Performance of coded multicarrier spread spectrum systems in the presence of nonlinearity

The major drawback of the multicarrier modulation technique is known to be its performance degradation with nonlinear amplification because of intermodulation products. In this paper, however, we show that the effect of a nonlinearity on bit error rate performance of multicarrier spread spectrum (MCSS) systems can be reduced significantly by increasing the spreading gain. Analytical results for the probability of bit error and bounds on the probability of error for convolutionally coded system are presented and optimum output backoff is also provided for coded and uncoded systems with different spreading gains.