Improved Frequency Synchronization Method for MB-OFDM Ultra-Wideband Communications

We present a fast converging scheme for estimating the coarse frequency offset in multi-band orthogonal frequency division multiplexing (MB-OFDM) based ultra-wideband (UWB) systems. Our estimator performs an averaging of initial estimate over multiple bands and shows an improved estimation of =3 times for band group 1 compared to our earlier proposed scheme. Cramer Rao lower bound (CRLB) on the estimation error and bit-error rate (BER) performances with our estimator, multi-band averaged frequency synchronizer (MBAFS), is studied and compared with for 100,000 noisy realizations in all UWB channel models (CM), CM1-CM4. To prove the efficiency of our scheme, we compare the estimation error variance with the reported results of ML estimation by Yak et al. and BLUE estimation by Jacobs et al., and show its superiority over. Also, computational complexity of MBAFS is analyzed for its usability evaluation.