In this letter, 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 communications. Based on an upper bound we derive for the error probability with random coding, we establish that for signal-to-noise ratio values of practical interest, PPM-UWB with TR can achieve rates on the order of C(∞) = P/N0 (nats/s), where C(∞) denotes the capacity of an additive white Gaussian noise channel in the UWB regime for average received power P and noise power spectrum density N0.
Bibliographical noteFunding Information:
Paper approved by D. I. Kim, the Editor for Spread Spectrum Transmission and Access of the IEEE Communications Society. Manuscript received June 13, 2005; revised November 14, 2005. This work was supported in part by the NSF-ITR under Grant EIA-0324864, and in part through collaborative participation in the Communications and Networks Consortium sponsored by the U.S. Army Research Laboratory under the Collaborative Technology Alliance Program, Cooperative Agreement DAAD19-01-2-0011. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation thereon.
- Achievable rates
- Transmitted-reference (TR)
- Ultra-wideband (UWB)