Optimal Error Rate Performance of Binary TH-UWB Receivers in Multiuser Interference

An exact mathematical model which explains the important characteristics of the probability density function (PDF) of the multiple access interference (MAI) in time-hopping UWB (TH-UWB) systems is discussed. The proposed model accurately foresees impulses, singularities, and heavy tails found in the distribution of the MAI. Also, it discloses precisely why a Gaussian approximation for the MAI in TH-UWB systems is highly inaccurate even in the presence of a large number of interferers. Then, using the maximum a posteriori (MAP) receiver rule and based on the obtained model for the PDF of the MAI, the optimal achievable BER performance of binary TH-UWB receivers is numerically determined. Finally, the performances of some recently proposed UWB receivers are benchmarked against the optimal performance.