CN105721033A - Beam forming method and system for multi-user millimetre-wave communication system - Google Patents

Abstract

The invention belongs to the technical field of digital information, and provides a beam forming method and system for a multi-user millimetre-wave communication system. The beam forming method comprises the following steps of: performing beam forming training of a user side according to a preset beam forming training algorithm so as to obtain a beam forming training result; according to the beam forming training result, judging whether a conflict user side exists or not, wherein the conflict user side is a user side for downlink sending of a beam forming vector by adopting the same base station side; if so, selecting a beam forming vector pair to be subjected to downlink sending/receiving for the conflict user side so as to obtain a beam forming vector index to be subjected to downlink receiving of the conflict user side; and sending the beam forming vector index to be subjected to downlink receiving of the conflict user side to the conflict user side, such that the conflict user side searches the corresponding beam forming vector to be subjected to downlink receiving according to the received index. A conflict judging process is added into the traditional beam forming mechanism; therefore, the beam forming vector is re-selected for the conflict user side; and thus, the achievable rate of the conflict user side in the traditional beam forming training method is increased.

Description

The beam form-endowing method of a kind of multi-user's millimeter-wave communication system and system

Technical field

The present invention relates to technical field of digital information, be specifically related to beam form-endowing method and the system of a kind of multi-user's millimeter-wave communication system.

Background technology

In recent years, along with millimeter wave (MillimeterWave) technology and extensive multiple-input and multiple-output (MassiveMulti-InputMulti-Output, MIMO) technology is considered as a part for following 5G key technology, causes the extensive concern of academia and industrial quarters.Millimeter wave frequency band has a large amount of available spectrum resources, it is possible to meet the service traffics demand that mobile communication is growing.Additionally, due to the wavelength of millimeter wave is shorter, according to antenna theory, the antenna size of millimeter-wave systems is also less, enabling places hundreds of even thousands of antennas in the little ranged space, is more beneficial for the application in reality system of the extensive antenna technology.Although millimeter-wave systems exists the shortcoming that channel path decline is excessive, but the beamforming technique that extensive antenna provides can be utilized to make up the shortcoming that the decline of millimeter wave channel path is excessive, it is applied to mobile communication for millimeter-wave technology and provides possibility.

In a Ge Dan community extensive antenna system of multi-user's millimeter wave, base station is equipped with root M antenna, simultaneously K user side of service, and each user side is equipped with N root antenna.Traditional digital precoding framework, by a digital pre-coding matrixThe data of K user side are mapped on M radio frequency link and antenna element, it is possible to obtain optimum precoding performance, but this framework needs M radio frequency link, thus causing the problems such as hardware complexity is high, power consumption is big.Therefore multi-user's millimeter-wave systems generally adopts mixing precoding framework, connects including full connection mixing precoding framework and son and mix precoding framework.As it is shown in figure 1, connect in mixing precoding framework complete, each radio frequency link is all connected with all M root antennas, and the signal from each radio frequency link is added in antenna end；As in figure 2 it is shown, in sub-connection mixing precoding framework, each radio frequency link connects M/K root antenna, and namely every antenna is only connected with a radio frequency link.

Under mixing precoding framework, the data of K user side first pass around oneDigital precode matrix be mapped on K radio frequency link, the signal on each radio frequency link, after up-conversion, is connected on antenna by the phase shifter.Accordingly, it is added after the shifted device of reception signal on user side every antenna, is connected on a radio frequency link.Under mixing precoding framework, downstream signal mode is represented byWherein y_kDigital end for kth user side receives signal, H_kFor the down channel matrix between kth user side and base station, F and B respectively simulates precoding and numeral pre-coding matrix, W_kRepresent the downlink reception wave beam forming vector of kth user side, n_kRepresent white Gaussian noise vector.It should be noted that and connect under mixing precoding framework complete, have F=[f₁,f₂,…,f_K], whereinRepresent the descending transmission wave beam forming vector of base station end of kth user side.And under sub-connection mixing precoding framework, haveWhereinRepresent the descending transmission wave beam forming vector of base station end of kth user side.Entirely connecting for Unify legislation and son connects mixing precoding framework, we define H_k,pThe channel matrix between the antenna of pth radio frequency link it is connected to for kth user side and base station end.For entirely connecting framework, owing to each radio frequency link is all connected to all antennas, thereforeAnd for sub-connection framework, have H_k=[H_k,1,H_k,2,…,H_k,k], i.e. H_k,pFor H_k?ToRow.By the restriction of device constraints, sending/receive wave beam forming vector can only select from predefined simulation code book, respectively the simulation code book W simulating code book F and user side of base station end.

