CN102891739A - Method and device for multi-point cooperative precoding based on codebook - Google Patents

Abstract

The invention discloses a method and a device for multi-point cooperative precoding based on a codebook, which are applied to a wireless communication system. The method comprises the following steps that: local cell users of a service base station and local cell users of a cooperative base station estimate information channels respectively; the local cell users of the service base station/the cooperative base station estimate expectation sub precoding code words/leakage sub precoding code words according to information channel estimation results, and feeding back corresponding precoding matrix indexes; the service base station interacts the information of the information channels with the cooperative base station, wherein the information comprises the precoding matrix indexes corresponding to the leakage sub precoding code words; the service base station constructs precoding code words according to the precoding matrix indexes fed back by the local cell users and the precoding matrix indexes interacted by the cooperative base station; and the service base station precodes transmission signals according to the precoding code words acquired by estimation. Due to the application of the precoding implementation manners, signal interference noise ratio can be acquired as higher as possible at expectation user receiving ends, and the interference is suppressed in all interference directions.

Description

A kind of multipoint cooperative precoding implementation method and device based on code book

Technical field

The present invention relates to wireless communication field, relate in particular to a kind of multipoint cooperative precoding implementation method and device based on code book.

Background technology

At 3Gpp Long Term Evolution (Long Term Evolution-Advanced, LTE-A) in the system, coordinated multipoint transmission (Coordinated Multiple Point, CoMP) technology solves presence of intercell interference as one, to improve the technology of cell edge and cell spectrum efficient, carried out comparatively deep research at LTE R10, but because time relationship, the design of a lot of technology is simplified.Finally continue in R10 the research except the design of the channel condition information pilot tone of compatible CoMP, all the other technology all be pulled to R11 and after study in the version.

Mutual by mobile subscriber's channel information between adjacent base station, adjacent base station takes certain interference avoidance strategy or a plurality of base station that the mobile subscriber is carried out joint transmission to disturbed user, mainly for Cell Edge User.Its objective is the interference that reduces edge customer, improve throughput and the spectrum utilization efficiency of cell edge data.CoMP uses schematic diagram as shown in Figure 1, and there are serving BS, cooperative base station in the base station.Wherein, H ₁₁The expression service cell eNB ₁To this community user UE ₁Channel, H ₁₂The expression service cell eNB ₁To adjacent cell user UE ₂Channel.Equally, H ₂₂Expression cooperation cell eNB ₂To this community user UE ₂Channel, H ₂₁Expression cooperation cell eNB ₂To adjacent cell user UE ₁Channel.

Usually, the CoMP uplink feedback adopts the form of partial feedback, i.e. the UE channel matrix that not exclusively feeds back the channel matrix of this residential quarter and not exclusively feed back adjacent cell, but feedback fraction channel information.Specifically, UE feeds back the pre-coding matrix index (Precoding Matrix Indicator, PMI) of this cell channel, and UE also feeds back the poorest precoding index (Worst Companion Indicator, WCI) to adjacent cell channel.

In patent CN200910273408.5 (a kind of inter-cell interference restraint method based on channel F norm projection scheduling), a kind of inter-cell interference restraint method based on channel F norm projection scheduling is provided, under the scene of many residential quarters multiuser MIMO, a plurality of base stations are by the central controller co-ordination on upper strata, by CoMP channel F norm projection user scheduling and piece diagonal angle precoding interference mitigation technology are combined, utilize the channel F norm projection user to dispatch capacity on the one hand, utilize on the other hand many block of cells diagonal angle to turn precoding processing into, reach on the basis of the availability of frequency spectrum that improves cell edge and disturb the purpose that suppresses.But the method complexity is higher, is difficult for realizing.

