Adaptive pipelined successive interference cancellation for a DS/CDMA system

We consider the use of an adaptive sigmoid function for a pipelined successive interference cancellation (PSIC) in a direct sequence/code multiple access system (DS/CDMA). The PSIC is a pipelined modification of a successive interference cancellation (SIC). To compensate the decoding delay of the SIC, the PSIC was proposed. Because the decision variable of the latter stage is more reliable than that of the early stage in the PSIC, the wrong derision of the early stage affects the decision of the final stage. So, we use a tentative decision function, which is adjusted depending on the variance of the multiple access interference (MAI). The analysis and computer simulation results of the adaptive PSIC (ADP-SIC) show that the ADP-SIC outperforms both of the SIC and the PSIC with almost same decoding delay