APPARATUS FOR DEMODULATING AND DECODING VIDEO SIGNALS.

摘要

An adaptive receiver includes an adaptive demodulator (10) and an adaptive decoder (12) for providing demodulated and decoded output data from a video signal encoded for satellite, terrestrial or cable transmission. The demodulator recovers demodulated output data by using an adaptive timing recovery network (25) and an adaptive carrier recovery network (25) that incorporates a selectable slicer network (30, 35, 40). In addition, an Automatic Gain Control network (25) within the demodulator provides a gain control output as a function of a difference between signals produced both prior to and following the slicer. The demodulator may also incorporate a signal quality detector that uses carrier recovery network signals to provide an estimate of the error in the demodulated output data. The decoder produces a Viterbi decoded output from the demodulated output data by using a selectable code rate Viterbi decoder.