DIGITAL TV RECEIVER CIRCUITRY FOR DETECTING AND SUPPRESSING NTSC CO-CHANNEL INTERFERENCE

摘要

PURPOSE: An apparatus for detecting/cutting NTSC interference signal in a digital TV is provided to restrict an artifact component of NTSC co-channel interference by obtaining a code decoding result value using a cut-off filtering. CONSTITUTION: A digital TV signal detector provides 2N-level codes having a code period of a predetermined time length. The 2N-level ode is accompanied by an artifact component of a co-channel interference analog TV signal. The codes is grouped as a successive data segment having a data segment synchronous code's header. The data segment includes a data area synchronous code. A circuit provides M single filter, and responds to the 2N-level code. Many code decoders generate a measurement result value of each code. A first code decoder measuring result value responds to the 2N-level code. Each code decoder makes a code decoding measurement result value to respond to one of the M single filters. A measurement result value is completely post-coded to the matched filtering. An optimum measurement selection circuit selects an optimum value from each code decoding result value, generates the last code decoding result value in a period for generating a synchronous code. Selecting the optimum value is dependent upon the first code decoding result value.