CHANNEL STATE INFORMATION FEEDBACK AND ACQUISITIONMETHOD AND DEVICE

• US 20180069613A1
• Filed: 02/03/2016
• Published: 03/08/2018
• Est. Priority Date: 03/31/2015
• Status: Active Grant

• Current Assignee: Datang Mobile Communications Equipment Company Limited (China Information Communication Technology Group Co. Ltd.)
• Original Assignee: China Academy of Telecom Technology (China Information Communication Technology Group Co. Ltd.)
• Inventors: LI, Hui, GAO, Qiubin, CHEN, Runhua, RAKESH, Tamrakar, CHEN, Wenhong
• Granted Patent: US 10,305,569 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0478 Special codebook structures directed to feedback optimisation
• CPC Class Codes: H04B 7/0479 for multi-dimensional arrays, e.g. horizontal or vertical pre-distortion matrix index [PMI]
• CPC Class Codes: H04B 7/06 at the transmitting station
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04B 7/0634 Antenna weights or vector/matrix coefficients
• CPC Class Codes: H04B 7/0639 Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection
• CPC Class Codes: H04B 7/066 Combined feedback for a number of channels, e.g. over several subcarriers like in orthogonal frequency division multiplexing [OFDM]
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports

Abstract

Disclosed are a channel state information feedback and acquisition method and device. The application comprises: acquiring, by a terminal, a first-dimension downlink reference signal resource, S second-dimension downlink reference signal resources and a first corresponding relationship of the above configured by a network device; measuring, by the terminal and according to the first-dimension downlink reference signal resource, a first-dimension downlink reference signal, and selecting, by the terminal and according to the measured first-dimension PMI and the first corresponding relationship, a resource for measuring a second-dimension downlink reference signal, measuring, according to the resource, the second-dimension downlink reference signal, and feeding back channel state information, wherein the second-dimension reference signal is transmitted after forming a first-dimension beamforming weight. The present application enables acquisition of channel state information between a network device and a terminal, and adjustment of the first-dimension beamforming weight for forming the second-dimension reference signal according to the PMI fed back by the first-dimension.

Claims

1. A method for feeding back channel state information, the method comprising:

obtaining, by a terminal, one first-dimension downlink reference signal resource, S second-dimension downlink reference signal resources, and a first correspondence relationship, configured by a network device, wherein the first correspondence relationship comprises a correspondence relationship between the S second-dimension downlink reference signal resources and N first-dimension beam-forming weights, and both S and N are integers greater than 1;

measuring, by the terminal, a first-dimension downlink reference signal according to the first-dimension downlink reference signal resource to obtain a first-dimension Pre-coding matrix Indicator (PMI), wherein the first-dimension PMI indicates one of the N first-dimension beam-forming weights;

selecting, by the terminal, one of the S second-dimension downlink reference signal resources for measuring a second-dimension downlink reference signal, according to the obtained first-dimension PMI and the first correspondence relationship; and

measuring, by the terminal, the second-dimension downlink reference signal, and feeding back channel state information, according to the selected resource for measuring the second-dimension downlink reference signal, wherein the second-dimension downlink reference signal transmitted over the selected second-dimension downlink reference signal resource is transmitted after being beam-formed using the first-dimension beam-forming weight corresponding to the resource.

2. The method according to claim 1, wherein if N is equal to S, then each first-dimension beam-forming weight corresponds to one of the second-dimension downlink reference signal resources in the first correspondence relationship;

or

if N is greater than S, then in the first correspondence relationship, at least one of the second-dimension downlink reference signal resources corresponds to a plurality of first-dimension beam-forming weights; and

one of the plurality of first-dimension beam-forming weights is used for beam-forming on the downlink reference signal transmitted over the second-dimension downlink reference signal resource, the other first-dimension beam-forming weights are not be used for beam-forming on any downlink reference signal, and a correlation metric between the other first-dimension beam-forming weights, and the first-dimension beam-forming weight for beam-forming on the downlink reference signal transmitted over the second-dimension downlink reference signal resource is greater than a threshold.

4. The method according to claim 2, wherein selecting, by the terminal, one of the S second-dimension downlink reference signal resources for measuring a second-dimension downlink reference signal, according to the obtained first-dimension PMI and the first correspondence relationship comprises:

referring, by the terminal, to the first correspondence relationship using the obtained first-dimension PMI, obtaining the second-dimension downlink reference signal resource uniquely corresponding to the first-dimension PMI, and determining the obtained second-dimension downlink reference signal resource as the resource for measuring the second-dimension downlink reference signal.

