Blind channel estimation for ultra wide-band communications employing pulse position modulation

Ultra wide-band (UWB) communication holds great potential for a 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 letter a completely blind channel estimation algorithm for UWB systems that employ pulse-position modulation, assuming perfect synchronization at the receiver. 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 fast Fourier transform 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 estimated channel from 500 information symbols, the performance can approach that with a known channel within 3 dB in signal-to-noise ratio for a bit error rate of 0.001.