In patent CN201010172626.2 (a kind of method, system and portable terminal of realizing coordinated multipoint transmission), the method of a kind of CoMP of realization is provided, and the transmission of adjacent cell evolved base station provides the downlink precoding reference signal of the beam shaping matrix that self adopts; The beam shaping matrix that portable terminal adopts according to the adjacent cell base station obtains optimum pre-coding matrix index; Terminal obtains the channel quality identification (CQI) of spatial domain Inter-Cell Interference Coordination, and optimum PMI and the CQI that will obtain feed back to base station in service sector; The CQI value of base station in service sector reference terminal spatial domain Inter-Cell Interference Coordination is dispatched, utilize optimum PMI to send the signal of the optimum precoding of process to passing through the method, can realize the CoMP of terminal spatial domain Inter-Cell Interference Coordination, the code book optimizing mode that the method adopts is loaded down with trivial details.

Therefore, be necessary to seek high accuracy, and succinct practical CoMP precoding implementation method.

Summary of the invention

The object of the present invention is to provide a kind of CoMP precoding implementation method and device based on code book, improve the Signal to Interference plus Noise Ratio that the desired user receiving terminal obtains, be suppressed at simultaneously the interference on each interference radiating way, reduce implementation complexity.

The objective of the invention is to be achieved through the following technical solutions.

A kind of multipoint cooperative precoding implementation method based on code book is applied to wireless communication system, may further comprise the steps:

This community user of this community user of serving BS and cooperative base station carries out respectively channel estimating;

According to described channel estimation results, this community user of serving BS/cooperative base station is estimated the sub-pre-encoding codeword of expectation, to serving BS/pre-coding matrix index corresponding to cooperative base station feedback; And estimate to reveal sub-pre-encoding codeword, to serving BS/pre-coding matrix index corresponding to cooperative base station feedback;

Serving BS and cooperative base station interactive channel information, this channel information comprise the pre-coding matrix index corresponding to the sub-pre-encoding codeword of leakage of this community user feedback;

The pre-coding matrix index structure pre-encoding codeword that serving BS comes alternately according to pre-coding matrix index and the cooperative base station of this community user feedback;

Serving BS is according to estimating that the pre-encoding codeword that obtains carries out precoding processing to transmitting.

Preferably, the process of described channel estimating comprises:

In the serving BS side, this community user estimate with this serving BS between channel matrix H reach and cooperative base station between channel matrix H;

In the cooperative base station side, this community user estimate with this cooperative base station between channel matrix H reach and serving BS between channel matrix H.

Preferably, this community user of described serving BS/cooperative base station estimates that the method for the sub-pre-encoding codeword of expectation is:

In the serving BS side, this community user calculates first the sub-pre-encoding codeword of accurate expectation, then chooses code word in the code book of precoding, the code word w in the traversal code book _i, respectively with the sub-pre-encoding codeword of accurate expectation

Each row do inner product with each row of pre-encoding codeword of the corresponding row columns of precoding codebook, inner product module value maximum be the sub-pre-encoding codeword W of expectation; In like manner, in cooperative base station one side, calculate the sub-pre-encoding codeword W of expectation.

Preferably, in the serving BS side, this community user basis

Calculate the sub-pre-encoding codeword of accurate expectation

Described μ is normalization factor, and I is unit matrix, and H is the channel matrix between this community user and serving BS.

Preferably, this community user of described serving BS/cooperative base station estimates that the method for revealing sub-pre-encoding codeword is:

In the serving BS side, this community user calculates first the sub-pre-encoding codeword of accurate leakage, then chooses code word in the code book of precoding, the code word w in the traversal code book _i, do inner product with each row of the sub-pre-encoding codeword of accurate leakage with each row of pre-encoding codeword of the corresponding row columns of precoding codebook respectively, sub-pre-encoding codeword is leaked in being of inner product module value minimum; In like manner, in the cooperative base station side, calculate and reveal sub-pre-encoding codeword.

Preferably, in the serving BS side, this community user basis

Calculate the sub-pre-encoding codeword of accurate leakage Described H is this community user of cooperative base station and the channel matrix between serving BS.

