Method and apparatus for detecting when the carrier signal and symbol timing for a television signal is recovered and a high definition television employing the method and apparatus

摘要

An apparatus is provided for detecting when a carrier signal and a symbol timing have been recovered for a demodulated signal corresponding to a received signal. The apparatus contains an estimating circuit and a detection signal generation circuit. The estimating circuit calculates an average value of the demodulated signal and outputs an estimation value which corresponds to the average value. The generation circuit detects when the carrier signal and the symbol timing of the demodulated signal have been recovered based on the estimation value and generates a corresponding recovery completion detection signal. Specifically, the generation circuit includes a carrier signal detection circuit and a symbol timing detection circuit. The carrier signal detection circuit determines that the carrier signal has been recovered when the estimation value exceeds a first threshold value, and the circuit generates a corresponding carrier recovery signal. The symbol timing detection circuit determines that the symbol timing has been recovered when the difference between the estimation value and a previous estimation value is less than a second threshold value, and the circuit generates a corresponding symbol timing recovery signal. The generation circuit outputs the recovery completion detection signal based on the carrier and symbol timing recovery signals. A method corresponding to the apparatus and a high definition television incorporating the apparatus are also provided.