Performance Analysis of Low-Weight Modified Prime Sequence Codes for Synchronous Optical Cdma Networks

Abstract

Low-weight modified prime sequence codes have been proposed for use in synchronous optical code-division multiple-access network (OCDMA) applications. The codes are constructed by removing last (P - w) successive ones from each code sequence and replacing them by zeros, maintaining the code length to be P2 which does not increase the auto- and cross-correlation constraints of the conventional modified prime sequence codes. Considering the influence of multi-user interference (MUI), the error performance of the codes is analyzed both by exact and Gaussian approximation methods and the results are compared. The analyses show that the proposed code can significantly reduce the system cost and can also alleviate the power loss, by choosing code weight w lower than the prime number P which can be determined in practice by the required bit error probability Pe < 10-9.