Preferably, the method for described serving BS structure pre-encoding codeword is:

Serving BS is selected the sub-pre-encoding codeword of corresponding expectation according to the pre-coding matrix index of this community user feedback, select the corresponding sub-pre-encoding codeword of revealing according to the pre-coding matrix index that cooperative base station is come alternately, to reveal again sub-pre-encoding codeword and be mapped on the expectation pre-encoding codeword plane of opening, with the mapping vector of this moment as pre-encoding codeword.

A kind of multipoint cooperative precoding implement device based on code book comprises:

Channel estimation module is located at each end side, be used for estimating current community user with reach for the channel matrix between the serving BS of its service and cooperative base station between channel matrix;

Pre-encoding codeword is estimated feedback module, be located at each end side, be connected with channel estimation module, be used for expecting sub-pre-encoding codeword and revealing sub-pre-encoding codeword according to the output estimation of channel estimation module, and feed back corresponding pre-coding matrix index to its serving BS;

The channel information interactive module is located at base station side, is used for realizing interactive channel information between current base station and other base stations, and this channel information comprises pre-coding matrix index corresponding to the sub-pre-encoding codeword of described leakage;

The pre-encoding codeword constructing module is located at base station side, is used for pre-coding matrix index and current base station and the mutual next pre-coding matrix index generation of cooperative base station pre-encoding codeword according to the community user feedback of current base station;

The precoding processing module is located at base station side, is connected with structure pre-encoding codeword module, is used for carrying out precoding processing to transmitting according to the pre-encoding codeword that generates.

Preferably, described pre-encoding codeword estimation feedback module comprises the sub-pre-encoding codeword estimation feedback unit of expectation and reveals sub-pre-encoding codeword estimation feedback unit, is respectively applied to expect sub-pre-encoding codeword and the sub-pre-encoding codeword of leakage and feed back corresponding pre-coding matrix index to serving BS according to described channel matrices estimation.

Compared with prior art, the embodiment of the invention has following beneficial effect:

By the present invention, when the LTE-Advanced system carries out the CoMP precoding, serving BS can be according to the pre-coding matrix index selecting period shop sign in the form of a streamer pre-encoding codeword of this community user feedback, select to leak sub-pre-encoding codeword by the pre-coding matrix index that adjacent cell is come alternately, then will leak sub-pre-encoding codeword DUAL PROBLEMS OF VECTOR MAPPING expires on the plane that the shop sign in the form of a streamer pre-encoding codeword opens, and incite somebody to action mapping vector at this moment as pre-encoding codeword, the pre-encoding codeword equivalence that will transmit to the user like this is the form of 2 sub-precodings, sub-precoding forming energy on the desired user direction is assembled, another sub-precoding then forms zero at each interference radiating way and falls into, thereby obtain high as far as possible Signal to Interference plus Noise Ratio at the desired user receiving terminal, suppress to disturb at each interference radiating way simultaneously, and implementation method simply is easy to realize.

Description of drawings

Accompanying drawing described herein is used to provide a further understanding of the present invention, consists of a part of the present invention, and illustrative examples of the present invention and explanation thereof are used for explaining the present invention, do not consist of improper restriction of the present invention.In the accompanying drawings:

Fig. 1 is that the two residential quarter two users that the present invention is based on the CoMP precoding of code book use schematic diagram;

Fig. 2 is the flow chart that the present invention is based on the CoMP precoding implementation method of code book;

Fig. 3 is that the CoMP precoding based on code book of the present invention realizes design sketch;

Fig. 4 is the structured flowchart of the CoMP precoding implement device based on code book of the present invention.

Embodiment

The present invention is in the CoMP precoding, when considering that simultaneously the precoding gain of this community user is larger, also take into account adjacent cell with the zero leakage of time-frequency resource user, according to channel information, when the structure pre-encoding codeword, to be expectation pre-encoding codeword and the projected forms of leaking pre-encoding codeword to the precoding processing equivalence that the user transmits, expectation precoding forming energy on the desired user direction converges, leak precoding and then form zero leakage at each interference radiating way, thereby obtain high as far as possible Signal to Interference plus Noise Ratio at the desired user receiving terminal, suppress to disturb at each interference radiating way simultaneously.

