CN101615937B - Multi-antenna transmitting method and multi-antenna transmitting device - Google Patents

Abstract

The invention provides a multi-antenna transmitting method and a multi-antenna transmitting device. The method comprises the following steps: through M antennas of an enhanced base station, receiving uplink reference signals transmitted in turn by UE by adopting N antennas of the UE within continuous N uplink periods of time of the UE; calculating and combining channel estimation corresponding to each of the N uplink periods of time to acquire a channel estimation matrix H corresponding to the M antennas and the N antennas; determining the corresponding relation between downlink ports and the antennas and processing each layer of data to be transmitted according to a precoding weight matrix between the downlink ports and beam forming weights in the downlink ports; and carrying out OFDM modulation of each antenna and transmitting the data to be transmitted. The multi-antenna transmitting method and the multi-antenna transmitting device make use of the symmetrical characteristic of uplink channels and downlink channels in a TDD LTE wireless communication system to realize downlink multi-antenna transmitting through a low-complexity algorithm without adopting a UE feedback beam forming weight index.

Description

A kind of multi-antenna emission method and many antennas emitter

Technical field

The present invention relates to Long Term Evolution (LTE, the Long Term Evolution) wireless communication system of time division duplex (TDD, Time Division Duplex), be specifically related to a kind of multi-antenna emission method and many antennas emitter in this system.

Background technology

In the LTE wireless communication system, use linear spatial domain precoding (Precoding) technology to improve the performance of system usually.Linear spatial domain method for precoding refers to: when there are many transmit antennas in transmitting terminal, can a plurality of data flow be mapped on the many antennas by the pre-encode operation of a linearity.Suppose that number of antennas is a, the data flow number is L, and when number of data streams was 1, when soon 1 data flow was mapped on a root antenna, the linear predictive coding in this spatial domain can be regarded as traditional beam form-endowing method again.Its principle mainly is just to make a plurality of data flow transmit in the spatial sub-channel of quadrature respectively by on the feasible respective orthogonal base that is in channel matrix that transmits of precoding, reduces the phase mutual interference between data flow, thereby improve systematic function.

Traditional down beam shaping refers to that base station (NodeB) side utilizes the strong coherence of channel and the electromagnetic principle of interference between different array elements in the less aerial array of array element distance usually, parameters such as the amplitude-phase that transmits of adaptive each array element of adjustment, feasible mixing transmits and forms with superimposed high-amplitude wave bundle in the particular terminal direction, increase the received signal power of particular terminal, reduce the interference to other users simultaneously.The antenna system that in existing TD-SCDMA, adopts for example.

The main distinction of method for precoding and traditional beamforming algorithm is that traditional beam form-endowing method is to carry out figuration according to the direction of terminal, thereby improves the received signal power of receiving terminal, and the interference that reaches simultaneously other receiving terminals suppresses; And pre-coding matrix generally is not to carry out figuration according to the direction of terminal, but generates according to the demand that reduces inter-beam interference, satisfies the demand of transmitting a plurality of data flow in the space.

Frequency Division Duplexing (FDD) (FDD, Frequency Division Duplex) the many input and output (MIMO of LTE system descending, Mutiple-Input Mutiple-Output) in the scheme, user terminal (UE) generates precoding vector according to the estimation to descending space channel characteristic, and utilizes ascending control channel to feed back to enhanced base station (eNodeB) side.Just owing to consider the problem of feedback information volume, stipulated the feedback weights tabulation under 2 ports and 4 port modes in the LTE agreement, for reducing the feedack amount, UE side actual feedback be index after weights are quantized, eNodeB determines corresponding precoding vector by shining upon in the code book that preserve this locality according to the beam shape-endowing weight value index that receives.

In TDD LTE system, can continue to use the method under the fdd mode, namely be produced by UE and feedback beam shape-endowing weight value index.But, owing to divide according to the time between the up-downgoing of TDD system, the downstream feedback time delay will inevitably be greater than the FDD system, so, if the weights index is to calculate by the UE side to feed back to the eNodeB side again after weights quantize, the then quantization error in this process, the required expense of feedback and feed back required time delay and all will bring adverse influence to the performance of system.

Summary of the invention

Technical problem to be solved by this invention provides a kind of multi-antenna emission method and many antennas emitter, under the situation that does not need UE feedback beam shape-endowing weight value index, utilize uplink and downlink channel symmetry in the TDD LTE wireless communication system, realized descending many antenna emissions by low complexity algorithm.

