METHOD AND APPARATUS FOR TRANSRECEIVING CHANNEL STATE INFORMATION IN WIRELESS COMMUNICATION SYSTEM

• US 20160112102A1
• Filed: 07/25/2014
• Published: 04/21/2016
• Est. Priority Date: 07/25/2013
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: KIM, Hyungtae, PARK, Jonghyun, SEO, Hanbyul, KIM, Kijun
• Granted Patent: US 9,893,778 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• 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 7/2656 for structure of frame, burst
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

The present invention relates to a wireless communication system. A method for a terminal reporting channel state information in a wireless communication system, according to one embodiment of the present invention, comprises the steps of: receiving, from a second cell interfering with communication between a first cell and the terminal, a second precoding matrix indicator (PMI) determined based on the interference; and transmitting, to the first cell, the second PMI and a channel quality indicator (CQI).

Claims

1. A method of reporting a channel state information (CSI) by a user equipment in a wireless communication system, the method comprising:

receiving, from a 2^nd cell causing interference to communication between a 1^st cell and the user equipment, a 2^nd PMI (precoding matrix indicator) determined based on the interference; and

transmitting the 2^nd PMI and a CQI (channel quality indicator) to the 1^st cell.

2. The method of claim 1, further comprising:

receiving a DCI (downlink control information) including a 1-bit flag,

wherein if the 1-bit flag corresponds to a 1^st value, a remaining payload of the DCI comprises the 2^nd PMI, and

wherein if the 1-bit flag corresponds to a 2^nd value, the remaining payload of the DCI comprises scheduling information.

3. The method of claim 1,

wherein the CQI is calculated based on a 1^st CSI process of the 1^st cell and a 2^nd CSI process of the 2^nd cell.

4. The method of claim 3,

wherein a same IMR (interference measurement resource) is used in the 1^st CSI process and the 2^nd CSI process.

5. The method of claim 1,

wherein the 2^nd PMI is received through an EPDCCH (enhanced physical downlink control channel).

6. The method of claim 5,

wherein a CSI process used for feedback of the 2^nd PMI is determined using a state of PQI (PDSCH RE mapping and quasi co-location indicator) connected to a set of EPDCCHs of the 2^nd cell.

7. The method of claim 1,

wherein, after the 2^nd PMI is received from the 2^nd cell, the 2^nd PMI is transmitted to the 1^st cell through a first PUSCH (physical uplink shared channel).

8. A user equipment for reporting a channel state information (CSI) in a wireless communication system, a user equipment comprising:

a radio frequency (RF) unit; and

a processor,

wherein the processor is configured;

to receive, from a 2^nd cell causing interference to communication between a 1^st cell and the user equipment, a 2^nd PMI (precoding matrix indicator) determined based on the interference,

to transmit the 2^nd PMI and a CQI (channel quality indicator) to the 1^st cell.

9. The user equipment of claim 8,

wherein the processor is further configured to receive a DCI (downlink control information) including a 1-bit flag,

wherein if the 1-bit flag corresponds to a 1^st value, a remaining payload of the DCI comprises the 2^nd PMI, and

wherein if the 1-bit flag corresponds to a 2^nd value, the remaining payload of the DCI comprises scheduling information.

10. The user equipment of claim 8,

wherein the CQI is calculated based on a 1^st CSI process of the 1^st cell and a 2^nd CSI process of the 2^nd cell.

11. The user equipment of claim 10,

wherein a same IMR (interference measurement resource) is used in the 1^st CSI process and the 2^nd CSI process.

12. The user equipment of claim 8,

wherein the 2^nd PMI is received through an EPDCCH (enhanced physical downlink control channel).

13. The user equipment of claim 12,

wherein a CSI process used for feedback of the 2^nd PMI is determined using a state of PQI (PDSCH RE mapping and quasi co-location indicator) connected to a set of EPDCCHs of the 2^nd cell.

14. The user equipment of claim 8,

wherein, after the 2^nd PMI is received from the 2^nd cell, the 2^nd PMI is transmitted to the 1^st cell through a first PUSCH (physical uplink shared channel).