A Multi-Band Timing Estimation and Compensation Scheme for Ultra-Wideband Communications

Abstract

An Ultra-Wideband (UWB) channel exhibits frequency dependent delay characteristics in different bands of transmission. In [6] we studied and quantified the differences of delay parameters over frequency bands 3.1-4.6 GHz in several UWB channel models (CM). Based on this observation, we proposed an adaptive timing synchronization scheme (ATS) which estimates and maintains the timing delays of each band separately. In this paper, we modify our ATS algorithm [6] by optimal selection of the threshold for timing estimation to reduce the mean-squared-error (MSE) and increase the synchronization probability of the estimator. The performance of UWB Multi- band OFDM (MB-OFDM) system with modified ATS algorithm is studied through computer simulations. We show that modified ATS gives signal-to-noise ratio (SNR) improvement of 1.7 dB at Bit Error Rate (BER) of 2times10-2, 2.2 dB at BER of 7times10-3, and 1.1 dB at BER of 5times10-3 for CM4, CM3, and CM2 respectively for uncoded MB-OFDM system over a non-adaptive synchronization scheme [5]. Also, algorithmic computational complexity analysis of modified ATS is provided for its usability evaluation.