Method and apparatus for obtaining channel quality indication

Patent metadata

Field	Value
Publication number	US-9531465-B2
Application number	US-201214385064-A
Country	US
Kind code	B2
Filing date	Aug 1, 2012
Priority date	Aug 1, 2012
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

Embodiments of the disclosure provide a method and apparatus for obtaining a CQI in a communication system, wherein the communication system comprises a UE, a CoMP measurement set including more than one BS/point, and one or more outside BSs/points which is outside the CoMP measurement set, and wherein the UE is served by a serving BS/point in the CoMP measurement set and interfered by at least one interfering BS/point in the CoMP measurement set and the one or more outside BSs/points. In the method according to embodiments of the present invention, a first interference from at least one outside BS/point which is outside the CoMP measurement set to the UE is estimated; a second interference from at least one interfering BS/point in the CoMP measurement set to the UE is estimated; and a target CQI based on the first interference and the second interference is obtained.

First claim

What is claimed is:

1. A method for obtaining a Channel Quality Indication (CQI) in a communication system, wherein the communication system comprises a user equipment (UE), a coordinated multi-point (CoMP) measurement set including more than one base station (BS)/point, and one or more outside BSs/points which is outside the CoMP measurement set, and wherein the UE is served by a serving BS/point in the CoMP measurement set and interfered by at least one interfering BS/point in the CoMP measurement set and the one or more outside BSs/points, the method comprising:
estimating a first interference from at least one outside BS/point which is outside the CoMP measurement set to the UE;
estimating a second interference from at least one interfering BS/point in the CoMP measurement set to the UE; and
obtaining a target CQI based on the first interference and the second interference,
wherein estimating the first interference from the at least one outside BS/point which is outside the CoMP measurement set to the UE comprises:
measuring channel information of a channel from the serving BS/point to the UE;
acquiring CQIs indicating quality of channels from BSs/points in the CoMP measurement set to the UE; and
estimating the first interference based on the measured channel information and the acquired CQIs.

2. The method of claim 1 , wherein estimating the first interference from the at least one outside BS/point which is outside the CoMP measurement set to the UE further comprises:
acquiring a CQI indicating quality of a channel from a reference BS/point to the UE, wherein the reference BS/point belongs to the at least one interfering BS/point in the CoMP measurement set;
acquiring a transmission power of the reference BS/point to the UE, a transmission power of the serving BS/point to the UE, a path loss of the reference BS/point to the UE, and a path loss of the serving BS/point to the UE; and
estimating the first interference based on the measured channel information, the acquired CQI, the transmission power of the reference BS/point to the UE, the transmission power of the serving BS/point to the UE, the path loss of the reference BS/point to the UE, and the path loss of the serving BS/point to the UE.

3. The method of claim 2 , wherein measuring channel information of the channel from the serving BS/point to the UE comprises:
receiving an uplink sounding reference signal from the UE; and
measuring the channel information based on the uplink sounding reference signal.

4. The method of claim 1 , wherein measuring channel information of the channel from the serving BS/point to the UE comprises:
receiving an uplink sounding reference signal from the UE; and
measuring the channel information based on the uplink sounding reference signal.

5. The method of claim 1 , wherein estimating the second interference from the at least one interfering BS/point in the CoMP measurement set to the UE comprises:
acquiring a beamforming matrix for transmission from the at least one interfering BS/point to the UE;
acquiring transmission powers of BSs/points in the CoMP measurement set to the UE, path losses of the BSs/points in the CoMP measurement set to the UE, and channel information of a channel from the at least one interfering BS/point to the UE; and
estimating the second interference based on the transmission powers of the BSs/points in the CoMP measurement set to the UE, the path losses of the BSs/points in the CoMP measurement set to the UE, the acquired beamforming matrix and the acquired channel information.

6. The method of claim 1 , wherein obtaining the target CQI based on the first interference and the second interference comprises:
calculating beamforming gain from the serving BS/point to the UE;
calculating quality of a channel from the serving BS/point to the UE according to the first interference, the second interference and the beamforming gain; and
obtaining the target CQI based on the calculated quality.

7. The method of claim 6 , wherein calculating the quality of the channel from the serving BS/point to the UE according to the first interference, the second interference and the beamforming gain comprises:
updating the second interference based on scheduling of the UE by the at least one interfering BS; and
calculating the quality of a channel from the serving BS/point to the UE according to the first interference, the updated second interference and the beamforming gain.

8. The method of claim 7 , wherein updating the second interference based on scheduling of the UE by the at least one interfering BS/point comprises:
obtaining a scheduling result which comprises information on scheduling of the UE by the at least one interfering BS;
acquiring a beamforming matrix for transmission from the at least one interfering BS/point to the UE based on the scheduling result;
estimating a third interference based on the acquired beamforming matrix, channel information of a channel from the at least one interfering BS/point to the UE, transmission powers of BSs/points in the CoMP measurement set to the UE, and path losses of the BSs/points in the CoMP measurement set to the UE; and
updating the second interference with the third interference.

9. An apparatus for obtaining a Channel Quality Indication (CQI) in a communication system, wherein the communication system comprises a user equipment (UE), a coordinated multi-point (CoMP) measurement set including more than one base station (BS)/point, and one or more outside BSs/points which is outside the CoMP measurement set, and wherein the UE is served by a serving BS/point in the CoMP measurement set and interfered by at least one interfering BS/point in the CoMP measurement set and the one or more outside BSs/points, the apparatus comprising:
at least one non-transitory memory operable to store program code; and
at least one processor operable to read said program code and operate as instructed by said program code to:
estimate a first interference from at least one outside BS/point which is outside the CoMP measurement set to the UE;
estimate a second interference from at least one interfering BS/point in the CoMP measurement set to the UE; and
obtain a target CQI based on the first interference and the second interference,
wherein the operation of estimating the first interference comprises:
measuring channel information of a channel from the serving BS/point to the UE;
acquiring CQIs indicating quality of channels from BSs/points in the CoMP measurement set to the UE; and
estimating the first interference based on the measured channel information and the acquired CQIs.

10. The apparatus of claim 9 , wherein the operation of estimating the first interference further comprises:
acquiring a CQI indicating quality of a channel from a reference BS/point to the UE, wherein the reference BS/point belongs to the at least one interfering BS/point in the CoMP measurement set;
acquiring a transmission power of the reference BS/point to the UE, a transmission power of the serving BS/point to the UE, a path loss of the reference BS/point to the UE, and a path loss of the serving BS/point to the UE; and
estimating the first interference based on the measured channel information, the acquired CQI, the transmission power of the reference BS/point to the UE, the transmission power of the serving BS/point to the UE, the path loss of the reference BS/point to the UE, and the path loss of the serving BS/point to the UE.

11. The apparatus of claim 10 , wherein operation of measuring the channel information of the channel from the serving BS/point to the UE comprises:
receiving an uplink sounding reference signal from the UE;

Assignees

• Wang Gang
• Lei Ming
• Nec (China) Co Ltd

Inventors

• Wang Gang
• Lei Ming

Classifications

• H04W72/542

  using measured or perceived quality · CPC title

• H04B17/24

  with feedback of measurements to the transmitter · CPC title

• H04B17/345

  Interference values ({signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]} H04B17/336) · CPC title

• H04B7/0632 Primary

  Channel quality parameters, e.g. channel quality indicator [CQI] · 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