CN102487308B - A kind of feedback method of channel quality instruction and device - Google Patents

Abstract

The invention discloses the feedback method of CQI, described method mainly comprises: CQI average when cell portion participates in cooperation in CQI when all communities participate in cooperation in CQI when UE obtains non tie up system in current C oMP measuring assembly, current C oMP measuring assembly and current C oMP measuring assembly, and by each CQI feedback of obtaining to network side; Or, UE obtain current C oMP measuring assembly Zhong Ge community independently in CQI and current C oMP measuring assembly except main Serving cell except all communities to the interference mean value δ self disturbed, and by the CQI of acquisition and disturb mean value δ to feed back to network side.The invention also discloses the feedback device of corresponding CQI, the invention enables network side to obtain current C oMP measuring assembly institute and comprise CQI when CQI in all cooperation set situations and non-cooperating are transmitted, thus accurately determine the cooperation set of suitable UE, and under the prerequisite ensureing feedback accuracy, feedback overhead can be reduced.

Description

Feedback method and device for channel quality indication

Technical Field

The present invention relates to CoMP technologies, and in particular, to a method and an apparatus for feeding back a channel quality indicator.

Background

In order to improve the cell edge and the cell average throughput and expand the coverage area of high data transmission rate, a coordinated multi-point transmission/reception (CoMP) technology is introduced into an advanced long-term evolution (LTE-a) system.

Currently, downlink CoMP techniques are classified into two categories: the first is Joint Processing (JP): each node in the cooperation set can obtain data information, and Physical Downlink Shared Channel (PDSCH) data is transmitted through a plurality of nodes or one node at the same time; the second is cooperative scheduling (CS/CB): the transmitted data information is only obtained in the serving cell, and the confirmation of user scheduling and beamforming is completed through the negotiation of the relevant cells in the cooperation set.

In order to support the downlink CoMP transmission technology, the current LTE-a has three feedback mechanisms as follows: first, explicit (explicit) feedback: the user directly feeds back the observed channel state information to the base station, so that the base station obtains complete channel response information without any transmission or receiver processing; second, implicit (implicit) feedback: after observing the channel state information, the user processes the obtained channel state information, converts the channel state information into a specific quantization value and feeds the specific quantization value back to the base station, such as Rank Indication (RI), Precoding Matrix Indication (PMI), and Channel Quality Indication (CQI); thirdly, using channel reciprocity, a base station estimates downlink channel state information through a Sounding Reference Signal (SRS) transmitted by a User Equipment (UE) in an uplink direction.

The prior art mainly has the following defects: in the CoMP technology, the coordination set is a subset of the CoMP measurement set, and is determined by a network side, such as an eNodeB, and if the UE feeds back the CQI to the network side, only the CQI independent of each cell and the PMI independent of each cell are fed back, the network side cannot obtain the corresponding CQI during cooperative transmission according to the independent PMIs, and thus cannot accurately determine the coordination set used by the UE; if the UE determines the CQI by adopting the previously applied cooperation set and only feeds back the CQI, when the cooperation set adopted by the UE is inconsistent with the currently determined cooperation set of the network side, the CQI value obtained by the network side is inaccurate, so that the cooperation set currently used by the UE and the cell actually participating in cooperation cannot be accurately determined; if the UE feeds back the CQI of each coordination point combination in addition to the CQI of each cell, although the feedback accuracy can be improved, the network side can accurately determine the coordination set used for the UE according to the CQI fed back by the UE, because there are many coordination point combinations, there are many CQIs to be fed back correspondingly, and thus the feedback overhead is too large.

Disclosure of Invention

In view of the above, a main object of the present invention is to provide a method and an apparatus for feeding back a channel quality indicator, so as to solve the problems that a network side of a CQI fed back by a UE cannot accurately determine a cooperating set used for the UE and that a feedback overhead in an existing CQI feedback mechanism is too large.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

the invention provides a CQI feedback method, which comprises the following steps: the UE obtains CQI when a non-cooperation mode exists in a current CoMP measurement set, CQI when all cells participate in cooperation in the current CoMP measurement set and average CQI when a part of cells participate in cooperation in the current CoMP measurement set, and feeds back the obtained CQI to a network side.

In the above scheme, the obtaining, by the UE, the CQI averaged when the partial cells participate in the cooperation includes: the UE obtains CQI of each cooperation set containing any two or more cells in the current CoMP measurement set; and then obtaining the average value of the CQI of each cooperation set with the same number of the contained cells according to the obtained CQI of each cooperation set, and obtaining the average CQI when partial cells participate in cooperation.

In the above scheme, the obtaining, by the UE, the CQI of each cooperation set including any two or more cells in the current CoMP measurement set includes: for any one cooperation set containing any two or more cells in the current CoMP measurement set, the UE obtains the ratio of the useful signal power to the sum of the total interference power and the noise in the cooperation set, and obtains the CQI of the cooperation set.

In the above scheme, the total interference power includes an interference power of an interfering cell to the UE, where the interference power of the interfering cell to the UE is obtained by the following method: and the UE measures the channel gain from the interference cell to the UE, then traverses all code words in the R8 codebook set C to obtain a transmission weight value corresponding to the channel gain, and obtains the interference power of the interference cell to the UE according to the measured channel gain and the obtained transmission weight value.

In the above scheme, the obtaining, by the UE, CQIs when all cells in the current CoMP measurement set participate in the cooperation includes: the UE obtains CQI of a cooperation set containing all cells in the current CoMP measurement set.

The invention also provides a CQI feedback device, which comprises: the first obtaining unit is used for obtaining CQI in a non-cooperation mode in a current CoMP measurement set, CQI when all cells in the current CoMP measurement set participate in cooperation, and average CQI when a part of cells in the current CoMP measurement set participate in cooperation; and the first feedback unit is used for feeding back the CQI obtained by the first acquisition unit to a network side.

In the above scheme, the calculation unit includes a first obtaining module, a second obtaining module, and a third obtaining module, where the first obtaining module is configured to obtain a CQI in a non-cooperative manner in a current CoMP measurement set; a second obtaining module, configured to obtain CQIs when all cells in the current CoMP measurement set participate in cooperation; and a third obtaining module, configured to obtain an average CQI when a part of cells in the current CoMP measurement set participate in cooperation.

In the foregoing solution, the third obtaining module is specifically configured to obtain CQIs of each cooperation set including any two or more cells in a current CoMP measurement set; and then obtaining the average value of the CQI of each cooperation set with the same number of the contained cells according to the obtained CQI of each cooperation set, and obtaining the average CQI when partial cells participate in cooperation.

In the foregoing solution, the second obtaining module is specifically configured to obtain, by the UE, CQIs of a cooperation set including all cells in a current CoMP measurement set.

The invention also provides a CQI feedback method, which comprises the following steps: and the UE obtains the independent CQI of each cell in the current CoMP measurement set and the interference average value of the interference of all the cells except the main service cell to the UE in the current CoMP measurement set, and feeds the obtained CQI and the interference average value back to the network side.

In the above scheme, the obtaining, by the UE, the CQI independent for each cell in the current CoMP measurement set includes: for any cell in the current CoMP measurement set, the UE obtains the ratio of the useful signal power from the cell to the UE to the external interference plus noise power of the current CoMP measurement set, and obtains the CQI independent from the cell; according to the acquisition method, the UE obtains the independent CQI of all the cells in the current CoMP measurement set.

In the above scheme, the obtaining, by the UE, the interference average value includes: the UE respectively obtains the interference power from other cells except the main service cell to the UE in the current CoMP measurement set, then obtains the ratio of the obtained interference power of each cell to the interference plus noise power from the other cells except the main service cell to the UE, and finally obtains the average value of the obtained ratios to obtain the interference average value.

In the above scheme, the obtaining, by the UE, interference power from each cell to the UE in the current CoMP measurement set except for the primary serving cell specifically includes: and the UE measures the channel gain from each cell to the UE, then traverses all code words in the R8 codebook set C to obtain a transmission weight value corresponding to the channel gain, and obtains the interference power of each cell to the UE according to the measured channel gain and the obtained transmission weight value.

