Performance of multiuser detection for 2-D spreading coded OFCDM communication systems over frequency and time selective fading channels

In this paper, we investigate the performance of multiuser detection in a 2-D spreading orthogonal frequency coded division multiplexing (OFCDM) communication system over frequency and time selective fading channels. We propose an adaptive orthogalized code allocation (AOCA) method to assign the OVSF codes to active users for OFCDM mobile communication systems. Simulation results show that the proposed AOCA scheme can suppress the MAIs induced by the non-orthogonality over time and frequency selective fading channels and then outperforms the conventional sequential code allocation (SCA) scheme at all system load.