For solving the problems of the technologies described above, it is as follows to the invention provides scheme:

A kind of multi-antenna emission method is applied in the long evolving system of time division duplex, may further comprise the steps:

A, enhanced base station receive UE adopts N the antenna of this UE to take turns emission in the N continuous of this UE in the individual up period uplink reference signals by M antenna of this base station;

B according to the predetermined value of uplink reference signals and the uplink reference signals that receives, calculate described N each self-corresponding channel estimating of up period, and merging obtains the channel estimate matrix H corresponding with a described M antenna and a described N antenna;

C determines the number L of downlink port according to the order v of H, and with described M antenna mean allocation to each downlink port;

D chooses the element relevant with each downlink port institute antenna distributed from H, construct the channel estimate matrix H of each downlink port correspondence _BF ^l, and calculate the interior beam shape-endowing weight value w of each downlink port _l, l=1 wherein, 2 ..., L;

E is according to H _BF ^lAnd w _l, calculate the precoding weight matrix V between downlink port;

F, data to be launched are mapped as the data to be launched of v layer, utilize precoding weight matrix V that each layer data to be launched are carried out precoding, obtain data after the precoding of each downlink port, and utilize beam shape-endowing weight value in each downlink port, respectively data after the precoding of each downlink port are carried out the wave beam forming weighting, obtain data after the weighting of each downlink port correspondence;

G carries out data divided antenna after the weighting of each downlink port correspondence to launch after the modulating in OFDM.

In the said method, among the described step B, described N each self-corresponding channel estimating of up period is respectively h ₁, h ₂..., h _N-1, h _NThe time, H=[h ₁h ₂H _N] ^T

In the said method, among the described step C, described order v according to H determines that the number L of downlink port comprises: if v=1 or 2, then L=v; Otherwise, L=4.

In the said method, among the described step C, further according to the correlation between antenna type and/or the antenna, described M antenna mean allocation arrived each downlink port.

In the said method, among the described step D, further according to the shape-endowing weight value algorithm based on the signal to noise ratio maximum, calculate described beam shape-endowing weight value w _l

In the said method, described step e specifically comprises:

According to beam shape-endowing weight value w _lChannel estimate matrix H with each downlink port correspondence _BF ^l, re-construct the channel estimate matrix H of all of the port _Precoding, wherein, $H_{\mathrm{Precoding}}=[H_{\mathrm{BF}}^1{\left(w_1\right)}^H{H}_{\mathrm{BF}}^2{\left(w_2\right)}^H\·\·\·H_{\mathrm{BF}}^L{\left(w_L\right)}^H];$

To H _PrecodingCarry out singular value decomposition, with the right singular matrix that obtains as to the precoding weight matrix V between described downlink port.

Said method also comprises: utilize the beam shape-endowing weight value in each downlink port, the downlink reference signal to each downlink port carries out the wave beam forming weighting respectively, obtains the downlink reference signal after the weighting of each downlink port correspondence; And the downlink reference signal divided antenna after the weighting of each downlink port correspondence carried out launching after the OFDM modulation.

In the said method, also comprise among the described step D: whether the order v that judges H equals 1: if, then utilize the beam shape-endowing weight value in the downlink port that data to be launched are carried out the wave beam forming weighting, data divided antenna after the weighting is carried out launching after the OFDM modulation, and process ends; Otherwise, execution in step E.

A kind of many antennas emitter is arranged on the enhanced base station side in the long evolving system of time division duplex, comprising:

The uplink channel estimation unit, be used for M antenna by described base station, receive the uplink reference signals that UE launches in turn at N the antenna of N continuous this UE of employing in the up period of this UE, and according to the predetermined value of uplink reference signals and the uplink reference signals that receives, calculate described N each self-corresponding channel estimating of up period, merging obtains the channel estimate matrix H corresponding with a described M antenna and a described N antenna;

The terminal port antennae map unit is used for determining according to the order v of H the number L of downlink port, and described M antenna mean allocation arrived each downlink port;

The wave beam forming computing unit is used for choosing the element relevant with each downlink port institute antenna distributed from H, constructs the channel estimate matrix H of each downlink port correspondence _BF ^l, and calculate the interior beam shape-endowing weight value w of each downlink port _l, l=1 wherein, 2 ..., L;