In the foregoing solution, after the UE feeds back the obtained CQI and the interference average to the network side, the method further includes: and the network side obtains the CQI in a non-cooperation mode in the current CoMP measurement set, the CQI when all cells in the current CoMP measurement set participate in cooperation and the CQI when a part of cells in the current CoMP measurement set participate in cooperation according to the independent CQI and the interference average value of each cell in the current CoMP measurement set fed back by the UE.

The invention also provides a CQI feedback device, which comprises: the second obtaining unit is used for obtaining independent CQI of each cell in the current CoMP measurement set and an interference average value of interference of all cells except the main service cell in the current CoMP measurement set on the UE; and the second feedback unit is used for feeding back the CQI and the average interference value obtained by the second acquisition unit to the network side.

In the foregoing solution, the second obtaining unit includes: the system comprises a fourth acquisition module and a fifth acquisition module, wherein the fourth acquisition module is used for acquiring independent CQI of each cell in the current CoMP measurement set; a fifth obtaining module, configured to obtain an interference average value of interference, to the UE, of all cells in the current CoMP measurement set except the primary serving cell.

In the foregoing solution, the fourth obtaining module is specifically configured to, for any cell in the current CoMP measurement set, obtain a ratio of a useful signal power from the cell to the UE to an interference plus noise power outside the current CoMP measurement set, so as to obtain a CQI independent of the cell; according to the acquisition method, the CQI of all independent cells in the current CoMP measurement set is obtained.

In the foregoing scheme, the fifth obtaining module is specifically configured to obtain interference powers from other cells to the current CoMP measurement set except for the primary serving cell, obtain ratios of the obtained interference powers of the cells to interference plus noise powers from the current CoMP measurement set to the cell, and finally obtain an average value of the obtained ratios to obtain the interference average value.

In the foregoing solution, the network side includes a third obtaining unit, configured to obtain, according to the independent CQIs of each cell in the current CoMP measurement set and the interference average fed back by the UE, a CQI in a non-coordinated manner in the current CoMP measurement set, CQIs in a coordinated manner of all cells in the current CoMP measurement set, and CQIs in a coordinated manner of some cells in the current CoMP measurement set.

According to the CQI feedback scheme provided by the invention, the UE only needs to feed back the CQI when the current CoMP measurement set is not CoMP, the CQI when all the CoMP measurement set participates in cooperation and part of the average CQI when the CoMP measurement set participates in cooperation, or only needs to feed back the CQI of each cell in the current CoMP measurement set and the interference average value of each cell in the current CoMP measurement set to the UE, so that the network side can obtain the CQI under the condition that the current CoMP measurement set contains all the coordination sets, and can also obtain the CQI when the CoMP measurement set does not participate in cooperation transmission, and therefore, the network side can accurately determine the coordination set of proper UE, accurately determine a proper downlink transmission Modulation Coding Scheme (MCS), and can reduce the feedback overhead on the premise of ensuring the feedback precision.

Drawings

Fig. 1 is a flowchart illustrating an implementation of a CQI feedback method according to the present invention;

FIG. 2 is a flow chart of another implementation of a CQI feedback method according to the present invention;

fig. 3 is a schematic diagram of a CoMP measurement set according to a first embodiment of the present invention;

fig. 4 is a schematic diagram illustrating a coordinated set included in a CoMP measurement set according to a first embodiment of the present invention;

fig. 5 is a schematic diagram illustrating a channel quality parameter fed back to a network side by a UE according to a first embodiment of the present invention;

fig. 6 is a diagram illustrating a second CoMP measurement set according to an embodiment of the present invention;

fig. 7 is a schematic diagram of a channel quality parameter fed back to a network side by a UE according to a second embodiment of the present invention;

fig. 8 is a schematic diagram of a channel quality parameter fed back to a network side by a UE according to a third embodiment of the present invention;

fig. 9 is a schematic diagram of the channel quality parameters fed back to the network side by the UE in the fourth embodiment of the present invention.

Detailed Description

In practical application, a network side, such as an eNodeB or other control nodes, such as a relay station, a macro base station, and the like, first determines a CoMP measurement set, and then determines a cooperation set used for the UE according to channel quality fed back by the UE when each cooperation set in the CoMP measurement set is transmitted. Here, the cooperation set is equal to or smaller than the measurement set.

The basic idea of the invention is: the UE obtains the average CQI when partial cells participate in the cooperation in the current CoMP measurement set, and replaces each CQI when the partial cells participate in the cooperation through the obtained average CQI and feeds the CQI back to the network side; or, the UE obtains the independent CQI of each cell in the current CoMP measurement set, the interference average value of the interference of all the cells except the main service cell in the current CoMP measurement set on the UE, and feeds the interference average value back to the network side, and the network side obtains the CQI during non-cooperative transmission in the current CoMP measurement set, the CQI when all the cells in the current CoMP measurement set participate in cooperation, and the approximate value of the CQI when a part of the cells in the current CoMP measurement set participate in cooperation, so that the feedback quantity when the CQI is fed back by the UE is reduced on the premise of ensuring the feedback precision.

Referring to fig. 1, a CQI feedback method according to the present invention mainly includes:

step 101: the UE obtains CQI when a non-cooperation mode exists in a current CoMP measurement set, CQI when all cells participate in cooperation in the current CoMP measurement set and average CQI when a part of cells participate in cooperation in the current CoMP measurement set;

step 102: the UE feeds back the obtained CQI to the network side.

The obtaining, by the UE, the CQI averaged when the partial cells participate in the cooperation may specifically include: the UE obtains CQI of each cooperation set containing any two or more cells in the current CoMP measurement set; and then obtaining the average value of the CQI of each cooperation set with the same number of the contained cells according to the obtained CQI of each cooperation set, and obtaining the average CQI when partial cells participate in cooperation.

Here, each cooperating set including any two or more cells in the current CoMP measurement set does not include a cooperating set including all the cells in the current CoMP measurement set.

If the current CoMP measurement set comprises four cells in total, the average CQIs obtained when the partial cells participate in the cooperation are two in total, wherein one of the CQIs is an average value of CQIs of a main serving cell and any one of the other cells in the current CoMP measurement set, and the other CQI is an average value of CQIs of a main serving cell and any two of the other cells in the current CoMP measurement set.

Specifically, for any one of the cooperation sets including any two or more cells in the current CoMP measurement set, the UE obtains a ratio of the useful signal power to the sum of the total interference power and the noise in the cooperation set, and obtains the CQI of the cooperation set. Wherein the total interference power includes an interference power of an interfering cell to the UE. Here, the cells that are not included in the coordinated set in the current CoMP measurement set are interfering cells of the UE, and the interfering cells of the UE are different if the coordinated set is different.

Here, the interference power of the interfering cell to the UE is obtained by: and the UE measures the channel gain from the interference cell to the UE, then traverses all code words in the R8 codebook set C to obtain a transmission weight value corresponding to the channel gain, and obtains the interference power of the interference cell to the UE according to the measured channel gain and the obtained transmission weight value.

In the case of JP, when obtaining a corresponding CQI for any one of the cooperating sets including any two or more cells in the current CoMP measurement set, the useful signal power of the UE is specifically the sum of the useful signal powers of the cells in the cooperating set to the UE, and the total interference power plus noise of the UE is specifically the sum of the interference power of the interfering cell in the current CoMP measurement set to the UE and the interference power plus noise outside the current CoMP measurement set.

Under the CS/CB condition, when obtaining a corresponding CQI for any one cooperation set including any two or more cells in the current CoMP measurement set, a useful signal power of the UE is specifically a useful signal power of a main serving cell of the UE serving the UE, and the total interference power plus noise of the UE is specifically a sum of interference power of each cell except the main serving cell in the current CoMP measurement set to the UE and interference power plus noise outside the current CoMP measurement set. And all the cells except the main serving cell in the current CoMP measurement set comprise all the cells except the main serving cell in the cooperation set and the interference cells except the cooperation set.

