Performance of multi-carrier CDMA system based on complex orthogonal wavelet packet in Nakagami-m fading channels

Based on the analysis of the principle of multi-carrier CDMA and the use of optimized complex orthogonal wavelet packet, a complex orthogonal wavelet packet based MC-CDMA system (COWP-MC-CDMA) is proposed in this paper. We investigate the system downlink performance with EGC technique and MRC technique in Nakagami-m fading channels, respectively; and derive corresponding bit error rate (BER) expression in detail. The system may overcome the decrease of spectrum efficiency of DFT based conventional MC-CDMA (DFT-MC-CDMA) due to inserting cyclic prefix (CP). Theoretical analysis and simulation results show the COWP-MC-CDMA system outperforms DFT-MC-CDMA as well as real wavelet packet based MC-CDMA (RWP-MC-CDMA) system, it has superior ability to combat multi-path fading and multiaccess interference (MAI). Moreover, the BER performance of proposed system is slightly superior to that of the conventional MC-CDMA with CP.