GENERALIZED PROJECTION ALGORITHM FOR BLIND INTERFERENCE SUPPRESSION IN DS CDMA COMMUNICATIONS/

New blind adaptive interference suppression algorithms for DS/CDMA com munication systems are presented, A generalized projection algorithm i s presented to update a multiple access interference (MAI) suppression filter in a static communication environment, The algorithm adaptivel y adjusts the filter coefficients by iteratively projecting them onto constraint sets, The constraint sets consist of data sets and property sets, which are obtained from the received signal and prior knowledge of the desired signal, respectively, A space alternating generalized projection algorithm with approximate EM mapping is also presented to suppress the MAI in a dynamic communication environment, This algorith m jointly estimates the filter and desired signal amplitude using a st ochastic approximation of the EM algorithm, The performance characteri stics of the proposed algorithms are shown by output signal-to-interfe rence ratio and bit-error-rate simulation results. The results show th at the proposed algorithms significantly outperform the existing adapt ive algorithms in steady state.