The UE obtains CQI when all cells in the current CoMP measurement set participate in cooperation, and the CQI is as follows: the UE obtains CQI of a cooperation set containing all cells in the current CoMP measurement set.

The CQI is obtained by PMI calculation based on an independent cell, and the CQI value directly corresponds to the channel quality between other cells except the main service cell and the target user.

Correspondingly, the present invention also provides a CQI feedback apparatus, which is characterized in that the apparatus includes: the first obtaining unit is used for obtaining CQI in a non-cooperation mode in a current CoMP measurement set, CQI when all cells in the current CoMP measurement set participate in cooperation, and average CQI when a part of cells in the current CoMP measurement set participate in cooperation; and the first feedback unit is used for feeding back the CQI obtained by the first acquisition unit to a network side.

The acquiring unit comprises a first acquiring module, a second acquiring module and a third acquiring module, wherein the first acquiring module is used for acquiring CQI in a non-cooperation mode in a current CoMP measuring set; a second obtaining module, configured to obtain CQIs when all cells in the current CoMP measurement set participate in cooperation; and a third obtaining module, configured to obtain an average CQI when a part of cells in the current CoMP measurement set participate in cooperation.

Specifically, the third obtaining module is specifically configured to obtain CQIs of respective cooperating sets including any two or more cells in a current CoMP measurement set; and then obtaining the average value of the CQI of each cooperation set with the same number of the contained cells according to the obtained CQI of each cooperation set, and obtaining the average CQI when partial cells participate in cooperation.

The second obtaining module is specifically configured to obtain, by the UE, CQIs of a cooperation set including all cells in a current CoMP measurement set.

In addition, the present invention also provides a CQI feedback method, as shown in fig. 2, the method mainly includes:

step 201: the UE obtains the CQI of each cell in the current CoMP measurement set and the interference average value of all the cells except the main service cell to the UE in the current CoMP measurement set;

step 202: and the UE feeds back the obtained CQI and the interference average value to the network side.

The obtaining, by the UE, CQI independent of each cell in a current CoMP measurement set includes: for any cell in the current CoMP measurement set, the UE obtains the ratio of the useful signal power from the cell to the UE to the external interference plus noise power of the current CoMP measurement set, and obtains the CQI independent from the cell; according to the acquisition method, the UE obtains the independent CQI of all the cells in the current CoMP measurement set.

Wherein the UE obtains the interference average value, including: the UE respectively obtains the interference power from other cells except the main service cell to the UE in the current CoMP measurement set, then obtains the ratio of the obtained interference power of each cell to the interference plus noise power from the other cells except the main service cell to the UE, and finally obtains the average value of the obtained ratios to obtain the interference average value.

Here, the obtaining, by the UE, interference power from each cell other than the primary serving cell to the UE in the current CoMP measurement set specifically includes: and the UE measures the channel gain from each cell to the UE, then traverses all code words in the R8 codebook set C to obtain a transmission weight value corresponding to the channel gain, and obtains the interference power of each cell to the UE according to the measured channel gain and the obtained transmission weight value.

After the UE feeds back the obtained CQI and the interference average to the network side, the method further includes: and the network side obtains the CQI in a non-cooperation mode in the current CoMP measurement set, the CQI when all cells in the current CoMP measurement set participate in cooperation and the CQI when a part of cells in the current CoMP measurement set participate in cooperation according to the independent CQI and the interference average value of each cell in the current CoMP measurement set fed back by the UE.

Specifically, the network side first obtains the relation among the CQI in the non-cooperation mode, the CQI in the cooperation of all cells, and the CQI in the cooperation of some cells and the fed back CQI and the interference average value as follows:

replacing the ratios of the interference power of the interference cells required by the CQI when the uncooperative mode is obtained, the CQI when all cells participate in cooperation and the CQI when part of cells participate in cooperation with the interference plus noise power of the interference cells outside the current CoMP measurement set to the UE by the interference average value fed back by the UE;

replacing the obtained CQI in the non-cooperation mode, the CQI in the cooperation of all cells and the ratio of the useful signal power of each cell required by the CQI in the cooperation of part of cells to the interference and noise power of each cell outside the current CoMP measurement set by the independent CQI of each cell fed back by the UE;

and obtaining a relation between the CQI and the independent CQI and the interference average value of each cell in the current CoMP measurement set fed back by the UE in the non-cooperation mode, a relation between the CQI and the independent CQI and the interference average value of each cell in the current CoMP measurement set fed back by the UE when all the cells participate in cooperation, and a relation between the CQI and the independent CQI and the interference average value of each cell in the current CoMP measurement set fed back by the UE when part of the cells participate in cooperation.

Then, the network side may obtain, according to the obtained relationships, a CQI in a non-cooperation manner in the current CoMP measurement set, a CQI in a cooperation of all cells in the current CoMP measurement set, and a CQI in a cooperation of some cells in the current CoMP measurement set by using the CQI and the interference average value of each cell in the current CoMP measurement set fed back by the UE.

Correspondingly, the present invention also provides a CQI feedback apparatus, which is characterized in that the apparatus includes: the second obtaining unit is used for obtaining the CQI of each cell in the current CoMP measurement set and the interference average value of the interference of all the cells except the main service cell in the current CoMP measurement set on the UE; and the second feedback unit is used for feeding back the CQI and the average interference value obtained by the second acquisition unit to the network side.

Wherein the second acquisition unit includes: the system comprises a fourth acquisition module and a fifth acquisition module, wherein the fourth acquisition module is used for acquiring independent CQI of each cell in the current CoMP measurement set; a fifth obtaining module, configured to obtain an average interference value to the UE of all cells in the current CoMP measurement set except the primary serving cell.

Specifically, the fourth obtaining module is specifically configured to: for any cell in the current CoMP measurement set, obtaining the ratio of the useful signal power from the cell to the UE to the external interference plus noise power of the current CoMP measurement set, and obtaining the CQI independent of the cell; according to the acquisition method, the CQI of all independent cells in the current CoMP measurement set is obtained.

The fifth obtaining module is specifically configured to: respectively obtaining the interference power from other cells except the main service cell to the CoMP measurement set, then obtaining the ratio of the obtained interference power of each cell to the interference plus noise power from the other cells except the main service cell in the CoMP measurement set, and finally obtaining the average value of the obtained ratios to obtain the interference average value.

The network side comprises a third obtaining unit, which is used for obtaining CQI in a non-cooperation mode in the current CoMP measurement set, CQI in cooperation of all cells in the current CoMP measurement set and CQI in cooperation of part of cells in the current CoMP measurement set according to the independent CQI and the interference average value of each cell in the current CoMP measurement set fed back by the UE.

The feedback device of the CQI provided by the invention can be arranged in the UE, and can also be arranged independently connected with the UE.

Example one

In this embodiment, the CQI is a linear value corresponding to a signal to interference plus noise ratio (SINR).

In this embodiment, a transmission type of Intra-user joint processing (Intra-site sujp, Intra-site single user joint processing) in a base station is adopted, as shown in fig. 3, a CoMP measurement set determined by a network side is composed of a cell 1, a cell 2, and a cell 3, where the cell 1 is a main serving cell of a UE, and as shown in fig. 4, the CoMP measurement set includes three types of cooperation sets: type 1 is primary serving cell 1+ cell 2; type 2 is primary serving cell 1+ cell 3; type 3 is primary serving cell 1+ cell 2+ cell 3. When the cooperation set is the main serving cell 1+ cell 2, the main serving cell 1 and the cell 2 serve the UE together, the cell 3 serves the interfering cell of the UE, when the cooperation set is the main serving cell 1+ cell 3, the main serving cell 1 and the cell 3 serve the UE together, the cell 2 serves the interfering cell of the UE, and when the cooperation set is the main serving cell 1+ cell 2+ cell 3, the main serving cell 1, the cell 2 and the cell 3 serve the UE together.

