A novel algorithm for DC offsets and flicker noise cancellation in direct conversion receivers

A novel algorithm is proposed in this paper to remove DC offsets, flicker noise and ISI simultaneously in a direct conversion receiver (DCR) by using adaptive filters and system identification. The time-varying complex DC offsets are treated as real DC values both in in-phase and quadrature channels separately and can be removed simultaneously with only one complex tap. Flicker noise is modeled as a complex autoregressive (AR) random process so the whole system to be identified transforms to an ARX model. After joint estimating the unknown coefficients in the model during training period, the desired signal can be estimated by using decision feedback method. Simulation results reveal the superior performance obtained by the proposed algorithm