A decision-directed symbol timing recovery circuit for ATSC digital TV receivers

In this paper we present and analyze a full-digital decision-directed symbo l timing recovery circuit based on the double-sampling maximum-likelihood e stimator. Intended for the ATSC digital TV system, the proposed scheme work s independently of the segment synchronization by extracting timing informa tion from the randomized data symbols even in the extremely small roll-off case. With the proposed method we get not only quick synchronization, but a lso robust timing recovery with reduced timing jitter compared to the conve ntional correlation method [1]. The simulation is performed using the 8-lev el PAM signal, and evaluated in terms of the steady-state timing jitter und er AWGN and multi path ghost channels. Additionally, initial timing acquisi tion and segment synchronization performance are also shown.