CN103391127A - Multipoint collaborative information feedback method and device - Google Patents

Abstract

The invention relates to a feedback method and device for multi-point coordination. An embodiment of the present invention provides a method for information feedback of CoMP. The method includes: selecting a subband group for channel state information-reference signal CSI-RS resources in a coordinated multi-point measurement set, the subband group including at least one subband; and feeding back an identifier of the selected subband group, the The identifier includes location information of the at least one subband in the selected subband group. The invention solves the problem of feedback based on each CSI-RS resource in the multi-point coordinated measurement set, and has good protocol compatibility.

Description

Method and device for information feedback of coordinated multi-point

technical field

The present invention relates to an information feedback method and device in wireless communication, in particular to a Coordinated Multi-Point (CoMP, Coordinated Multi-Point) information feedback method and device in wireless communication.

Background technique

Coordinated multi-point transmission is a very promising technology in the Long Term Evolution-Advanced project (LTE-Advanced, Long Term Evolution-Advanced), which can effectively reduce inter-cell interference (ICI, inter-cell interference) and improve high data Rate coverage, cell edge throughput and/or system throughput. There are many different types of technical solutions for the specific implementation of multi-point coordination, such as coordinated scheduling/beamforming (CS/CB, Coordinated Scheduling/Beamforming), dynamic point selection (DPS, Dynamic Point Selection), joint transmission (JT, Joint Transmission ).

As for the CoMP transmission mechanism, the current protocol fails to provide a satisfactory solution to the industry. Taking the current protocol 36.213 as an example, the channel quality indicator (CQI, Channel Quality Indicator) of the subband selected by the user equipment (UE, User Equipment) is fed back in a 2-2 mode. This is an aperiodic channel state information (CSI, Channel State Information) reporting mechanism on a Physical Uplink Shared Channel (PUSCH, Physical Uplink Shared Channel). The user equipment selects at least one preferred subband, and reports a single precoding matrix index (PMI, Precoding Matrix Indicator)/channel quality indicator (CQI, Channel Quality Indicator) and a single subband index based on the at least one subband, so as to provide Further scheduling on the network side. The problem is that the aperiodic reporting mechanism on the physical uplink shared channel only supports multiple input multiple output (MIMO, Multiplr Inputs Multiple Outputs) and carrier aggregation (CA, Carrier Aggregation) schemes of a single cell, and does not support multipoint at all. cooperation. Therefore, it is also unable to meet the requirement of separately performing feedback based on each Channel State Information-Reference Signal (CSI-RS, Channel State Information-Reference Signal) resource participating in CoMP.

Therefore, an ideal CoMP feedback mechanism has become another hot spot in the industry, and it is also one of the problems that must be solved for the further development of CoMP technology.

Contents of the invention

An object of the present invention is to provide a novel CoMP feedback method and device to solve the CoMP feedback problem.

An embodiment of the present invention provides a method for information feedback of CoMP. The method includes: selecting a subband group for channel state information-reference signal CSI-RS resources in a coordinated multi-point measurement set, the subband group including at least one subband; and feeding back an identifier of the selected subband group, the The identifier includes location information of the at least one subband in the selected subband group.

According to another embodiment of the present invention, the method further includes receiving upper layer signaling, the upper layer signaling indicating whether the CSI-RS resource selection subband groups in the CoMP measurement set are selected jointly or separately. In an embodiment, the joint selection refers to selecting the same subband group for all CSI-RS resources in the measurement set, and the separate selection refers to selecting a subband group for each CSI-RS resource in the measurement set. When the coordinated multi-point solution is joint transmission, the subband group selected for the CSI-RS resource in the coordinated multi-point measurement set is joint selection. When the coordinated multi-point scheme is coordinated scheduling/beamforming or dynamic point selection, the subband group selected for the CSI-RS resource in the coordinated multi-point measurement set is jointly selected or selected separately. According to an embodiment of the present invention, the method further includes feeding back channel state information such as precoding matrix index and channel quality indication of each CSI-RS resource in the measurement set on the broadband and the selected subband group. In another embodiment, the method is periodic or aperiodic feedback.

The embodiment of the present invention also provides a user equipment, which is used for information feedback of coordinated multi-point. The user equipment includes: a subband group selection device, which selects a subband group for channel state information-reference signal CSI-RS resources in a coordinated multi-point measurement set, and the subband group includes at least one subband; and an identifier feedback device, An identifier of the selected subband group is fed back, where the identifier includes position information of at least one subband in the selected subband group.

