On high data rate space-time codes for ultra-wideband systems

In this paper, the advantage of applying space-time (ST) coding on ultra wideband (UWB) systems is discussed. In order to achieve very high data rates and important performance gains combined pulse position modulation (PPM) and pulse amplitude modulation (PAM) constellations along with full diversity and full rate ST codes are used at the transmitter side. The proposed coding-decoding scheme takes into account the nature of the highly frequency selective channel and the multi-dimensional constellation. Furthermore, the coding gain is optimized over different constellations and the possibility of compromising performance to lower peak-to-average power ratios (PAPR) is discussed. Moreover, for simplified receiver structures, V-BLAST decoding scheme was adapted to multi-dimensional signals. Results show considerable performance gains and better immunity against inter symbol interference (ISI) and multi user interference (MUI).