Published in Gowda, C.H., Annampedu, V., & Viswanathan, R. (1998). Diversity combining in antenna array base station receiver for DS/CDMA system. 1998 IEEE International Conference on Communications, 1998 (ICC 98) Conference Record, v. 3, 1360-1364. doi: 10.1109/ICC.1998.683048 ©1998 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.


This paper analyses few schemes for combining base station antenna array signals in wireless DS/CDMA. The performances of equal gain combining (EGC), likelihood rank test (LRT) and a modified rank test (MRT) are evaluated using simulation studies. The results indicate that, under certain assumptions on multiple access interference statistics, the probability of error of MRT is lower than that of EGC, if a few high power interfering users are present along with a low power user of interest. If there are a moderately large number of users and if the received power of all the users are nearly the same, then EGC outperforms MRT. In fact, under this condition, the performance of EGC is close to that of the optimal likelihood ratio test.