5. The method according to claim 1, wherein if N is greater than S, then each of the S first-dimension beam-forming weights among the N first-dimension beam-forming weights corresponds respectively to one of the second-dimension downlink reference signal resources in the first correspondence relationship;

wherein selecting, by the terminal, one of the S second-dimension downlink reference signal resources for measuring a second-dimension downlink reference signal, according to the obtained first-dimension PMI and the first correspondence relationship comprises;

referring, by the terminal, to the first correspondence relationship using the obtained first-dimension PMI; and

if a second-dimension downlink reference signal resource corresponding to the first-dimension PMI is found, then determining the found second-dimension downlink reference signal resource as the resource for measuring the second-dimension downlink reference signal;

or

if no second-dimension downlink reference signal resource corresponding to the first-dimension PMI is found, then selecting one of the S first-dimension beam-forming weights according to the correlations between these S first-dimension beam-forming weights, and the first-dimension beam-forming weight indicated by the first-dimension PMI, referring to the first correspondence relationship for the second-dimension downlink reference signal resource corresponding to the selected first-dimension beam-forming weight, and determining the found second-dimension downlink reference signal resource as the resource for measuring the second-dimension downlink reference signal.

7. The method according to claim 1, wherein if N is less than S, then each first-dimension beam-forming weight corresponds to one of the second-dimension downlink reference signal resources in the first correspondence relationship, and all the first-dimension beam-forming weights corresponding to the second-dimension downlink reference signal resources in the first correspondence relationship belong to a second set;

and

the second set comprises at least S first-dimension beam-forming weights, there is a second correspondence relationship between the first-dimension beam-forming weights in the second set, and the first-dimension beam-forming weights in the first set, at least one of the first-dimension beam-forming weights in the first set corresponds to more than one of the first-dimension beam-forming weights in the second set, and the first set is configured in the terminal as a codebook for measuring the first-dimension downlink reference signal.

8. The method according to claim 7, wherein the method further comprises:

obtaining, by the terminal, the second correspondence relationship configured by the network device; and

selecting, by the terminal, one of the S second-dimension downlink reference signal resources for measuring a second-dimension downlink reference signal, according to the obtained first-dimension PMI and the first correspondence relationship comprises;

referring, by the terminal, to the second correspondence relationship using the obtained first-dimension PMI, and obtaining the first-dimension beam-forming weight in the second set corresponding to the first-dimension PMI, wherein the first-dimension PMI indicates the first-dimension beam-forming weight in the first set; and

referring, by the terminal, to the first correspondence relationship using the obtained first-dimension beam-forming weight in the second set, obtaining the corresponding second-dimension downlink reference signal resource, and determining the obtained second-dimension downlink reference signal resource as the resource for measuring the second-dimension downlink reference signal.

9. The method according to claim 1, wherein the channel state information fed back by the terminal after measuring the second-dimension downlink reference signal comprises the index of the selected second-dimension downlink reference signal resource for measuring the second-dimension downlink reference signal, and a second-dimension PMI, a Rank Indicator (RI), and a Channel Quality Indicator (CQI) obtained by measuring the second-dimension downlink reference signal according to the selected resource for measuring the second-dimension downlink reference signal.

10. The method according to claim 1, wherein after the terminal obtains the first-dimension PMI, the method further comprises:

feeding, by the terminal, the obtained first-dimension PMI back to the network device.

14. The method according to claim 1, wherein if N is equal to S, then each first-dimension beam-forming weight corresponds to one of the second-dimension downlink reference signal resources in the first correspondence relationship;

or

if N is greater than S, then in the first correspondence relationship, at least one of the second-dimension downlink reference signal resources corresponds to a plurality of first-dimension beam-forming weights; and

one of the plurality of first-dimension beam-forming weights is used for beam-forming on the downlink reference signal transmitted over the second-dimension downlink reference signal resource, the other first-dimension beam-forming weights are not be used for beam-forming on any downlink reference signal, and a correlation metric between the other first-dimension beam-forming weights, and the first-dimension beam-forming weight for beam-forming on the downlink reference signal transmitted over the second-dimension downlink reference signal resource is greater than a threshold, or

if N is greater than S, then each of the S first-dimension beam-forming weights among the N first-dimension beam-forming weights corresponds respectively to one of the second-dimension downlink reference signal resources in the first correspondence relationship;

or

if N is less than S, then each first-dimension beam-forming weight corresponds to one of the second-dimension downlink reference signal resources in the first correspondence relationship, and all the first-dimension beam-forming weights corresponding to the second-dimension downlink reference signal resources in the first correspondence relationship belong to a second set and the second set comprises at least S first-dimension beam-forming weights, there is a second correspondence relationship between the first-dimension beam-forming weights in the second set, and the first-dimension beam-forming weights in the first set, at least one of the first-dimension beam-forming weights in the first set corresponds to more than one of the first-dimension beam-forming weights in the second set, and the first set is configured in the terminal as a codebook for measuring the first-dimension downlink reference signal.

