sky in this best subset that instruction is selected according to channel gain by this base station The index of line.

Alternatively, as another embodiment, transmitter 92 is used for utilizing code book report to quantify CSI, and the size of this code book takes Certainly in the size of this best subset.

Alternatively, as another embodiment, the size information that processor 91 is additionally operable to based on receiving from this base station determines this The size of best subset, or at this mobile station, select the size of this best subset.

Alternatively, as another embodiment, transmitter 92 is additionally operable to the transmitting sky in this best subset of this base station repeats The quantization CSI launching antenna beyond line.

Figure 10 shows the block diagram of the base station in one embodiment of the invention.Base station 100 can have at least one transmission point, Each transmission point is equipped with multiple transmitting antennas.As shown in Figure 10, base station 100 includes receiver 101 and transmitter 102.

Receiver 101 is for receiving report from mobile station, and this report is reported based on channel gain from each selected biography Quantized channel status information CSI of the best subset launching antenna determined for this transmission point in multiple transmitting antennas of defeated point.

Transmitter 102 is for sending data based on this quantization CSI.

Therefore, the embodiment of the present invention selects to launch the best subset of antenna based on channel gain, and to selected subset Feed back, thus reduce feedback overhead.

The parts of base station 100 can realize the respective process that the BS described in embodiment based on Fig. 1 to Fig. 6 is relevant, for For the sake of simplicity, here is omitted.

Alternatively, as an embodiment, base station 100 can also include processor 103, is used for obtaining multiple of transmission point Penetrate the channel gain of antenna, and select there is the transmitting antenna of maximum channel gain as best subset.

Alternatively, as another embodiment, base station 100 can also include processor 103, many for obtaining this transmission point The channel gain of individual transmitting antenna, and select this channel gain transmitting antenna more than threshold value as best subset.

Alternatively, as another embodiment, transmitter 102 is additionally operable to send instruction information, this instruction information to mobile station For indicating the index launching antenna in this best subset to mobile station.

Alternatively, as another embodiment, receiver 101 is additionally operable to receive instruction information, this instruction information from mobile station The index launching antenna in this best subset that instruction is selected according to channel gain by this mobile station.

Alternatively, as another embodiment, the report quantifying CSI uses code book, and the size of this code book depends on optimal son The size of collection.

Alternatively, as another embodiment, receiver 101 is additionally operable to receive for indicating this best subset from mobile station The size information of size.

Alternatively, as another embodiment, base station 100 can also include processor 103, for selecting to be somebody's turn to do in this base station The size of best subset.

Alternatively, as another embodiment, receiver 101 is additionally operable to receive report from mobile station, and this report is used for reporting The quantization CSI launching antenna launched beyond antenna in this best subset.

In embodiments of the present invention, MS can be following any one, can be fixing or mobile, and fixing MS Example can include subscriber equipment, terminal, mobile station, subscriber unit or website etc..The example of mobile MS can include cell phone, Personal digital assistant (PDA), radio modem, radio communication device, hand-held device, laptop computer, wireless phone Or WLL (WLL) website etc..

It should be noted that the term of such as " first, second etc. " that use within a context is only used for an entity or operation Separate with another entity or operating space, and be not intended to represent the actual relationship between these entities or operation or order.It addition, art Language " includes ", " comprising " or its modification are intended to carry out including rather than in the way of removing property in the way of inclusive, therefore wraps Include the process of certain element, method, object or equipment and will not only include this element, it is also possible to include being not expressly set out other Element, or farther include the element that this process, method, object or equipment are intrinsic.Unless otherwise defined, term " includes one Individual ... by being not excluded for, element defined in " includes that the process of described element, method, object or equipment get rid of other identical elements Exist.

Description according to embodiments of the present invention, those skilled in the art are clearly understood that, the present invention can be combined by software Necessary general hardware implementation, naturally it is also possible to only realized by hardware, but the former is preferred.Based on this understanding, the present invention Solution itself or present invention part that prior art is made contributions can realize with the form of software product, and soft Part product can be stored in storage medium, such as ROM/RAM, hard disk, compact-disc etc., comprises that to enable to computer installation (individual People's computer, server or network equipment etc.) perform the method described in embodiment or section Example.

Although describing the present invention by the way of preferred embodiment, it should be noted that those skilled in the art can be to enforcement Example carries out multiple amendment or deformation, and these amendments or deformation should fall within the scope of protection of the present invention.

Claims (32)

1. a communication means for mobile station, described mobile station is serviced by base station, and described base station has at least one transmission point, often Individual described transmission point is equipped with multiple transmitting antennas, and described method includes:

Based on channel gain, from multiple transmitting antennas of each selected transmission point, determine transmitting antenna for described transmission point Best subset；And

Quantized channel status information CSI launching antenna in best subset described in described base station repeats.

Method the most according to claim 1, wherein said putting for each transmission determines that the best subset launching antenna includes:

Obtain the described channel gain of the plurality of transmitting antenna of described transmission point；And

Select there is the transmitting antenna of maximum channel gain as described best subset.

Method the most according to claim 1, wherein said putting for each transmission determines that the best subset launching antenna includes:

Obtain the described channel gain of the plurality of transmitting antenna of described transmission point；And

Select the described channel gain transmitting antenna more than threshold value as described best subset.

The most according to the method in claim 2 or 3, also include:

The index launching antenna in best subset described in described base station repeats.

Method the most according to claim 1, wherein said putting for each transmission determines that the best subset launching antenna includes:

Determining described best subset based on the instruction information received from described base station, described instruction information indicates by described base station root According to the index launching antenna in the described best subset that channel gain selects.