Step 1: the UE calculates CQI in the non-cooperative mode according to each cooperative set listed in FIG. 4_non-compAfter the 1 st cooperation set and the 2 nd cooperation set are averagedAnd CQI of the 3 rd cooperation set_{1，2，3，JP}。

First, the UE calculates the CQI in the non-cooperative mode, that is, calculates the CQI when only the primary serving cell 1 serves the UE_non-comp. Here, the UE calculates the power of the main serving cell 1 to its own useful signal, and the sum of all interference powers and noises of the current UE, and then calculates the ratio of the useful signal power and the sum of all interference powers and noises to obtain the CQI when only the main serving cell 1 serves the UE_non-comp. The sum of all interference powers and noise of the current UE is specifically: and the sum of the interference power of each cell except the main service cell to the UE in the current CoMP measurement set and the interference power and noise outside the current CoMP measurement set.

Specifically, the UE calculates the CQI when obtaining the non-cooperative method according to the following formula (1)_non-comp，

${\mathrm{CQI}}_{\mathrm{non}-\mathrm{comp}}=\frac{{\left|\right|H_1{W}_1\left|\right|}^2{P}_1^t}{I+N+P_2^r+P_3^r}---\left(1\right)$

Wherein the moleculeThe power of the useful signal received by the UE;is the transmit power from the primary serving cell 1 to the UE, I is the interference power outside the current CoMP measurement set, N is the gaussian white noise power,is the interference power of cell 2 to the UE in the current CoMP measurement set,is the interference power of cell 3 to the UE in the current CoMP measurement set. Here, H₁、All the measurement methods can be obtained by UE measurement, and the specific measurement method is a common technique in the art and will not be described herein again.

Next, the UE calculates CQIs for the 1 st, 2 nd, and 3 rd cooperation sets in JP case, respectively, based on the various cooperation sets listed in fig. 4.

Specifically, the UE counts according to the following formula (2)Calculating the CQI when the cooperation set is the main service cell 1+ cell 2_1，2，JPCalculating the CQI when the cooperation set is the main service cell 1+ cell 3 according to the following formula (3)_1，3，JPCalculating the CQI when the cooperation set is the main service cell 1+ cell 2+ cell 3 according to the following formula (4)_{1，2，3，JP}。

${\mathrm{CQI}}_{\mathrm{1,2},\mathrm{JP}}=\frac{{\left|\right|H_1{W}_1\left|\right|}^2{P}_1^t+{\left|\right|H_2{W}_2\left|\right|}^2{P}_2^t}{{\left|\right|H_3{F}_3\left|\right|}^2{P}_3^t+I+N}=\frac{{\left|\right|H_1{W}_1\left|\right|}^2{P}_1^t+{\left|\right|H_2{W}_2\left|\right|}^2{P}_2^t}{\underset{w\∈C}{E}\left[{\left|\right|H_{3}w\left|\right|}^2\right]P_3^t+I+N}---\left(2\right)$

${\mathrm{CQI}}_{1,3,\mathrm{JP}}=\frac{{\left|\right|H_1{W}_1\left|\right|}^2{P}_1^t+{\left|\right|H_3{W}_3\left|\right|}^2{P}_3^t}{{\left|\right|H_2{F}_2\left|\right|}^2{P}_2^t+I+N}=\frac{{\left|\right|H_1{W}_1\left|\right|}^2{P}_1^t+{\left|\right|H_3{W}_3\left|\right|}^2{P}_3^t}{\underset{w\∈C}{E}\left[{\left|\right|H_{2}w\left|\right|}^2\right]P_2^t+I+N}---\left(3\right)$

${\mathrm{CQI}}_{\mathrm{1,2,3},\mathrm{JP}}=\frac{{\left|\right|H_1{W}_1\left|\right|}^2{P}_1^t+{\left|\right|H_2{W}_2\left|\right|}^2{P}_2^t+{\left|\right|H_3{W}_3\left|\right|}^2{P}_3^t}{I+N}---\left(4\right)$

Wherein,is the instantaneous transmit power of cell 2 to the UE,is the instantaneous transmit power of cell 3 to the UE.

Wherein H₁、H₂、H₃Channel gains, W, for cell 1, cell 2, cell 3 to UE, respectively₁、W₂、W₃Respectively a cell 1, a cell 2,Cell 3 to UE serving user transmit weights.

Here, the service user transmits a weight value W₁The UE obtains the channel gain H according to the Cell-specific reference signal (CRS)₁For the channel gain H₁The matrix is subjected to Singular Value Decomposition (SVD) to obtain the best transmit weights. The service user emission weight W of any other cell except the main service cell in the current CoMP measurement set_iIs PMI_iThe UE can obtain the channel gain H from the cell to the UE according to the measurement_iRight singular matrix obtained after SVD of matrix is quantized to obtain PMI_i. In the case of JP, the resulting PMI is the optimal paired precoding matrix indicator (BCI). In this embodiment, independent PMIs of cell 2 and cell 3 are calculated respectively to obtain corresponding service user transmission weight W₂、W₃。

Wherein, F₂、F₃Interfering users transmit weights to the UE in cell 2 and cell 3 respectively, interference power to the UE in cell 2 and cell 3, respectively. Here, the interfering user transmission weight F of any other cell except the primary serving cell_iIs to measure cell 2 to self channel gain H 'by interfering UEs located within cell 2'_iObtained, therefore, the UE cannot obtain F_i。

In this embodiment, when any cell in the current CoMP measurement set except the primary serving cell is an interfering cell of the UE, the interference power of the cell to the UE is determined by the interference power of the cellObtaining, i.e. UE measures the channel gain H from the interfering cell to itself_iThen, all code words in the R8 codebook set C are traversed to obtainChannel gain H_iCorresponding emission weight value w is calculated, and channel gain H is calculated_iThe square of the modulus of the product of the obtained transmission weight w and the instantaneous transmission power from the interfering cell to the UEAnd obtaining the interference power of the interference cell to the UE. Wherein, the UE measures a channel gain H by using a channel state information reference signal (CSI-RS)_i。

Here, ,for the interference power of cell 2 to the UE,is the interference power of cell 3 to the UE.

The interference power outside the current CoMP measurement set includes power N + I of interference plus noise outside the current CoMP measurement set, and can be calculated according to the following formula (5).

$I+N\≈I+N+P_2^r+P_3^r-\left(\underset{w\∈C}{E}\right[{\left|\right|H_{2}w\left|\right|}^2]P_2^t+\underset{w\∈C}{E}[{\left|\right|H_{3}w\left|\right|}^2\left]P_3^t\right)---\left(5\right)$

In particular, the total interference power measured by the UESubtracting the sum of the interference power of each cell except the main service cell to the UE in the current CoMP measurement setAnd (4) approximately obtaining the external interference plus noise power N + I of the current CoMP measurement set.

In addition, the interference plus noise power N + I outside the current CoMP measurement set can also be directly measured by the UE under the condition of muting (CSI-RSmuting) of resource elements of the local cell at the CSI-RS placement position of resource blocks of other cells.

Finally, for two cooperation sets listed in fig. 4, each of which is composed of a main serving cell and a cell, the UE calculates an average value of CQIs in the two cooperation sets.

Specifically, as shown in the following equation (6), the CQI when the cooperation set is the primary serving cell 1+ cell 2 is calculated_1，2，JPCQI when the cooperative set is a main serving cell 1+ cell 3_1，3，JPIs averaged to obtain

$\stackrel{\‾}{\mathrm{CQI}}=({\mathrm{CQI}}_{\mathrm{1,2},\mathrm{JP}}+{\mathrm{CQI}}_{\mathrm{1,3},\mathrm{JP}})/2---\left(6\right)$

Here, regardless of whether the cooperation set determined later is based on the cooperation between cell 1 and cell 2 or between cell 1 and cell 3, the UE is used when feeding back CQI to the network sideIn place of feedback CQI_1，2，JPAnd CQI_1，3，JPThus, the feedback amount can be reduced while ensuring the feedback accuracy.