3. (canceled)

6. (canceled)

11. A method for obtaining channel state information, the method comprising:

configuring, by a network device, a terminal with one first-dimension downlink reference signal resource, S second-dimension downlink reference signal resources, and a first correspondence relationship comprising a correspondence relationship between the S second-dimension downlink reference signal resources and N first-dimension beam-forming weights, wherein both S and N are integers greater than 1;

transmitting, by the network device, a first-dimension downlink reference signal according to the first-dimension downlink reference signal resource, and transmitting second-dimension downlink reference signals according to the second-dimension downlink reference signal resources, wherein the second-dimension downlink reference signal transmitted over each second-dimension downlink reference signal resource is transmitted after being beam-formed using the first-dimension beam-forming weight corresponding to the resource; and

receiving, by the network device, channel state information measured and fed back by the terminal using the second-dimension downlink reference signal, and obtaining a channel state of the terminal from the channel state information, wherein the channel state information is obtained by the terminal by selecting one of the S second-dimension downlink reference signal resources for measuring the second-dimension downlink reference signal, according to a first-dimension Pre-coding matrix Indicator (PMI) obtained by measuring the first-dimension downlink reference signal, and the first correspondence relationship, and then measuring the second-dimension downlink reference signal according to the selected second-dimension downlink reference signal resource, and the first-dimension PMI indicates one of the N first-dimension beam-forming weights.

12. The method according to claim 11, wherein the channel state information fed back by the terminal after measuring the second-dimension downlink reference signal comprises the index of the selected second-dimension downlink reference signal resource for measuring the second-dimension downlink reference signal, and a second-dimension PMI, a Rank Indicator (RI), and a Channel Quality Indicator (CQI) obtained by measuring the second-dimension downlink reference signal according to the selected resource for measuring the second-dimension downlink reference signal;

and

obtaining, by the network device, the channel state of the terminal from the channel state information comprises;

determining, by the network device, the first-dimension beam-forming weight corresponding to the second-dimension downlink reference signal resource according to the index of the second-dimension downlink reference signal resource, and the first correspondence relationship; and

combining, by the network device, a pre-coding matrix indicated by the second-dimension PMI with the determined first-dimension beam-forming weight into a pre-coding matrix of the terminal.

13. The method according to claim 11, wherein the method further comprises:

receiving, by the network device, first-dimension PMIs fed back by terminals in a coverage area of the network device; and

performing, by the network device, one or more of the following first operation to third operation according to the first-dimension PMIs fed back by the terminals in the coverage area of the network device;

in a first operation, in the instance of N>

S, selecting the S first-dimension beam-forming weights from the N first-dimension beam-forming weights to perform beam-forming on the downlink reference signals transmitted over the S second-dimension downlink reference signal resources;

in a second operation, in the instance of N>

S, after selecting the S first-dimension beam-forming weights from the N first-dimension beam-forming weights to perform beam-forming on the downlink reference signals transmitted over the S second-dimension downlink reference signal resources, determining a distribution of the terminals according to the first-dimension PMIs fed back by the terminals in the coverage area of the network device, reselecting the S first-dimension beam-forming weights from the N first-dimension beam-forming weights according to the distribution of the terminals to perform beam-forming on the downlink reference signals transmitted over the S second-dimension downlink reference signal resources, and notifying a correspondence relationship between the reselected S first-dimension beam-forming weights, and the S second-dimension downlink reference signal resources to the terminals;

in a third operation, determining a distribution of the terminals in the coverage area of the network device in the first dimension, and adjusting the first-dimension beam-forming weights according to the distribution of the terminals in the coverage area of the network device in the first dimension.

15-17. -17. (canceled)

18. A terminal, comprising at least one processor and a memory, wherein the memory is configured to store computer readable program codes, the at least one processor is configured to execute the computer readable program codes to:

obtain one first-dimension downlink reference signal resource, S second-dimension downlink reference signal resources, and a first correspondence relationship, configured by a network device, wherein the first correspondence relationship comprises a correspondence relationship between the S second-dimension downlink reference signal resources and N first-dimension beam-forming weights, and both S and N are integers greater than 1;

measure a first-dimension downlink reference signal according to the first-dimension downlink reference signal resource to obtain a first-dimension Pre-coding matrix Indicator (PMI), wherein the first-dimension PMI indicates one of the N first-dimension beam-forming weights;

select one of the S second-dimension downlink reference signal resources for measuring a second-dimension downlink reference signal, according to the obtained first-dimension PMI and the first correspondence relationship; and

measure the second-dimension downlink reference signal, and feed back channel state information, according to the selected resource for measuring the second-dimension downlink reference signal, wherein the second-dimension downlink reference signal transmitted over the selected second-dimension downlink reference signal resource is transmitted after being beam-formed using the first-dimension beam-forming weight corresponding to the resource.

