On MMSE timing recovery using oversampling

The realization of stochastic gradient MMSE (minimum mean square error) time recovery algorithms for digital receivers is analyzed and discussed in the framework of the hypothesis of oversampling the received signal with respect to synchronous sampling. It is shown that very simple and effective algorithms, especially suitable for digital implementation, are possible. A convergence analysis based on a random walk model is also presented. Results on convergence rate, timing phase asymptotic distribution, and timing jitter are obtained. Computer simulation is used to investigate the performance of a simple timing recovery algorithm, based on this approach, in a digital radio system. The algorithm convergence is shown in various fading conditions, timing jitter is measured, and theoretical results are confirmed.