The pre-coding matrix computing unit is used for according to H _BF ^lAnd w _l, calculate the precoding weight matrix V between downlink port;

The layering map unit is for the data to be launched that data to be launched are mapped as the v layer;

Precoding unit is used for utilizing precoding weight matrix V that each layer data to be launched are carried out precoding, obtains data after the precoding of each downlink port;

The wave beam forming unit is used for utilizing the beam shape-endowing weight value in each downlink port, respectively data after the precoding of each downlink port is carried out the wave beam forming weighting, obtains data after the weighting of each downlink port correspondence;

The OFDM modulating unit carries out data divided antenna after the weighting of each downlink port correspondence to launch after the OFDM modulation.

In the said apparatus, described terminal port antennae map unit is further used in v=1 or 2, and the number L=v of downlink port is set; When v is worth for other, the number L=4 of downlink port is set.

In the said apparatus, described pre-coding matrix computing unit is further used for according to beam shape-endowing weight value w _lChannel estimate matrix H with each downlink port correspondence _BF ^l, re-construct the channel estimate matrix H of all of the port _Precoding, wherein, $H_{\mathrm{Precoding}}=[H_{\mathrm{BF}}^1{\left(w_1\right)}^H{H}_{\mathrm{BF}}^2{\left(w_2\right)}^H\·\·\·H_{\mathrm{BF}}^L{\left(w_L\right)}^H];$ To H _PrecodingCarry out singular value decomposition, with the right singular matrix that obtains as to the precoding weight matrix V between described downlink port.

In the said apparatus, described wave beam forming unit also is used for utilizing the beam shape-endowing weight value in each downlink port, and the downlink reference signal to each downlink port carries out the wave beam forming weighting respectively, obtains downlink reference signal after the weighting of each downlink port correspondence;

Described OFDM modulating unit also is used for the downlink reference signal divided antenna after the weighting of each downlink port correspondence is carried out launching after the OFDM modulation.

From the above as can be seen, a kind of multi-antenna emission method provided by the invention and many antennas emitter, utilize the characteristics of up-downgoing channel symmetry in the TDD system, when guaranteeing systematic function, thereby avoided utilizing downstream feedback to reduce system load, the systemic loss of energy of having avoided the code book mapping to bring simultaneously.And the present invention adopts many antennas mode of emission in turn according to the situation of existing UE employing single-antenna transmission by UE, when having guaranteed the up-downgoing channel symmetry, does not increase UE equipment complexity.The present invention distributes the antenna mapping relations by self adaptation in TDD LTE system, utilizes the advantage of precoding and wave beam forming, effectively improves descending received power, thereby has improved systematic function.At last, the present invention has realized the descending MIMO scheme of many antennas under the situation that does not increase the reference signal number, and can be according to the mapping relations between the adaptive adjustment port of channel situation and antenna, use pre-coding scheme between the interior wave beam forming of downlink port and downlink port simultaneously, be beneficial to very much Project Realization.

Description of drawings

Fig. 1 is the frame structure schematic diagram of LTE TDD;

Fig. 2 is the flow chart of the method for the descending many antenna emissions of the described realization of the embodiment of the invention;

Fig. 3 is the corresponding relation schematic diagram between a kind of downlink port and the antenna in the embodiment of the invention;

Fig. 4 is the corresponding relation schematic diagram between another kind of downlink port and the antenna in the embodiment of the invention;

Fig. 5 is the corresponding relation schematic diagram between another downlink port and the antenna in the embodiment of the invention;

Fig. 6 is the structural representation of many antennas emitter of eNodeB side in the embodiment of the invention.

Embodiment

Core concept of the present invention is: utilize the TDD system performance, under the situation that the uplink and downlink channel reciprocity exists, the eNodeB side can be utilized fully to the estimated value adaptive configuration antenna of the upstream space characteristic of channel and the mapping relations between port, directly generate downlink precoding weights and the interior beam shape-endowing weight value of port between port, thereby the system's time delay, overhead losses and the quantization error that cause of feedback influence that performance is brought again after can avoiding the UE side to calculate weights quantizing, and introducing wave beam forming, thereby the performance of raising system.The invention will be further described by specific embodiment below in conjunction with accompanying drawing.