In order to make technical problem to be solved by this invention, technical scheme and beneficial effect clearer, clear, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, is not intended to limit the present invention.

Embodiment of the method

This embodiment provides CoMP precoding implementation method, wherein eNB under two cell scenario ₁, eNB ₂Number of transmit antennas be 4, UE ₁, UE ₂Reception antenna is 2, and the number of plies of each UE is 2, as shown in Figure 2, comprises the steps:

As described in step 201, estimate base station eNB ₁With this community user UE ₁Between channel matrix $H_{11}=\left[\begin{array}{cccc}{h}_{\mathrm{11,11}}& h_{\mathrm{11,12}}& h_{\mathrm{11,13}}& h_{\mathrm{11,14}}\\ h_{\mathrm{11,21}}& h_{\mathrm{11,22}}& h_{\mathrm{11,23}}& h_{\mathrm{11,24}}\end{array}\right],$ And base station eNB ₁With adjacent cell user UE ₂Between channel matrix $H_{12}=\left[\begin{array}{cccc}{h}_{\mathrm{12,11}}& h_{\mathrm{12,12}}& h_{\mathrm{12,13}}& h_{\mathrm{12,14}}\\ h_{\mathrm{12,21}}& h_{\mathrm{12,22}}& h_{\mathrm{12,23}}& h_{\mathrm{12,24}}\end{array}\right].$

To cooperation cell eNB ₂, estimate cooperation cell eNB ₂With this community user UE ₂Between channel matrix H ₂₂And cooperation cell eNB ₂With adjacent cell user UE ₁Between channel matrix H ₂₁

As described in step 202, estimate the expectation pre-encoding codeword, at UE ₁Side, according to

Might as well establish μ=1, the order of supposing channel is 2, then can remember ${\tilde{W}}_{11}=\left[\begin{array}{cc}1& 1\\ -1& 1\\ {\mathrm{sg}}_{31}& {\mathrm{sg}}_{32}\\ {\mathrm{sg}}_{41}& {\mathrm{sg}}_{42}\end{array}\right],$ Following formula can be written as:

$H_{11}\·\left[\begin{array}{cc}1& 1\\ -1& 1\\ {\mathrm{sg}}_{31}& {\mathrm{sg}}_{32}\\ {\mathrm{sg}}_{41}& {\mathrm{sg}}_{42}\end{array}\right]=\left[\begin{array}{cc}1& 0\\ 0& 1\end{array}\right]---\left(1\right)$

(1) formula of finding the solution obtains:

${\mathrm{sg}}_{31}=\frac{1-(h_{\mathrm{11,11}}-h_{\mathrm{11,12}})+(h_{\mathrm{11,21}}-h_{\mathrm{11,22}})\×\frac{h_{\mathrm{11,14}}}{h_{\mathrm{11,24}}}}{h_{\mathrm{11,13}}-h_{\mathrm{11,23}}\×\frac{h_{11,14}}{h_{\mathrm{11,24}}}}$

${\mathrm{sg}}_{41}=\frac{1-(h_{\mathrm{11,11}}-h_{\mathrm{11,12}})+(h_{\mathrm{11,21}}-h_{\mathrm{11,22}})\×\frac{h_{\mathrm{11,13}}}{h_{\mathrm{11,23}}}}{h_{\mathrm{11,14}}-h_{11,24}\×\frac{h_{\mathrm{11,13}}}{h_{\mathrm{11,23}}}}$

${\mathrm{sg}}_{32}=\frac{1-({\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{11,21}}+h_{\mathrm{11,22}})+(h_{\mathrm{11,11}}+h_{\mathrm{11,12}})\&times;\frac{h_{\mathrm{11,24}}}{h_{\mathrm{11,14}}}}{h_{\mathrm{11,23}}-h_{\mathrm{11,13}}\&times;\frac{h_{\mathrm{11,24}}}{h_{\mathrm{11,14}}}}$

