Estimation of symbol rate from the autocorrelation function

The estimation of the symbol rate (or symbol duration Ts) of a symbol sequence in noise has important applications in symbol timing recovery and radio surveillance. Since a symbol sequence has spectral peaks at intervals 1/Ts, Ts estimation centers mostly on the establishment of spectral rate lines from the sequence. Examples include the delay and multiply circuit, and the cyclostationarity based estimators. This paper presents an alternative. It first computes the autocorrelation function of a sequence, which has a first discontinuity at lag Ts. Locating this discontinuity then gives an estimate of Ts. Simulation results show that, for the range of signal-to-noise-ratios under consideration, errors of less than 3% of Ts are achievable.