Blind Adaptive Multiuser Detection for DS-CDMA Utilizing a Sinusoidally-Distributed DSE-CMA

The use of adaptive filtering to mitigate the multiple access interference (MAI) in the direct-sequence code division multiple access (DS-CDMA) systems is studied in this paper. Blind adaptive algorithm based on our recently proposed sinusoidally-distributed dithered signed-error constant modulus algorithm (S-DSE-CMA) is introduced to adapt the filter coefficients. This algorithm retains the averaged transient behavior of the constant modulus algorithm (CMA). We evaluate the performance of an adaptive multi-user detector utilizing the S-DSE-CMA scheme against the existed uniformly-distributed DSE-CMA (U-DSE-CMA). It is shown that the new scheme converges faster than the conventional scheme. Simulation results of averaged mean-squared error (MSE) trajectories for synchronous and asynchronous DS-CDMA are presented.