Optimum asymptotic multiuser efficiency of randomly spread CDMA

Analysis and design of trellis codes optimized for a binary symmetric markov source with maximum a posteriori detection , " IEEE Trans. , " Source-channel optimized trellis codes for bitonal image transmission over AWGN channels, " IEEE Trans. [20] P. J. Lee, " Computation of bit error rate of coherent M-ary PSK with gray code bit mapping, " IEEE Trans. A unified approach to the performance analysis of digital communication over generalized fading channels, " Joint source-channel decoding using the residual redundancy in compressed images, " in Proc. Abstract—This correspondence analyzes the high signal-to-noise ratio (SNR) performance of optimum multiuser detectors for synchronous direct-sequence spread spectrum with random spreading in an additive white Gaussian noise channel. Under very general conditions on the received powers, we show that the optimum asymptotic efficiency of a-user system with spreading gain converges to 1 almost surely as , and is kept equal to an arbitrary nonzero constant. Therefore, the asymptotic behavior of the minimum bit error rate is equivalent to that of a single-user system.