A Robust Timing and Frequency Synchronization Scheme for DVB-T2 System

In this paper, a new P1 symbol with repeat and conjugate symmetric correlation among the main part and the two guard intervals is proposed, with which a robust timing and frequency synchronization method is presented for the Second-generation Terrestrial Digital Video Broadcasting (DVB-T2) to improve the initial synchronization performance. The processing of the timing synchronization includes two steps, a coarse symbol timing offset (STO) estimation and a fine STO estimation. The coarse STO estimation is based on the conjugate symmetric correlation while the fine STO is carried out by searching for the first arriving path, which can be obtained when the conjugate symmetric correlation-value is greater than a threshold determined by the given false alarm probability for the first time in the searching windows, to avoid the delayed STO estimate under multipath channels. After completing timing synchronization, carrier frequency offset (CFO) is estimated based on the repeat correlation of the new P1 symbol. Simulation results show that the proposed method not only achieves superior timing and frequency synchronization performance than the Doblado´s method under the AWGN and the Rayleigh fading channel, wherein the mean square error (MSE) of STO estimation is lower than to 100 at signal to noise ratio (SNR) >6dB while the performance of CFO estimation also obtains 10dB gain at 10^-4 MSE, but also provides a more accurate STO and CFO estimation under the Mobile channel even if the terminal velocity is up to 240km/h.