Method of transmitting channel information in wireless communication system

• US 8,259,698 B2
• Filed: 07/24/2008
• Issued: 09/04/2012
• Est. Priority Date: 08/06/2007
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Park, Yong Bae
• Primary Examiner(s): Blanton, John
• Assistant Examiner(s): LINDENBAUM, ALAN LOUIS
• Application Number:
  US12/179,426
• Publication Number:
  US 20090040998A1
• Time in Patent Office: 1,503 Days
• Field of Search: None
• US Class Current: 370/345
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0028 Formatting
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/1671 the supervisory signal being transmitted together with control information

Abstract

A method of transmitting channel information in a wireless communication system includes generating a channel quality indicator (CQI) including a channel variation indicating temporal changes in downlink channel condition, and transmitting the CQI through an uplink physical channel. Since a modulation and coding scheme is determined by considering changes in channel environment, reception performance of a user equipment can be improved and reliable service can be provided.

Claims

1. A method of transmitting channel information in a time division duplex (TDD) wireless communication system, the method comprising:

receiving, at a user equipment from a base station, downlink data included in a radio frame, wherein the radio frame includes two subframes, each of the two subframes including one uplink time slot and six downlink time slots, each of the six downlink time slots including two data symbols and a midamble, wherein the downlink data is included in a plurality of downlink time slots, of the six downlink time slots, and wherein the downlink data is received through a high speed downlink shared channel (HS-DSCH);

obtaining, at the user equipment, received signal strength indications (RSSIs) of a plurality of midambles for the plurality of downlink time slots according to the equation A_i=√

{square root over (I²+Q²)}, wherein A_i denotes an RSSI of a midamble for an i^th downlink time slot of the plurality of downlink time slots, wherein I denotes an in-phase component of the midamble for the i^th downlink time slot, and wherein Q denotes a quadrature-phase component of the midamble for the i^th downlink time slot;

obtaining, at the user equipment, a moving average of the RSSIs of the plurality of midambles according to the equation

2. The method of claim 1, wherein the channel variation in the CQI is extended by using a repetition code.

3. The method of claim 1, wherein the channel variation is divided into 4 states by using 2-bit mapping.

4. The method of claim 1, further comprising transmitting, by the user equipment, an acknowledgement/non-acknowledgement (ACK/NACK) signal to the base station through the HS-SICH.

5. The method of claim 1, wherein the CQI including the channel variation is transmitted through predetermined HS-SICHs among a plurality of HS-SICHSs.

6. The method of claim 5, wherein the CQI including a recommended modulation format (RMF) is transmitted through remaining HS-SICHSs among the plurality of HS-SICHSs.

7. A user equipment in a time division duplex (TDD) wireless communication system, the user equipment comprising:

a radio frequency (RF) unit configured for transmitting and receiving a radio signal; and

a processor coupled to the RF unit, and configured for;

receiving, from a base station, downlink data included in a radio frame, wherein the radio frame includes two subframes, each of the two subframes including one uplink time slot and six downlink time slots, each of the six downlink time slots including two data symbols and a midamble, wherein the downlink data is included in a plurality of downlink time slots, of the six downlink time slots, and wherein the downlink data is received through a high speed downlink shared channel (HS-DSCH);

obtaining received signal strength indications (RSSIs) of a plurality of midambles for the plurality of downlink time slots according to the equation A_i=√

{square root over (I²+Q²)}, wherein A_i denotes an RSSI of a midamble for an i^th downlink time slot of the plurality of downlink time slots, wherein I denotes an in-phase component of the midamble for the i^th downlink time slot, and wherein Q denotes a quadrature-phase component of the midamble for the i^th downlink time slot;

obtaining a moving average of the RSSIs of the plurality of midambles according to the equation