A novel approach to UWB data detection with symbol-level synchronization

Differentially modulated ultra-wideband (UWB) systems have recently attracted a lot of attention since they can avoid the costly channel estimation required by coherent schemes. The conventional differential-detector (DD), however, shows an inevitable 3 dB performance loss and suffers from multiple access and intersymbol interference. Multiple symbol differential detection (MSDD) provides an attractive solution that alleviates the SNR loss, but still calls for accurate timing recovery. In this paper, we show how to relax the severe timing requirements of the MSDD thereby only relying on symbol-level synchronization. Further, the detection complexity can be kept at an affordable level by pursuing a sphere decoding approach. Simulation results corroborate the effectiveness of the proposed system when operating in typical dense multipath propagation scenarios.