Blind Compensation of Frequency-Dependent I/Q Imbalance in Direct Conversion OFDM Receivers

In this letter, we investigate the problem of in-phase (I) and quadrature (Q) imbalance compensation in orthogonal frequency division multiplexing direct conversion receivers. A blind method is proposed to estimate and compensate for the frequency-dependent I/Q imbalance based on the kurtosis criterion. The global minimization of the kurtosis based cost function is proven. Simulation results are given to demonstrate that the proposed method is effective for mitigating intercarrier interference and achieves a lower symbol error rate compared to the existing methods.