Ultra-wideband (UWB) transmissions have well-documented advantages for low-power, peer-to-peer, and multiple-access communications. Space-time coding (STC), on the other hand, has gained popularity as an effective means of boosting rates and performance. Existing UWB transmitters rely on a single antenna, while ST coders have mostly focused on digital linearly modulated transmissions. In this paper, we develop ST codes for analog (and possibly nonlinearly) modulated multiantenna UWB systems. We show that the resulting analog system is able to collect not only the spatial diversity, but also the multipath diversity inherited by the dense multipath channel, with either coherent or noncoherent reception. Simulations confirm a considerable increase in both bit-error rate performance and immunity against timing jitter, when wedding STC with UWB transmissions.
Bibliographical noteFunding Information:
Paper approved by Z. Kostic, the Editor for Wireless Communication of the IEEE Communications Society. Manuscript received August 7, 2002; revised July 24, 2003. This work was supported 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. This work was also supported in part by the National Science Foundation under Grant EIA-0324864. This paper was presented in part at the IEEE Conference on Ultra-Wideband Systems and Technologies, Baltimore, MD, May 2002.
- Noncoherent detection
- Pulse-position modulation (PPM)
- Space-time coding (STC)
- Timing jitter
- Ultra-wideband (UWB)