At first introduce the frame structure of LTE TDD.According to third generation partner program (3GPP) TS 36.211V8.1.0 agreement, frame structure in the TDD LTE system as shown in Figure 1, in this frame structure, the radio frames of a 10ms is divided into two fields, the time slot that it is 0.5ms that each field is divided into 10 length (coding from 0 to 9), two time slots are formed the subframe that length is 1ms, comprise 5 subframes (coding from 0 to 4) in the field.Subframe 1 comprises 3 special time slots: descending pilot frequency time slot (DwPTS, DownlinkPilot Time Slot), protection be (GP) and uplink pilot time slot (UpPTS, Uplink Pilot TimeSlot) at interval.In first field of above-mentioned frame structure, subframe 0 and DwPTS always are used for downlink transfer, and subframe 2 and UpPTS always are used for to uplink, and other subframe can be the uplink and downlink transmission according to concrete environment configurations.According to concrete environment, second field of above-mentioned frame structure can be identical with first sub-frame configuration, also last 3 subframes of this second field all can be configured to for downlink transfer.

Introduce the concept of up period herein.The described up period is the time cycle that is used for uplink according to the 3GPP protocol definition, and concrete can be each subframe that is used for uplink in the above-mentioned frame structure, can also be uplink pilot time slot UpPTS.In the TDD system, UE is distributing to transmitting for the subframe of uplink and the time period of UpPTS of oneself.For UE, the N continuous of this a UE up period refers to not exist other the subframe and the UpPTS that are used for this UE uplink between this N up period.Here, may there be subframe or DwPTS for downlink transfer between up period in this N continuous.

Please refer to Fig. 2, the described method that realizes descending many antenna emissions in TDD LTE wireless communication system of present embodiment specifically may further comprise the steps:

Step 21, UE adopts N the antenna of this UE to launch uplink reference signals in turn in the N continuous of this UE in the up period.Consider the problems such as equipment complexity of UE, the UE end selects an antenna to launch in each up period in the LTE system of present embodiment, adopts all antennas to receive simultaneously during reception.In order to guarantee the symmetry of up-downgoing channel in the TDD system, therefore, require UE in the up period its N transmit antennas to be taked the method for emission in turn in its N continuous here.

Step 22, the eNodeB in the LTE system receives the reference signal that UE launches by M the antenna of this eNodeB, according to the predetermined value of known reference signal and the reference signal that receives, calculates the channel estimating of current up period correspondence.Here, concrete channel estimation method can utilize various existing channel estimation methods of the prior art to calculate, for example least square (LS, Least Square) and least mean-square error (MMSE, Minimum Mean Square Error) algorithm etc.Wherein, be example with the LS algorithm, suppose that known reference signal is s _RS, the reference signal that receives is r _RS, then this moment channel estimating h _NCan be obtained by formula (1):

h _N＝r _RS/s _RS (1)

Step 23 is supposed the current N of being a up period, with continuous (N-1) each the self-corresponding channel estimating h of individual up period that received before the current up period ₁, h ₂..., h _N-1Channel estimating h with the current up period _NMerge and obtain the channel estimate matrix H=[h corresponding with all antennas ₁h ₂H _N] ^THere, described all antennas comprise described M antenna of eNodeB and described N antenna of UE side, and the size of matrix H is N * M.

Step 24 calculates the order of H, is shown below:

v＝rank(H) (2)

Wherein v is the order of channel estimate matrix H, also represents the number of plies of emission data simultaneously; Select downlink port number L according to the size of v, following calculation criterion arranged:

$L=\left\{\begin{array}{cc}1,& v=1\\ 2,& v=2\\ 4,& \mathrm{else}\end{array}\right.----\left(3\right)$

If i.e.: v=1 or 2, then L=v; Otherwise, L=4.

Described M antenna mean allocation to each downlink port, according to the number of L, can be obtained the number of antennas in each downlink port $K=\frac{M}{L}.$ Here, specifically which antenna is configured to same downlink port, can be configured according to the correlation between antenna type and/or the antenna.