19. The terminal according to claim 18, wherein:

if N is equal to S, then each first-dimension beam-forming weight corresponds to one of the second-dimension downlink reference signal resources in the first correspondence relationship;

or

if N is greater than S, then in the first correspondence relationship, at least one of the second-dimension downlink reference signal resources corresponds to a plurality of first-dimension beam-forming weights; and

one of the plurality of first-dimension beam-forming weights is used for beam-forming on the downlink reference signal transmitted over the second-dimension downlink reference signal resource, the other first-dimension beam-forming weights are not be used for beam-forming on any downlink reference signal, and a correlation metric between the other first-dimension beam-forming weights, and the first-dimension beam-forming weight for beam-forming on the downlink reference signal transmitted over the second-dimension downlink reference signal resource is greater than a threshold;

wherein the at least one processor is configured to execute the computer readable program codes to;

refer to the first correspondence relationship using the obtained first-dimension PMI, obtain the second-dimension downlink reference signal resource corresponding to the first-dimension PMI, and determine the obtained second-dimension downlink reference signal resource as the resource for measuring the second-dimension downlink reference signal.

21. The terminal according to claim 18, wherein if N is greater than S, then each of the S first-dimension beam-forming weights among the N first-dimension beam-forming weights corresponds respectively to one of the second-dimension downlink reference signal resources in the first correspondence relationship;

and

the at least one processor is configured to execute the computer readable program codes to;

refer to the first correspondence relationship using the obtained first-dimension PMI; and

if a second-dimension downlink reference signal resource corresponding to the first-dimension PMI is found, determine the found second-dimension downlink reference signal resource as the resource for measuring the second-dimension downlink reference signal;

or

if no second-dimension downlink reference signal resource corresponding to the first-dimension PMI is found, select one of the S first-dimension beam-forming weights according to the correlations between these S first-dimension beam-forming weights, and the first-dimension beam-forming weight indicated by the first-dimension PMI, refer to the first correspondence relationship for the second-dimension downlink reference signal resource corresponding to the selected first-dimension beam-forming weight, and determine the found second-dimension downlink reference signal resource as the resource for measuring the second-dimension downlink reference signal.

22. The terminal according to claim 18, wherein if N is less than S, then each first-dimension beam-forming weight corresponds to one of the second-dimension downlink reference signal resources in the first correspondence relationship, and all the first-dimension beam-forming weights corresponding to the second-dimension downlink reference signal resources in the first correspondence relationship belong to a second set, wherein the second set comprises at least S first-dimension beam-forming weights, there is a second correspondence relationship between the first-dimension beam-forming weights in the second set, and the first-dimension beam-forming weights in the first set, at least one of the first-dimension beam-forming weights in the first set corresponds to more than one of the first-dimension beam-forming weights in the second set, and the first set is configured in the terminal as a codebook for measuring the first-dimension downlink reference signal;

the at least one processor is configured to execute the computer readable program codes to;

obtain the second correspondence relationship configured by the network device; and

to refer to the second correspondence relationship using the obtained first-dimension PMI, and obtain the first-dimension beam-forming weight in the second set corresponding to the first-dimension PMI, wherein the first-dimension PMI indicates the first-dimension beam-forming weight in the first set; and

refer to the first correspondence relationship using the obtained first-dimension beam-forming weight in the second set, obtain the corresponding second-dimension downlink reference signal resource, and to determine the obtained second-dimension downlink reference signal resource as the resource for measuring the second-dimension downlink reference signal.

