Accurate BER of time-hopping and direct-sequence UWB systems in multi-user interference

An exact analysis is derived for precisely calculating the bit error probability of time-hopping and direct-sequence ultra-wideband systems with multi-user interference. This analysis differs from past work in that it is assumed that multiple pulses in a frame from an interfering user can cause interference to the desired user. The Gaussian approximation is shown to be inaccurate for predicting the bit error rate for medium and large signal-to-noise ratio values. The performances of time-hopping and direct-sequence modulation schemes are accurately compared for different numbers of users and frame lengths.