Adaptive array processing for time-varying interference mitigation in IEEE 802.16 systems

In this work, we propose an adaptive technique for interference mitigation based on Minimum Variance Distortionless Response (MVDR) beamforming for the uplink of a WiMAX-compliant system. This method is designed to cope with time-varying interference due to the asynchronous access of users in the neighboring cells. Channel parameters needed for beam-forming are obtained by exploiting both the preambles in the transmitted frames and the pilot subcarriers embedded in each information-bearing OFDM symbol. The effectiveness of the proposed technique is shown through numerical simulations of a standard WiMAX uplink over standard multipath channels.