PERFORMANCE ANALYSIS OF TURBO-CODED MC-CDMA SYSTEM BASED ON COMPLEX WAVELET PACKET AND SPACE-TIME CODING IN RAYLEIGH FADING CHANNEL

摘要

In this paper, by adopting the turbo codes as channel coding and the optimized complex wavelet packet as multi-carrier modulation, a novel turbo-coded MC-CDMA system based on complex wavelet packet and space-time coding is proposed, and the system bit error rate (BER) performance is investigated in Rayleigh fading channel. The system can make full use of space-time codes' transmit diversity gain and turbo codes' good ability against fading channel to improve the BER performance significantly; and it can overcome the decrease of sepcturm efficency of conventional MC-CDMA due to inserting cyclic prefix (CP) by utilizing superior characteristics of the complex wavelet packet . The simulation results show that the proposed space-time coded MC-CDMA system based on complex wavelet packet performs better than conventional space-time coded MC-CDMA system, and slightly outperforms the conventional MC-CDMA with CP. Moreover, the application of space-time coding technique concatenated with turbo codes strengthens the system ability to combat various interferences in fading channel.