Under mixing precoding framework, design simulation precoding and numeral pre-coding matrix are too high with the Global Optimal Problem complexity maximizing overall system capacity simultaneously, therefore generally will simulate precoding and the separately design of numeral pre-coding matrix, and wave beam forming will train the process namely referred to from simulating the transmission/reception wave beam forming vector selecting each user side optimum code book.Tradition wave beam forming training mechanism adopts and maximizes signal-to-noise ratio (SNR) Criterion, namely maximizes the received signal to noise ratio of each user side, and ignores and disturb between user side, it is possible to is expressed as { f_k,w_k}=argmax | | w^TH_k,kF | | s.t.w ∈ W, f ∈ F, { f here_k,w_kRepresent that kth user side sends/receive wave beam forming vector.Complete analog end send/receive weight vector design after, we can obtain descending equivalent channelWhereinFor the equivalent channel coefficient between base station end jth radio frequency link and i-th user side.Utilize broken zero (Zero-forcing, ZF) precoding algorithms, it is possible to obtaining digital precode matrix is:Wherein Λ is pair of horns battle array, distributes for transmitting power between user side.

Due to the characteristic that the decay of millimeter wave channel path is big, the scattering object negligible amounts of millimeter wave multipath channel, can be by millimeter wave Channel Modeling generally $H=\sqrt{\frac{\mathrm{MN}}{N_{\mathrm{ray}}}}\underset{l=1}{\overset{N_{\mathrm{ray}}}{\mathrm{\Σ}}}{a}_l{\∂}_{\mathrm{UE}}({\mathrm{\θ}}_l^{\mathrm{UE}},{\mathrm{\φ}}_l^{\mathrm{UE}}){\∂}_{\mathrm{BS}}^H({\mathrm{\θ}}_l^{\mathrm{BS}},{\mathrm{\φ}}_l^{\mathrm{BS}}),$ Wherein,Representing the down channel between user side and base station, N and M represents the antenna amount that user side and base station are equipped with, N respectively_rayFor multipath number, a_lRepresent the channel coefficients of corresponding scattering path,WithRepresenting the antenna response vector of user side and base station respectively, θ and φ respectively horizontally and vertically arrives angle.

Traditional wave beam forming training mechanism mainly includes exhaustive search and single feedback etc..Exhaustive search mechanism search all possible transmission/reception wave beam forming vector is right, user side measures the channel quality under every pair of transmission/reception wave beam forming vector, therefrom select one group that makes received signal to noise ratio maximum, and the index sending wave beam forming vector is fed back to base station.Exhaustive search mechanism can reach the performance of optimum, but complexity is higher.Wave beam forming training is split as two flow processs by single feedback mechanism, first all possible transmission wave beam forming vector of base station search, user side uses omni-beam to receive and estimate channel quality, and user side therefrom selects optimum transmission wave beam forming vectorial and indexed to feed back to base station.Subsequently, the fixing wave beam forming vector that sends in base station, the reception wave beam forming vector that user side search is optimum.Compared with exhaustive search mechanism, the complexity of single feedback mechanism is substantially reduced, but also results in certain performance loss simultaneously, and its complexity increases with the increase of user's terminal number in addition.

Summary of the invention

For the defect that prior art exists, the present invention proposes beam form-endowing method and the system of a kind of multi-user's millimeter-wave communication system, to solve in existing multi-user's millimeter-wave communication system, wave beam forming selects the problem that mechanism needs to improve the achievable rate of the user side that wave beam conflict occurs with higher complexity.

For this purpose it is proposed, first aspect, the present invention provides the beam form-endowing method of a kind of multi-user's millimeter-wave communication system, including:

According to default wave beam forming training algorithm, user side is carried out wave beam forming training, obtain wave beam forming training result；

According to described wave beam forming training result, it may be judged whether there is conflict user side, described conflict user side is the user side adopting the descending transmission wave beam forming vector of identical base station end；

If there is conflict user side, then selecting to treat that descending transmission/reception wave beam forming vector is right for described conflict user side, obtaining the index treating downlink reception wave beam forming vector of described conflict user side；

The index treating downlink reception wave beam forming vector of described conflict user side is sent to described conflict user side, so that described conflict user side is treated that downlink reception wave beam forming vector index is searched corresponding treat that downlink reception wave beam forming is vectorial according to what received.

Wherein, also include:

If being absent from conflict user side, then according to described wave beam forming training result, send wave beam forming vector to described each user side.

Wherein, the wave beam forming training algorithm that described basis is preset, carry out wave beam forming training, obtain wave beam forming training result, including:

According to default wave beam forming training algorithm, carry out wave beam forming training, obtain each transmission/reception wave beam forming vector under equivalent channel quality, select descending transmission/reception wave beam forming vector right for each user side according to maximizing signal-to-noise ratio (SNR) Criterion；

Receive the index of the descending transmission wave beam forming vector of base station end of each user side, obtaining wave beam forming training result, the index of described base station end descending transmission wave beam forming vector is the index of the descending transmission wave beam forming vector of the base station end making each user side signal to noise ratio maximum.