Step 2: the UE will calculate the CQI_non-comp、CQI_{1，2，3，JP}And the channel quality parameter and other channel quality parameters are fed back to the network side through a PUSCH.

Here, the other channel quality parameters may include: PCI (phase correction factor), RI, and PMI independent for each cell in the CoMP measurement set.

Specifically, in this embodiment, the channel quality parameters fed back by the UE to the network side are shown in fig. 5, and include the calculated CQ_Inon-comp、CQI_{1，2，3，JP}PMI of cell 1₁PNI of cell 2₂PMI of cell 3₃PCI, and RI. Here, ,CQI_{1，2，3，JP}all correspond to JP.

And step 3: and finally determining the cells actually participating in the cooperation by the network side according to the channel quality parameters fed back by the UE to obtain a cooperation set used by the UE under the JP condition.

Specifically, the network side determines a suggested cooperation set according to the channel quality parameters fed back by the UE and the current scheduling condition, and sends a cooperation request to each cell in the cooperation set, and then the network side determines the actual cooperation-participating cells used by the UE in the final JP condition according to the response condition of each cell, and the set formed by the determined actual cooperation-participating cells is the cooperation set used by the UE in the JP condition.

Example two

In this embodiment, an Intra-base-station coordinated scheduling/coordinated beamforming (Intra-site cs/CB) transmission type is adopted between the network side and the UE, as shown in fig. 6, a CoMP measurement set determined by the network side is composed of a cell 1, a cell 2, and a cell 3, where the cell 1 is a main serving cell of the UE, and the CoMP measurement set includes a coordinated set completely the same as that in the first embodiment.

Step 1: the UE calculates CQI in the non-cooperative mode according to each cooperative set listed in FIG. 4_non-compAfter the 1 st cooperation set and the 2 nd cooperation set are averagedAnd CQI of the 3 rd cooperation set_{1，2，3，CB}。

First, the UE calculates the CQI in the non-cooperative mode, that is, calculates the CQI when only the primary serving cell 1 serves the UE_non-compSpecific procedure and embodiment one calculate CQI_non-compThe process of (a) is exactly the same.

Next, the UE calculates CQIs for the 1 st, 2 nd, and 3 rd cooperation sets in CS/CB according to the various cooperation sets listed in fig. 4.

Specifically, the UE calculates the CQI when the cooperation set is the primary serving cell 1+ cell 2 according to the following formula (7)_1，2，CBCalculating the CQI when the cooperation set is the main service cell 1+ cell 3 according to the following formula (8)_1，3，CBCalculating the CQI when the cooperation set is the main service cell 1+ cell 2+ cell 3 according to the following formula (9)_{1，2，3，CB}，

${\mathrm{CQI}}_{\mathrm{1,2},\mathrm{CB}}=\frac{{\left|\right|H_1{W}_1\left|\right|}^2{P}_1^t}{{\left|\right|H_2{W}_2\left|\right|}^2{P}_2^t+\underset{w\∈C}{E}\left[{\left|\right|H_{3}w\left|\right|}^2\right]P_3^t+I+N}---\left(7\right)$

${\mathrm{CQI}}_{\mathrm{1,3},\mathrm{CB}}=\frac{{\left|\right|H_1{W}_1\left|\right|}^2{P}_1^t}{\underset{w\∈C}{E}\left[{\left|\right|H_{2}w\left|\right|}^2\right]P_2^t+{\left|\right|H_3{W}_3\left|\right|}^2{P}_3^t+I+N}---\left(8\right)$

${\mathrm{CQI}}_{\mathrm{1,2,3},\mathrm{CB}}=\frac{{\left|\right|H_1{W}_1\left|\right|}^2{P}_1^t}{{\left|\right|H_2{W}_2\left|\right|}^2{P}_2^t+{\left|\right|H_3{W}_3\left|\right|}^2{P}_3^t+I+N}---\left(9\right)$

In this embodiment, independent PMIs of cell 1, cell 2 and cell 3 are obtained, and corresponding serving user transmission weights W are obtained₁、W₂、W₃. The service user emission weight W of any other cell except the main service cell in the current CoMP measurement set_iIs PMI_iThe UE may obtain the cell-to-UE channel gain H based on the measurement_iObtaining a right singular matrix after SVD decomposition of the matrix or obtaining PMI by quantizing the right singular matrix after orthogonalizing the right singular matrix_i. In the CS/CB case, the resulting PMI is the worst paired precoding matrix indicator (WCI).

Specifically, the transmission weight W of cell 2₂Is the channel gain H to the cell 2 to the UE₂SVD is carried out to obtain a right singular matrix, and the right singular matrix is orthogonalized and quantized to obtain the WCI₂Similarly, the transmission weight W of cell 3₃Is the channel gain H to cell 3 to UE₃The WCI is obtained by performing quantization after the right singular matrix obtained by SVD (singular value decomposition) is orthogonal₃。

In the present embodiment, the first and second electrodes are,for the interference power of cell 2 to the UE,the calculation method for the interference power of the cell 3 to the UE is exactly the same as the first embodiment.

The interference power outside the current CoMP measurement set includes power N + I of interference plus noise outside the current CoMP measurement set, and the calculation method is completely the same as that in the first embodiment.

In case of CS/CB, CQI is calculated_1，2，CBWhen the cooperation set is the main service cell 1+ cell 2, the cell 2 serves the signal power of the UEAs the interference of the cell 2 to the UE, the CQI is calculated similarly_1，3，CBWhen the cooperation set is the main service cell 1+ cell 3, the signal power from the cell 3 to the UE is transmitted to the UECalculating CQI as interference of cell 3 to UE_{1，2，3，CB}When the cooperation set is the main service cell 1+ cell 2+ cell 3, the signal power from the cell 2, the cell 3 to the UE is transmitted to the UEAs interference to the UE from cell 2 and cell 3, respectively.

Finally, for the two cooperation sets listed in fig. 4, which are both a main serving cell plus one cell, the UE calculates the average of the CQIs of the two cooperation sets under the CS/CB condition.

Specifically, as shown in the following equation (10), the CQI when the cooperation set is the primary serving cell 1+ cell 2 is calculated_1，2，CBCQI when the cooperative set is a main serving cell 1+ cell 3_1，3，CBIs averaged to obtain

$\stackrel{\‾}{\mathrm{CQI}}=({\mathrm{CQI}}_{\mathrm{1,2},\mathrm{CB}}+{\mathrm{CQI}}_{\mathrm{1,3},\mathrm{CB}})/2---\left(10\right)$

Step 2: the UE will calculate the CQI_non-comp、CQI_{1，2，3，CB}Feeding back the data and other channel quality parameters to a network side through a PUSCH;

here, the other channel quality parameters may include: and the RI and the PMI independent from each cell in the CoMP measurement set.

Specifically, in this embodiment, the channel quality parameters fed back to the network side by the UE are as shown in fig. 7, and include the calculated CQI_non-comp、CQI_{1，2，3，CB}PMI of cell 1₁PMI of cell 2₂PMI of cell 3₃And an RI, where,CQI_{1，2，3，CB}all correspond to CS/CB.

And step 3: and finally determining the cells actually participating in the cooperation by the network side according to the channel quality parameters fed back by the UE to obtain a cooperation set used by the UE under the CS/CB condition.

Specifically, the network side determines a suggested cooperation set according to the channel quality parameters fed back by the UE and the current scheduling condition, and sends a cooperation request to each cell in the cooperation set, and then the network side determines the actual cooperation-participating cells used by the UE under the final CS/CB condition according to the response conditions of each cell in the cooperation set, where the set formed by the determined actual cooperation-participating cells is the cooperation set used by the UE under the CS/CB condition.

EXAMPLE III

In the following description, the CQI independent of each cell is a linear value corresponding to the SINR.

In this embodiment, an Intra-siteSUJP transmission type is adopted, and a CoMP measurement set determined by a network side is composed of a cell 1, a cell 2, and a cell 3, specifically as shown in fig. 3, where the cell 1 is a main serving cell of a UE, and three coordination sets included in the CoMP measurement set are shown in fig. 4, which is the same as the first embodiment.

