METHOD FOR ESTIMATING AND RESTRAINING DISTRIBUTED IQ IMBALANCE

摘要

Disclosed is a method for estimating and restraining a distributed IQ imbalance. The method comprises: demodulating a received OFDM system signal, and outputting a training signal S(k) and a data signal Y(k) in a frequency domain; for the training signal S(k), removing modulation information in the training signal S(k) to obtain an interference item J(k) caused by IQ imbalance; then, for each subcarrier in a frame in which the training signal S(k) is located, estimating IQ imbalance parameters A(k) and B(k) caused by a transmit end and a receive end; updating IQ imbalance parameters Ã(k) and B͂(k) of a system according to A(k) and B(k); performing channel equalization on a frequency domain signal Y(k) to acquire a signal X^(k); and correcting the IQ imbalance for X^(k). The present invention has a wide application range, can estimate and restrain IQ imbalance related to or unrelated to a frequency in a radio frequency circuit at a transmit end or a receive end, can effectively prevent influence of frequency deviation, and has low calculation complexity.