${\mathrm{sg}}_{42}=\frac{1-({\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{11,21}}+h_{\mathrm{11,22}})+(h_{\mathrm{11,11}}+h_{\mathrm{11,12}})\&times;\frac{h_{\mathrm{11,23}}}{h_{\mathrm{11,13}}}}{h_{\mathrm{11,24}}-h_{\mathrm{11,14}}\&times;\frac{h_{\mathrm{11,23}}}{h_{\mathrm{11,13}}}}$

Thereby accurately expected sub-pre-encoding codeword

Further, in the code book of precoding, choose code word, the code word w in the traversal code book _i(wherein i is the code word number in the corresponding code book) is respectively with the sub-pre-encoding codeword of accurate expectation

Each row do inner product with each row of pre-encoding codeword of the corresponding row columns of precoding codebook, inner product module value maximum be the sub-pre-encoding codeword of expectation

$W_{11}=\underset{i}{\max }\left|\mathrm{dot}({\tilde{W}}_{11},w_i)\right|$

Wherein the inner product operator is asked in dot () expression, | | modular operator is asked in expression,

I inner product module value the maximum in the code word chosen in expression, and the codeword selection of corresponding inner product maximum schedules to last shop sign in the form of a streamer pre-encoding codeword W ₁₁, the pre-encoding codeword index of this moment is PMI ₁₁, UE ₁To this cell base station eNB ₁Feedback PMI ₁₁

Similar, at UE ₂Side obtains expecting sub-pre-encoding codeword W ₂₂:

$W_{22}=\underset{i}{\max }\left|\mathrm{dot}({\tilde{W}}_{22},w_i)\right|$

Corresponding pre-encoding codeword index is PMI ₂₂, to this cell base station eNB ₂Feedback PMI ₂₂

As described in step 203, estimate to leak pre-encoding codeword W ₁₂

Estimate to leak pre-encoding codeword, at UE ₁Side, according to

The order of supposing channel is 2, then can remember ${\tilde{W}}_{12}=\left[\begin{array}{cc}1& 1\\ -1& 1\\ {\mathrm{If}}_{31}& {\mathrm{If}}_{32}\\ {\mathrm{If}}_{41}& {\mathrm{If}}_{42}\end{array}\right],$ Following formula can be written as:

${\mathrm{<figure-callout\; id="21"\; label="H"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">H</figure-callout>}}_{21}\&CenterDot;\left[\begin{array}{cc}1& 1\\ -1& 1\\ {\mathrm{If}}_{31}& {\mathrm{If}}_{32}\\ {\mathrm{If}}_{41}& {\mathrm{If}}_{42}\end{array}\right]=\left[\begin{array}{cc}0& 0\\ 0& 0\end{array}\right]---\left(2\right)$

(2) formula of finding the solution obtains:

${\mathrm{If}}_{31}=\frac{-({\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,11}}-{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,12}})+({\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{21,21}-{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,22}})\&times;\frac{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,14}}}{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,24}}}}{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,13}}-{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,23}}\&times;\frac{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,14}}}{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,24}}}}$

${\mathrm{If}}_{41}=\frac{-({\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,11}}-{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,12}})+({\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,21}}-{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,22}})\&times;\frac{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,13}}}{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,23}}}}{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{21,14}-{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,24}}\&times;\frac{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,13}}}{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,23}}}}$

${\mathrm{If}}_{32}=\frac{-({\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">\; <figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>\; </figure-callout>}}_{\mathrm{21,21}}+{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,22}})+({\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,11}}+{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,12}})\&times;\frac{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,24}}}{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,14}}}}{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,23}}-{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,13}}\&times;\frac{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,24}}}{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,14}}}}$

${\mathrm{If}}_{42}=\frac{-({\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">\; <figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>\; </figure-callout>}}_{\mathrm{21,21}}+{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,22}})+({\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,11}}+{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,12}})\&times;\frac{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,23}}}{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,13}}}}{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,24}}-{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,14}}\&times;\frac{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,23}}}{{\mathrm{<figure-callout\; id="21"\; label="h"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">h</figure-callout>}}_{\mathrm{21,13}}}}$

