TERMINAL, BASE STATION, COMMUNICATION SYSTEM AND COMMUNICATION METHOD

• US 20140023157A1
• Filed: 04/02/2012
• Published: 01/23/2014
• Est. Priority Date: 04/05/2011
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Shimezawa, Kazuyuki, Nogami, Toshizo
• Granted Patent: US 9,680,539 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0486 taking channel rank into account
• 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: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0618 Space-time coding
• CPC Class Codes: H04L 2025/03808 Transmission of equaliser coefficients
• CPC Class Codes: H04L 25/03949 equalizer selection or adaptation based on feedback multiple signaling inclusive of a precoding command for adapting the transmitter H04L1/0031; feedback for transmit diversity systems H04B7/0619; selection of codebook or precoding matrix for MIMO diversity systems H04B7/0456

Abstract

In a communication system in which a base station is able to adaptively control a terminal, a base station, a terminal, a communication system and a communication method which are capable of efficiently supporting a precoding process are provided. The terminal that communicates with the base station selects any of a plurality of codebook subsets obtained by code-booking a precoding weight known to both the base station and the terminal, on the basis of control information which is set by the base station.

Claims

1. A terminal that communicates with a base station,

wherein any of a plurality of codebook subsets obtained by code-booking a precoding weight known to both the base station and the terminal is selected on the basis of a communication mode which is set by the base station.

2. The terminal according to claim 1, wherein a channel state between the base station and the terminal is measured on the basis of a channel-state-measurement reference signal transmitted by the base station, and

feedback information is generated on the basis of the channel state and the selected codebook subset.

3. A terminal that communicates with a base station,

wherein any of a plurality of codebook subsets obtained by code-booking a precoding weight known to both the base station and the terminal is selected on the basis of control information indicating whether an X-PDCCH region which is set by the base station is set.

4. The terminal according to claim 3, wherein a channel state between the base station and the terminal is measured on the basis of a channel-state-measurement reference signal transmitted by the base station, and

feedback information is generated on the basis of the channel state and the selected codebook subset.

5. The terminal according to claim 3, wherein the X-PDCCH region is a region in which the base station is able to transmit control information from the base station to the terminal, using a portion of a resource capable of mapping an information data signal to the terminal.

6. The terminal according to claim 3, wherein the X-PDCCH region is a region capable of transmitting a signal obtained by multiplexing a terminal-specific reference signal specific to the terminal to control information from the base station to the terminal.

7. A base station that communicates with a terminal,

wherein the base station sets a communication mode with respect to the terminal,

transmits a channel-state-measurement reference signal to the terminal, and

receives feedback information which is notified from the terminal, and

wherein the feedback information is generated in the terminal on the basis of

any of a plurality of codebook subsets, selected on the basis of the communication mode, which are obtained by code-booking a precoding weight known to both the base station and the terminal, and

a channel state between the base station and the terminal which is measured on the basis of the channel-state-measurement reference signal.

8-16. -16. (canceled)