Wherein, the formula of described maximization signal-to-noise ratio (SNR) Criterion is:

{f_k,w_k}=argmax | | w^TH_k,kF | | s.t.w ∈ W, f ∈ F,

In formula, f_kThe descending transmission wave beam forming vector of base station end for serving kth user side, w_kFor serving the downlink reception wave beam forming vector of kth user side, H_k,kBe connected to the down channel matrix between the antenna sets of kth radio frequency link for kth user side, f and w is that the alternative descending transmission/reception wave beam forming vector calculated by formula is right, w^TFor the transposed vector by the descending transmission wave beam forming vector of the base station end calculated of formula, argmax is for taking maximum symbol, | | | | for two norms of vector, the wave beam forming code book of W and F respectively user side and base station end, s.t. it is constraints, must selecting from user side wave beam forming code book W for retraining user side reception down beam shaping vector w, base station end sends wave beam forming vector f and must select from base station end wave beam forming code book F.

Wherein, described according to described wave beam forming training result, it may be judged whether to there is conflict user side, including:

Index according to described descending transmission wave beam forming vector, it is determined that the descending transmission wave beam forming vector of base station end of described each user side；

The descending transmission wave beam forming vector of base station end according to described each user side, it may be judged whether there is conflict user side.

Wherein, judge whether described in conflict user side formula be:

f_i=f_j, i ≠ j,

In formula, f_iAnd f_jThe respectively descending transmission wave beam forming vector of the base station end of ith and jth user side.

Wherein, there is conflict user side if described, then select to treat that the descending transmission of base station end/reception wave beam forming vector is right for described conflict user side, obtain the index of the base station end wave beam forming vector to be received of described conflict user side, including:

Calculate the N of each user side in described conflict user side_dIndividual notable wave beam forming vector is right, constructs notable wave beam to setWherein, described N_dIndividual notable wave beam forming vector is to the N for reaching maximum received signal to noise ratio_dIndividual different wave beam forming vector is right, N_dFor preset constant, p_kFor the index of kth conflict user side, 1≤k≤K_c, K_cNumber for the user side that conflicts；

Receive the N of described each conflict user side_dThe notable wave beam forming vector index of transmission of individual notable wave beam forming vector centering；

The quadrature training sequence sent on radio frequency link according to described conflict user side, scans the N of described conflict client feeds back_dIndividual notable wave beam forming vector is right, so that described conflict user side is measured and feeds back equivalent channel coefficient；

According to described transmission notable wave beam forming vector index and described equivalent channel coefficient, based on pre-set criteria, at described notable wave beam to setIn scope, select to treat that descending transmission/reception wave beam forming vector is right for described conflict user side.

Wherein, described pre-set criteria is:

$\left\{\right\{f_{p_1},w_{p_1}\},...,\{f_{p_{K_c}},w_{p_{K_c}}\left\}\right\}=\mathrm{argmax}\underset{k=1}{\overset{K_c}{\mathrm{\Σ}}}{\log }_2(1+{\mathrm{SIR}}_{p_k})s.t.\{f_{p_k},w_{p_k}\}\∈{\mathrm{\Ω}}_{p_k},$

In formula,For kth conflict user side signal-to-noise ratio,It is the descending transmission wave beam forming vector of base station end of the selection of the 1st conflict user side,It is the downlink reception wave beam forming vector of the 1st conflict user side,It is K_cThe descending transmission wave beam forming vector of base station end of individual conflict user side,It is K_cThe downlink reception wave beam forming vector of individual conflict user side,The descending transmission wave beam forming of base station end for kth conflict user side is vectorial,Downlink reception wave beam forming vector for kth conflict user side, argmax is for taking maximum symbol, and Σ is summation symbol, and s.t. is constraints, for constraint for each conflict user side, its descending transmission/receptions wave beam forming vector correspondence from notable wave beam to setIn choose.

Second aspect, the present invention provides the beam-forming system of a kind of multi-user's millimeter-wave communication system, including:

Training module, for according to the wave beam forming training algorithm preset, carrying out wave beam forming training to user side, obtain wave beam forming training result；

Judge module, for according to described wave beam forming training result, it may be judged whether there is conflict user side, described conflict user side is the user side adopting the descending transmission wave beam forming vector of identical base station end；

Selecting module, for when there is conflict user side, selecting to treat that descending transmission/reception wave beam forming vector is right for described conflict user side, obtaining the index treating downlink reception wave beam forming vector of described conflict user side；

First sending module, for the index treating downlink reception wave beam forming vector of described conflict user side is sent to described conflict user side, so that described conflict user side is treated that downlink reception wave beam forming vector index is searched corresponding treat that downlink reception wave beam forming is vectorial according to what received.