Find the solution and accurately leaked sub-pre-encoding codeword

In the code book of precoding, choose code word, the code word w in the traversal code book _i(wherein i is the code word number in the corresponding code book) is respectively with the sub-pre-encoding codeword of accurate leakage

Each row do inner product with each row of pre-encoding codeword of the corresponding row columns of precoding codebook, sub-pre-encoding codeword is leaked in being of inner product module value minimum: $W_{12}=\underset{i}{\min }\left|\mathrm{dot}({\tilde{W}}_{12},w_i)\right|$

Wherein

I the inner product module value reckling in the code word chosen in expression, and the codeword selection of corresponding inner product minimum is for leaking sub-pre-encoding codeword W ₁₂, the pre-encoding codeword index of this moment is WCI ₁₂, to this cell base station eNB ₁Feedback WCI ₁₂

Similar, at UE ₂Side, according to

Find the solution this formula and accurately leaked sub-pre-encoding codeword

Obtain leaking sub-pre-encoding codeword W ₂₁:

${\mathrm{<figure-callout\; id="21"\; label="W"\; filenames="HDA0000076934630000011.png,HDA0000076934630000031.png"\; state="\{\{state\}\}">W</figure-callout>}}_{21}=\underset{i}{\min }\left|\mathrm{dot}({\tilde{W}}_{21},w_i)\right|$

Corresponding pre-coding matrix index is WCI ₂₁, UE ₂To this cell base station eNB ₂Feedback WCI ₂₁

As described in step 204, information interaction, serving BS eNB ₁With cooperative base station eNB ₂By X2 mouth interactive channel information, i.e. base station eNB ₁To base station eNB ₂Transmit pre-coding matrix index WCI ₁₂, base station eNB ₂To base station eNB ₁Transmit pre-coding matrix index WCI ₂₁

As described in step 205, the structure pre-encoding codeword is by expectation pre-encoding codeword W ₁₁With leakage pre-encoding codeword W ₂₁Between mapping, obtain base station eNB ₁Corresponding this community user UE ₁, adjacent cell user UE ₂Pre-encoding codeword, i.e. W ₁=W ₂₁--mapping--＞W ₁₁

Suppose expectation pre-encoding codeword W ₁₁=[SV1 SV ₂], and leak pre-encoding codeword W ₂₁=[IV ₁IV ₂], then final precoding is: W ₁=[SIV ₁SIV ₂], wherein,

$\left\{\begin{array}{c}{\mathrm{<figure-callout\; id="1"\; label="SIV"\; filenames="HDA0000076934630000041.png"\; state="\{\{state\}\}">SIV</figure-callout>}}_1=({\mathrm{<figure-callout\; id="1"\; label="IV"\; filenames="HDA0000076934630000041.png"\; state="\{\{state\}\}">IV</figure-callout>}}_1^{*},{\mathrm{SV}}_1)\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="SV"\; filenames="HDA0000076934630000041.png"\; state="\{\{state\}\}">SV</figure-callout>}}_1+({\mathrm{<figure-callout\; id="1"\; label="IV"\; filenames="HDA0000076934630000041.png"\; state="\{\{state\}\}">IV</figure-callout>}}_1^{*},{\mathrm{SV}}_2)\&CenterDot;{\mathrm{SV}}_2\\ {\mathrm{SIV}}_2=({\mathrm{IV}}_2^{*},{\mathrm{SV}}_1)\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="SV"\; filenames="HDA0000076934630000041.png"\; state="\{\{state\}\}">SV</figure-callout>}}_1+({\mathrm{IV}}_2^{*},{\mathrm{SV}}_2)\&CenterDot;{\mathrm{SV}}_2\end{array}\right..$

As described in step 206, precoding processing is for base station eNB ₁, according to the pre-encoding codeword W that estimates to obtain ₁X carries out precoding processing, i.e. W to transmitting ₁X.

