A new digital signal processing implementation of OFDM timing recovery

In this paper, we present a novel and pure digital timing recovery scheme in orthogonal frequency division multiplexing (OFDM) system without additional pilots. This optimum estimator is derived based on the maximum likelihood (ML) criterion with the decision directed approach. Sub-optimum schemes based on correlation extraction and SCCL algorithm are also developed. Simulations show that the estimation variance of the optimum scheme approaches zero for signal-to-noise ratio greater than 6 dB with number of subcarriers equals to 256. And the SCCL-based suboptimum scheme is simpler and efficient to apply in closed loop operation