Multiple-Access Performance of Transmitted Reference UWB Communications with M-ary PPM

To increase the data rate for transmitted reference (TR) ultra-wideband (UWB) systems, M-ary pulse position modulation (PPM) is used in this paper. The multiple-access performance of such systems is investigated in a multipath environment. A new method to derive the variance of the Gaussian random variable resulted from multiple-access interference (MAI) is developed using the power delay profile (PDP) of the channel. By applying an upper bound, a general relationship is reached for system parameters such as the number of supported users, the bit error probability, the required Eb/No, and the data rate. Tradeoffs between system parameters are discussed as well in this paper.