On optimal data detection for UWB transmitted reference systems

Transmitted reference (TR) modulation schemes, initially proposed for spread-spectrum systems in the 1920's have regained popularity in the context of ultra-wideband (UWB) communications, where accurate channel estimation is a challenging task. In the conventional TR approach, a reference signal (without data modulation) is received and employed in a correlator receiver for data modulated signals. By exploiting the statistics of the received signals, optimal and suboptimal data detection schemes for a single-user UWB communication system employing antipodal modulation with TR are investigated and compared to the conventional TR receiver. The proposed schemes can cope with a variable number of reference and data modulated pulses. By construction, the modulation and demodulation methods work for arbitrary channels. The efficacy of the new methods is investigated via simulations emulating an indoor multipath channel. These simulation results reveal that the proposed detection schemes provide significant performance improvements in terms of bit error rate over the conventional TR receiver structure.