Exact BER performance of asynchronous DS-CDMA systems using quadriphase spreading and QPSK modulation over rayleigh channels
Xiang Liu, L. Hanzo · 2006
An accurate closed-form expression is derived for calculating the average BER in an asynchronous DS-CDMA system using random complex-valued spreading sequences for transmission over Rayleigh channels. This accurate solution is based on the characteristic function (CF) approach and only requires a single numerical integration. Our numerical simulation results verify its accuracy, and also demonstrate the relative inaccuracy of the Gaussian approximation