Wherein, also include:

Second sending module, when being used for being absent from conflict user side, according to described wave beam forming training result, sends wave beam forming vector to described each user side.

The beam form-endowing method of a kind of multi-user's millimeter-wave communication system provided by the invention and system, by adding conflict judge process in traditional wave beam forming training method, user side for the conflict of descending transmission wave beam, according to pre-set criteria, reselect wave beam forming vector, improve significantly tradition wave beam forming training method in conflict user side achievable rate, and, by re-searching for being limited to the notable wave beam forming vector centering of conflict user side, therefore there is relatively low complexity.

Accompanying drawing explanation

In order to be illustrated more clearly that disclosure embodiment or technical scheme of the prior art, the accompanying drawing used required in embodiment or description of the prior art will be briefly described below, apparently, accompanying drawing in the following describes is only some embodiments of the disclosure, for those of ordinary skill in the art, under the premise not paying creative work, it is also possible to obtain other accompanying drawing according to these figure.

Fig. 1 is the model schematic of full connection hybrid coding framework of the prior art；

Fig. 2 is the model schematic of sub-connection hybrid coding framework of the prior art；

The flow chart of the beam form-endowing method of multi-user's millimeter-wave communication system that Fig. 3 provides for one embodiment of the invention；

Fig. 4 is that in one embodiment of the invention, notable wave beam forming is vectorial to schematic diagram；

The principle schematic of the beam form-endowing method of multi-user's millimeter-wave communication system that Fig. 5 provides for one embodiment of the invention；

Fig. 6 is channel multi-path number N in one embodiment of the invention_rayWhen=3, the Cumulative Distribution Function simulation curve figure of conflict user side achievable rate；

Fig. 7 is channel multi-path number N in one embodiment of the invention_rayWhen=6, the Cumulative Distribution Function simulation curve figure of conflict user side achievable rate；

The structural representation of the beam-forming system of multi-user's millimeter-wave communication system that Fig. 8 provides for one embodiment of the invention.

Detailed description of the invention

Below in conjunction with the accompanying drawing in disclosure embodiment, the technical scheme in disclosure embodiment is clearly and completely described, it is clear that described embodiment is only a part of embodiment of the present invention, rather than whole embodiments.Based on the embodiment in the disclosure, the every other embodiment that those of ordinary skill in the art obtain under not making creative work premise, broadly fall into the scope of disclosure protection.

As it is shown on figure 3, the disclosure one embodiment provides the beam form-endowing method of multi-user's millimeter-wave communication system, the method comprises the steps S1 to S4:

The wave beam forming training algorithm that S1, basis are preset, carries out wave beam forming training to user side, obtains wave beam forming training result；

Specifically, the wave beam forming training algorithm preset in this step S1 is exhaustive search or single feedback search.

It should be noted that, the wave beam forming training algorithm that this place adopts is by way of example only, the present embodiment does not limit the particular type of wave beam forming training algorithm, and those skilled in the art can select other wave beam forming training algorithm to carry out wave beam forming training according to practical situation.

S2, according to described wave beam forming training result, it may be judged whether there is conflict user side, described conflict user side is the user side adopting the descending transmission wave beam forming vector of identical base station end；

If S3 exists conflict user side, then select to treat that descending transmission/reception wave beam forming vector is right for described conflict user side, obtain the index treating downlink reception wave beam forming vector of described conflict user side；

S4, the index treating downlink reception wave beam forming vector of described conflict user side is sent to described conflict user side, so that described conflict user side is treated that downlink reception wave beam forming vector index is searched corresponding treat that downlink reception wave beam forming is vectorial according to what received.

The beam form-endowing method of a kind of multi-user's millimeter-wave communication system that the present embodiment provides, by adding conflict judge process in traditional wave beam forming training method, user side for the conflict of descending transmission wave beam, reselect wave beam forming vector, improve significantly tradition wave beam forming training method in conflict user side achievable rate.

In the present embodiment, also include not shown step S3`；

If S3` is absent from conflict user side, then according to described wave beam forming training result, send wave beam forming vector to described each user side.

It should be noted that when judging not conflict user side, the beam form-endowing method in the present embodiment is identical with traditional beam form-endowing method.

