In this paper, parallel interference cancellation and decoding for convolutionally coded DS-CDMA systems is investigated. Firstly, we derive a reduced-complexity PIC/ decoding (simplified PIC/decoding). Secondly, two forms of simplified PIC/decoding are analyzed, and compared with the exact PIC/decoding over Rayleigh fading channel. It shows that the simplified PIC/decoding achieves the performance close to the exact PIC/decoding if the tentative decisions of coded symbols are linearly computed in terms of the sum of initial a priori loglikelihood rate (LLR) and updated a priori LLR, while a significant performance loss will occur if the tentative decisions of coded symbols are linearly computed in terms of the updated a priori LLR only. Besides, we compare the simplified PIC/decoding with matched-filter (MF) receiver and conventional PIC/decoding, which shows that the simplified PIC/decoding dominantly outperforms the MF receiver and conventional PIC/decodings. From these results we conclude that the proposed simplified PIC/decoding exhibits a favorable performance/complexity trade-off and is therefore more suitable for future practical application.
展开▼
