Joint-Iterative Power Allocation and Interference Suppression Using MBER Technique for Cooperative CDMA Systems

In this work, we study a joint iterative power allocation and interference suppression technique based on the minimization of the bit error rate (BER) cost function for cooperative direct-sequence code division multiple-access (DS-CDMA)systems that employ multiple relays and the amplify-and-forward (AF) strategy. We develop stochastic gradient (SG) algorithms based on the minimum-BER (MBER) criterion to jointly update the parameter vectors that allocate the power levels among the relays subject to a power constraint and the linear receiver. Simulation results show that the proposed adaptive algorithms significantly outperform the two other comparison schemes.