Estimation of carrier and sampling frequency offset for Ultra Wide Band multiband OFDM systems

Ultra wide band (UWB) systems based on multiband orthogonal frequency division multiplexing (MB-OFDM) modulation, similarly to traditional OFDM systems, are particularly sensitive to oscillators instability, as carrier and sampling frequency offsets between the transmitter and the receiver destroy the subchannel orthogonality. Precise carrier and sampling frequency offsets estimation and compensation at the receiver side are therefore necessary, and should use methods with moderate complexity due to the high system transmission rates that require fast acquisition times. We formulate algorithms that are based upon the received frequency domain symbols, where the effect of both offsets can be observed, and jointly estimate them with either a linear least squares or maximum likelihood approach. The performance of the algorithms is assessed through simulation in a realistic UWB channel scenario and compared with previous literature results.