CN101834701A - Method, system and user equipment for realizing coordinated multiple point (CoMP) transmission - Google Patents

Abstract

The invention discloses a method for realizing coordinated multiple point (CoMP) transmission. The method comprises that: a neighboring cell evolved node B (eNB) transmits a downlink precoding reference signal (RQI-RS) providing a beam-forming matrix adopted per se; user equipment (UE) obtains an optimal precoding matrix index (PMI) according to the beam-forming matrix provided by the RQI-RS and adopted by the neighboring cell eNB; the UE obtains a channel quality indicator (CQI) of spatial domain inter-cell interference coordination (ICIC), and feeds the optimal PMI and the CQI back to a service cell eNB; and the service cell eNB performs scheduling according to a CQI value of the spatial domain ICIC of the UE and sends an potimal precoded signal to the UE by using the optimal PMI. The invention also discloses a system and the UE for realizing the CoMP transmission. Through the scheme of the invention, the CoMP of the spatial domain ICIC of the UE can be realized.

Description

A kind of method, system and portable terminal of realizing the multipoint cooperative transmission

Technical field

The present invention relates to wireless communication technology, relate in particular to a kind of method, system and portable terminal of realizing the multipoint cooperative transmission.

Background technology

In radio communication, the application that communication for coordination is the most successful is exactly multipoint cooperative transmission (CoMP), it is the most important enhancement mode transmission technology of enhanced long-period evolution system (LTE-A, LTE Advance), is the effective ways that solve Cell Edge User and average throughput.In mobile communication system, because the portable terminal (UE) of cell edge is in interference-limited environment, generally can adopt fractional frequency reuse modes such as (FFR) to suppress presence of intercell interference (ICI, Inter-Cell Interference), can reduce this regional average throughput like this.Advanced international mobile telecommunication system (IMT-A, International MobileTelecommunication-Advanced) covers for cell edge and the requirement of capacity in order to satisfy, and must adopt technology such as CoMP.

In the standardized process of LTE-A, the progress of CoMP is slower at present, though many optional transmission and feedback scheme are arranged, is difficult to build consensus.Under these circumstances, the simple extension for the Inter-Cell Interference Coordination that has existed among the Rel.9 (ICIC, Inter-Cell Interference Coordination) scheme is easy to promote the progress of CoMP in standard more.

In LTE+ version 9 (Rel.9), ICIC is by relative narrow band transmission power (RNTP, RNTP, Relative Narrowband Tx Power), UL disturbs excessive indication (IOI, Interference OverloadIndication) and UL high interference indication (HII, High Interference Indication) message realize alternately X2 interface.The ICIC of Rel.9 realizes at frequency domain, for fear of adjacent area interference, some or several evolved base station (eNB) must reduce transmitting power or not transmit on the part bandwidth, to make bandwidth vacant like this, cause availability of frequency spectrum loss, if ICIC is expanded to the spatial domain, just can avoid this situation to take place to a great extent.

In the prior art, ICIC is expanded to the spatial domain can be realized by the mode of mutual optimum between the eNB or the poorest paired pre-coding matrix index (Best or worst Companion PMIs), such as: eNB1 notice eNB2 wishes or does not wish the paired pre-coding matrix index that it adopts; Also can realize by the mode of wishing the signal covariance matrix that adopt adjacent sub-district between the eNB alternately.But these methods all require UE to increase new feedback content on the basis of the feedback content of Rel.9 definition, and between eNB, need special-purpose link to realize the CoMP of spatial domain ICIC, the more resource of consumption systems, various feedback methods need X2 interface to provide as far as possible little transmission delay could guarantee its validity simultaneously, cause present validity to various feedback methods still to have dispute.

Summary of the invention

In view of this, main purpose of the present invention is to provide a kind of realization coordinated multi-point transmission method, system and portable terminal, make UE under the condition of the feedback content that does not change the Rel.9 definition substantially, realize the CoMP of UE spatial domain ICIC, on performance, save system resource, elevator system average frequency spectrum utilance.