Step 1: and the UE respectively calculates the CQI of each cell in the current CoMP measurement set and the interference average value of the interference of all the cells except the main service cell to the UE.

Firstly, UE calculates CQI independent from cell 1 respectively₁Cell 2 independent CQI₂CQI independent of cell 3₃. Here, for any cell, the UE calculates a ratio of power of a user signal served by the cell to the UE to interference plus noise power outside the current CoMP measurement set, and obtains CQI independent of the cell.

Specifically, according to equation (11), the UE calculates CQI independent of cell 1 separately₁Cell 2 independent CQI₂CQI independent of cell 3₃。

${\mathrm{CQI}}_1=\frac{{\left|\right|H_1{W}_1\left|\right|}^2{P}_1^t}{I+N},{\mathrm{CQI}}_2=\frac{{\left|\right|H_2{W}_2\left|\right|}^2{P}_2^t}{I+N},{\mathrm{CQI}}_3=\frac{{\left|\right|H_3{W}_3\left|\right|}^2{P}_3^t}{I+N}---\left(11\right)$

Wherein,respectively representing useful signal powers of a cell 1, a cell 2 and a cell 3 serving the UE, and the method for calculating the interference plus noise power 1+ N outside the current CoMP measurement set is the same as the first embodiment.

Secondly, the UE calculates the average interference value of the interference of all cells except the main service cell to the UE in the current CoMP measurement set.

Specifically, in this embodiment, all cells except the primary serving cell in the current CoMP measurement set include cell 2 and cell 3, and according to equation (12), the UE calculates the ratio of the interference power of cell 2 to itself to the interference plus noise power outside the current CoMP measurement set respectivelyAnd the ratio of the interference power of the cell 3 to itself to the interference plus noise power outside the current CoMP measurement setAnd then calculating the average value of the two ratios respectively corresponding to the two cells to obtain the interference average value.

$\mathrm{\δ}=\left(\frac{\underset{W\∈C}{E}\left[{\left|\right|H_{2}w\left|\right|}^2\right]P_2^t+\underset{W\∈C}{E}\left[{\left|\right|H_{3}w\left|\right|}^2\right]P_3^t}{I+N}\right)/2---\left(12\right)$

Wherein, in the formula (12),is the instantaneous transmit power of cell 2 to the UE,is the instantaneous transmit power of cell 3 to the UE, the interference power of cell 2Interference power of cell 3The calculation method is completely the same as that in the first embodiment, and is not described herein again.

When the UE feeds back the CQI to the network side, the CQI of the cell 1 can be fed back₁CQI of cell 2₂CQI of cell 3₃And, instead of feeding back the CQI of the cell 1₁CQI of cell 2₂CQI of cell 3₃、CQI_1，2，JP、CQI_1，3，JPAnd CQI_{1，2，3，JP}Thus, the feedback amount can be reduced while ensuring the feedback accuracy. Then, the network side can use the interference average value to replace the interference power to the UE when the cell 2 or the cell 3 is taken as the interference cell, and the CQI is calculated and obtained_1，2，JP、CQI_1，3，JP。

The obtained interference average value is quantized according to a method of quantizing SINR into CQI, and the feedback overhead of 4 bits is needed. Specifically, the quantization is performed into 16 levels, and the 16 levels correspond to different CQI sequence numbers, and the specific process is a common technical means in the art and is not described herein again.

Step 2: the UE will calculate the CQI₁、CQI₂、CQI₃And, feedback to the network side together with other channel quality parameters;

here, the other channel quality parameters are exactly the same as in the first embodiment.

Specifically, in this embodiment, the channel quality parameters fed back by the UE to the network side are as shown in fig. 8, and include calculated CQI₁、CQI₂、CQI₃PMI of cell 1₁PMI of cell 2₂PMI of cell 3₃PCI, and RI.

And step 3: CQI fed back by the network side according to the UE₁、CQI₂、CQI₃And obtaining the CQI under the specific JP cooperation mode and the CQI under the non-cooperation mode.

Specifically, according to equations (13) to (16), the network side feeds back CQI according to the UE₁、CQI₂、CQI₃And calculating the CQI when the cooperation set is the main service cell 1+ cell 2_1，2，JPCQI when the cooperation set is a main service cell 1+ cell 3_1，3，JPCollaborationCQI when aggregated as a primary serving cell 1+ cell 2+ cell 3_{1，2，3，JP}And CQI in non-cooperative mode_non-comp。

${\mathrm{CQI}}_{\mathrm{1,2},\mathrm{JP}}=\frac{{\left|\right|H_1{W}_1\left|\right|}^2{P}_1^t+{\mathrm{\ρ}}_1^2{\left|\right|H_2{W}_2\left|\right|}^2{P}_2^t}{{\left|\right|H_3{F}_3\left|\right|}^2{P}_3^t+I+N}=\frac{\frac{{\left|\right|H_1{W}_1\left|\right|}^2}{I+N}{P}_1^t+{\mathrm{\ρ}}_1^2\frac{{\left|\right|H_2{W}_2\left|\right|}^2}{I+N}{P}_2^t}{\frac{{\left|\right|H_3{F}_3\left|\right|}^2{P}_3^t}{I+N}+1}\≈\frac{{\mathrm{CQI}}_1+{\mathrm{\ρ}}_1^2{\mathrm{CQI}}_2}{\frac{\underset{W\∈C}{E}[{\left|\right|H_{3}w\left|\right|}^2{P}_3^t}{I+N}+1}\≈\frac{{\mathrm{CQI}}_1+{\mathrm{\ρ}}_1^2{\mathrm{CQI}}_2}{\mathrm{\δ}+1}---\left(13\right)$

${\mathrm{CQI}}_{1,3,\mathrm{JP}}=\frac{{\left|\right|H_1{W}_1\left|\right|}^2{P}_1^t+{\mathrm{\ρ}}_2^2{\left|\right|H_3{W}_3\left|\right|}^2{P}_3^t}{{\left|\right|H_2{F}_2\left|\right|}^2{P}_2^t+I+N}\≈\frac{\frac{{\left|\right|H_1{W}_1\left|\right|}^2}{I+N}{P}_1^t+{\mathrm{\ρ}}_2^2\frac{{\left|\right|H_3{W}_3\left|\right|}^2}{I+N}{P}_3^t}{\mathrm{\δ}+1}=\frac{{\mathrm{CQI}}_1+{\mathrm{\ρ}}_2^2{\mathrm{CQI}}_3}{\mathrm{\δ}+1}---\left(14\right)$

${\mathrm{CQI}}_{\mathrm{1,2,3},\mathrm{JP}}=\frac{{\left|\right|H_1{W}_1\left|\right|}^2{P}_1^t+{\mathrm{\ρ}}_1^2{\left|\right|H_2{W}_2\left|\right|}^2{P}_2^t+{\mathrm{\ρ}}_2^2{\left|\right|H_3{W}_3\left|\right|}^2{P}_3^t}{I+N}={\mathrm{CQI}}_1+{\mathrm{\ρ}}_1^2{\mathrm{CQI}}_2+{\mathrm{\ρ}}_2^2{\mathrm{CQI}}_3---\left(15\right)$

${\mathrm{CQI}}_{\mathrm{non}-\mathrm{comp}}=\frac{{\left|\right|H_1{W}_1\left|\right|}^2{P}_1^t}{{\left|\right|H_2{F}_2\left|\right|}^2{P}_2^t+{\left|\right|H_3{F}_3\left|\right|}^2{P}_3^t+I+N}=\frac{{\mathrm{CQI}}_1}{2\×\mathrm{\δ}+1}---\left(16\right)$

Wherein, when the cooperation set is the main service cell 1+ the cell 2, the cell 3 is the interference cell of the UE, and the CQI is calculated_1，2，JPWhen used in formula (13)Instead of the formerObtaining the interference power of the cell 3 to the UE; then the interference power of the cell 3 to the UE is calculatedRatio of external interference plus noise power I + N of current CoMP setReplacing the interference average value fed back by the UE; the ratio of useful signal power of a cell 1 to UE service to the external interference plus noise power I + N of the current CoMP setWith CQI for cell 1 fed back by UE₁Instead, the ratio of the useful signal power served by cell 2 to the UE to the current CoMP set external interference plus noise power I + NWith CQI for cell 2 fed back by UE₂Instead, a relational expression is obtainedSimilarly, the derivation processes of equations (14) to (16) are similar to equation (13), and are not described herein again. Thus, the network side only needs to feedback the CQI of the cell 1 according to the UE₁CQI of cell 2₂CQI of cell 3₃And interference average value, can obtain CQI_1，2，JP、CQI_1，3，JP、CQI_{1，2，3，JP}、CQI_non-comp。

Similarly, for any cell i, its interference power to the UE can be usedOrIt is shown that the calculated values of the two are approximately equal, which has been described in detail in the first embodiment, and are not described herein again.

