Analytical approach to I/Q imbalance in OFDM, CDMA and MC-CDMA based systems

Abstract

Growing requirements set upon communications transceivers lead to high sensitivity to non-idealities of analog front-end components. Mismatches in the amplitudes and phases of the I and Q signal branches is one of the major concerns resulting in insufficient rejection of the image frequency band. This paper presents a novel analytical model of I/Q imbalance in OFDM, CDMA and MC-CDMA based communications systems. According to the obtained results, I/Q imbalance effects depend heavily on the applied spreading code class and cell load in case of CDMA and MC-CDMA, which should be taken into account in the system and receiver design. Outcomes of the theoretical studies are verified by extensive system simulations.