Nonlinear interference mitigation in multiple-access ultra-wideband communications

In this paper we analyze the performance of synchronous ultra-wideband (UWB) communications in the presence of interference. We consider a nonlinear interference suppression technique for multiple-access (MA) time-hopping (TH) pulse-position modulation (PPM) UWB systems in an AWGN channel. In practice, the multiple-access interference (MAI) is not Gaussian distributed, and the optimum receiver can be very complicated to implement. In previous research the Gaussian approximation to the interference is used when evaluating the system performance. Since Gaussian interference is actually the worst case type of interference, substantial improvement can be made when the actual non-Gaussian interference is properly taken into account. In this work, we find the exact probability density function (PDF) of the interference, and the exact bit error rate (BER). Furthermore, this PDF can be used in a locally optimum Bayes detector (LOBD) to derive the suboptimum receiver with less complexity.