Turbo Interference Cancellation／Decoding for Convolutionally Coded Multi-Carrier DS-CDMA

摘要

In this paper, by applying Turbo principle to convolutionally coded multi-carrier Direct-sequence Code-division multiple access (DS-CDMA), we propose Turbo Parallel interference cancellation integrating Frequency diversity combining (FDC-PIC), which is termed Turbo FDC-PIC/decoding, and by analysis, several modifications are given. We make analysis and simulations for Turbo FDC-PIC/decoding and its modifications by the computer. The simulation results show that Turbo FDC-PIC/decoding acquires better performance with a posteriori Log-likelihood rate (LLR) feedback than with a priori LLR feedback. Whether hard, or soft decisions, Turbo FDC-PIC/decoding with a posteriori LLR feedback acquires better performance, while Turbo FDC-PIC/decoding with a priori LLR feedback acquires good performance only with soft decision. Besides, Turbo FDC-PIC/decoding with a posteriori LLR feedback has a lower complexity than tha twith a priori LLR feedback, which indicates that Turbo FDC-PIC/decoding with a posteriori LLR feedback is more favorable for future application because of its better performance and relatively lower implementation complexity.