For achieving the above object, technical scheme of the present invention is achieved in that

A kind of method that realizes the multipoint cooperative transmission provided by the invention, this method comprises:

Adjacent sub-district eNB transmission provides the downlink precoding reference signal (RQI-RS) of the beam shaping matrix that self adopts;

The beam shaping matrix that the adjacent sub-district eNB that UE provides according to RQI-RS adopts obtains optimum pre-coding matrix index (PMI);

UE obtains the channel quality identification (CQI) of spatial domain ICIC, and the optimum PMI and the CQI that will obtain feed back to service cell eNB;

Service cell eNB is dispatched with reference to the CQI value of UE spatial domain ICIC, utilizes optimum PMI to send the signal of the optimum precoding of process to UE.

In the such scheme, described adjacent sub-district eNB transmission provides the RQI-RS of the beam shaping matrix that self adopts to be specially: adjacent sub-district eNB is on the identical frequency band of transmitting downlink data, adopt identical spatial domain wave beam, identical power and the identical parameter relevant, transmission RQI-RS with downlink data.

In the such scheme, the CQI that described UE obtains spatial domain ICIC is specially: UE determines that service cell eNB adopts the beam shaping method of optimum PMI, adjacent sub-district eNB employing constant, and for different PRB or the frequency range that service cell eNB adopts, UE obtains different CQI.

In the such scheme, the beam shaping matrix that the adjacent sub-district eNB that described UE provides according to RQI-RS adopts obtains optimum PMI, is specially: the beam shaping matrix that establishing RQI-RS provides adjacent sub-district eNB to adopt is w _I, adjacent sub-district eNB is H to the channel of UE _2,1, service cell eNB is H to the channel of UE _1,1, σ ²Be the noise variance that every reception antenna of UE receives, the optional pre-coding matrix f of UE self _NThe code book F that constitutes is F={f ₁, f ₂..., f _N, N is a natural number; According to following formula:

$w_1=\underset{f\∈F}{\arg \max }\frac{{\left|\right|H_{\mathrm{1,1}}f\left|\right|}^2}{{\left|\right|f^{*}\left|\right|}^2{\mathrm{\σ}}^2+{\left|\right|f^{*}{H}_{\mathrm{1,1}}{H}_{\mathrm{2,1}}{w}_I\left|\right|}^2}$

Wherein, with w ₁The corresponding numbering of matrix in F is as optimum PMI.

A kind of realization multipoint cooperative system for transmitting provided by the invention, this system comprises: eNB, UE; Wherein,

Described eNB is divided into adjacent sub-district eNB and service cell eNB with respect to UE;

Adjacent sub-district eNB is used to transmit the RQI-RS that the beam shaping matrix that self adopts is provided;

Service cell eNB is used for dispatching with reference to the CQI value of UE spatial domain ICIC, utilizes optimum PMI to send the signal of the optimum precoding of process to UE;

UE, the beam shaping matrix that the adjacent sub-district eNB that is used for providing according to RQI-RS adopts obtains optimum PMI; Obtain the CQI of spatial domain ICIC, and the optimum PMI and the CQI that will obtain feed back to service cell eNB.

In the such scheme, the CQI that described UE is used to obtain spatial domain ICIC is specially: UE determines that the beam shaping matrix that service cell eNB adopts optimum PMI, adjacent sub-district eNB to adopt is constant, for different PRB or the frequency range that service cell eNB adopts, UE obtains different CQI.

A kind of UE that realizes the multipoint cooperative transmission provided by the invention, this UE comprises: PMI module, CQI module, feedback module; Wherein,

The PMI module, the beam shaping matrix that the adjacent sub-district eNB that is used for providing according to RQI-RS adopts obtains optimum PMI;

The CQI module is used to obtain the CQI of spatial domain ICIC;

Feedback module, the optimum PMI and the CQI that are used for obtaining feed back to service cell eNB.

