Method and apparatus for utilizing channel state information in a wireless communication system

• US 20040165558A1
• Filed: 02/24/2004
• Published: 08/26/2004
• Est. Priority Date: 03/23/2001
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Howard, Steven J., Ketchum, John W., Ling, Fuyun, Wallace, Mark, Walton, Jay R.
• Granted Patent: US 7,590,182 B2
• Time in Patent Office: Days
• US Class Current: 370/334
• CPC Class Codes: H04B 7/0417 Feedback systems
• 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 7/0854 using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion
• CPC Class Codes: H04B 7/0891 Space-time diversity rake receivers H04B1/7115; space-time decoding H04L1/0631
• 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 1/0015 characterised by the adaptation strategy
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 2025/03414 Multicarrier
• CPC Class Codes: H04L 2025/03426 transmission using multiple-input and multiple-output channels
• CPC Class Codes: H04L 2025/03802 Signalling on the reverse channel
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/021 Estimation of channel covariance
• CPC Class Codes: H04L 25/0228 with direct estimation from sounding signals
• CPC Class Codes: H04L 25/0244 with inversion
• CPC Class Codes: H04L 25/0248 Eigen-space methods
• CPC Class Codes: H04L 25/03159 operating in the frequency domain H04L25/03165, H04L25/03178 take precedence
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0044 : allocation of payload
• CPC Class Codes: H04L 5/006 : Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/0091 : Signaling for the administration of the divided path

Abstract

Techniques for transmitting data from a transmitter unit to a receiver unit in a multiple-input multiple-output (MIMO) communication system. In one method, at the receiver unit, a number of signals are received via a number of receive antennas, with the received signal from each receive antenna comprising a combination of one or more signals transmitted from the transmitter unit. The received signals are processed to derive channel state information (CSI) indicative of characteristics of a number of transmission channels used for data transmission. The CSI is transmitted back to the transmitter unit. At the transmitter unit, the CSI from the receiver unit is received and data for transmission to the receiver unit is processed based on the received CSI.

Claims

1. A method for transmitting data from a transmitter unit to a receiver unit in a multiple-input multiple-output (MIMO) communication system, comprising:

at the receiver unit,

receiving a plurality of signals via a plurality of receive antennas, wherein the received signal from each receive antenna comprises a combination of one or more signals transmitted from the transmitter unit,

processing the plurality of received signals to provide estimates of modulation symbols transmitted from the transmitter unit,

estimating signal-to-noise-plus-interference (SNR) of a plurality of transmission channels used for data transmission, and

transmitting SNR estimates for the transmission channels back to the transmitter unit; and

at the transmitter unit, processing data for transmission to the receiver unit in accordance with the received SNR estimates.

2. The method of claim 1, wherein the SNR of each of the plurality of transmission channels is estimated, and the SNR estimates for each transmission channel is transmitted back to the transmitter unit.

3. The method of claim 1, further comprising:

at the receiver unit,

deriving characterizations for the plurality of transmission channels used for data transmission, and

transmitting the characterizations back to the transmitter unit.

4. The method of claim 3, further comprising:

at the transmitter unit, pre-conditioning modulation symbols prior to transmission to the receiver unit in accordance with characterizations for the plurality of transmission channels.

5. The method of claim 1, wherein the received modulation symbols are processed in accordance with a channel correlation matrix inversion (CCMI) scheme.

6. The method of claim 1, wherein the received modulation symbols are processed in accordance with a minimum unbiased mean square error (UMMSE) scheme.

7. The method of claim 1, wherein the processing at the transmitter unit includes coding data for each transmission channel in accordance with the received SNR estimate for the transmission channel.

8. The method of claim 7, wherein the processing of the processing at the transmitter unit further includes modulating coded data for each transmission channel based on a modulation scheme selected based on the received SNR estimate for the transmission channel.