Two-Step Frequency Estimation Algorithm For PSAM Systems

In this paper, we describe and analyze a new two-step frequency estimation algorithm for pilot symbol assisted modulation (PSAM) systems with a non-uniform pilot pattern. The burst structure includes some consecutive pilots at the beginning of each burst and some sparse ones over the burst. Compared with the FFT-based (Fast Fourier Transform based) algorithm, its computational complexity is reduced greatly. It facilitates the estimation of large frequency offsets and high accuracy. Its estimation range is about plusmn20% of the symbol rate and its accuracy is close to the Cramer-Rao bound (CRB) for a low signal-to-noise ratio (SNR).