Abstract: Estimation and compensation of sampling clock and residual frequency offset in OFDM systems are an important issue. Using discrete preamble, we derive near optimal and sub optimal estimation based on the maximum likelihood (ML) estimation theory, and then analyze the estimation performance and discuss the design of discrete preamble to achieve best estimation performance. We also give a closed loop scheme for accurate and fast sampling clock tracking. Validity of the proposed method is verified in simulation.

Key words: sampling clock, residual frequency offset, discrete preamble