In the present embodiment, step S1: " according to default wave beam forming training algorithm, user side being carried out wave beam forming training, obtain wave beam forming training result ", the following fine division step S11 to S12 including not shown:

S11, according to the wave beam forming training algorithm preset, carry out wave beam forming training, obtain each transmission/receptions wave beam forming vector under equivalent channel quality, right according to maximizing signal-to-noise ratio (SNR) Criterion selection descending transmission/reception wave beam forming vector for each user side；

S12, receive the index of the descending transmission wave beam forming vector of the base station end of each user side, obtaining wave beam forming training result, the index of described base station end descending transmission wave beam forming vector is the index of the descending transmission wave beam forming vector of the base station end making each user side signal to noise ratio maximum.

Specifically, the formula of the maximization signal-to-noise ratio (SNR) Criterion in the present embodiment step S11 is:

{f_k,w_k}=argmax | | w^TH_k,kF | | s.t.w ∈ W, f ∈ F,

In formula, f_kThe descending transmission wave beam forming vector of base station end for serving kth user side, w_kFor serving the downlink reception wave beam forming vector of kth user side, H_k,kBe connected to the down channel matrix between the antenna sets of kth radio frequency link for kth user side, f and w is that the alternative descending transmission/reception wave beam forming vector calculated by formula is right, w^TFor the transposed vector by the descending transmission wave beam forming vector of the base station end calculated of formula, argmax is for taking maximum symbol, | | | | for two norms of vector, the wave beam forming code book of W and F respectively user side and base station end, s.t. it is constraints, must selecting from user side wave beam forming code book W for retraining user side reception down beam shaping vector w, base station end sends wave beam forming vector f and must select from base station end wave beam forming code book F.

It should be noted that, in formula, f and w does not have clear and definite implication, being that the alternative descending transmission/reception wave beam forming vector calculated by the formula of above-mentioned maximization signal-to-noise ratio (SNR) Criterion is right, the effect of argmax selects to make from these alternative vector centerings exactly | | | | a pair maximum vector is right.

Specifically, the size of W and F respectively Q and P.

It should be noted that this formula describe be according to maximize signal-to-noise ratio (SNR) Criterion be each user select best transmission/receive wave beam forming vector to process, namely from alternative w and f, select best a pair, as { f_k,w_k}。

Specifically, the step S2 in the present embodiment: " according to described wave beam forming training result, it may be judged whether there is conflict user side ", the following fine division step S21 to S22 including not shown:

S21, index according to described descending transmission wave beam forming vector, it is determined that the descending transmission wave beam forming vector of the base station end of described each user side；

S22, according to the descending transmission wave beam forming vector of the base station end of described each user side, it may be judged whether there is conflict user side.

Specifically, it may be judged whether the formula that there is conflict user side is:

f_i=f_j, i ≠ j,

In formula, f_iAnd f_jThe respectively descending transmission wave beam forming vector of the base station end of ith and jth user side.

Whether the descending transmission wave beam forming vector passed through according to user side in the present embodiment is identical, can effectively judge whether conflict user side, and make punching figure user side reselect wave beam forming vector according to judged result, improve significantly tradition wave beam forming training method in conflict user side achievable rate.

Specifically, step S3 in the present embodiment: " if there is conflict user side; then select to treat that descending transmission/reception wave beam forming vector is right for described conflict user side; obtain the index treating downlink reception wave beam forming vector of described conflict user side ", the following fine division step S31 to S34 including not shown:

S31, each user side calculated in described conflict user side N_dIndividual notable wave beam forming vector is right, constructs notable wave beam to setWherein, described N_dIndividual notable wave beam forming vector is to the N for reaching maximum received signal to noise ratio_dIndividual different wave beam forming vector is right, N_dFor preset constant, p_kFor the index of kth conflict user side, 1≤k≤K_c, K_cNumber for the user side that conflicts；

Specifically, Fig. 4 illustrates that notable wave beam forming vector is to schematic diagram, wherein, the size of base station end code book and user side code book is 4, numeral in figure represent corresponding send/receive wave beam forming vector under equivalent channel coefficient, reddish brown part represents two the notable wave beam forming vectors obtained, i.e. Ω={ { f²,w³}{f³,w²?.The notable wave beam forming vector size N to set_dGenerally only small, this parameter is relevant to channel multi-path number, under sparse millimeter wave channel condition, and N_d=2 can obtain good performance, and because of the number K of conflict user side_cAlso only small, therefore, the complexity of the wave beam forming training mechanism of enhancingRelatively low.

S32, receive the N of described each conflict user side_dThe notable wave beam forming vector index of transmission of individual notable wave beam forming vector centering；

S33, according on the radio frequency link of described conflict user side send quadrature training sequence, scan the N of described conflict client feeds back_dIndividual notable wave beam forming vector is right, so that described conflict user side is measured and feeds back equivalent channel coefficient；

Specifically, equivalent channel coefficient includes the equivalent channel coefficient between the radio frequency link that the equivalent channel coefficient between each conflict user side correspondence radio frequency link is corresponding with other conflict user side.

