CN103812545A - Feedback method and device for channel state information - Google Patents

Abstract

The invention provides a feedback method and a device for channel state information. According to one embodiment, the feedback method for channel state information comprises steps of dividing a plurality of cross-polarization antennas on one transmission point into a plurality of antenna groups, defining each antenna group as one channel state information-reference resource (CSI-RS) and sending the defined CSI-RS information, wherein each antenna group comprises four pairs of cross-polarization antennas and at least one antenna with the same polarization direction. The method further comprises steps of selectively allocating the phase feedback of the specific two in the defined CSI-RS and sending the phase feedback allocation by using wireless resource control signaling. According to feedback method and the device for channel state information, dispersion gain of the cluster-shaped linear array can be improved, and pre-coding and scheduling of multiple users and multiple data flows at the network side are supported.

Description

Feedback method and device for channel state information

technical field

The present invention relates to channel state information (CSI, channel state information) feedback in wireless communication, in particular to a feedback method and device for channel state information.

Background technique

The Long Term Evolution (LTE, Long Term Evolution) project is the largest new technology research and development project launched by the Third Generation Partnership Project (3GPP, 3rd Generation Partnership Project) in recent years. Technology (OFDM/FDMA) as the core technology is regarded as "quasi-4G" technology. LTE will be the most important wide-area broadband mobile communication system in the world in the future. In the future, all 2G/3G/3.5G technologies will reach the same goal by different routes and will evolve to the LTE/LTE-A (LTE-Advanced) stage. At present, there are multiple LTE/LTE-A standard versions in the industry, such as R10 and R11, and many promising technical solutions have been proposed, such as Coordinated Multi-Point (CoMP, Coordinated Multi-Point) that has attracted much attention.

At the same time, as a technology that is constantly developing and improving, LTE/LTE-A must also have some problems that need to be solved urgently. For example, according to the latest coordinated multi-point technology, a clustered linear array (CLA) of densely spaced cross-polarized antennas has a higher priority than a uniform linear array of vertically polarized antennas. However, the existing codebooks, such as the codebook provided by R10, are mainly aimed at antennas arranged in a uniform linear array. If a codebook suitable for uniform linear array antennas is used for clustered linear array antennas, quantization errors due to codebook inappropriateness will lead to non-codebook-based precoding in CoMP precoding) severe performance loss.

Therefore, it becomes another important subject in LTE/LTE-A to provide a codebook suitable for a clustered linear array of cross-polarized antennas and better solve the problem of channel state information feedback.

Contents of the invention

One of the objectives of the present invention is to provide a codebook suitable for clustered linear arrays of cross-polarized antennas.

An embodiment of the present invention provides a method for feeding back channel state information, which includes: dividing several cross-polarized antennas on a transmission point into multiple antenna groups, and each antenna group includes four pairs of cross-polarized antennas or at least one Antennas having the same polarization direction; defining each antenna group as a channel state information-reference resource CSI-RS resource; and sending information of the defined CSI-RS resource.

In an embodiment, when the antennas on the transmission point are 3D cross-polarized antennas, the antennas of each antenna group are from the same row or column of the 3D cross-polarized antennas. The method may further include selectively configuring phase feedback between specific two of the defined CSI-RS resources, and sending the phase feedback configuration using radio resource control signaling. One or more of the defined CSI-RS resources can be configured to a CoMP measurement set of a UE. In one embodiment, the defined CSI-RS resources transmit different data to the same user equipment, and in another embodiment, only part of the defined CSI-RS resources transmit data to the same user equipment.

An embodiment of the present invention provides another method for feeding back channel state information. The method includes: selecting an antenna from a pair of cross-polarized antennas on a transmission point, and the pair of cross-polarized antennas defines the first channel state information. -referring to a CSI-RS resource; defining the selected antenna as a second CSI-RS resource; and correcting the channel state information of the first CSI-RS resource by using the channel state information of the second CSI-RS resource.