For example, be example with the number of antennas M=8 of eNodeB side, according to the concrete configuration mode of different channel sequence just like three kinds of antennas and the port of Fig. 3～shown in Figure 5.Wherein, among Fig. 3, L=1, K=8, all 8 antennas all are configured to this downlink port 0; Among Fig. 4, L=2, K=4, per 4 antennas are configured to a downlink port; And among Fig. 5, L=4, K=2, per 2 antennas are configured to a downlink port.Here, common M is configured to 4 integral multiple.When antenna number M can the rest may be inferred during for other values obtains.

Step 25 is according to channel estimate matrix H=[h ₁h ₂H _N] ^T, obtaining all antenna corresponding channel estimation value in each downlink port respectively, the matrix that re-constructs into each downlink port correspondence is H _BF ^l, l=1,2 ..., L, its size is N * K.Concrete, from H, choose the element relevant with each downlink port institute antenna distributed, construct the channel estimate matrix H of each downlink port correspondence _BF ^lAccording to H _BF ^l, the channel correlation matrix that calculates each downlink port correspondence is:

$R^l={\left(H_{\mathrm{BF}}^l\right)}^{*}\×H_{\mathrm{BF}}^l---\left(5\right)$

Respectively to L channel correlation matrix R ^l, calculate the beam shape-endowing weight value w of all antennas in each downlink port _l, l=1,2 ..., L, as follows based on the shape-endowing weight value calculation criterion of signal to noise ratio maximum:

$w_l=\underset{w_l}{\arg }\left(\max \left(\frac{{\left(w_l\right)}^{*}\·R^l\·w_l}{{\left(w_l\right)}^{*}\·R_N\·w_l}\right)\right)---\left(6\right)$

Wherein, (w _l) ^*Expression w _lConjugate transpose, R _NThe channel correlation matrix of expression noise, beam shape-endowing weight value w _lSize be K * 1;

Step 26 when the order v of channel estimate matrix H＞1, needs to calculate the precoding weight matrix V between downlink port.According to channel estimate matrix H=[h ₁h ₂H _N] ^T, utilize each downlink port to calculate shape-endowing weight value w _l, l=1,2 ..., L is respectively with the channel estimation value H of each port _BF ^l, l=1,2 ..., L multiplies each other, and re-constructs the channel estimate matrix of port $H_{\mathrm{Precoding}}=[H_{\mathrm{BF}}^1{\left(w_1\right)}^H{H}_{\mathrm{BF}}^2{\left(w_2\right)}^H\·\·\·H_{\mathrm{BF}}^L{\left(w_L\right)}^H],$ Its size is N * L, to H _PrecodingCarry out singular value decomposition according to following formula, can get:

H _Precoding＝UDV ^H (4)

Wherein, the right singular matrix unitary matrix V that obtains is the precoding weight matrix V between downlink port, and the size of V is L * v, enters step 27 then;

When the order v=1 of channel estimate matrix, then utilize the beam shape-endowing weight value in the downlink port that data to be launched are directly carried out the wave beam forming weighting, then, data divided antenna after the weighting is carried out launching after the OFDM modulation, and process ends.

Step 27, data to be launched are mapped as the data to be launched of v layer, utilize precoding weight matrix V that each layer data to be launched are carried out precoding, obtain data after the precoding of each downlink port, beam shape-endowing weight value in each downlink port of recycling, respectively data after the precoding of each downlink port are carried out the wave beam forming weighting, obtain data after the weighting of each downlink port correspondence.

For example, suppose that certain moment physical down link sharing channel (PDSCH, Physical DownlinkShared Channel) emission data is d _s, size is v * 1, v is the emission number of data layers; The precoding weight matrix is V between its corresponding port of institute _s, size is L * v, s=1 wherein, and 2 ..., S represents different subcarrier sequence number in the UE bandwidth, then data are after the precoding:

${\tilde{x}}_s=V_s{d}_s---\left(7\right)$

Size be L * 1, the emission data of a corresponding L downlink port respectively.And then respectively the data in each downlink port are carried out the wave beam forming weighting, obtain the weighting of each downlink port correspondence after data be:

$x_s^l={\left(w_{l,s}\right)}^H{\tilde{x}}_s\left(l\right)---\left(8\right)$

x _s ^lSize is K * 1.Wherein, w _{L, s}The beam shape-endowing weight value of representing the subcarrier s of l downlink port, its size is K * 1; (w _{L, s}) ^HExpression w _{L, s}Conjugation; Represent the data on the subcarrier s of l downlink port, its size is 1 * 1.Then $x_s={[x_s^1{x}_s^2\·\·\·x_s^L]}^T$ The data of all antennas on each subcarrier after expression process precoding and the wave beam forming weighting, size is M * 1.