It should be noted that the equivalent channel coefficient in the present embodiment is the equivalent channel coefficient between the radio frequency link that other conflict user side is corresponding, i.e. inter-user interference, for:

${\mathrm{SIR}}_{p_k}=\frac{{\left|w_{p_k}^T{H}_{p_k,p_k}{f}_{p_k}\right|}^2}{{\mathrm{\Σ}}_{i=1,i\≠k}^{K_c}{\left|w_{p_k}^T{H}_{p_k,p_i}{f}_{p_i}\right|}^2},1\≤k\≤K_c,$

In formula,For serving pth_kThe radio frequency link of individual conflict user side and pth_kEquivalent channel coefficient between individual conflict user side,For serving pth_kThe radio frequency link of individual conflict user side and pth_iEquivalent channel coefficient between individual conflict user side, namely to p_iThe inter-user interference of individual conflict user side.

S34, according to described transmission notable wave beam forming vector index and described equivalent channel coefficient, based on pre-set criteria, at described notable wave beam to setIn scope, select to treat that descending transmission/reception wave beam forming vector is right for described conflict user side.

Specifically, the pre-set criteria in the present embodiment is for maximizing user capacity criterion.

The beam form-endowing method of a kind of multi-user's millimeter-wave communication system that the present embodiment provides, by according to maximizing user capacity criterion, at notable wave beam to setIn scope, selecting to treat that descending transmission/reception wave beam forming vector is right for conflict user side, therefore, this beam form-endowing method can by relatively low complexity, the achievable rate of the conflict user side in the wave beam forming training method of raising tradition greatly.

Specifically, the pre-set criteria in the step S34 in the present embodiment is:

$\left\{\right\{f_{p_1},w_{p_1}\},...,\{f_{p_{K_c}},w_{p_{K_c}}\left\}\right\}=\arg max\underset{k=1}{\overset{K_c}{\mathrm{\Σ}}}{\log }_2(1+{\mathrm{SIR}}_{p_k})s.t.\{f_{p_k},w_{p_k}\}\∈{\mathrm{\Ω}}_{p_k},$

In formula,For kth conflict user side signal-to-noise ratio,It is the descending transmission wave beam forming vector of base station end of the selection of the 1st conflict user side,It is the downlink reception wave beam forming vector of the 1st conflict user side,It is K_cThe descending transmission wave beam forming vector of base station end of individual conflict user side,It is K_cThe downlink reception wave beam forming vector of individual conflict user side,The descending transmission wave beam forming of base station end for kth conflict user side is vectorial,Downlink reception wave beam forming vector for kth conflict user side, argmax is for taking maximum symbol, and ∑ is summation symbol, and s.t. is constraints, for constraint for each conflict user side, its descending transmission/receptions wave beam forming vector correspondence from notable wave beam to setIn choose.

Specifically, Fig. 5 illustrates the principle schematic of the beam form-endowing method of multi-user's millimeter-wave communication system, as shown in Figure 5, the position of two user sides in figure is nearer, if adopting traditional wave beam forming mechanism, cause the user side that base station adopts the service of same transmission wave beam forming vector different, cause serious inter-user interference, two adopt the beam form-endowing method in the present embodiment, can certain user therein be switched in another high-amplitude wave bundle, inter-user interference is greatly reduced, and then improves user's achievable rate.

The performance that multi-user's millimeter-wave communication system is carried out wave beam forming by tradition wave beam forming mechanism and the beam form-endowing method in the present embodiment is adopted to compare analysis separately below:

Adopt the system block diagram of multi-user's millimeter-wave communication system of tradition wave beam forming mechanism as shown in Figure 2: wherein, base station end number of antennas is M=256, service K=4 can user simultaneously, each user has N=8 root antenna, base station end and user side all adopt the DFT wave beam forming code book of classics, codebook size is P=64 and Q=8 respectively, and code book is determined by following codebook matrix:

${\[C\]}_{u,v}=j^{\[\frac{i\×\left(\right(v+N_c/2\left){\mathrm{modN}}_c\right)}{N_c/4}\]},1\≤u\≤N_a,1\≤v\≤N_c,$

In formula, it is N sized by C_a×N_cCodebook matrix, [C]_u,vFor the element value of codebook matrix u row v row, N_aRepresent antenna number, N_cRepresenting codebook size, channel multi-path is assumed to be N_ray=3 and N_ray=6, the standard deviation of channel angle extension is 15 degree, and receiving terminal signal to noise ratio is 10dB.