20. (canceled)

23. A network device, comprising:

configure a terminal with one first-dimension downlink reference signal resource, S second-dimension downlink reference signal resources, and a first correspondence relationship comprising a correspondence relationship between the S second-dimension downlink reference signal resources and N first-dimension beam-forming weights, wherein both S and N are integers greater than 1;

transmit a first-dimension downlink reference signal according to the first-dimension downlink reference signal resource, and transmit second-dimension downlink reference signals according to the second-dimension downlink reference signal resources, wherein the second-dimension downlink reference signal transmitted over each second-dimension downlink reference signal resource is transmitted after being beam-formed using the first-dimension beam-forming weight corresponding to the resource; and

receive channel state information measured and fed back by the terminal using the second-dimension downlink reference signal, and t-e obtain a channel state of the terminal from the channel state information, wherein the channel state information is obtained by the terminal by selecting one of the S second-dimension downlink reference signal resources for measuring the second-dimension downlink reference signal, according to a first-dimension Pre-coding matrix Indicator (PMI) obtained by measuring the first-dimension downlink reference signal, and the first correspondence relationship, and then measuring the second-dimension downlink reference signal according to the selected second-dimension downlink reference signal resource, and the first-dimension PMI indicates one of the N first-dimension beam-forming weights.

24. The network device according to claim 23, wherein the channel state information fed back by the terminal after measuring the second-dimension downlink reference signal comprises the index of the selected second-dimension downlink reference signal resource for measuring the second-dimension downlink reference signal, and a second-dimension PMI, a Rank Indicator (RI), and a Channel Quality Indicator (CQI) obtained by measuring the second-dimension downlink reference signal according to the selected resource for measuring the second-dimension downlink reference signal;

and

the at least one processor is configured to execute the computer readable program codes to;

determine the first-dimension beam-forming weight corresponding to the second-dimension downlink reference signal resource according to the index of the second-dimension downlink reference signal resource, and the first correspondence relationship; and

combine a pre-coding matrix indicated by the second-dimension PMI with the determined first-dimension beam-forming weight into a pre-coding matrix of the terminal.

25. The network device according to claim 24, wherein the at least one processor is configured to execute the computer readable program codes to:

receive first-dimension PMIs fed back by terminals in a coverage area of the network device; and

perform one or more of the following first operation to third operation according to the first-dimension PMIs fed back by the terminals in the coverage area of the network device;

in a first operation, in the instance of N>

S, selecting the S first-dimension beam-forming weights from the N first-dimension beam-forming weights to perform beam-forming on the downlink reference signals transmitted over the S second-dimension downlink reference signal resources;

in a second operation, in the instance of N>

S, after selecting the S first-dimension beam-forming weights from the N first-dimension beam-forming weights to perform beam-forming on the downlink reference signals transmitted over the S second-dimension downlink reference signal resources, determining a distribution of the terminals according to the first-dimension PMIs fed back by the terminals in the coverage area of the network device, reselecting the S first-dimension beam-forming weights from the N first-dimension beam-forming weights according to the distribution of the terminals to perform beam-forming on the downlink reference signals transmitted over the S second-dimension downlink reference signal resources, and notifying a correspondence relationship between the reselected S first-dimension beam-forming weights, and the S second-dimension downlink reference signal resources to the terminals;

in a third operation, determining a distribution of the terminals in the coverage area of the network device in the first dimension, and adjusting the first-dimension beam-forming weights according to the distribution of the terminals in the coverage area of the network device in the first dimension.

26. The network device according to claim 23, wherein:

if N is equal to S, then each first-dimension beam-forming weight corresponds to one of the second-dimension downlink reference signal resources in the first correspondence relationship;

or

if N is greater than S, then in the first correspondence relationship, at least one of the second-dimension downlink reference signal resources corresponds to a plurality of first-dimension beam-forming weights; and

one of the plurality of first-dimension beam-forming weights is used for beam-forming on the downlink reference signal transmitted over the second-dimension downlink reference signal resource, the other first-dimension beam-forming weights are not be used for beam-forming on any downlink reference signal, and a correlation metric between the other first-dimension beam-forming weights, and the first-dimension beam-forming weight for beam-forming on the downlink reference signal transmitted over the second-dimension downlink reference signal resource is greater than a threshold, or

if N is greater than S, then each of the S first-dimension beam-forming weights among the N first-dimension beam-forming weights corresponds respectively to one of the second-dimension downlink reference signal resources in the first correspondence relationship;

or

if N is less than S, then each first-dimension beam-forming weight corresponds to one of the second-dimension downlink reference signal resources in the first correspondence relationship, and all the first-dimension beam-forming weights corresponding to the second-dimension downlink reference signal resources in the first correspondence relationship belong to a second set, wherein the second set comprises at least S first-dimension beam-forming weights, there is a second correspondence relationship between the first-dimension beam-forming weights in the second set, and the first-dimension beam-forming weights in the first set, at least one of the first-dimension beam-forming weights in the first set corresponds to more than one of the first-dimension beam-forming weights in the second set, and the first set is configured in the terminal as a codebook for measuring the first-dimension downlink reference signal.