Performance of multiuser detection for optical CDMA .2. Asymptotic analysis

This paper presents characterizations of optimum multiuser detection in intensity-modulation direct-detection CDMA channels based on asymptotic analysis of simple bounds on optimum performance. Technical difficulties in applying large deviation techniques to the evaluation of asymptotic multiuser efficiencies are rigorously addressed. These same difficulties also lead to derivation of conditions under which the linear multiuser detection achieves known-interference (hence, optimum) performance. Asymptotic analysis of the conventional correlation receiver, including derivation of the optimal decision threshold for on-off signaling formats, is also presented.