Low complexity timing synchronization and channel estimation for DVB-T2 over long echo channels

摘要

This paper proposes a low complexity fine frame synchronization method based on channel impulse response (CIR) estimation for DVB-T2 system. The proposed algorithm resolves the CIR rotation ambiguity, which is caused by the error in the coarse frame synchronization due to stronger secondary paths, using a novel scheme for channel and SNR estimation. Unlike previous methods that utilize the data symbols, which are of variable size, for resolving the ambiguity, we utilize the first preamble P1. We also avoid the effect of decision errors in our SNR estimation. Finally, a Wiener filter interpolation is applied in the frequency domain based on the estimated delay spread. Performance evaluations are performed on channels with long and strong echoes, which is the case for single frequency networks (SFNs), and on the Rayleigh (P1) and Rician (F1) channels as well. Improved performance is obtained with low complexity in the CIR estimation and SNR estimation modules.