In an embodiment, the user equipment further includes an upper-layer signaling receiving device for receiving upper-layer signaling; the upper-layer signaling indicates whether to select subband groups jointly or separately for the CSI-RS resource selection in the CoMP measurement set. In another embodiment, the user equipment further includes a channel state information feedback device, which feeds back channels such as the precoding matrix index and channel quality indication of each CSI-RS resource in the measurement set on the broadband and the selected subband group. status information.

Compared with the prior art, the present invention provides a novel coordinated multi-point information feedback method and device, which solves the problem of feedback based on each CSI-RS resource in the coordinated multi-point measurement set. Moreover, the present invention can flexibly support the selection of the same or different subband groups for the CSI-RS resources in the measurement set when different coordinated multi-point schemes are used, and correspondingly feed back the identifiers of multiple or one subband groups selected; thus facilitating The network side performs coordinated multi-point scheduling and other related operations.

Description of drawings

1 is a flowchart of an information feedback method for CoMP according to an embodiment of the present invention; and

Fig. 2 is a structural block diagram of a user equipment for information feedback of coordinated multi-point according to an embodiment of the present invention.

Detailed ways

In order to better understand the spirit of the present invention, it will be further described below in conjunction with some preferred embodiments of the present invention.

With the further development of the 3rd Generation Partnership Project (3GPP, 3rd Generation Partnership Project), there are some clear requirements for the feedback of Coordinated Multi-point, one of which is that the feedback of Coordinated Multi-point should be based on the Coordinated Multi-point measurement set Each CSI-RS resource within. Therefore, the modes in the current protocol 36.213, such as the 2-2 mode, cannot be directly transplanted to CoMP. Especially for the coordinated multi-point using the joint transmission scheme, it is difficult to realize the subsequent joint transmission on the network side if each CSI-RS resource that selects the subband according to the existing method is simply included in the coordinated multi-point measurement set Processing, such as joint scheduling, joint precoding, etc.

To this end, an embodiment of the present invention provides a novel CoMP feedback method and device, which uses the sufficient capacity of the physical uplink shared link to carry more feedback information, based on each A CSI-RS resource performs aperiodic or periodic feedback.

Fig. 1 is a flowchart of an information feedback method 10 for CoMP according to an embodiment of the present invention. It should be pointed out that the description order of the steps in the flow chart is not equal to the sequence in actual application, and should not be regarded as a limitation of the present invention. The same applies to other method steps involved in the present invention.

According to this embodiment, the method 10 includes: at step 100, the device for feedback, such as user equipment, receives the CSI-RS resource configured by the network side, such as the base station, for its CoMP measurement set.

In step 101, the user equipment selects subband groups for the CSI-RS resources in the CoMP measurement set, and each subband group includes at least one subband, such as M subbands. The specific subband group selection method may be different or the same depending on the coordinated multi-point solution applied by the user equipment.

For example, when the coordinated multi-point scheme adopted by the user equipment is joint transmission, selecting subband groups for all CSI-RS resources in the coordinated multi-point measurement set is joint selection. The so-called joint selection refers to selecting the same subband group for all CSI-RS resources in the coordinated multi-point measurement set. For example, for all CSI-RS resources in the coordinated multi-point measurement set, if there are two CSI-RS resources in total, the bandwidth used can be divided into S subbands, at least one of which, such as M (1≤M≤S) A subband is a subband group. The user equipment will select a preferred subband group for all CSI-RS resources from the S subbands according to certain criteria such as maximum capacity, maximum signal-to-noise ratio, etc., to transmit information. Specifically, according to an embodiment of the present invention, the certain criterion for selection is the maximum capacity criterion, and the first subband group among the S subbands may be tried to be selected first, and the two CSI-RS resources in the measurement set are used for the The capacity of the first subband group is evaluated to obtain the capacity of the two CSI RS resources in the measurement set when the first subband group is applied. Next, try to select the second subband group in the S subbands, evaluate the capacity when the two CSI-RS resources in the measurement set use the second subband group, and obtain the two CSI-RS resources in the measurement set using the The capacity of the second subband group. And so on, until the capacity of all possible subband groups in the S subbands applied to the CSI-RS resources in the measurement set has been evaluated. Then compare the capacity of different subband groups when applied to all CSI-RS resources in the measurement set, and finally select the subband group with the largest capacity as the preferred subband of all CSI-RS resources in the measurement set according to the maximum capacity criterion Group. Through joint selection, it is possible to avoid selecting different subband groups for the CSI-RS resources in the coordinated multi-point measurement set, making it difficult or even impossible for the network side to perform operations such as joint scheduling, joint precoding, and joint link adaptation.

