Turbo parallel interference cancellation/decoding for coded synchronous multi-carrier DS-CDMA

Abstract

In this paper, by applying Turbo principle to convolutionally coded synchronous multi-carrier DS-CDMA, we propose Turbo parallel interference cancellation and decoding, which is termed Turbo PIC/decoding. By analysis, we derive a modified form of Turbo PIC/decoding. We make simulations for Turbo PIC/decoding and its modified form by the computer. The simulation results show that Turbo PIC/decoding obtains the most dominant performance improvement for the first three iterations, but up to the fourth iteration, the performance improves little. It is also shown that both Turbo PIC/decoding and its modified form acquire better performance with a posteriori log-likelihood rate (LLR) feedback than with a priori LLR feedback and with the same LLR feedback, the modified form is only slightly inferior to the Turbo PIC/decoding with a lower complexity. Besides, we also compare the performance of the modified forms of the Turbo PIC/decoding with different interference cancellation (IC) weights, which shows that the modified form of Turbo PIC/decoding exhibits better performance with IC weights than with no IC weights for each iteration.