Steady-State Performance of Constrained Normalized Adaptive Filters for CDMA Systems

Constrained normalized adaptive filters are used as a computationally efficient class of receivers to decrease multiple access interference (MAI). Some receivers estimate the amplitude and/or use different normalization parameters in order to improve the convergence speed. In this paper, we derive the steady-state performance of this class of receivers, from which it is revealed that the normalization parameters that aim at increasing the convergence speed deteriorate the steady-state performance if the step-size is not changed. Additionally, we prove that an estimate of the desired user´s amplitude can greatly improve the steady-state performance. Computer simulations show remarkably good agreement with our analysis