FEEDBACK AND RATE ADAPTATION FOR MIMO TRANSMISSION IN TIME DIVISION DUPLEXED (TDD) COMMUNICATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To reduce a quantity of feedback information transmitted for a MIMO transmission in a wireless communication device.SOLUTION: A transmitter sends a first reference signal to a receiver. The receiver selects a precoding matrix on the basis of the first reference signal and in accordance with a selection criterion. The receiver estimates noise and interference at the receiver, and determines channel quality information (CQI) or modulation and coding scheme (MCS) information on the basis of the precoding matrix and the estimated noise and interference. The receiver sends the CQI or MCS information and a second reference signal to the transmitter. The transmitter selects the precoding matrix on the basis of the second reference signal and in accordance with the same selection criterion used by the receiver. The transmitter then sends a MIMO transmission to the receiver on the basis of the CQI or MCS information obtained from the receiver and the precoding matrix selected by the transmitter.