Maximum Likelihood Synchronization for DVB-T2 in Unknown Fading Channels

In this paper, we consider the timing and carrier frequency offset (CFO) estimation problem for digital video broadcasting-second generation terrestrial (DVB-T2) transmissions by utilizing the P1 symbol. Unlike previous studies, an unknown fading channel scenario is considered. Two maximum likelihood (ML) methods are derived by modeling the transmitted signal as a stochastic and, respectively, a deterministic unknown waveform. The proposed stochastic ML (SML) algorithm can jointly estimate the received signal power, time delay, and CFO. By ignoring the presence of null carriers in the P1 symbol, the SML method can be simplified with a lower complexity. Meanwhile, the proposed deterministic ML method is more flexible and computationally simpler compared with the SML method. Numerical results are presented to illustrate the performances of the proposed estimators along with several existing solutions for DVB-T2 signal synchronization. In addition, Cramér-Rao lower bounds are evaluated for the considered estimation problem.