I/Q imbalance compensation in direct-conversion OFDM receivers

Abstract

The use of direct-conversion receivers has widely been considered for digital cellular and radio messaging systems because it is quite suitable for highly integrated low power schemes. However, the direct-conversion receiver can suffer from severe interference due to inphase/quadrature (I/Q) mismatch because it does not employ bandpass filters to suppress the image band signal. In this paper, we propose a noble scheme for compensating the I/Q imbalance in the direct-conversion OFDM transceiver. The proposed scheme can improve the compensation performance by using more accurate reference signal that can be extracted from the nature of the OFDM signal. The performance of the proposed scheme is analyzed and verified by computer simulation.