Serial-Parallel Combined MCI Cancellation in OFCDM Systems

Orthogonal frequency and code division multiplexing (OFCDM) systems have received extensive research recently. This paper proposes a serial-parallel combined MCI (SPMCI) cancellation algorithm for frequency domain de-spreading, derivates an improved minimum mean square error (MMSE) weighting factor and analyzes the performance of the proposed algorithm. Time and code division multiplexing (TCDM) pilot channel is used for channel estimation, which integrates the advantages of time division and code division structure. Simulation results show that the proposed algorithm is superior to the traditional parallel MCI cancellation (PMCI) in slow flat fading channels, especially at O-stage MCI cancellation. Moreover, the BER performance of the proposed algorithm improves as code index increases.