A carrier frequency recovery scheme for extended ATSC systems

Efforts to extend Advanced Television Systems Committee (ATSC) 8-Vestigial Side Band (8-VSB) systems for the terrestrial 3D HDTV broadcasting services have begun in Korea. For example, a new system concept to use pseudo-noise (PN) sequence as frame header in the process of frame building is proposed. We will define the new system as extended ATSC systems. VSB modulation is used for extended ATSC system. In this paper, we propose a carrier frequency recovery (CFR) scheme for extended ATSC systems. The proposed CFR scheme is composed of a coarse CFR scheme using the Fitz algorithm and a fine CFR scheme using a simple PN sequence correlation algorithm. Symbol information of VSB modulation is contained in the In-phase (I) channel, and the Quadrature-phase (Q) channel is just the Hilbert transform of I channel. Thus, VSB modulated symbols cannot have a fixed phase like QAM modulated symbols, and become sensitive to the carrier frequency offset (CFO). Therefore, we perform phase correction of the received PN sequence. Simulations show using the proposed CFR scheme obtains very good BER performance for extended ATSC systems.