Joint semi-blind channel and timing estimation for generalized UWB transmitted reference systems

Synchronization is one of the most critical issues in ultra-wideband communications due to the short duration of the pulses. In this work, a semi-blind synchronization scheme based on maximum-likelihood techniques to recover both symbol and frame timing is developed. The proposed algorithm performs joint timing and channel estimation and is thus robust against moderate timing errors. The probability of acquisition is computed based on correlated Gaussian random variables and analytical results are shown to be accurate for moderate to high SNR values relative to simulated performance. The results reveal that the proposed algorithm achieves a significant performance gain in terms of mean-squared error and bit-error-rate in comparison to proposed frame rate (FR) based algorithms. The impact of a low resolution analog-to-digital converter is shown to be marginal