Theoretical Analysis and Performance of the Decorrelating Detector for DS-CDMA Signals in Nonlinear Channels

We analyze the effects of the nonlinear distortions, introduced by the transmitting high-power amplifier (HPA), on the performance of the linear decorrelating multiuser detector in direct- sequence code-division multiple-access (DS-CDMA) downlink systems. By assuming and motivating the Gaussian distribution of the nonlinear distortion noise, the symbol-error rate (SER) and the total degradation (TD) has been derived theoretically in additive white Gaussian noise (AWGN) and frequency-flat Rayleigh fading channels. Simulation results show that the analytical model is quite accurate in many scenarios.