In one embodiment, the rank indicator of the first CSI-RS resource is 1. The second CSI-RS resource does not transmit data to the UE, but the second CSI-RS resource can be configured to a CoMP measurement set of the UE.

An embodiment of the present invention provides a method for feeding back channel state information at the terminal side, the method including: receiving information of multiple CSI-RS resources, wherein each of the multiple CSI-RS resources is defined by an antenna group, and the antenna A group is obtained by dividing several cross-polarized antennas on a transmission point, and each antenna group includes four pairs of cross-polarized antennas or at least one antenna with the same polarization direction; receiving multiple CSI-RS resources specific a phase feedback configuration between the two; and feeding back the phase of the particular one of the two relative to the other based on the phase feedback configuration.

In one embodiment, the phase feedback configuration is received through RRC signaling.

In addition, an embodiment of the present invention provides a base station, including: an antenna group division device, which divides several cross-polarized antennas on a transmission point into multiple antenna groups, each antenna group includes four pairs of cross-polarized antennas or at least An antenna with the same polarization direction; a CSI-RS resource definition device, which defines each antenna group as a channel state information-reference resource CSI-RS resource; and a sending device, which sends the information of the defined CSI-RS resource .

The base station may include a phase feedback configuration device for selectively configuring phase feedback between specific two defined CSI-RS resources, and sending the phase feedback configuration using radio resource control signaling. It may also include a measurement set configuration device, configured to configure one or more of the defined CSI-RS resources to a coordinated multi-point measurement set of a user equipment.

The base station according to another embodiment of the present invention includes an antenna selection device, which selects an antenna from a pair of cross-polarized antennas on a transmission point, and the pair of cross-polarized antennas defines a first channel state information-reference resource CSI-RS resources; CSI-RS resource defining means, defining the selected antenna as a second CSI-RS resource; and correcting means, using the channel state information of the second CSI-RS resource to correct the channel state of the first CSI-RS resource information.

The present invention also provides user equipment. According to an embodiment of the present invention, the user equipment includes: a resource information receiving device for receiving information of a plurality of CSI-RS resources, wherein each of the plurality of CSI-RS resources is controlled by an antenna group Definition, the antenna group is divided by several cross-polarized antennas on a transmission point, and each antenna group contains four pairs of cross-polarized antennas or at least one antenna with the same polarization direction; the phase feedback configuration receiving device, receiving A phase feedback configuration between the two specified in the CSI-RS resources; and a phase feedback device for feeding back a phase of one of the two specified relative to the other based on the phase feedback configuration.

The present invention solves the channel state information feedback problem of the clustered linear array in LTE/LTE-A, improves the dispersion gain (diversity gain) of the clustered linear array, and can support multi-user and multi-data stream precoding and scheduling on the network side , and can achieve standard downward compatibility and upward development.

Description of drawings

FIG. 1 is a flowchart of a channel state information feedback method according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a channel state information feedback method applied to a two-antenna cross-polarized antenna cluster linear array according to an embodiment of the present invention;

FIG. 3 illustrates a flowchart of a channel state information feedback method according to an embodiment of the present invention;

4 is a schematic diagram of a channel state information feedback method applied to a cross-polarized 3D antenna according to an embodiment of the present invention;

5 is a flow chart of a method for feedbacking channel state information of a cross-polarized antenna with two antennas according to an embodiment of the present invention;

Fig. 6 is a schematic diagram of a specific application example of the method shown in Fig. 5;

FIG. 7 is a schematic block diagram of a structure of a base station according to an embodiment of the present invention;

Fig. 8 is a schematic block diagram of a structure of a base station according to another embodiment of the present invention;

Fig. 9 is a schematic block diagram of a structure of a user equipment 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.

In LTE/LTE-A R11, the user equipment can be configured to report one or more channel state information for each component carrier (CC: ComponentCarrier). In the case of CoMP, each channel state information is configured by a combination of a channel part and an interference part, where the channel part is a non-zero power (NZP, non-zero power) channel state information in the CoMP measurement set - Reference signal (CSI-RS, Channel State Information-Reference Signal) resource. For different channel state information, the configured non-zero power CSI-RS resources may be different.