Method the most according to any one of claim 1 to 5, wherein said in best subset described in described base station repeats Launch antenna quantized channel status information CSI include:

Utilizing code book to report described quantization CSI, the size of described code book depends on the size of described best subset.

Method the most according to claim 5, also includes:

The size information being used for indicating the size of described best subset is received from described base station；Or

The size of described best subset is selected at described mobile station.

Method the most according to any one of claim 1 to 7, also includes:

The quantization CSI launching antenna launched beyond antenna in best subset described in described base station repeats.

9. a communication means for base station, described base station has at least one transmission point, and each described transmission point is equipped with multiple Launching antenna, described method includes:

Receiving report from mobile station, described report is for reporting based on channel gain from multiple of each selected transmission point Penetrate quantized channel status information CSI of the best subset launching antenna determined in antenna for described transmission point；And

Data are sent based on described quantization CSI.

Method the most according to claim 9, also includes:

Obtain the described channel gain of the plurality of transmitting antenna of described transmission point；And

Select there is the transmitting antenna of maximum channel gain as described best subset.

11. methods according to claim 9, also include:

Obtain the described channel gain of the plurality of transmitting antenna of described transmission point；And

Select the described channel gain transmitting antenna more than threshold value as described best subset.

12., according to the method described in claim 10 or 11, also include:

Sending instruction information to mobile station, described instruction information for indicating the transmitting antenna in described best subset to mobile station Index.

13. methods according to claim 9, also include:

Instruction information is received, the institute that described instruction information is selected according to channel gain by described mobile station for instruction from mobile station State the index launching antenna in best subset.

14. use code book according to the method according to any one of claim 9 to 13, the described report of wherein said quantization CSI, The size of described code book depends on the size of described best subset.

15. methods according to claim 14, also include:

The size information being used for indicating the size of described best subset is received from described mobile station；Or

The size of described best subset is selected in described base station.

16., according to the method according to any one of claim 9 to 15, also include:

Receiving report from mobile station, described report is for reporting the antenna of launching launched beyond antenna in described best subset Quantify CSI.

17. 1 kinds of mobile stations, described mobile station is serviced by base station, and described base station has at least one transmission point, each described biography Defeated point includes equipped with multiple transmitting antennas, described mobile station:

Determine unit, be used for based on channel gain, be described transmission from multiple transmitting antennas of each selected transmission point Point determines the best subset launching antenna；And

Reporting unit, for quantized channel status information CSI launching antenna in best subset described in base station repeats.

18. movement stations according to claim 17, wherein said determine unit for obtain described transmission point described many The described channel gain of individual transmitting antenna, and select there is the transmitting antenna of maximum channel gain as described best subset.

19. movement stations according to claim 17, wherein said determine unit for obtain described transmission point described many The described channel gain of individual transmitting antenna, and select the described channel gain transmitting antenna more than threshold value as described optimal son Collection.

20. according to the movement station described in claim 18 or 19, and described reporting unit is additionally operable to son optimal described in base station repeats The index launching antenna concentrated.

21. movement stations according to claim 17, wherein said determine that unit is for based on the finger received from described base station Showing that information determines described best subset, described instruction information indicates the described optimal son selected by described base station according to channel gain The index launching antenna concentrated.

22. according to the movement station according to any one of claim 17 to 21, and wherein said reporting unit is used for utilizing code book report Accusing and quantify CSI, the size of described code book depends on the size of described best subset.

23. movement stations according to claim 22, wherein said determine that unit is additionally operable to based on receiving from described base station Size information determines the size of described best subset, or selects the size of described best subset at described mobile station.

24. movement stations according to any one of claim 1 to 7, wherein said reporting unit is additionally operable to described base station Report the quantization CSI launching antenna launched beyond antenna in described best subset.

25. 1 kinds of base stations, described base station has at least one transmission point, and each described transmission is put equipped with multiple transmitting antennas, Described base station includes:

Receiver, for receiving report from mobile station, described report is reported based on channel gain from each selected transmission point Multiple transmitting antennas in quantized channel status information CSI of best subset launching antenna that determines for described transmission point；With And

Transmitter, for sending data based on described quantization CSI.

26. base stations according to claim 25, also include processor, for obtaining the plurality of transmitting of described transmission point The described channel gain of antenna, and select there is the transmitting antenna of maximum channel gain as described best subset.

27. base stations according to claim 25, also include processor, for obtaining the plurality of transmitting of described transmission point The described channel gain of antenna, and select the described channel gain transmitting antenna more than threshold value as described best subset.

28. according to the base station described in claim 26 or 27, and wherein said transmitter is additionally operable to send instruction information to mobile station, Described instruction information for indicating the index launching antenna in described best subset to mobile station.

29. base stations according to claim 25, wherein said receiver is additionally operable to receive instruction information from mobile station, described The instruction information index launching antenna in the described best subset that instruction is selected according to channel gain by described mobile station.

30. use code according to the base station according to any one of claim 25 to 29, the described report of wherein said quantization CSI This, the size of described code book depends on the size of described best subset.

31. base stations according to claim 30, wherein

Described receiver is additionally operable to receive the size information of size for indicating described best subset from described mobile station；Or

Described base station also includes processor, for selecting the size of described best subset in described base station.

32. according to the method according to any one of claim 25 to 31, and wherein said receiver is additionally operable to receive from mobile station Report, described report is for reporting the quantization CSI launching antenna launched beyond antenna in described best subset.