A kind of method, system and portable terminal of realizing the multipoint cooperative transmission provided by the invention, adjacent sub-district eNB transmission provides the RQI-RS of the beam shaping matrix that self adopts; The beam shaping matrix that the adjacent sub-district eNB that UE provides according to RQI-RS adopts obtains optimum PMI; UE obtains the CQI of spatial domain ICIC, and the optimum PMI and the CQI that will obtain feed back to service cell eNB; Service cell eNB is dispatched with reference to the CQI value of UE spatial domain ICIC, utilizes optimum PMI to send the signal of the optimum precoding of process to UE; So, can make UE under the condition of the feedback content that does not change the Rel.9 definition substantially, realize the CoMP of UE spatial domain ICIC, compared with prior art, saved the dedicated link of realizing spatial domain ICIC between the eNB, on performance, save system resource, elevator system average frequency spectrum utilance.

Description of drawings

Fig. 1 realizes the schematic diagram of the method flow of multipoint cooperative transmission for the present invention;

Fig. 2 realizes the schematic diagram of multipoint cooperative system for transmitting structure for the present invention;

Fig. 3 realizes the structural representation of the portable terminal of multipoint cooperative transmission for the present invention.

Embodiment

Basic thought of the present invention is: adjacent sub-district eNB transmission provides the RQI-RS of the beam shaping matrix that self adopts; The beam shaping matrix that the adjacent sub-district eNB that UE provides according to RQI-RS adopts obtains optimum PMI; UE obtains the CQI of spatial domain ICIC, and the optimum PMI and the CQI that will obtain feed back to service cell eNB; Service cell eNB is dispatched with reference to the CQI value of UE spatial domain ICIC, utilizes optimum PMI to send the signal of the optimum precoding of process to UE.

The present invention is described in further detail below by drawings and the specific embodiments.

The present invention realizes the method for multipoint cooperative transmission, and as shown in Figure 1, this method comprises following step;

Step 101: adjacent sub-district eNB transmission provides the RQI-RS of the beam shaping matrix that self adopts;

Concrete, adjacent sub-district eNB adopts identical spatial domain wave beam, identical power and the identical parameter relevant with downlink data on the identical frequency band of transmitting downlink data, transmit RQI-RS;

Described RQI-RS is designed to low expense precoding reference signal (LPRS, Low-overheadPrecoded Reference Signals), can indicate information such as the spatial domain wave beam of self cell signal and signal modulation system, be used to estimate to be about to transmit on the corresponding time (PRB) interference characteristic in short-term of data, beam shaping matrix that adjacent sub-district eNB adopts and other features of signal are provided;

The beam shaping matrix that the adjacent sub-district eNB that step 102:UE provides according to RQI-RS adopts obtains optimum PMI;

Concrete, when UE is in the edge of Serving cell and adjacent sub-district, be subjected to the interference of adjacent cell signal, at this moment, adopting maximum ratio to merge (MRC, Maximum Ratio Combining) technology reception RQI-RS with UE is example, and the beam shaping matrix that establishing RQI-RS provides adjacent sub-district eNB to adopt is w _I, UE is by channel estimating, and obtain: adjacent sub-district eNB is H to the channel of UE _2,1, service cell eNB is H to the channel of UE _1,1, σ ²Be the noise variance that every reception antenna of UE receives, the optional pre-coding matrix f of UE self _NThe code book F that constitutes is F={f ₁, f ₂..., f _N, N is a natural number; Shown in formula (1):

$w_1=\underset{f\∈F}{\arg \max }\frac{{\left|\right|H_{\mathrm{1,1}}f\left|\right|}^2}{{\left|\right|f^{*}\left|\right|}^2{\mathrm{\σ}}^2+{\left|\right|f^{*}{H}_{\mathrm{1,1}}{H}_{\mathrm{2,1}}{w}_I\left|\right|}^2}---\left(1\right)$

Wherein, select w ₁The corresponding numbering of matrix in F is as optimum PMI.

