Ultra wide-band communications with blind channel estimation based on first-order statistics

Ultra wideband (UWB) communication holds great potential for significantly improved data rate in future wireless systems. Accurate channel estimation and synchronization are critical for successful operation of a UWB system. We propose in this paper a completely blind channel estimation and synchronization algorithm for UWB systems that employ pulse-position modulation. The algorithm exploits the first-order cyclostationarity in the received signal and performs certain circular deconvolution. The complexity is extremely low - only some "overlap-add" operations and FFT operations are needed. The algorithm is capable of simultaneously estimating multiple (say, more than 60) channel taps and there is no ambiguity in either the amplitude or the phase of the estimated channel. It is shown that using the estimated channel from 500 information symbols, the performance can approach that with the known channel within 2 dB in signal to noise ratio for bit error rate less than 0.01.