For the downlink reference signal of each downlink port, also be to utilize the beam shape-endowing weight value in each downlink port to carry out the wave beam forming weighting, obtain the downlink reference signal after the weighting.

Step 28 is carried out the OFDM modulation with data divided antenna after the weighting, namely carries out the OFDM modulation respectively at each antenna.Wherein the transmitting terminal downlink data of m antenna are:

X(m)＝IFFT([x ₁(m)x ₂(m)…x _S(m)] ^T) (9)

In the following formula, s=1,2 ..., S, m=1,2 ..., M.

At last, after being added Cyclic Prefix operations such as (CP, Cyclic Prefix), these emission data carry out downlink.

For downlink reference signal, same also is to launch after the OFDM modulation carrying out through the downlink reference signal divided antenna after the wave beam forming weighting.Concrete can be, the downlink reference signal after data after the weighting and the weighting is merged into one road signal, goes here and there then and transform to obtain multi-path parallel signal; After this multi-path parallel signal carried out inverse fast fourier transform IFFT and add CP handling, launch by antenna.

From the above as can be seen, the described multi-antenna emission method of present embodiment is compared with the method for the descending MIMO of realization in the existing FDD LTE system, and present embodiment has following advantage:

1) adopts the situation of single-antenna transmission according to existing UE, on the basis that does not increase UE equipment complexity, take turns radiation pattern by many antennas and guaranteed the up-downgoing channel symmetry, be beneficial to Project Realization;

2) taken full advantage of the up-downgoing channel symmetry characteristic of TDD system itself.When guaranteeing the precoding performance, avoid utilizing downstream feedback, thereby reduced the system feedback load, and the systemic loss of energy of having avoided the code book mapping to bring.

3) realized downlink scheme under many antennas situation.Self adaptation is distributed the antenna mapping relations in TDD LTE system, utilizes the advantage of precoding and wave beam forming, effectively improves descending received power, has improved systematic function.

4) present embodiment has been realized the descending MIMO scheme of many antennas under the situation that does not increase the reference signal number, and can be according to the mapping relations between the adaptive adjustment port of channel situation and antenna, use pre-coding scheme between the interior wave beam forming of downlink port and downlink port simultaneously, be beneficial to very much Project Realization.

For realizing above-mentioned multi-antenna emission method, present embodiment also provides a kind of transceiver system of realizing the MIMO scheme under LTE tdd frame structure.The described transceiver system of present embodiment is provided with up transmitter unit in the UE side, is used for the reference signal that adopts N the antenna of this UE to launch in turn in the individual up period in the N continuous of this UE.The described transceiver system of present embodiment is provided with many antennas emitter in enhanced base station eNodeB side, and as shown in Figure 6, this many antennas emitter specifically comprises:

The uplink channel estimation unit, be used for M antenna by described base station, receive the reference signal that UE launches in turn at N the antenna of N continuous this UE of employing in the up period of this UE, and according to the predetermined value of reference signal and the reference signal that receives, calculate described N each self-corresponding channel estimating of up period, merging obtains the channel estimate matrix H corresponding with a described M antenna and a described N antenna;

The terminal port antennae map unit is used for determining according to the order v of H the number L of downlink port, and described M antenna mean allocation arrived each downlink port;

The wave beam forming computing unit is used for choosing the element relevant with each downlink port institute antenna distributed from H, constructs the channel estimate matrix H of each downlink port correspondence _BF ^l, and calculate the interior beam shape-endowing weight value w of each downlink port _l, l=1 wherein, 2 ..., L;

The pre-coding matrix computing unit is used for according to H _BF ^lAnd w _l, calculate the precoding weight matrix V between downlink port;

The layering map unit is for the data to be launched that data to be launched are mapped as the v layer;

Precoding unit is used for utilizing precoding weight matrix V that each layer data to be launched are carried out precoding, obtains data after the precoding of each downlink port;

The wave beam forming unit is used for utilizing the beam shape-endowing weight value in each downlink port, respectively data after the precoding of each downlink port is carried out the wave beam forming weighting, obtains data after the weighting of each downlink port correspondence;

The OFDM modulating unit carries out data divided antenna after the weighting of each downlink port correspondence to launch after the OFDM modulation.