Step 103:UE obtains the CQI of spatial domain ICIC;

Concrete, the beam shaping method that UE hypothesis service cell eNB adopts optimum PMI, adjacent sub-district eNB to adopt is constant, and promptly the beam shaping matrix is constant, different PRB or frequency range for the service cell eNB employing, UE obtains different CQI, and wherein the algorithm of CQI is a prior art, does not give unnecessary details at this.

Optimum PMI and CQI that step 104:UE will obtain feed back to service cell eNB;

Step 105: service cell eNB is dispatched with reference to the CQI value of UE spatial domain ICIC, utilizes optimum PMI to send the signal of the optimum precoding of process to UE;

The scheduling mode among the Rel.9 is adopted in the described scheduling of this step.

Based on said method, the present invention also provides a kind of realization multipoint cooperative system for transmitting, and as shown in Figure 2, this system comprises: eNB, UE 21; Wherein,

Described eNB can be divided into adjacent sub-district eNB 22 and service cell eNB 23 with respect to UE 21;

Adjacent sub-district eNB 22 is used to transmit the RQI-RS that the beam shaping matrix that self adopts is provided;

Service cell eNB 23 is used for dispatching with reference to the CQI value of UE 21 spatial domain ICIC, utilizes optimum PMI to send the signal of the optimum precoding of process to UE 21;

UE 21, and the beam shaping matrix that the adjacent sub-district eNB 22 that is used for providing according to RQI-RS adopts obtains optimum PMI; Obtain the CQI of spatial domain ICIC, and the optimum PMI that will obtain and CQI feed back to service cell eNB 23;

The CQI that described UE 21 obtains spatial domain ICIC is specially: the beam shaping matrix that UE 21 hypothesis service cell eNB 23 adopt optimum PMI, adjacent sub-district eNB 21 to adopt is constant, for different PRB or the frequency range that service cell eNB 23 adopts, UE 21 obtains different CQI;

Further, described UE 21 comprises as shown in Figure 3: PMI module 211, CQI module 212, feedback module 213; Wherein,

PMI module 211, the beam shaping matrix that the adjacent sub-district eNB that is used for providing according to RQI-RS adopts obtains optimum PMI;

CQI module 212 is used to obtain the CQI of spatial domain ICIC;

Feedback module 213, the optimum PMI and the CQI that are used for obtaining feed back to service cell eNB.

Based on said system, the present invention also provides a kind of UE that realizes the multipoint cooperative transmission, and UE21 comprises: PMI module 211, CQI module 212, feedback module 213 as shown in Figure 3; Wherein,

PMI module 211, the beam shaping matrix that the adjacent sub-district eNB that is used for providing according to RQI-RS adopts obtains optimum PMI;

CQI module 212 is used to obtain the CQI of spatial domain ICIC;

Feedback module 213, the optimum PMI and the CQI that are used for obtaining feed back to service cell eNB.

The above is preferred embodiment of the present invention only, is not to be used to limit protection scope of the present invention, all any modifications of being done within the spirit and principles in the present invention, is equal to and replaces and improvement etc., all should be included within protection scope of the present invention.

Claims (8)

1. method that realizes multipoint cooperative transmission is characterized in that this method comprises:

Adjacent sub-district evolved base station (eNB) transmission provides the downlink precoding reference signal (RQI-RS) of the beam shaping matrix that self adopts;

The beam shaping matrix that the adjacent sub-district eNB that portable terminal (UE) provides according to RQI-RS adopts obtains optimum pre-coding matrix index (PMI);

UE obtains the channel quality identification (CQI) of spatial domain Inter-Cell Interference Coordination (ICIC), and the optimum PMI and the CQI that will obtain feed back to service cell eNB;

Service cell eNB is dispatched with reference to the CQI value of UE spatial domain ICIC, utilizes optimum PMI to send the signal of the optimum precoding of process to UE.

