This ATSC Demodulator IP is extracted from the production chip and silicon-proven IP core. It integrates a digital terrestrial ATSC receiver 8VSB demodulation and FEC, and a downstream interactive out-of-band (OOB) receiver (QPSK Demodulation). On-chip SRAMs avoid the need
for external memory components. In the case of OpenCable compliant products, this IP provides the support for a unidirectional (in-band and OOB downstream) configuration and enables a low-cost frequency-agile OOB by embedding an OOB tuner.
The ATSC IP device provides an interface to the CableCARD module to facilitate the processing of digital information which is received over the following communication channels:
● an in-band video channel, which carries MPEG-2 transport streams,
● an OOB downstream data channel.
Digital terrestrial ATSC receiver:
This receiver implements the following functions:
● 8VSB demodulator,
● Forward error correction.
The ATCS receiver handles severe multipath conditions. A robust synchronization circuit drives an NCO to lock the carrier frequency and an internal symbol timing recovery loop. It is designed to operate under severe channel degradations, including possible nulling of the VSB pilot.
The equalizer has a unique configuration that enables equalization of strong ghost signals while minimizing noise enhancement. The equalizer also has sufficient length and speed to handle the complex signal conditions that exist in both indoor and outdoor environments.
The receiver also includes a phase tracker to correct high-frequency phase noise from the tuner and integrates the requisite ATSC Annex D FEC decoder with trellis decoder, deinterleaver and Reed-Solomon.
It handles a wide range of symbol rates, ranging from the highest practical rates to rates as low as 0.87 Mbaud, even in the presence of a significant frequency offset. The ATSC IP QAM receiver provides all demodulation and FEC functions required for the recovery of QAM modulated bitstreams. It outputs error-corrected MPEG-2 transport streams in a wide variety of formats with programmable data clock frequency.