Interference mitigation in transmitted-reference ultra-wideband (UWB) receivers

Transmitted-reference (TR) ultra-wideband transceivers have recently become increasingly popular for their simplicity, capability to reduce the stringent UWB timing requirements, and robust performance in multipath channels. However, the performance of TR receivers is considerably limited by the severity of noise-on-noise component introduced by various types of channel noise such as additive white Gaussian noise (AWGN) or narrowband interference (NBI) on the transmitted signal. It is expected that such receivers will perform poorly at low signal-to-noise ratio links, or in the presence of strong narrowband interferers. In this paper we propose a novel technique that maximizes the extraction of information from reference pulses for UWB-TR receivers. The scheme efficiently processes the incoming signal to suppress different types of interference prior to signal detection. The method described introduces a feedback loop mechanism to enhance the signal-to-noise ratio of reference pulses in a conventional TR receiver. The performance of a conventional TR receiver and a feedback loop TR receiver in the presence of AWGN and strong narrowband interference is investigated by analysis and computer simulations. Our studies show that the reference enhancing feedback loop mechanism greatly improves the robustness of the link performance of TR receivers in the presence of non-UWB interference with modest increase in complexity.