Low-Complexity Fine Frequency Synchronization for MB-OFDM Based UWB Systems

—In this paper, a fine frequency synchronization method with low complexity is proposed for Multi-Band Orthogonal Frequency Division Multiplexing (MB-OFDM) based Ultra-Wideband (UWB) systems. Low complexity is still one of the major difficulties in the design of fine frequency synchronizer for MB-OFDM UWB systems due to arctangent operations and Numerically Controlled Oscillator (NCO), both of which have high computational complexity, are usually needed in fine frequency synchronizer. In this paper, the proposed fine frequency synchronization scheme directly estimates the sine/cosine values of the residual phases of all sub-carriers by simplifying them as values of a linear function. Then, the estimated sine/cosine values are directly used for frequency offset compensation. In this way, the highly complex arctangent operation and NCO are not needed any more in the proposed scheme. Simulation results show the proposed scheme has high performance.