Adopt the beam form-endowing method in the present embodiment, be N at channel multi-path_ray=3 and N_rayWhen=6, the Cumulative Distribution Function simulation curve figure of conflict user side achievable rate distinguishes as shown in Figure 6 and Figure 7: can be seen that, compared with the Cumulative Distribution Function of the conflict user side achievable rate adopted in traditional wave beam forming mechanism, notable wave beam forming therein vector to set sizes be set to 2.It can be seen that the beam form-endowing method in the present embodiment greatly increases the achievable rate of user side, it is N at channel multi-path_rayWhen=3, traditional wave beam forming mechanism is adopted to have the achievable rate of user side of 50% lower than 4bps/Hz, adopt in the wave beam forming mechanism in the present embodiment, the achievable rate of the user side of 90% is more than 7bps/Hz, at the same time it can also be find out, the increase of keyed channel multi-path number, the gain that beam form-endowing method in the present embodiment brings reduces, and is more suitable for sparse millimeter wave channel circumstance.

As shown in Figure 8, another embodiment of the disclosure provides the beam-forming system of a kind of multi-user's millimeter-wave communication system, including: training module 10, judge module 20, selection module 30 and the first sending module 40；

Training module 10, for according to the wave beam forming training algorithm preset, carrying out wave beam forming training to user side, obtain wave beam forming training result；

Judge module 20, for according to described wave beam forming training result, it may be judged whether there is conflict user side, described conflict user side is the user side adopting the descending transmission wave beam forming vector of identical base station end；

Selecting module 30, for when there is conflict user side, selecting to treat that descending transmission/reception wave beam forming vector is right for described conflict user side, obtaining the index treating downlink reception wave beam forming vector of described conflict user side；

First sending module 40, for the index treating downlink reception wave beam forming vector of described conflict user side is sent to described conflict user side, so that described conflict user side is treated that downlink reception wave beam forming vector index is searched corresponding treat that downlink reception wave beam forming is vectorial according to what received.

In the present embodiment, this system also includes the second not shown sending module 50:

Second sending module 50, when being used for being absent from conflict user side, according to described wave beam forming training result, sends wave beam forming vector to described each user side.

The beam-forming system of a kind of multi-user's millimeter-wave communication system that the present embodiment provides, by adding conflict judge process in traditional wave beam forming training method, user side for the conflict of descending transmission wave beam, reselect wave beam forming vector, improve significantly tradition wave beam forming training method in conflict user side achievable rate.

One of ordinary skill in the art will appreciate that: various embodiments above only in order to technical scheme to be described, is not intended to limit；Although the present invention being described in detail with reference to foregoing embodiments, it will be understood by those within the art that: the technical scheme described in foregoing embodiments still can be modified by it, or wherein some or all of technical characteristic is carried out equivalent replacement；And these amendments or replacement, do not make the essence of appropriate technical solution depart from the scope of the claims in the present invention.

Claims (10)

1. the beam form-endowing method of multi-user's millimeter-wave communication system, it is characterised in that including:

According to default wave beam forming training algorithm, user side is carried out wave beam forming training, obtain wave beam forming training result；

According to described wave beam forming training result, it may be judged whether there is conflict user side, described conflict user side is the user side adopting the descending transmission wave beam forming vector of identical base station end；

If there is conflict user side, then selecting to treat that descending transmission/reception wave beam forming vector is right for described conflict user side, obtaining the index treating downlink reception wave beam forming vector of described conflict user side；

The index treating downlink reception wave beam forming vector of described conflict user side is sent to described conflict user side, so that described conflict user side is treated that downlink reception wave beam forming vector index is searched corresponding treat that downlink reception wave beam forming is vectorial according to what received.

2. method according to claim 1, it is characterised in that also include:

If being absent from conflict user side, then according to described wave beam forming training result, send wave beam forming vector to described each user side.

3. method according to claim 1, it is characterised in that the wave beam forming training algorithm that described basis is preset, carries out wave beam forming training, obtains wave beam forming training result, including:

According to default wave beam forming training algorithm, carry out wave beam forming training, obtain each transmission/reception wave beam forming vector under equivalent channel quality, select descending transmission/reception wave beam forming vector right for each user side according to maximizing signal-to-noise ratio (SNR) Criterion；

Receive the index of the descending transmission wave beam forming vector of base station end of each user side, obtaining wave beam forming training result, the index of described base station end descending transmission wave beam forming vector is the index of the descending transmission wave beam forming vector of the base station end making each user side signal to noise ratio maximum.

