Maximum Likelihood Estimation of Time and Carrier Frequency Offset for DVB-T2

The new terrestrial digital video broadcasting standard DVB-T2 provides a specific symbol - called P1-symbol for the initial time and frequency synchronization. In this paper the maximum likelihood (ML) time and carrier frequency offset (CFO) synchronization scheme, which exploits the structure of the P1 symbol in both time and frequency domains is derived. Two lower-complexity solutions are then proposed: 1) a ML estimator that only exploits the time structure of the P1 symbol and 2) a pseudo ML (PML) scheme that resorts to a suboptimal CFO estimator while still performing ML time synchronization. The proposed schemes are compared in terms of both synchronization capabilities and implementation complexity. The Cramer-Rao bounds for the CFO estimators are also evaluated. Simulation results in a typical DVB-T2 scenario show that both ML and PML schemes have a very close performance while significantly outperforming existing schemes.