Integrated Receiver Structure of Staged Decoder and CCI Canceller for CDMA with Multilevel Coded Modulation

摘要

This work presents a direct sequence spread-spectrum multiaccess (DS/CDMA) receiver that employs integrated structure of staged decoder and CCI (co-channel interference) canceller, when multilevel coded modulation is used and the system undergoes fading channel. We exploit the attractive multistage decoding method of multilevel coding. Each stage decoding is jointly done with the data estimation process and thus replicas of CCI can be formed with high precision, which ultimately results 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 CCI canceller in fading channels. Computer simulation results show the significant coding gain that can be achieved by the proposed scheme in comparison with the conventional scheme. The effect of estimation error as well as unequal power is also investigated.