Here, described terminal port antennae map unit can also be further used in v=1 or 2, and the number L=v of downlink port is set; When v is worth for other, the number L=4 of downlink port is set.

Here, described pre-coding matrix computing unit is further used for according to beam shape-endowing weight value w _lChannel estimate matrix H with each downlink port correspondence _BF ^l, can also re-construct the channel estimate matrix H of all of the port _Precoding, wherein, $H_{\mathrm{Precoding}}=[H_{\mathrm{BF}}^1{\left(w_1\right)}^H{H}_{\mathrm{BF}}^2{\left(w_2\right)}^H\·\·\·H_{\mathrm{BF}}^L{\left(w_L\right)}^H];$ To H _PrecodingCarry out singular value decomposition, with the right singular matrix that obtains as to the precoding weight matrix V between described downlink port.

Here, described wave beam forming unit also is used for utilizing the beam shape-endowing weight value in each downlink port, and the downlink reference signal to each downlink port carries out the wave beam forming weighting respectively, obtains downlink reference signal after the weighting of each downlink port correspondence; Described OFDM modulating unit can also be further used for the downlink reference signal divided antenna after the weighting is carried out launching after the OFDM modulation.Concrete, can be by the MUX unit with weighting after downlink reference signal addition after the weighting of data and each downlink port be merged into one road signal, go here and there then and transform and obtain multi-path parallel signal; After this multi-path parallel signal carried out inverse fast fourier transform IFFT and add CP handling, launch by antenna.

In sum, the described multi-antenna emission method of the embodiment of the invention and many antennas emitter utilize up-downgoing channel symmetry in the TDD LTE wireless communication system, do not take to have realized under the situation of UE closed loop feedback beam shape-endowing weight value index many antennas emissions.

Should be noted that at last, above embodiment is only unrestricted in order to technical scheme of the present invention to be described, those of ordinary skill in the art is to be understood that, can make amendment or be equal to replacement technical scheme of the present invention, and not breaking away from the spiritual scope of technical solution of the present invention, it all should be encompassed in the middle of the claim scope of the present invention.

Claims (10)

1. a multi-antenna emission method is applied in the long evolving system of time division duplex, it is characterized in that, may further comprise the steps:

A, enhanced base station receive UE adopts N the antenna of this UE to take turns emission in the N continuous of this UE in the individual up period uplink reference signals by M antenna of this base station;

B, the uplink reference signals that receives according to the predetermined value of uplink reference signals and each up period, calculate described N each self-corresponding channel estimating of up period respectively, and merging obtains the channel estimate matrix H corresponding with a described M antenna and a described N antenna;

C determines the number L of downlink port according to the order v of H, and with described M antenna mean allocation to each downlink port, wherein, described order v according to H determines that the number L of downlink port comprises: if v=1 or 2, then L=v; Otherwise, L=4;

D chooses the element relevant with each downlink port institute antenna distributed from H, construct the channel estimate matrix of each downlink port correspondence

And calculate beam shape-endowing weight value w in each downlink port _l, l=1 wherein, 2 ..., L;

E, according to

And w _l, calculate the precoding weight matrix V between downlink port;

F, data to be launched are mapped as the data to be launched of v layer, utilize precoding weight matrix V that each layer data to be launched are carried out precoding, obtain data after the precoding of each downlink port, and utilize beam shape-endowing weight value in each downlink port, respectively data after the precoding of each downlink port are carried out the wave beam forming weighting, obtain data after the weighting of each downlink port correspondence;

G carries out data divided antenna after the weighting of each downlink port correspondence to launch after the modulating in OFDM.

2. the method for claim 1 is characterized in that, among the described step B, is respectively h described N each self-corresponding channel estimating of up period ₁, h ₂..., h _N-1, h _NThe time, described channel estimate matrix H=[h ₁h ₂H _N] ^T

3. the method for claim 1 is characterized in that, among the described step C, further according to the correlation between antenna type and/or the antenna, described M antenna mean allocation is arrived each downlink port.

