INTEGRATED RECEIVER STRUCTURE OF STAGED DECODER AND CCI CANCELER FOR CDMA WITH MULTILEVEL CODED MODULATION

This work presents a direct sequence spread-spectrum multiaccess (DS/C DMA) receiver that employs integrated structure of staged decoder and CCI (co-channel interference) canceller, when multilevel coded modulat ion is used and the system undergoes fading channel. We exploit the at tractive multistage decoding method of multilevel coding. Each stage d ecoding is jointly done with the data estimation process and thus repl icas of CCI can be formed with high precision, which ultimately result s in performance improvement without any additional decoding delay or circuit complexity. We have chosen appropriate multilevel 8-PSK coded modulation schemes for the integrated receiver of staged decoder and C CI canceller in fading channels. Computer simulation results show the significant. coding gain that can be achieved by the proposed scheme i n comparison with the conventional scheme. The effect of estimation er ror as well as unequal power is also investigated.