Where ρ is_iThe correlation coefficient between the PMI finally determined and used by the network side and the PMI fed back by the UE is obtained by the network side through calculation according to the PMI finally determined and used and the PMI fed back by the UE. In the case of JP, the correlation coefficient ρ_iApproaching 1. In this embodiment, ρ₁、ρ₂The network side determines the PMI used finally according to the network side and the PMI of the cell 1 fed back by the UE₁PMI of cell 2₂PMI of cell 3₃And (4) calculating.

And 4, step 4: and the network side determines a cooperation set using JP for the UE according to the calculated CQI in various cooperation modes and the calculated CQI in non-cooperation modes of the specific JP.

Specifically, the network side determines a suggested cooperation set according to the calculated CQI under various cooperation modes and CQI under non-cooperation modes of the specific JP and the current scheduling condition, and sends a cooperation request to each cell in the cooperation set, and then the network side determines the actually cooperative cell used by the UE under the final JP condition according to the response condition of each cell in the cooperation set, wherein the set formed by the determined actually cooperative cells is the cooperation set used by the UE under the JP condition.

Specifically, the network side feeds back CQI according to the UE₁、CQI₂、CQI₃And, and the calculated CQI_1，2，JP、CQI_1，3，JP、CQI_{1，2，3，JP}And CQI_non-compA cooperation set using JP for the UE is determined.

Example four

In this embodiment, an Intra-sitec cs/CB transmission type is adopted, and a CoMP measurement set determined by a network side is composed of a cell 1, a cell 2, and a cell 3, as specifically shown in fig. 6, where the cell 1 is a main serving cell of a UE, and three coordination sets included in the CoMP measurement set are shown in fig. 4, which is the same as in the first embodiment.

Step 1: exactly the same as step 1 in example three.

Step 2: the UE will calculate the CQI₁、CQI₂、CQI₃And, feedback to the network side together with other channel quality parameters;

here, the other channel quality parameters are exactly the same as in the second embodiment.

Specifically, in this embodiment, the channel quality parameters fed back to the network side by the UE are as shown in fig. 9, and include calculated CQI₁、CQI₂、CQI₃PMI of cell 1₁PMI of cell 2₂PMI of cell 3₃And RI.

And step 3: CQI fed back by the network side according to the UE₁、CQI₂、CQI₃And obtaining the CQI under the specific CS/CB cooperation mode and the CQI under the non-cooperation mode.

Specifically, according to equations (17) to (20), the network side feeds back CQI according to the UE₁、CQI₂、CQI₃、CQI And calculating the CQI when the cooperation set is the main service cell 1+ cell 2_1，2，CBCQI when the cooperation set is a main service cell 1+ cell 3_1，3，CBCQI when the cooperation set is a main service cell 1+ a cell 2+ a cell 3_{1，2，3，CB}And CQI in non-cooperative mode_non-comp。

${\mathrm{CQI}}_{\mathrm{1,2,3},\mathrm{CB}}=\frac{{\left|\right|H_1{W}_1\left|\right|}^2{P}_1^t}{{\mathrm{\ρ}}_1^2{\left|\right|H_2{F}_2\left|\right|}^2{P}_2^t+{{\mathrm{\ρ}}_2^2\left|\right|H_3{F}_3\left|\right|}^2{P}_2^t+I+N}=\frac{{\mathrm{CQI}}_1}{{\mathrm{\ρ}}_1^2{\mathrm{CQI}}_2+{\mathrm{\ρ}}_2^2{\mathrm{CQI}}_3+1}---\left(17\right)$

${\mathrm{CQI}}_{\mathrm{1,2},\mathrm{CB}}=\frac{{\left|\right|H_1{W}_1\left|\right|}^2{P}_1^t}{{\mathrm{\ρ}}_1^2{\left|\right|H_2{F}_2\left|\right|}^2{P}_2^t+{\left|\right|H_3{F}_3\left|\right|}^2{P}_3^t+I+N}\≈\frac{{\mathrm{CQI}}_1}{{\mathrm{\ρ}}_1^2{\mathrm{CQI}}_2+\mathrm{\δ}+1}---\left(18\right)$

${\mathrm{CQI}}_{\mathrm{1,3},\mathrm{CB}}=\frac{{\left|\right|H_1{W}_1\left|\right|}^2{P}_1^t}{{\left|\right|H_2{F}_2\left|\right|}^2{P}_2^t+{{\mathrm{\ρ}}_2^2\left|\right|H_3{F}_3\left|\right|}^2{P}_3^t+I+N}\≈\frac{{\mathrm{CQI}}_1}{\mathrm{\δ}+{\mathrm{\ρ}}_2^2{\mathrm{CQI}}_3+1}---\left(19\right)$

${\mathrm{CQI}}_{\mathrm{non}-\mathrm{comp}}=\frac{{\left|\right|H_1{W}_1\left|\right|}^2{P}_1^t}{{\left|\right|H_2{F}_2\left|\right|}^2{P}_2^t+{\left|\right|H_3{F}_3\left|\right|}^2{P}_3^t+I+N}=\frac{{\mathrm{CQI}}_1}{2\×\mathrm{\δ}+1}---\left(20\right)$

Wherein the correlation coefficient ρ₁、ρ₂The network side determines the PMI used finally according to the network side and the PMI of the cell 1 fed back by the UE₁PMI of cell 2₂PMI of cell 3₃And (4) calculating. CS/CB, when PMI is WCI, correlation coefficient rho_iApproaching to 1, when PMI is BCI, the correlation coefficient ρ_iApproaching 0.

Here, in equations (17) to (20), similar to the specific derivation processes of equations (13) to (16) in the third embodiment, details are not repeated here, and according to the final derivation results obtained by equations (17) to (20), the network side only needs to feedback the CQI of cell 1 according to the UE₁CQI of cell 2₂CQI of cell 3₃And interference average value, can calculate CQI_1，2，CB、CQI_1，3，CB、CQI_{1，2，3，CB}、CQI_non-copm。

And 4, step 4: and the network side determines to use the CS/CB cooperation set for the UE according to the calculated CQI under the specific CS/CB cooperation mode and the calculated CQI under the non-cooperation mode.

Specifically, the network side determines a suggested cooperation set according to the calculated specific CQI of the CS/CB in various cooperation modes, the calculated CQI of the CS/CB in non-cooperation modes, and the scheduling condition, and sends a cooperation request to each cell in the cooperation set, and then the network side finally determines the actually cooperating cell used by the UE under the CS/CB condition according to the response condition of each cell, and a set formed by the determined actually cooperating cells is the cooperation set used by the UE under the CS/CB condition.

In the above four embodiments, all the formulas adopt the maximum ratio combining detection algorithm, and it should be noted that, the above formula adopts the maximum ratio combining detection algorithmAll formulas can also be realized by a Minimum Mean Square Error (MMSE) detection algorithm, that is, all formulas containPart of the process can be replaced by the following formula (21), and the specific implementation process is a means commonly used in the art and is not described herein again.

