Golay sequence based time-domain compensation of frequency-dependent I/Q imbalance

A time-domain frequency-dependent I/Q imbalance compensation scheme based on Golay complementary sequence for receiver is presented. By utilizing property of Golay sequence, the signal and its conjugate interference (image interference) in preamble are separated by correlation and used to estimate I/Q imbalance parameters. After that, a Least Square (LS) estimation of compensation flter is obtained and adopted in the compensation structure. Two applications of the presented algorithm are discussed: we could either estimate the channel along with I/Q imbalance or estimate the imbalance parameter only to maintain a lower cost. Both applications are testified by simulation. The results show that the image interference is significantly suppressed even in poor SNR condition, and the computation cost of the algorithms is low.