Performance of nonlinearly amplified multicarrier spread spectrum systems in the presence of multipath fading

We analyze the effect of a nonlinearity on the bit error rate performance of multicarrier spread spectrum (MCSS) systems in the presence of multipath fading. A 5th order polynomial model is used to represent the amplifier amplitude nonlinearities (AM/AM) and a flat Rayleigh fading channel is assumed for each modulated carrier. It is found that for the additive white Gaussian noise and multipath fading channel, the bit error degradation from a nonlinear amplification is not as significant as in the additive white Gaussian noise channel alone.