Maximum Likelihood Frequency Offset Estimation & Cramer Rao Bound for Ultra-Wideband (UWB) Multi-Band OFDM Systems

The maximum likelihood (ML) estimator and the Cramer Rao Bound (CRB) for frequency offset estimation are derived and compared against each other in a multi-band orthogonal frequency division multiplexing (MB-OFDM) ultra-wideband (UWB) system. A total of 100 UWB channel realizations, as proposed by IEEE 802.15 channel modeling sub-committee, for each channel model (CM) 1: line-of-sight for 0-4 m and CM2: non-line-of-sight for 0-4 m are simulated to demonstrate the convergence of the ML estimator variance with the CRB for high signal-to-noise ratio (SNR)