DIGITAL RECEIVER WITH MARCH FILTER RESPONSIVE TO FIELD SYNCHRONIZATION CODE IN THE FINAL I-F SIGNAL ENVELOPE

摘要

PURPOSE: A digital receiver having a matched filter responsive to a field synchronization code of a final IF signal envelope is to obtain synchronization between HDTV channels rapidly. CONSTITUTION: A wireless receiver receives digital TV signals including a pseudo-random sequence of a data field synchronization code and a symbol code. The wireless receiver comprises a tuner(5), an envelope detector(28) and a matched filter(27). The tuner generates an analog intermediate-frequency (IF) carrier wave, which has an envelope representing an amplitude variation in response to the pseudo-random sequence and the symbol code and is modulated according to the digital TV signals. The envelope detector detects the amplitude of the envelope amplitude variation. The matched filter generates a response pulse used for a symbol synchronization. A synchronization detection circuit includes a symbol synchronization unit controlled by the response pulse for detecting the analog IF carrier wave.