A Low Complexity Multiuser Interference Compensation Scheme for OFDMA Uplink

This paper investigates the multiuser interference mitigation for the uplink of an orthogonal frequency division multiple access system in a doubly selective fading channel. The proposed algorithm squeezes the interference of subcarrier k into 2τ+1 neighboring subcarriers by preprocessing the received signal and yields a banded structure interference matrix. Specifically, the value of τ mainly depends on the carrier frequency offsets and determines the squeezing depth which in turn influences the receiver implementation complexity. Simulation results show that the bit error rate performance of our proposed algorithm approaches the existing full length minimum mean square error equalizer with a significant reduction on complexity.