With the development of LTE/LTE-A technology, a clustered linear array (CLA, clustered linear array) of cross-polarized antennas will be more and more widely used. However, the existing codebook, such as the codebook provided by R10, is mainly used for 2-antenna and 4-antenna uniform linear arrays. If the codebook provided by R10 is directly used for the polarized antennas arranged in clustered linear arrays, quantization errors caused by inappropriate codebooks will inevitably lead to serious performance loss, such as reducing the dispersion gain.

The method and device for channel state information feedback (including feedback configuration at the network side and feedback at the terminal side) according to an embodiment of the present invention can solve the above problems.

FIG. 1 is a flowchart of a channel state information feedback method according to an embodiment of the present invention, the method includes: at step 10, dividing several cross-polarized antennas on a transmission point into multiple antenna groups on the network side, Each antenna group contains four pairs of cross-polarized antennas or at least one antenna with the same polarization direction. In an embodiment, 2 or 4 cross-polarized antennas can be divided into two groups, and the antennas in each group have the same polarization direction, for example, they are all vertically polarized. In an embodiment, 8 pairs of 16 cross-polarized antennas can be divided into 2 groups, and each group is 4 pairs of cross-polarized antennas. In step 12, each divided antenna group is defined as a CSI-RS resource. Then in step 14, the network side, such as the base station, sends the defined CSI-RS resource information to the terminal side, such as the user equipment.

FIG. 2 is a schematic diagram of a channel state information feedback method applied to a two-antenna cross-polarized antenna cluster linear array according to an embodiment of the present invention. In Figure 2, X identifies a pair of cross-polarized antennas, and "/" or "\" respectively identify an antenna with a different polarization direction (the same follows). Transmission point 20, namely CSI-RS resource #1, includes two polarized antennas. Divide the two antennas into two groups 22, 24, each group 22, 24 is defined as a new CSI-RS resource, the first group 22 is CSI-RS resource #1-1, and the second group 24 is CSI-RS resource #1-2; then send the information of the CSI-RS resource #1-1 and the CSI-RS resource #1-2 to the corresponding terminal, thereby completing the feedback configuration of the channel state information. The terminal can receive data from CSI-RS resource #1-1 and CSI-RS resource #1-2 respectively, and feed back CSI-RS resource #1-1 and CSI-RS resource respectively according to the received feedback configuration about the two Channel status information of #1-2.

The channel state information feedback method according to an embodiment of the present invention further includes specifying the phase feedback between the two in the CSI-RS resources defined by selective configuration on the network side, and using radio resource (RRC, RadioResource Control) information command to send the phase feedback configuration. For example, for the embodiment shown in FIG. 2 , the user equipment may be configured to feed back the phase of the CSI-RS resource #1-2 relative to the CSI-RS resource #1-1, and the specific configuration is shown in Table 1.

Table 1 Selective Phase Feedback Configuration

CSI-RS Resources Phase Feedback Configuration CSI-RS Resource #1-1 No phase feedback CSI-RS Resources #1-2 Reports phase relative to CSI-RS resource #1-1

Correspondingly, on the terminal side, FIG. 3 illustrates a flowchart of a channel state information feedback method according to an embodiment of the present invention. As shown in FIG. 3 , the method for channel state information feedback includes: at step 30, receiving information about a plurality of CSI-RS resources defined by antenna groups as described above, such as the above-mentioned CSI-RS resource #1-1 and CSI-RS resource #1-1 RS Resources #1-2. In step 32, the phase feedback configuration between specific two of the multiple CSI-RS resources is received, such as receiving the phase feedback configuration about CSI-RS resource #1-1 and CSI-RS resource #1-2 as described in Table 1 . Then at step 34 the phase of one relative to the other is fed back based on the received phase feedback configuration, for example the phase of reporting relative to CSI-RS resource #1-1.