For cooperative base station eNB ₂, its processing procedure and base station eNB ₁Similar, no longer narration here.

Fig. 3 is the design sketch of implementing according to the CoMP precoding based on code book of the embodiment of the invention, for serving BS eNB ₁, energy centralization forms UE to this community user after the precoding ₁, zero falls into trend adjacent cell user UE ₂For cooperative base station eNB ₂, energy centralization forms UE to this community user after the precoding ₂, zero falls into trend adjacent cell user UE ₁

Device embodiment

According to embodiments of the invention, a kind of precoding implement device is provided, be applied to the LTE-Advanced system.Fig. 4 is the structured flowchart according to the CoMP precoding of the embodiment of the invention, this device comprises: end side channel estimation module 41, expectation pre-encoding codeword are estimated and feedback module and the estimation of leakage pre-encoding codeword and feedback module 42, channel information interactive module 43 and precoding processing module 44, the below is described in detail said structure.

Channel estimation module 41 is located at end side, for Serving cell, is used for estimating user UE ₁With base station eNB ₁Between channel matrix H ₁₁, and estimating user UE ₁With base station eNB ₂Between channel matrix H ₂₁Equally, concerning cooperation cell, be used for estimating user UE ₂With base station eNB ₂Between channel matrix H ₂₂, and estimating user UE ₂With base station eNB ₁Between channel matrix H ₁₂

Pre-encoding codeword is estimated feedback module 42, comprise that the expectation pre-encoding codeword is estimated and feedback unit is estimated and feedback unit with the leakage pre-encoding codeword, be located at end side, be connected to channel estimation module 41, be used for according to the delivery channel foundation of channel estimation module 41 and the relation between expectation precoding and leakage precoding.

Channel information interactive module 43 is located at base station side, is used for the mutual transmission of channel information.

Structure pre-encoding codeword module 44 is connected to channel information interactive module 43, is used for generating pre-encoding codeword.

Precoding processing module 45 is connected to structure pre-encoding codeword module 44, is used for the CoMP precoding of residential quarter.

The practical function of the modules of the above device is referring to the specific implementation process of said method, no longer praises at this and states.

Above-mentioned explanation illustrates and has described a preferred embodiment of the present invention, but as previously mentioned, be to be understood that the present invention is not limited to the disclosed form of this paper, should not regard the eliminating to other embodiment as, and can be used for various other combinations, modification and environment, and can in invention contemplated scope described herein, change by technology or the knowledge of above-mentioned instruction or association area.And the change that those skilled in the art carry out and variation do not break away from the spirit and scope of the present invention, then all should be in the protection range of claims of the present invention.

Claims (9)

1. the multipoint cooperative precoding implementation method based on code book is applied to wireless communication system, it is characterized in that the method may further comprise the steps:

This community user of this community user of serving BS and cooperative base station carries out respectively channel estimating;

According to described channel estimation results, this community user of serving BS/cooperative base station is estimated the sub-pre-encoding codeword of expectation, to serving BS/pre-coding matrix index corresponding to cooperative base station feedback; And estimate to reveal sub-pre-encoding codeword, to serving BS/pre-coding matrix index corresponding to cooperative base station feedback;

Serving BS and cooperative base station interactive channel information, this channel information comprise the pre-coding matrix index corresponding to the sub-pre-encoding codeword of leakage of this community user feedback;

The pre-coding matrix index structure pre-encoding codeword that serving BS comes alternately according to pre-coding matrix index and the cooperative base station of this community user feedback;

Serving BS is according to estimating that the pre-encoding codeword that obtains carries out precoding processing to transmitting.

2. multipoint cooperative precoding implementation method as claimed in claim 1 is characterized in that the process of described channel estimating comprises:

In the serving BS side, this community user estimate with this serving BS between channel matrix H reach and cooperative base station between channel matrix H;

In the cooperative base station side, this community user estimate with this cooperative base station between channel matrix H reach and serving BS between channel matrix H.

