TV receiver and analog TV signal processing method
View Patent ↗The present invention provides a TV receiver and an analog TV signal processing method. The TV receiver includes a tuner, an analog-to-digital converter, and a digital filter module. The tuner is utilized to receive an RF signal and generate a first signal; the analog-to-digital converter is coupled to the tuner for converting the first signal to a digital signal, and the digital filter module is coupled to the analog-to-digital converter for filtering the digital signal in order to filter an analog TV signal contained in the RF signal in digital domain.
1. A TV receiver comprising:
a tuner, for receiving an RF signal to generate a first signal;
an analog-to-digital converter, coupled to the tuner, for converting the first signal into a digital signal;
a digital filter module, coupled to the analog-to-digital converter, for filtering the digital signal to filter an analog TV signal comprised in the RF signal in digital domain and processing an audio carrier suppression for the analog TV signal in digital domain;
a digital-to-analog converter, coupled to the digital filter module, for converting the filtered digital signal into a second signal;
an analog TV demodulator, coupled to the digital-to-analog converter, for performing analog TV demodulation upon the second signal so as to demodulate the analog TV signal contained in the RF signal; and
a digital TV demodulator, coupled to the analog-to-digital converter, for performing digital TV demodulation upon the digital signal so as to demodulate a digital TV signal contained in the RF signal.
2. The TV receiver of claim 1 , wherein the tuner further comprises a digital TV signal intermediate frequency filter for performing digital TV filtering upon the first signal to filter an intermediate frequency of the first signal.
3. The TV receiver of claim 2 , wherein the digital TV signal intermediate frequency filter comprises a surface acoustic wave (SAW) filter.
4. The TV receiver of claim 2 , wherein the digital TV signal intermediate frequency filter comprises a low pass filter.
5. The TV receiver of claim 1 , wherein the digital filter module has a characteristic of a Nyquist slope.
6. The TV receiver of claim 1 , wherein the digital filter module comprises:
a low pass filter for implementing a characteristic of a Nyquist slope; and
a high pass filter for processing the audio carrier suppression.
7. The TV receiver of claim 6 , wherein the low pass filter comprises a raised cosine filter.
8. The TV receiver of claim 1 , wherein the digital filter module comprises a band pass filter for processing audio signals.
9. The TV receiver of claim 1 , wherein the digital filter module comprises:
an upsampler for upsampling the filtered signal; and
an upconverter, coupled to the upsampler, for raising the frequency of the filtered signal.
10. The TV receiver of claim 9 , wherein the digital TV demodulator comprises an analog filter for filtering out an image signal generated during operation of the upconverter.
11. A method for processing an analog TV signal comprising:
tuning an RF signal to generate a first signal comprising an analog TV signal;
performing analog-to-digital conversion on the first signal, to generate a digital signal;
filtering the digital signal to filter the analog TV signal comprised in the first signal in digital domain and processing an audio carrier suppression for the analog TV signal in digital domain, and then generate a filtered signal;
performing digital-to-analog conversion on the filtered signal, to generate a second signal;
performing analog TV demodulation upon the second signal so as to demodulate the analog TV signal;
performing digital TV demodulation upon the digital signal outputted by the analog-to-digital conversion, so as to demodulate a digital TV signal comprised in the first signal.
12. The method of claim 11 , further comprising performing digital TV filtering upon the first signal to filter an intermediate frequency of the first signal.
13. The method of claim 12 , wherein the intermediate frequency filtering is performed by a surface acoustic wave (SAW) filter.
14. The method of claim 12 , wherein the intermediate frequency filtering is performed by a low pass filter.
15. The method of claim 11 , wherein the filtered signal has a characteristic of a Nyquist slope.
16. The method of claim 11 , wherein the digital signal is filtered by a low pass filter implementing a characteristic of a Nyquist slope, and wherein the audio carrier suppression is processed by a high pass filter.
17. The method of claim 16 , wherein the low pass filter comprises a raised cosine filter.
18. The method of claim 11 , wherein the digital signal is filtered by a band pass filter for processing audio signals.
19. The method of claim 11 , further comprising:
upsampling the filtered signal; and
raising the frequency of the upsampled signal.
20. The method of claim 19 , further comprising filtering out an image signal in the raised frequency signal.