A new successive interference cancellation for asynchronous CDMA

This paper introduces a new multi-user detection method, successive interference cancellation based on the order of log-likelihood-ratio (LLR-SIC), for asynchronous code division multiple access (CDMA) systems. LLR-SIC operates on the fact that the most reliable user, i.e. the user with the largest log- likelihood-ratio (LLR) absolute value, should be first detected and cancelled from received signal. Simulation results show that LLR-SIC significantly outperforms partial parallel interference cancellation (P-PIC) over multi-path Rayleigh fading channels. And the results also show that LLR-SIC can even support overloaded systems in which the number of users is greater than the spreading factor.