Signal receiving end of digital television and signal processing method thereof
A signal receiving end of a digital television includes: an analog-to-digital converter (ADC), converting an input signal from an analog format to a digital format, the input signal including a target signal and an interference signal; a digital gain control circuit, coupled to the ADC, adjusting an amplitude of the target signal according to a gain; a detecting module, coupled to the digital gain control circuit, detecting a variance in the gain to generate a detection value; and a control circuit, coupled to the digital gain control circuit, determining a gain setting parameter according to the detection value. Wherein, the digital gain control circuit further updates the gain according to the gain setting parameter.
1. A signal receiving end of a digital television, comprising:
an analog-to-digital converter (ADC), converting an input signal from an analog format to a digital format, the input signal comprising a target signal and an interference signal;
a digital gain control circuit, coupled to the ADC, adjusting an amplitude of the target signal according to a gain;
a detecting module, coupled to the digital gain control circuit, detecting a variance of the gain to generate a detection value; and
a control circuit, coupled to the digital gain control circuit, determining a gain setting parameter according to the detection value;
wherein, the digital gain control circuit further updates the gain according to the gain setting parameter, the gain setting parameter has a greater absolute value when the detection value is larger, and the gain setting parameter has a smaller absolute value when the detection value is smaller.
2. The signal receiving end according to claim 1 , further comprising:
a filter, coupled between the ADC and the digital gain control circuit, filtering out the interference signal to generate the target signal.
3. The signal receiving end according to claim 2 , wherein the interference signal is an adjacent channel interference (ACI) signal of the target signal, and the filter is one of a band-pass filter, a high-pass filter and a low-pass filter.
4. The signal receiving end according to claim 1 , wherein the detection value is associated with a change in the ACI.
5. The signal receiving end according to claim 1 , wherein the detecting module is a function module of the control circuit and is formed by a program code, and the control circuit executes the program code to generate the detection value.
6. The signal receiving end according to claim 1 , wherein the digital gain control circuit updates the gain further according to the amplitude.
7. The signal receiving end according to claim 1 , wherein the digital gain control circuit updates the gain further according to a difference between the adjusted target signal and an ideal value.
8. A signal processing method for a digital television receiving end, comprising:
converting an input signal from an analog format to a digital format, the input signal comprising a target signal and an interference signal;
adjusting an amplitude of the target signal according to a gain;
detecting a variance of the gain to generate a detection value;
determining a gain setting parameter according to the detection value, comprising:
determining the gain setting parameter to have a greater absolute value when the detection value is larger; and
determining the gain setting parameter to have a smaller absolute value when the detection value is smaller; and
updating the gain according to the gain setting parameter.
9. The signal processing method according to claim 8 , further comprising:
filtering the input signal to filter out the interference signal to generate the target signal.
10. The signal processing method according to claim 8 , wherein the detection value is associated with a change in the ACI.
11. The signal processing method according to claim 8 , further comprising:
updating the gain according to the amplitude.
12. The signal processing method according to claim 8 , further comprising:
updating the gain according to a difference between the adjusted target signal and an ideal value.
13. A signal processing method for a digital television receiving end, comprising:
converting an input signal from an analog format to a digital format, the input signal comprising a target signal and an interference signal;
adjusting an amplitude of the target signal according to a gain;
detecting a variance of the gain to generate a detection value;
determining a gain setting parameter according to the detection value; and
updating the gain according to the gain setting parameter and amplitude, comprising:
determining the gain to have a greater absolute value when the amplitude is larger; and
determining the gain to have a smaller absolute value when the amplitude is smaller.
14. A signal processing method for a digital television receiving end, comprising:
converting an input signal from an analog format to a digital format, the input signal comprising a target signal and an interference signal;
adjusting an amplitude of the target signal according to a gain;
detecting a variance of the gain to generate a detection value;
determining a gain setting parameter according to the detection value; and
updating the gain according to the gain setting parameter and a difference between the adjusted target signal and an ideal value, comprises:
updating the gain to have a greater absolute value when the difference is larger; and
updating the gain to have a smaller absolute value when the difference is smaller.