Performance of multicode DS/CDMA with noncoherent M-ary orthogonal modulation subject to power amplifier nonlinear distortion

To avoid estimating the phase of the received signals, the reverse link of IS-95 cellular systems uses M-ary orthogonal modulation with noncoherent reception. An accurate approximation is derived for the bit error rate (BER) of multicode DS/CDMA with noncoherent M-ary modulation in wideband fading channels, when the transmitted signal is nonlinearly distorted by a power amplifier. The amplitude distortion is modeled by a third-order memoryless polynomial. The analysis is shown to closely match the Monte Carlo system simulations.