4. the method for claim 1 is characterized in that, among the described step D, further based on the shape-endowing weight value algorithm of signal to noise ratio maximum, calculates described beam shape-endowing weight value w _l

5. the method for claim 1 is characterized in that, described step e specifically comprises:

According to beam shape-endowing weight value w _lChannel estimate matrix with each downlink port correspondence Re-construct the channel estimate matrix H of all downlink ports _Precoding, wherein,

$H_{\mathrm{Precoding}}=\left[\begin{array}{cccc}{H_{\mathrm{BF}}^1\left(w_1\right)}^H& {H_{\mathrm{BF}}^2\left(w_2\right)}^H& \·\·\·& {H_{\mathrm{BF}}^L\left(w_L\right)}^H\end{array}\right];$

To H _PrecodingCarry out singular value decomposition, with the right singular matrix that obtains as to the precoding weight matrix V between described downlink port.

6. the method for claim 1 is characterized in that, described method also comprises:

Utilize the beam shape-endowing weight value in each downlink port, the downlink reference signal to each downlink port carries out the wave beam forming weighting respectively, obtains the downlink reference signal after the weighting of each downlink port correspondence; And the downlink reference signal divided antenna after the weighting of each downlink port correspondence carried out launching after the OFDM modulation.

7. the method for claim 1, it is characterized in that, also comprise among the described step D: whether the order v that judges H equals 1: if, then utilize the beam shape-endowing weight value in the downlink port that data to be launched are carried out the wave beam forming weighting, and data divided antenna after the weighting carried out launching after the OFDM modulation, and process ends; Otherwise, execution in step E.

8. antenna emitter more than a kind is arranged on the enhanced base station side in the long evolving system of time division duplex, it is characterized in that, comprising:

The uplink channel estimation unit, be used for M antenna by described base station, receive the uplink reference signals that UE launches in turn at N the antenna of N continuous this UE of employing in the up period of this UE, and the uplink reference signals that receives according to the predetermined value of uplink reference signals and each up period, calculate described N each self-corresponding channel estimating of up period respectively, merging obtains the channel estimate matrix H corresponding with a described M antenna and a described N antenna;

The terminal port antennae map unit is used for determining according to the order v of H the number L of downlink port, and described M antenna mean allocation arrived each downlink port, and wherein, described terminal port antennae map unit is further used in v=1 or 2, and the number L=v of downlink port is set; When v is worth for other, the number L=4 of downlink port is set;

The wave beam forming computing unit is used for choosing the element relevant with each downlink port institute antenna distributed from H, constructs the channel estimate matrix of each downlink port correspondence

And calculate beam shape-endowing weight value w in each downlink port _l, l=1 wherein, 2 ..., L;

The pre-coding matrix computing unit is used for basis

And w _l, calculate the precoding weight matrix V between downlink port;

The layering map unit is for the data to be launched that data to be launched are mapped as the v layer;

Precoding unit is used for utilizing precoding weight matrix V that each layer data to be launched are carried out precoding, obtains data after the precoding of each downlink port;

The wave beam forming unit is used for utilizing the beam shape-endowing weight value in each downlink port, respectively data after the precoding of each downlink port is carried out the wave beam forming weighting, obtains data after the weighting of each downlink port correspondence;

The OFDM modulating unit carries out data divided antenna after the weighting of each downlink port correspondence to launch after the OFDM modulation.

9. device as claimed in claim 8 is characterized in that,

Described pre-coding matrix computing unit is further used for according to beam shape-endowing weight value w _lChannel estimate matrix with each downlink port correspondence Re-construct the channel estimate matrix H of all of the port _Precoding, wherein, $H_{\mathrm{Precoding}}=\left[\begin{array}{cccc}{H_{\mathrm{BF}}^1\left(w_1\right)}^H& {H_{\mathrm{BF}}^2\left(w_2\right)}^H& \·\·\·& {H_{\mathrm{BF}}^L\left(w_L\right)}^H\end{array}\right];$ To H _PrecodingCarry out singular value decomposition, with the right singular matrix that obtains as to the precoding weight matrix V between described downlink port.

10. device as claimed in claim 8 is characterized in that,

Described wave beam forming unit also is used for utilizing the beam shape-endowing weight value in each downlink port, and the downlink reference signal to each downlink port carries out the wave beam forming weighting respectively, obtains downlink reference signal after the weighting of each downlink port correspondence;

Described OFDM modulating unit also is used for the downlink reference signal divided antenna after the weighting of each downlink port correspondence is carried out launching after the OFDM modulation.

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