In another embodiment of the present invention, one or more of the defined CSI-RS resources may be configured to a coordinated multi-point measurement set of a user equipment, and the configuration is transparent to the user equipment.

These CSI-RS resources defined according to the antenna group are not limited to transmitting the same data to the same user equipment, but may transmit different data, may transmit no data or only part of the CSI-RS resources transmit data. As far as the embodiment shown in FIG. 2 is concerned, both CSI-RS resource #1-1 and CSI-RS resource #1-2 can send data to the user equipment, or neither can send data, or only one of them is like CSI-RS resource #1-2. RS resource #1-1 transmits.

FIG. 4 is a schematic diagram of a channel state information feedback method applied to a cross-polarized 3D antenna according to an embodiment of the present invention. When grouping 3D polarized antennas, it is necessary to group them in rows or columns, and polarized antennas in different rows and columns will not be grouped into the same antenna group; and it is not necessary to group all rows or columns. In this embodiment, the 3D antennas contained in the first CSI-RS resource 40 (CSI-RS resource #4) are a combination of 16 antennas in two rows and four columns. After grouping, the four pairs of cross antennas in the second row are defined as the second CSI-RS resource 42 (CSI-RS resource #4-1), and the four cross antennas in the first column are divided into two groups according to the polarization direction, respectively Defined as the third CSI-RS resource 44 (CSI-RS resource #4-2) and the third CSI-RS resource 46 (CSI-RS resource #4-3); the first line is not used to define a new CSI-RS resource. In other embodiments, the cross antennas in the first row may also be grouped, and the cross antennas in the first row or the second row may be further grouped according to the polarization direction; similarly, the same is true for each column.

For the embodiment shown in FIG. 4 , it is optional to configure the user equipment to feed back the phase of the CSI-RS resource #4-3 relative to the CSI-RS resource #4-2. The specific configuration is shown in Table 2.

Table 1 Selective Phase Feedback Configuration

CSI-RS Resources Phase Feedback Configuration

CSI-RS Resource #4-1 No phase feedback CSI-RS Resource #4-2 No phase feedback CSI-RS Resource #4-3 Report phase relative to CSI-RS resource #4-2

According to another embodiment of the present invention, for a cross-polarized antenna with two antennas, in order to avoid feedback of received channel state information, such as a precoding matrix index (PMI, Precoding Matrix Indicator)/channel quality indicator (CQI, Channel Quality Indicator) Inaccurate, the channel state information of one of the antennas can be selected to correct it. Fig. 5 is a flow chart of a method for feeding back channel state information of cross-polarized antennas with two antennas according to an embodiment of the present invention, and Fig. 6 is a schematic diagram of a specific application example of the method shown in Fig. 5 . 5 and 6, the method includes, in step 50, selecting an antenna from a transmission point 60, that is, a pair of cross-polarized antennas on the first CSI-RS resource 60 (CSI-RS resource #1), compared The preferred rank indicator (RI, RankIndicator) of the first CSI-RS resource is 1; in step 52, the selected antenna is defined as the second CSI-RS resource 62 (CSI-RS resource #1-1); Step 54 uses the channel state information of the second CSI-RS resource 62 to correct the channel state information of the first CSI-RS resource 60 . Since the second CSI-RS resource 62 has only one antenna port, the user equipment will only feed back one channel quality indicator, so the channel quality indicator of the second CSI-RS resource 62 can be used to correct the original CSI-RS resource, that is, the first CSI-RS Resource CQI/PMI feedback.

The second CSI-RS resource 62 is only used to assist in correcting channel state information feedback, and does not transmit data to the user equipment, but can be configured to the CoMP measurement set of the user equipment, and this configuration is also transparent to the user equipment.

