Convergence analysis of adaptive DS-CDMA receivers in multi-path channels

This paper objectively investigates the convergence and transient behaviors of symbol-rate adaptive receivers for direct sequence-code division multiple access (DS-CDMA) communication system in dispersive multi-path environment. The input signal vector is modeled as a simple stochastic model to simplify the analyses of the least mean square (LMS) and normalized least mean square (NLMS) adaptive receivers. The mean square error (MSE) learning curve, which is based on ensemble averaging of the squared estimation error, is applied to analyze the convergences of the adaptive receivers for DS-CDMA systems interfered with multiple access interference (MAI) and inter-symbol interference (ISI). The analytical results are verified with computer simulations. Computer simulations show that the analytical results are consistent with simulations.