2. method according to claim 1, it is characterized in that, described adjacent sub-district eNB transmission provides the RQI-RS of the beam shaping matrix that self adopts to be specially: adjacent sub-district eNB is on the identical frequency band of transmitting downlink data, adopt identical spatial domain wave beam, identical power and the identical parameter relevant, transmission RQI-RS with downlink data.

3. method according to claim 1, it is characterized in that, the CQI that described UE obtains spatial domain ICIC is specially: UE determines that service cell eNB adopts the beam shaping method of optimum PMI, adjacent sub-district eNB employing constant, for different PRB or the frequency range that service cell eNB adopts, UE obtains different CQI.

4. method according to claim 1 is characterized in that, the beam shaping matrix that the adjacent sub-district eNB that described UE provides according to RQI-RS adopts obtains optimum PMI, is specially: the beam shaping matrix that establishing RQI-RS provides adjacent sub-district eNB to adopt is w _I, adjacent sub-district eNB is H to the channel of UE _2,1, service cell eNB is H to the channel of UE _1,1, σ ²Be the noise variance that every reception antenna of UE receives, the optional pre-coding matrix f of UE self _NThe code book F that constitutes is F={f ₁, f ₂..., f _N, N is a natural number; According to following formula:

$w_1=\underset{f\∈F}{\arg \max }\frac{{\left|\right|H_{\mathrm{1,1}}f\left|\right|}^2}{{\left|\right|f^{*}\left|\right|}^2{\mathrm{\σ}}^2+{\left|\right|f^{*}{H}_{\mathrm{1,1}}{H}_{\mathrm{2,1}}{w}_I\left|\right|}^2}$

Wherein, with w ₁The corresponding numbering of matrix in F is as optimum PMI.

5. realize the multipoint cooperative system for transmitting for one kind, it is characterized in that this system comprises: eNB, UE; Wherein,

Described eNB is divided into adjacent sub-district eNB and service cell eNB with respect to UE;

Adjacent sub-district eNB is used to transmit the RQI-RS that the beam shaping matrix that self adopts is provided;

Service cell eNB is used for dispatching with reference to the CQI value of UE spatial domain ICIC, utilizes optimum PMI to send the signal of the optimum precoding of process to UE;

UE, the beam shaping matrix that the adjacent sub-district eNB that is used for providing according to RQI-RS adopts obtains optimum PMI; Obtain the CQI of spatial domain ICIC, and the optimum PMI and the CQI that will obtain feed back to service cell eNB.

6. system according to claim 5, it is characterized in that, the CQI that described UE is used to obtain spatial domain ICIC is specially: UE determines that the beam shaping matrix that service cell eNB adopts optimum PMI, adjacent sub-district eNB to adopt is constant, for different PRB or the frequency range that service cell eNB adopts, UE obtains different CQI.

7. according to claim 5 or 6 described systems, it is characterized in that described UE comprises: PMI module, CQI module, feedback module; Wherein,

The PMI module, the beam shaping matrix that the adjacent sub-district eNB that is used for providing according to RQI-RS adopts obtains optimum PMI;

The CQI module is used to obtain the CQI of spatial domain ICIC;

Feedback module, the optimum PMI and the CQI that are used for obtaining feed back to service cell eNB.

8. a UE who realizes the multipoint cooperative transmission is characterized in that this UE comprises: PMI module, CQI module, feedback module; Wherein,

The PMI module, the beam shaping matrix that the adjacent sub-district eNB that is used for providing according to RQI-RS adopts obtains optimum PMI;

The CQI module is used to obtain the CQI of spatial domain ICIC;

Feedback module, the optimum PMI and the CQI that are used for obtaining feed back to service cell eNB.

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