Method and device for low-complexity feedback in a multiuser and multipoint cooperative communication system

Patent metadata

Field	Value
Publication number	US-9735853-B2
Application number	US-201113982603-A
Country	US
Kind code	B2
Filing date	May 11, 2011
Priority date	Jan 30, 2011
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

Provided are a method and device for low-complexity feedback in a multiuser and multipoint cooperative communication system. The base station in the multiuser and multipoint cooperative communication system transmits a feedback stop signal to a terminal in order for the terminal receiving the feedback stop signal to stop feedback for a predetermined period. The terminal receiving the feedback stop signal stops the feedback of channel information for a period indicated by the feedback stop signal.

First claim

The invention claimed is:

1. A method of feeding back channel information by a terminal in a Multiple Input Multiple Output (MIMO) communication system comprising a base station and a plurality of terminals, the method comprising:
receiving a feedback stop signal from the base station;
discontinuing transmission of feedback associated with channel information for a time period indicated by information comprised in the feedback stop signal, the time period being determined by the base station based on a number of terminals communicating with the base station and a transmission rank of the base station; and
transmitting the feedback associated with the channel information to the base station after the time period elapses,
wherein a length of the time period is inversely proportional to the transmission rank of the base station, and
wherein the transmission rank denotes a number of simultaneously-scheduled terminals of the plurality of terminals.

2. The method of claim 1 ,
wherein the feedback stop signal comprises information associated with the time period in subframes, and
wherein a number of subframes included in the time period is based on the number of terminals communicating with the base station and on a number of transmission ranks of the terminals communicating with the base station.

3. The method of claim 2 , wherein the number of subframes is proportional to the number of the terminals communicating with the base station and inversely proportional to the number of the transmission ranks of the terminals communication with the base station.

4. The method of claim 1 , wherein the transmitting of the feedback comprises performing periodic feedback of channel information based on a predetermined feedback interval after the time period elapses.

5. The method of claim 1 , wherein the feedback stop signal is received on a Downlink Control Channel (DCI).

6. The method of claim 1 , further comprising:
discontinuing transmission of the feedback of the channel information during the time period.

7. The method of claim 1 , wherein the time period comprises at least one subframe following a subframe in which the feedback stop signal is received.

8. The method of claim 1 , wherein the channel information comprises at least one of a Precoding Matrix Indicator (PMI), Channel Quality Information (CQI), and a Rank Indicator (RI).

9. A communication method of a base station in a Multiple Input Multiple Output (MIMO) communication system comprising the base station and a plurality of terminals, the method comprising:
generating a feedback stop signal, the feedback stop signal being based on a number of terminals communicating with the base station;
transmitting the feedback stop signal to at least one terminal wherein the at least one terminal discontinues transmission of feedback associated with channel information for a time period indicated by information comprised in the feedback stop signal; and
receiving the feedback associated with the channel information from the at least one terminal after the time period elapses,
wherein the time period being determined by the base station based on the number of terminals communicating with the base station and a transmission rank of the base station,
wherein a length of the time period is inversely proportional to the transmission rank of the base station, and
wherein the transmission rank denotes a number of simultaneously-scheduled terminals of the plurality of terminals.

10. The method of claim 9 , wherein the generating of the feedback stop signal comprises:
determining a number of subframes in which to discontinue transmission of the feedback of the channel information based on the number of terminals communicating with the base station and on a number of transmission ranks of the terminals communicating with the base station; and
generating the feedback stop signal comprising information about the determined number of subframes.

11. The method of claim 10 , wherein the determining of the number of subframes comprises:
determining the number of subframes to be proportional to the number of the terminals communicating with the base station, and
determining the number of subframes to be inversely proportional to the number of the transmission ranks of the terminals communicating with the base station.

12. The method of claim 9 , wherein the feedback stop signal is transmitted over a Downlink Control Channel (DCI).

13. A method of feeding back channel information by a terminal in a multipoint Multiple Input Multiple Output (MIMO) communication system comprising the terminal and a plurality of base stations cooperating with each other, the method comprising:
receiving a feedback stop signal from at least one of the plurality of base stations;
discontinuing transmission of feedback associated with channel information for a time period indicated by information comprised in the feedback stop signal, the time period being determined by the base station based on a number of terminals communicating with the at least one of the plurality of base station and a transmission rank of the base stations; and
transmitting the feedback associated with the channel information to the at least one of the plurality of base stations after the time period elapses,
wherein a length of the time period is inversely proportional to the transmission rank of the base station, and
wherein the transmission rank denotes a number of simultaneously-scheduled terminals of the plurality of terminals.

14. The method of claim 13 ,
wherein the feedback stop signal comprises information associated with the time period in subframes, and
wherein a number of subframes included in the time period is determined based on number of terminals communicating with the at least one of the plurality of base stations and on a number of transmission ranks of the terminals communicating with the at least one of the plurality of base stations.

15. The method of claim 13 , wherein the transmitting of the feedback comprises performing periodic feedback of channel information based on a predetermined feedback interval after the time period elapses.

16. A terminal for transmitting feedback information associated with channel information in a Multiple Input Multiple Output (MIMO) communication system comprising a base station and a plurality of terminals, the terminal comprising:
a receiver configured to receive a feedback stop signal from the base station, the feedback stop signal being based on a number of terminals communicating with the base station; and
a transmitter configured to transmit the feedback associated with the channel information to the base station after a time period elapses,
wherein the terminal discontinues transmission of feedback associated with channel information based on information comprised in the feedback stop signal from the base station,
wherein the time period is determined by the base station based on the number of terminals communicating with the base station and a transmission rank of the base station,
wherein a length of the time period is inversely proportional to the transmission rank of the base station, and
wherein the transmission rank denotes a number of simultaneously-scheduled terminals of the plurality of terminals.

17. The terminal of claim 16 , wherein the transmitter is further configured to transmit periodic feedback associated with the channel information based on a predetermined feedback interval after the time period elapses.

Assignees

• Li Hua
• Choi Jun Il
• Clerckx Bruno
• Samsung Electronics Co Ltd

Inventors

• Li Hua
• Choi Jun Il
• Clerckx Bruno

Classifications

• H04B7/0452

  Multi-user MIMO systems · CPC title

• H04B7/024 Primary

  Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems · CPC title

• H04B7/0417

  Feedback systems · CPC title

• H04B7/0643 Primary

  Feedback on request · CPC title

• H04B7/063

  Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection · CPC title