DIGITAL SIGNAL PROCESSOR FOR MULTISTANDARD TELEVISION RECEPTION

摘要

A television converter uses digital signal processing (DSP) (12, 26) to provide compatibility with different television standards including NTSC and PAL video standards and FM, BTSC, DIN, Home Theatre, NICAM and independent digital audio standards. Audio processing (26) is accomplished without passing the audio through a Nyquist filter (72) used for video. This eliminates AM to PM conversion improving luminance linearity and differential gain and phase. It also prevents video information from phase modulating the audio intercarrier, thereby eliminating video "buzz" components in the audio. The audio processing (26) includes a synchronous FM demodulator (40) and a separate synchronous FM/QPSK demodulator (44) for handling the different audio standards. Handling historical analog TV standards with DSP also enables the advantageous combination of analog and digital television reception within a single digital VLSI ASIC.