3. multipoint cooperative precoding implementation method as claimed in claim 2 is characterized in that, this community user of described serving BS/cooperative base station estimates that the method for the sub-pre-encoding codeword of expectation is:

In the serving BS side, this community user calculates first the sub-pre-encoding codeword of accurate expectation, then chooses code word in the code book of precoding, the code word w in the traversal code book _i, respectively with the sub-pre-encoding codeword of accurate expectation

Each row do inner product with each row of pre-encoding codeword of the corresponding row columns of precoding codebook, inner product module value maximum be the sub-pre-encoding codeword W of expectation; In like manner, in cooperative base station one side, calculate the sub-pre-encoding codeword W of expectation.

4. multipoint cooperative precoding implementation method as claimed in claim 3 is characterized in that, in the serving BS side, and this community user basis

Calculate the sub-pre-encoding codeword of accurate expectation

Described μ is normalization factor, and I is unit matrix, and H is the channel matrix between this community user and serving BS.

5. multipoint cooperative precoding implementation method as claimed in claim 3 is characterized in that, this community user of described serving BS/cooperative base station estimates that the method for revealing sub-pre-encoding codeword is:

In the serving BS side, this community user calculates first the sub-pre-encoding codeword of accurate leakage, then chooses code word in the code book of precoding, the code word w in the traversal code book _i, do inner product with each row of the sub-pre-encoding codeword of accurate leakage with each row of pre-encoding codeword of the corresponding row columns of precoding codebook respectively, sub-pre-encoding codeword is leaked in being of inner product module value minimum; In like manner, in the cooperative base station side, calculate and reveal sub-pre-encoding codeword.

6. multipoint cooperative precoding implementation method as claimed in claim 5 is characterized in that, in the serving BS side, and this community user basis

Calculate the sub-pre-encoding codeword of accurate leakage

Described H is this community user of cooperative base station and the channel matrix between serving BS.

7. such as the arbitrary described multipoint cooperative precoding implementation method of claim 1 to 6, it is characterized in that the method for described serving BS structure pre-encoding codeword is:

Serving BS is selected the sub-pre-encoding codeword of corresponding expectation according to the pre-coding matrix index of this community user feedback, select the corresponding sub-pre-encoding codeword of revealing according to the pre-coding matrix index that cooperative base station is come alternately, to reveal again sub-pre-encoding codeword and be mapped on the expectation pre-encoding codeword plane of opening, with the mapping vector of this moment as pre-encoding codeword.

8. the multipoint cooperative precoding implement device based on code book is applied to wireless communication system, it is characterized in that this device comprises:

Channel estimation module is located at each end side, be used for estimating current community user with reach for the channel matrix between the serving BS of its service and cooperative base station between channel matrix;

Pre-encoding codeword is estimated feedback module, be located at each end side, be connected with channel estimation module, be used for expecting sub-pre-encoding codeword and revealing sub-pre-encoding codeword according to the output estimation of channel estimation module, and feed back corresponding pre-coding matrix index to its serving BS;

The channel information interactive module is located at base station side, is used for realizing interactive channel information between current base station and other base stations, and this channel information comprises pre-coding matrix index corresponding to the sub-pre-encoding codeword of described leakage;

The pre-encoding codeword constructing module is located at base station side, is used for pre-coding matrix index and current base station and the mutual next pre-coding matrix index generation of cooperative base station pre-encoding codeword according to the community user feedback of current base station;

The precoding processing module is located at base station side, is connected with structure pre-encoding codeword module, is used for carrying out precoding processing to transmitting according to the pre-encoding codeword that generates.

9. multipoint cooperative precoding implement device as claimed in claim 8, it is characterized in that, described pre-encoding codeword estimation feedback module comprises the sub-pre-encoding codeword estimation feedback unit of expectation and reveals sub-pre-encoding codeword estimation feedback unit, is respectively applied to expect sub-pre-encoding codeword and the sub-pre-encoding codeword of leakage and feed back corresponding pre-coding matrix index to serving BS according to described channel matrices estimation.

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