In addition, the present invention also provides a channel state information feedback device implementing the above channel state information feedback method, such as a base station or user equipment. Fig. 7 is a schematic block diagram of the structure of a base station 70 according to an embodiment of the present invention. The base station 70 includes an antenna group division device 700, which divides several cross-polarized antennas on a transmission point into multiple antenna groups, and each antenna group includes four pairs of cross-polarized antennas or at least one antenna with the same polarization direction . Of course, when the antenna on the transmission point is a 3D cross-polarized antenna, the antennas of each antenna group come from the same row or column in the 3D cross-polarized antenna; the CSI-RS resource definition device 702 defines each antenna group as a channel State information-reference resource CSI-RS resource; and sending means 704, sending the information of the defined CSI-RS resource to the user equipment.

In other embodiments, the base station 70 further includes a phase feedback configuration device for selectively configuring phase feedback between specific two defined CSI-RS resources, and sending the phase feedback configuration by using radio resource control signaling. It may also be a measurement set configuration device, which configures one or more of the defined CSI-RS resources to a coordinated multi-point measurement set of a user equipment.

Fig. 8 is a schematic structural block diagram of a base station 80 according to another embodiment of the present invention. The base station 80 includes an antenna selection device 800, which selects an antenna from a pair of cross-polarized antennas on a transmission point, and the pair of cross-polarized antennas defines a first channel state information-reference resource CSI-RS resource; CSI-RS The resource defining unit 802 defines the selected antenna as a second CSI-RS resource; and the correcting unit 804 uses the channel state information of the second CSI-RS resource to correct the channel state information of the first CSI-RS resource.

The base station 80 may also include a measurement set configuration device for configuring the second CSI-RS resource to a CoMP measurement set of a user equipment.

Fig. 9 is a schematic block diagram of a structure of a user equipment 90 according to an embodiment of the present invention. The user equipment 90 includes a resource information receiving unit 902, which receives information of a plurality of CSI-RS resources, wherein each of the plurality of CSI-RS resources is defined by an antenna group, and the antenna group is composed of several cross poles on a transmission point Polarized antennas are divided, and each antenna group includes four pairs of cross-polarized antennas or at least one antenna with the same polarization direction; the phase feedback configuration receiving device 904 receives the phase between specific two of the multiple CSI-RS resources a feedback configuration; and phase feedback means 906 for feeding back the phase of one of the specified two relative to the other based on the phase feedback configuration.

The invention reduces the quantization error of the channel state information feedback by grouping the cross-polarized antennas according to the polarization direction, improves the dispersion gain of the clustered linear array, and can support multi-user multi-data stream precoding and scheduling on the network side . It is not only suitable for multi-point cooperation but also for multi-user-multiple input multiple output (MU-MIMO, Multiple User-Multiple Input Multiple Output) system.

It should be pointed out that 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 (30)

