Joint estimation and compensation of frequency-selective I/Q imbalance using loop-back method in OFDM systems

Analog front-ends for wide-band wireless communication systems exhibit frequency-selective inphase and quadrature (I/Q) imbalance due to asymmetry in devices and layouts. This imbalance leads to a significant degradation of the performance in orthogonal frequency division multiplexing (OFDM) systems. In this paper, using a loop-back method, a joint transmitter (TX) and receiver (RX) estimation and compensation algorithm is proposed to estimate and compensate frequency-selective I/Q imbalance. Simulation results show that the proposed algorithm can effectively eliminate the influence of frequency-selective I/Q imbalance with a very low complexity.