4. method according to claim 3, it is characterised in that the formula of described maximization signal-to-noise ratio (SNR) Criterion is:

{f_k,w_k}=argmax | | w^TH_k,kF | | s.t.w ∈ W, f ∈ F,

In formula, f_kThe descending transmission wave beam forming vector of base station end for serving kth user side, w_kFor serving the downlink reception wave beam forming vector of kth user side, H_k,kBe connected to the down channel matrix between the antenna sets of kth radio frequency link for kth user side, f and w is that the alternative descending transmission/reception wave beam forming vector calculated by formula is right, w^TFor the transposed vector by the descending transmission wave beam forming vector of the base station end calculated of formula, argmax is for taking maximum symbol, | | | | for two norms of vector, the wave beam forming code book of W and F respectively user side and base station end, s.t. it is constraints, must selecting from user side wave beam forming code book W for retraining user side reception down beam shaping vector w, base station end sends wave beam forming vector f and must select from base station end wave beam forming code book F.

5. method according to claim 3, it is characterised in that described according to described wave beam forming training result, it may be judged whether to there is conflict user side, including:

Index according to described descending transmission wave beam forming vector, it is determined that the descending transmission wave beam forming vector of base station end of described each user side；

The descending transmission wave beam forming vector of base station end according to described each user side, it may be judged whether there is conflict user side.

6. method according to claim 5, it is characterised in that described in judge whether conflict user side formula be:

f_i=f_j, i ≠ j,

In formula, f_iAnd f_jThe respectively descending transmission wave beam forming vector of the base station end of ith and jth user side.

7. method according to claim 3, it is characterized in that there is conflict user side if described, then select to treat that descending transmission/reception wave beam forming vector is right for described conflict user side, obtain the index of the wave beam forming to be received vector of described conflict user side, including:

Calculate the N of each user side in described conflict user side_dIndividual notable wave beam forming vector is right, constructs notable wave beam to setWherein, described N_dIndividual notable wave beam forming vector is to the N for reaching maximum received signal to noise ratio_dIndividual different wave beam forming vector is right, N_dFor preset constant, p_kFor the index of kth conflict user side, 1≤k≤K_c, K_cNumber for the user side that conflicts；

Receive the N of described each conflict user side_dThe notable wave beam forming vector index of transmission of individual notable wave beam forming vector centering；

The quadrature training sequence sent on radio frequency link according to described conflict user side, scans the N of described conflict client feeds back_dIndividual notable wave beam forming vector is right, so that described conflict user side is measured and feeds back equivalent channel coefficient；

According to described transmission notable wave beam forming vector index and described equivalent channel coefficient, based on pre-set criteria, at described notable wave beam to setIn scope, select to treat that descending transmission/reception wave beam forming vector is right for described conflict user side.

8. method according to claim 7, it is characterised in that described pre-set criteria is:

$\left\{\right\{f_{p_1},w_{p_1}\},...,\{f_{p_{K_c}},w_{p_{K_c}}\left\}\right\}=\arg max\underset{k=1}{\overset{K_c}{\Σ}}{\log }_2(1+{\mathrm{SIR}}_{p_k})s.t.\{f_{p_k},w_{p_k}\}\∈{\mathrm{\Ω}}_{p_k},$

In formula,For kth conflict user side signal-to-noise ratio,It is the descending transmission wave beam forming vector of base station end of the selection of the 1st conflict user side,It is the downlink reception wave beam forming vector of the 1st conflict user side,It is K_cThe descending transmission wave beam forming vector of base station end of individual conflict user side,It is K_cThe downlink reception wave beam forming vector of individual conflict user side,The descending transmission wave beam forming of base station end for kth conflict user side is vectorial,Downlink reception wave beam forming vector for kth conflict user side, argmax is for taking maximum symbol, and ∑ is summation symbol, and s.t. is constraints, for constraint for each conflict user side, its descending transmission/receptions wave beam forming vector correspondence from notable wave beam to setIn choose.

9. the beam-forming system of multi-user's millimeter-wave communication system, it is characterised in that including:

Training module, for according to the wave beam forming training algorithm preset, carrying out wave beam forming training to user side, obtain wave beam forming training result；

Judge module, for according to described wave beam forming training result, it may be judged whether there is conflict user side, described conflict user side is the user side adopting the descending transmission wave beam forming vector of identical base station end；

Selecting module, for when there is conflict user side, selecting to treat that descending transmission/reception wave beam forming vector is right for described conflict user side, obtaining the index treating downlink reception wave beam forming vector of described conflict user side；

First sending module, for the index treating downlink reception wave beam forming vector of described conflict user side is sent to described conflict user side, so that described conflict user side is treated that downlink reception wave beam forming vector index is searched corresponding treat that downlink reception wave beam forming is vectorial according to what received.

10. system according to claim 9, it is characterised in that also include:

Second sending module, when being used for being absent from conflict user side, according to described wave beam forming training result, sends wave beam forming vector to described each user side.