1. A method for feeding back channel state information, comprising: Divide several cross-polarized antennas on a transmission point into multiple antenna groups, each antenna group contains four pairs of cross-polarized antennas or at least one antenna with the same polarization direction; Each antenna group is defined as a channel state information-reference resource CSI-RS resource; information of the defined CSI-RS resource is sent. 2. The method of claim 1, further comprising selectively configuring phase feedback between specific two of the defined CSI-RS resources, and sending the phase feedback configuration using RRC signaling. 3. The method of claim 1, further comprising configuring one or more of the defined CSI-RS resources to a CoMP measurement set of a UE. 4. The method of claim 1, wherein the defined CSI-RS resources transmit different data to the same UE. 5. The method according to claim 1, wherein only part of the defined CSI-RS resources transmits data to the same UE. 6. The method according to claim 1, wherein when the antennas on the transmission point are 3D cross-polarized antennas, the antennas of each antenna group are from the same row or column of the 3D cross-polarized antennas. 7. A method for feeding back channel state information, comprising: Select an antenna from a pair of cross-polarized antennas on a transmission point, and the pair of cross-polarized antennas defines a first channel state information-reference resource CSI-RS resource; defining the selected antenna as a second CSI-RS resource; Correcting the channel state information of the first CSI-RS resource by using the channel state information of the second CSI-RS resource. 8. The method of claim 7, further comprising configuring the second CSI-RS resource to a CoMP measurement set of a UE. 9. The method of claim 7, wherein the second CSI-RS resource does not transmit data to the UE. 10. The method of claim 7, wherein the rank indicator of the first CSI-RS resource is 1. 11. A method for feeding back channel state information, comprising: Receiving a plurality of channel state information-reference resources CSI-RS resources, wherein each of the plurality of CSI-RS resources is defined by an antenna group consisting of several cross-polarized The antennas are divided, and each antenna group includes four pairs of cross-polarized antennas or at least one antenna with the same polarization direction; Receive phase feedback configurations between specific two of the multiple CSI-RS resources; The phase of one of the two relative to the other is fed back based on the phase feedback configuration. 12. The method of claim 11, wherein the phase feedback configuration is received via radio resource control signaling. 13. The method of claim 11, further comprising receiving different data from the plurality of CSI-RS resources. 14. The method of claim 11, further comprising receiving data from only a portion of the plurality of CSI-RS resources. 15. The method of claim 11, wherein when the antennas on the transmission point are 3D cross-polarized antennas, the antennas of each antenna group are from the same row or column of the 3D cross-polarized antennas. 16. A base station, comprising: The antenna group division device divides several cross-polarized antennas on a transmission point into multiple antenna groups, and each antenna group contains four pairs of cross-polarized antennas or at least one antenna with the same polarization direction; The CSI-RS resource defining device defines each antenna group as a channel state information-reference resource CSI-RS resource; The sending device sends the defined CSI-RS resource information. 17. The base station as claimed in claim 16, further comprising a phase feedback configuration device, selectively configuring phase feedback between specific two in the defined CSI-RS resources, and using radio resource control signaling to send the phase feedback configure. 18. The base station as claimed in claim 16, further comprising measurement set configuration means for configuring one or more of the defined CSI-RS resources to a CoMP measurement set of a UE. 19. The base station of claim 16, wherein the defined CSI-RS resources transmit different data to the same UE. 20. The base station according to claim 16, wherein only part of the defined CSI-RS resources transmits data to the same UE. 21. The base station according to claim 16, wherein when the antennas on the transmission point are 3D cross-polarized antennas, the antennas of each antenna group are from the same row or column of the 3D cross-polarized antennas. 22. A base station, comprising: The antenna selection device selects an antenna from a pair of cross-polarized antennas on a transmission point, and the pair of cross-polarized antennas defines a first channel state information-reference resource CSI-RS resource; a CSI-RS resource defining device, defining the selected antenna as a second CSI-RS resource; The correction device uses the channel state information of the second CSI-RS resource to correct the channel state information of the first CSI-RS resource. 23. The base station as claimed in claim 22, further comprising measurement set configuration means for configuring the second CSI-RS resource to a CoMP measurement set of a UE. 24. The base station of claim 22, wherein the second CSI-RS resource does not transmit data to the UE. 25. The base station of claim 22, wherein the rank indicator of the first CSI-RS resource is 1. 26. A user equipment comprising: The resource information receiving device receives information of a plurality of CSI-RS resources, wherein each of the plurality of CSI-RS resources is defined by an antenna group, and the antenna group is composed of several cross-polarized antennas on a transmission point obtained by division, and each antenna group includes four pairs of cross-polarized antennas or at least one antenna with the same polarization direction; The phase feedback configuration receiving device receives the phase feedback configuration between specific two of the plurality of CSI-RS resources; Phase feedback means for feeding back the phase of one of the two relative to the other based on the phase feedback configuration. 27. The user equipment according to claim 26, which receives the phase feedback configuration through radio resource control signaling. 28. The user equipment of claim 26, which receives different data from the plurality of CSI-RS resources. 29. The user equipment of claim 26, which receives data from only a portion of the plurality of CSI-RS resources. 30. The user equipment according to claim 26, wherein when the antennas on the transmission points are 3D cross-polarized antennas, the antennas of each antenna group are from the same row or column of the 3D cross-polarized antennas .

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