Published in Coronel, O., & Viswanathan, R. (1995). Crosscorrelation functions of DS codes and probability of error evaluations for a multiple access channel. Conference Record, IEEE Military Communications Conference, 1995 (MILCOM '95), v. 1, 70 - 74. doi: 10.1109/MILCOM.1995.483274 ©1995 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.


We derive a computationally feasible closed form error expression for probability of error for a small multiple access DS-BPSK system operating in a Rayleigh fading environment. Two properties of the crosscorrelation functions of the DS codes help reduce the number of error probability evaluations required when one considers all possible phase shifts of the users’ codes. Examination of the error rates for different phases of three maximal-length codes reveal that the probability of error is only weakly dependent on the phases.