$\left\{{[{\left(H_1{W}_1\right)}^H\×\left(H_1{W}_1\right)+{\mathrm{\σ}}^2{I}_{n_T}]}^{-1}{\left(H_1{W}_1\right)}^H\right\}\×\left(H_1{W}_1\right)\×P_1^t---\left(21\right)$

Wherein σ²Is the variance of the noise, and is,is a unit matrix, n_TIs the number of transmitting antennas, σ²May be measured by the UE.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, and any modifications, equivalents, improvements, etc. that are within the spirit and principle of the present invention should be included in the present invention.

Claims (16)

1. A method for feeding back a Channel Quality Indicator (CQI), the method comprising:

the UE obtains CQI when a non-cooperation mode exists in a current coordinated multi-point transmission CoMP measurement set, CQI when all cells participate in cooperation in the current CoMP measurement set and average CQI when a part of cells participate in cooperation in the current CoMP measurement set, and feeds the obtained CQI back to a network side;

wherein the obtaining, by the UE, the CQI averaged when the partial cells participate in the cooperation includes:

the UE obtains CQI of each cooperation set containing any two or more cells in the current CoMP measurement set;

and then obtaining the average value of the CQI of each cooperation set with the same number of the contained cells according to the obtained CQI of each cooperation set, and obtaining the average CQI when partial cells participate in cooperation.

2. The CQI feedback method according to claim 1, wherein the UE obtains the CQI of each cooperating set including any two or more cells in the current CoMP measurement set, and the CQI is:

for any one cooperation set containing any two or more cells in the current CoMP measurement set, the UE obtains the ratio of the useful signal power to the sum of the total interference power and the noise in the cooperation set, and obtains the CQI of the cooperation set.

3. The CQI feedback method according to claim 2, wherein the total interference power comprises an interference power of an interfering cell to the UE, and wherein the interference power of the interfering cell to the UE is obtained by:

and the UE measures the channel gain from the interference cell to the UE, then traverses all code words in the R8 codebook set C to obtain a transmission weight value corresponding to the channel gain, and obtains the interference power of the interference cell to the UE according to the measured channel gain and the obtained transmission weight value.

4. The CQI feedback method according to claim 1, wherein the UE obtains the CQI when all cells in the current CoMP measurement set participate in the cooperation, and the CQI is:

the UE obtains CQI of a cooperation set containing all cells in the current CoMP measurement set.

5. An apparatus for feeding back a Channel Quality Indicator (CQI), the apparatus comprising: a first obtaining unit and a first feedback unit, wherein,

the first acquisition unit is used for acquiring CQI (channel quality indicator) in a non-cooperation mode in a current coordinated multi-point transmission CoMP measurement set, CQI when all cells in the current CoMP measurement set participate in cooperation and average CQI when a part of cells in the current CoMP measurement set participate in cooperation;

a first feedback unit, configured to feed back the CQI obtained by the first obtaining unit to a network side;

the first obtaining unit includes a third obtaining module, configured to obtain an average CQI when a part of cells in a current CoMP measurement set participate in cooperation, and specifically includes: obtaining CQI of each cooperation set containing any two or more cells in the current CoMP measurement set; and then obtaining the average value of the CQI of each cooperation set with the same number of the contained cells according to the obtained CQI of each cooperation set, and obtaining the average CQI when partial cells participate in cooperation.

6. The CQI feedback apparatus according to claim 5, wherein said first obtaining unit further comprises a first obtaining module, a second obtaining module, wherein,

a first obtaining module, configured to obtain a CQI in a non-cooperative manner in a current CoMP measurement set;

and a second obtaining module, configured to obtain CQIs when all cells in the current CoMP measurement set participate in the cooperation.

7. The apparatus for feeding back CQI according to claim 6, wherein said second obtaining module is specifically configured to,

and acquiring the CQI of the cooperation set containing all the cells in the current CoMP measurement set.

8. A method for feeding back a Channel Quality Indicator (CQI), the method comprising:

the UE obtains independent CQI of each cell in a current coordinated multi-point transmission CoMP measurement set and an interference average value of interference of all cells except a main service cell to the UE in the current CoMP measurement set, and feeds the obtained CQI and the interference average value back to a network side;

the CQI and the interference average value are used by the network side to obtain, according to the obtained CQI and the interference average value, a CQI in a current CoMP measurement set in a non-coordinated manner, a CQI in a current CoMP measurement set when all cells participate in coordination, and a CQI in a current CoMP measurement set when some cells participate in coordination.

9. The CQI feedback method according to claim 8, wherein the UE obtains CQI independent of each cell in a current CoMP measurement set, and comprises:

for any cell in the current CoMP measurement set, the UE obtains the ratio of the useful signal power from the cell to the UE to the external interference plus noise power of the current CoMP measurement set, and obtains the CQI independent from the cell; according to the method for acquiring the independent COI of any cell in the current CoMP measurement set, the UE acquires the independent CQI of all cells in the current CoMP measurement set.

10. The CQI feedback method according to claim 8, wherein the UE obtains the interference average value, comprising:

the UE respectively obtains the interference power from other cells except the main service cell to the UE in the current CoMP measurement set, then obtains the ratio of the obtained interference power of each cell to the interference plus noise power from the other cells except the main service cell to the UE, and finally obtains the average value of the obtained ratios to obtain the interference average value.

11. The CQI feedback method according to claim 10, wherein the UE obtains interference power from each cell other than the primary serving cell to the UE in the current CoMP measurement set, specifically:

and the UE measures the channel gain from each cell to the UE, then traverses all code words in the R8 codebook set C to obtain a transmission weight value corresponding to the channel gain, and obtains the interference power of each cell to the UE according to the measured channel gain and the obtained transmission weight value.

12. The CQI feedback method according to claim 8, wherein after the UE feeds back the obtained CQI and the interference average to the network side, the method further comprises:

and the network side obtains the CQI in a non-cooperation mode in the current CoMP measurement set, the CQI when all cells in the current CoMP measurement set participate in cooperation and the CQI when a part of cells in the current CoMP measurement set participate in cooperation according to the independent CQI and the interference average value of each cell in the current CoMP measurement set fed back by the UE.

13. An apparatus for feeding back a Channel Quality Indicator (CQI), the apparatus comprising: a second acquisition unit and a second feedback unit, wherein,

a second obtaining unit, configured to obtain independent CQIs of all cells in a current coordinated multi-point transmission CoMP measurement set, and an interference average value of interference of all cells except a primary serving cell with the UE in the current CoMP measurement set;

a second feedback unit, configured to feed back the CQI and the average interference value obtained by the second obtaining unit to a network side;

the CQI and the interference average value are used for enabling a third obtaining unit in the network side to obtain, according to the obtained CQI and the interference average value, a CQI in a non-cooperation manner in a current CoMP measurement set, a CQI in a cooperation of all cells in the current CoMP measurement set, and a CQI in a cooperation of some cells in the current CoMP measurement set.

14. The CQI feedback apparatus according to claim 13, wherein the second obtaining unit includes: a fourth acquisition module and a fifth acquisition module, wherein,

a fourth obtaining module, configured to obtain independent CQIs of each cell in a current CoMP measurement set;

a fifth obtaining module, configured to obtain an interference average value of interference, to the UE, of all cells in the current CoMP measurement set except the primary serving cell.

15. The apparatus for feeding back CQI according to claim 14, wherein the fourth obtaining module is specifically configured to,

for any cell in the current CoMP measurement set, obtaining the ratio of the useful signal power from the cell to the UE to the external interference plus noise power of the current CoMP measurement set, and obtaining the CQI independent of the cell; according to the acquisition method, the CQI of all independent cells in the current CoMP measurement set is obtained.

16. The apparatus for feeding back CQI according to claim 14, wherein the fifth obtaining module is specifically configured to,

respectively obtaining the interference power from other cells except the main service cell to the CoMP measurement set, then obtaining the ratio of the obtained interference power of each cell to the interference plus noise power from the other cells except the main service cell in the CoMP measurement set, and finally obtaining the average value of the obtained ratios to obtain the interference average value.