When the coordinated multi-point scheme is coordinated scheduling/beamforming or dynamic point selection, the selection of subband groups for channel state information-reference signal CSI-RS resources in the coordinated multi-point measurement set is jointly selected or selected separately. The so-called separate selection refers to the selection of subband groups for each CSI-RS resource in the coordinated multi-point measurement set. Therefore, the subband groups selected for each CSI-RS resource may be the same or different. Also taking the aforementioned coordinated multi-point configuration as an example, for all CSI-RS resources in the measurement set, such as the bandwidth used by two CSI-RS resources, can be divided into S subbands, at least one of which, such as M(1≤ M≤S) subbands are a subband group. The user equipment will select a preferred subband group for all CSI-RS resources from the S subbands to transmit information according to certain criteria such as maximum capacity and maximum SNR. Specifically, according to an embodiment of the present invention, the certain criterion for selection is the maximum signal-to-noise ratio criterion, and for the first CSI-RS resource in the measurement set, it may first try to select the first subband among the S subbands band group, and evaluate the corresponding SNR; then try to select the second sub-band group in S sub-bands, and evaluate its SNR; and so on, until all possible sub-bands in S sub-bands The signal-to-noise ratios of band groups applied to the first CSI-RS resource have been evaluated. Then compare the signal-to-noise ratios when different sub-band groups are applied to the first CSI-RS resource, and select the sub-band group with the largest signal-to-noise ratio as the first CSI-RS resource according to the maximum signal-to-noise ratio criterion Preferred subband set. In the same way, subband groups may be selected for other CSI-RS resources in the measurement set, such as the second CSI-RS resource.

According to an embodiment of the present invention, the network side may send upper layer signaling to instruct the user equipment to select subband groups for the CSI-RS resources in the coordinated multi-point measurement set through joint selection or separate selection.

In step 102, the user equipment will feed back the identifier of the selected subband group to the network side, where the identifier includes position information of at least one subband included in the selected subband group for use by the network side. For joint selection, since the same subband group is selected for all CSI-RS resources in the measurement set, only the identifier of the same subband group is fed back. For separate selection, since the subband group selected for each CSI-RS resource in the measurement set is different, the user equipment will feed back the identifier of the subband group selected for each CSI-RS resource. The identifier includes position information of at least one subband included in the selected subband group.

According to an embodiment of the present invention, in addition to feeding back the position information of the selected subband group, that is, the identifier, the user equipment also feeds back the precoding of each CSI-RS resource in the measurement set on the broadband and the selected subband group Channel state information such as matrix index and channel quality indication.

An embodiment of the present invention also provides information feedback for CoMP, such as the user equipment 20 . Fig. 2 is a structural block diagram of a user equipment 20 according to an embodiment of the present invention. The user equipment 20 includes: a subband group selection device 200, which selects a subband group for channel state information-reference signal CSI-RS resources in a coordinated multi-point measurement set, and the subband group includes at least one subband; and identifier feedback The device 201 feeds back an identifier of the selected subband group, where the identifier includes position information of at least one subband included in the selected subband group.

In other embodiments, the user equipment 20 may further include an upper layer signaling receiving means 202 for receiving upper layer signaling. The upper layer signaling indicates whether to select subband groups jointly or separately for channel state information-reference signal CSI-RS resource selection in the coordinated multi-point measurement set. In an embodiment, the user equipment 20 may further include a channel state information feedback device 203, which feeds back the precoding matrix index and channel quality indication of each CSI-RS resource in the measurement set on the broadband and the selected subband group and other channel status information.

The structural block diagram of the user equipment 20 is only used as an example, and does not completely limit the information feedback apparatus of the present invention. For example, for those skilled in the art, the identifier feedback device 201 and the channel state information feedback device 203 can be completely integrated together.

