Method and apparatus for performing analog-to-digital conversion on multiple input signals

1. A method of a signal processing apparatus for processing a plurality of signals, the method comprising:

receiving an output signal from a single analog-to-digital converter (A/D);

extracting, by circuitry of the signal processing apparatus, a first signal from the output signal;

extracting, by the circuitry, a second signal from the same output signal;

demodulating, by the circuitry, the first signal extracted from the output signal; and

demodulating, by the circuitry, the second signal extracted from the same output signal.

2. The method according to claim 1 , wherein

the first signal corresponds to a third signal carried in a forward application transport (FAT) channel, and

the second signal corresponds to a fourth signal carried in an out-of-band (OOB) channel.

3. The method according to claim 1 , further comprising:

summing first and second intermediate signals, which correspond to the first and second signal respectively; and

outputting the summed first and second intermediate signals into the single A/D.

4. The method according to claim 3 , wherein

the first and second intermediate signals are associated with different channels placed within a predetermined sampling frequency (Fs) of the A/D, in a non-overlapping manner, such that the sampling of Fs spectrally folds down the channels associated with the first and second signals between −Fs and 0 Hz or 0 Hz to Fs on the frequency spectrum.

5. The method according to claim 3 , wherein

the first and second intermediate signals are associated with different channels placed within half of a predetermined sampling frequency (Fs) of the A/D, in a non-overlapping manner, such that the sampling of Fs spectrally folds down the channels associated with the first and second signals between −0.5Fs and 0 Hz or 0.5 Fs and Fs on the frequency spectrum.

6. The method according to claim 3 , further comprising:

receiving an RF input including a plurality of RF signals;

extracting one of the plurality of RF signals; and

generating the first intermediate signal based on a predetermined sampling frequency (Fs) of the A/D and a center carrier frequency of the one of the plurality of RF signals.

7. The method according to claim 6 , further comprising:

receiving the RF input including the plurality of RF signals;

extracting a different one of the plurality of RF signals; and

generating the second intermediate signal based on the Fs and a center carrier frequency of the different one of the plurality of RF signals.

8. The method according to claim 3 , wherein

the first intermediate signal has a center frequency of 3Fs-Fs/4,

the second intermediate signal has a center frequency of 2Fs-Fs/16, and the Fs is a predetermined sampling frequency of the A/D.

9. The method according to claim 3 , wherein at least one of the first and second intermediate signals corresponds to a digital television signal.

10. A non-transitory computer-readable storage medium having embedded therein instructions which, when executed by a processor, cause the processor to control a signal processing apparatus to perform a method comprising:

receiving an output signal from a single analog-to-digital converter (A/D);

extracting a first signal from the output signal;

extracting a second signal from the same output signal;

demodulating the first signal extracted from the output signal; and

demodulating the second signal extracted from the same output signal.

11. A signal processing apparatus, comprising:

circuitry configured to

receive an output signal from a single analog-to-digital converter (A/D);

extract a first signal from the output signal;

extract a second signal from the same output signal;

demodulate the first signal extracted from the output signal; and

demodulate the second signal extracted from the same output signal.

12. The apparatus according to claim 11 , wherein

the first signal corresponds to a third signal carried in a forward application transport (FAT) channel, and

the second signal corresponds to a fourth signal carried in an out-of-band (OOB) channel.

13. The apparatus according to claim 11 , wherein the circuitry is further configured to:

sum first and second intermediate signals, which correspond to the first and second signal respectively; and

output the summed first and second intermediate signals into the single A/D.

14. The apparatus according to claim 13 , wherein

the first and second intermediate signals are associated with different channels placed within a predetermined sampling frequency (Fs) of the A/D, in a non-overlapping manner, such that the sampling of Fs spectrally folds down the channels associated with the first and second signals between −Fs and 0 Hz or 0 Hz to Fs on the frequency spectrum.

15. The apparatus according to claim 13 , wherein

the first and second intermediate signals are associated with different channels placed within half of a predetermined sampling frequency (Fs) of the A/D, in a non-overlapping manner, such that the sampling of Fs spectrally folds down the channels associated with the first and second signals between −0.5Fs and 0 Hz or 0.5 Fs and Fs on the frequency spectrum.

16. The apparatus according to claim 13 , wherein the circuitry is further configured to:

receive an RF input including a plurality of RF signals;

extract one of the plurality of RF signals; and

generate the first intermediate signal based on a predetermined sampling frequency (Fs) of the A/D and a center carrier frequency of the one of the plurality of RF signals.

17. The apparatus according to claim 16 , wherein the circuitry is further configured to:

receive the RF input including the plurality of RF signals;

extract a different one of the plurality of RF signals; and

generate the second intermediate signal based on the Fs and a center carrier frequency of the different one of the plurality of RF signals.

18. The apparatus according to claim 13 , wherein

the first intermediate signal has a center frequency of 2Fs-Fs/4,

the second intermediate signal has a center frequency of 2Fs-Fs/16, and the Fs is a predetermined sampling frequency of the A/D.

19. The apparatus according to claim 13 , wherein at least one of the first and second intermediate signals corresponds to a digital television signal.