Performance comparisons between two signaling formats for UWB communications

Two signaling formats for ultrawide bandwidth indoor communications are compared in terms of bit error rate performance in the presence of multiple access interference. The channel exhibits multipath propagation and its impulse response is either assumed known or is estimated with least squares methods. Computer simulations show that, even with perfect channel knowledge, time-hopping pulse-amplitude modulation is superior to time-hopping pulse-position modulation. The superiority increases with the number of users and becomes substantial in the presence of channel estimation errors. An intuitive explanation of this fact is provided.