Joint carrier and sampling frequency offset estimation for MB-OFDM UWB system

In this paper, a novel joint carrier and sampling frequency offset estimation scheme for Multi-Band Orthogonal Frequency Division Multiplexing (MB-OFDM) ultra wideband (UWB) system is introduced. We investigate the relationship between carrier and sampling frequency offset when they have a common error source and derive the joint estimation scheme. The proposed scheme consists of two stages. In the first stage, a robust estimation of the frequency offset is carried out using preamble symbols. In the second stage, pilot subcarriers within OFDM symbols is used to track the phase distortion caused by the presence of estimation error, if any, in the first stage. Extensive simulation is carried out and the results show that when coupled with the appropriate compensation algorithms, the proposed scheme is effective in limiting the MB-OFDM system performance degradation due to frequency offset to within 0.5 dB.