The information feedback method and device for coordinated multi-point of the present invention solve the problem of feedback based on each CSI-RS resource in the coordinated multi-point measurement set. Moreover, it can flexibly support the selection of the same or different subband groups for the CSI-RS resources in the measurement set when different coordinated multi-point schemes are adopted, and correspondingly feed back the identifiers of the selected subband groups or one subband group. For example, for a joint-scheduled coordinated multi-point scheme, joint selection can be used to avoid selecting different subband groups for the CSI-RS resources in the coordinated multi-point measurement set, which cannot meet the joint-scheduled coordinated multi-point requirement.

Considering the development status of the current 3GPP project, the feedback mechanism of the CoMP of the present invention can be directly supplemented to the existing mode in the agreement 36.213, such as the 2-2 mode, making it an extended 2-2 mode; or in the agreement New patterns are defined in 36.213, such as the 2-4 pattern. Therefore, the present invention also has good protocol compatibility.

In addition, due to the development of technology and the updating of standards, components with the same function often have multiple different names. The technical terms used in the patent application of the present invention are for explaining and demonstrating the technical solutions of the present invention, and should be based on their functions agreed in the technical field, rather than being interpreted arbitrarily based on the similarities and differences of the names.

The technical content and technical features of the present invention have been disclosed above, but those skilled in the art may still make various substitutions and modifications based on the teaching and disclosure of the present invention without departing from the spirit of the present invention. Therefore, the protection scope of the present invention should not be limited to the content disclosed in the embodiments, but should include various replacements and modifications that do not depart from the present invention, and are covered by the claims of this patent application.

Claims (12)

1. A method for information feedback of multi-point coordination; the method includes: selecting a subband group for channel state information-reference signal CSI-RS resources in a coordinated multipoint measurement set, the subband group comprising at least one subband; and feeding back an identifier of the selected subband group, where the identifier includes position information of the at least one subband in the selected subband group. 2. The method according to claim 1, further comprising receiving upper layer signaling, the upper layer signaling indicating whether the CSI-RS resource selection subband group for the coordinated multi-point measurement set is jointly selected or selected separately; The joint selection refers to selecting the same subband group for all CSI-RS resources in the measurement set, and the separate selection refers to selecting a subband group for each CSI-RS resource in the measurement set. 3. The method according to claim 2, wherein when the coordinated multi-point scheme is joint transmission, selecting the subband group for the CSI-RS resource in the coordinated multi-point measurement set is joint selection. 4. The method according to claim 2, wherein when the coordinated multi-point scheme is coordinated scheduling/beamforming or dynamic point selection, the CSI-RS resource selection subband group in the coordinated multi-point measurement set is a joint Select or select individually. 5. The method according to claim 2, further comprising feeding back channel state information such as precoding matrix index and channel quality indication of each CSI-RS resource in the measurement set on the broadband and the selected subband group . 6. The method of claim 1, which is periodic or aperiodic feedback. 7. A user equipment, used for information feedback of multi-point coordination; the user equipment includes: The subband group selection device selects a subband group for the channel state information-reference signal CSI-RS resource in the coordinated multi-point measurement set, and the subband group includes at least one subband; and The identifier feedback means feeds back the identifier of the selected subband group, where the identifier includes position information of the at least one subband in the selected subband group. 8. The user equipment according to claim 7, further comprising upper layer signaling receiving means for receiving upper layer signaling; the upper layer signaling indicates that the CSI-RS resource selection subband group for the coordinated multi-point measurement set Whether it is joint selection or separate selection; the joint selection refers to selecting the same subband group for all CSI-RS resources in the measurement set, and the separate selection refers to the selection of each CSI-RS resource in the measurement set subband group. 9. The user equipment according to claim 8, wherein when the coordinated multi-point scheme is joint transmission, selecting the subband group for the CSI-RS resource in the measurement set of coordinated multi-point is joint selection. 10. The user equipment according to claim 8, wherein when the coordinated multi-point scheme is coordinated scheduling/beamforming or dynamic point selection, the CSI-RS resource selection subband group for the coordinated multi-point measurement set is Select jointly or separately. 11. The user equipment according to claim 8, further comprising a channel state information feedback device for feeding back the precoding matrix index and the precoding matrix index and Channel state information such as channel quality indicator. 12. The user equipment according to claim 7, which is periodic or aperiodic feedback.

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