Achievable Rates of Pulse-Position Modulated Impulse Radio with Transmitted Reference

In this paper, we study the achievable rates of practical ultra-wideband (UWB) systems using pulse position modulation (PPM) and transmitted-reference (TR) transceivers. TR obviates the need for complex channel estimation, which is particularly challenging in the context of UWB. Based on an upper bound we derive for the error probability with random coding, we establish that for SNR values of practical interest, PPM-UWB with TR can achieve rates on the order of C(¿) = P/N0 (nats/second), where C(¿) denotes the capacity of an AWGN channel in the UWB regime for average received power P and noise power spectrum density N0.