UWB sequence optimization for enhanced energy capture and interference mitigation

We propose a novel approach to UWB signal detection, based on sequence optimization for the multipath transmission channel. The transmit waveform is made up of a train of delayed and scaled pulses, the amplitudes of which can be represented by a real-valued sequence. The correlator template at the receiver is formed of another real-valued sequence. Both sequences are jointly optimized such that the correlation of the received signal with the correlation template is maximized. This results in coherent combining of a substantial number of the multipath components at the receiver, leading to very high-energy capture with the use of a simple receiver. The method is generalized to a multiuser scenario, where the signal-to-noise-plus-interference ratio of a particular user is maximized. Also, the applicability of the scheme to signal detection in the presence of high power narrowband interference is illustrated. Simulation results based on UWB channel measurements show that the proposed method leads to significant improvement in terms of effective energy capture and interference mitigation over traditional receiver structures, with less complexity.