Pulse position precoding exploiting UWB power constraints

Due to dense multipath channels, coherent receivers in ultra-wideband impulse radio (UWB-IR) technology are high in hardware complexity and power consumption. This makes coherent receivers n downlink transmission of low data rate (LDR) applications, where a more complex node communicates with many basic sensors, unreasonable. Precoding schemes are known solutions to transfer receiver complexity to transmitter side, while maintaining receiver performance. We sketch performance and scalability potential of precoding schemes in LDR systems in presence of drastic Federal Communications Commission´s (FCC) power constraints. This is done by symbol error rate (SER) analysis of an easily realizable pulse position pre-coding (PPP) scheme, supported by simulation results over measured UWB channels. Under realistic conditions, PPP gains up to 9 dB are demonstrated, and it is shown that already a few PPP pulses are sufficient to significantly reduce receiver complexity, at the expense of more transmit power.