| This paper presents asymptotic multiuser efficiency (AME) performance analysis of the decorrelator based successive interference cancellation (DBSIC) DS-CDMA multiuser receiver. DBSIC is similar to the conventional SIC receiver except that a decorrelator is used at each detection stage prior to cancellation. AMEs of DBSIC are compared with
those of single-user matched filter, optimum, decorrelating and conventional SIC receivers over both additive white Gaussian noise (AWGN) and Rayleigh fading channels for several values of the spreading codes correlation. It is shown that over AWGN channels, DBSIC receiver has a lower AME than the optimum receiver when the interfering user is weaker than the user of interest but approaches the unity optimum receiver AME as the interferer becomes stronger than the user of interest. For all spreading codes correlation considered, DBSIC has a similar AME curve shape as the conventional SIC receiver but has higher AME performance for all user energy ratios. The AME of DBSIC is better than that of
decorrelating detector when the interferer is much weaker or slightly stronger than the user of interest and has worse performance when the interferer is not much weaker. Over Rayleigh fading channels, DBSIC has AME performance in between decorrelating and matched filter receivers. It is observed that AME of DBSIC approaches to that of the decorrelating receiver as the interferer becomes stronger. |