USRE37326EExpiredUtility
HDTV receiver
Est. expiryApr 12, 2014(expired)· nominal 20-yr term from priority
Inventors:Dae Jin Kim
H04N 7/015H04N 5/4446H04N 21/426H04N 5/455H04N 5/50
50
PatentIndex Score
12
Cited by
7
References
51
Claims
Abstract
An HDTV receiver is disclosed including a tuning portion for selecting one of a plurality of RF signals received, and converting a selected RF signal into an intermediate frequency signal; a demodulator/FPLL for demodulating the intermediate frequency signal output from the tuning portion into a baseband signal in which the frequency and phase are locked, and outputting an AFC signal; a first local oscillator for forming a frequency signal which can be varied from a reference frequency to a specific frequency, and outputting the thus-formed frequency signal to the demodulator/FPLL; and a VSB filter for VSB-filtering the baseband signal output from the demodulator/FPLL.
Claims
exact text as granted — not AI-modifiedWhat is claimed is:
1. An HDTV receiver comprising:
a tuning portion for selecting one of a plurality of RF signals received, and converting a selected RF signal into an intermediate frequency signal;
a demodulator/FPLL for demodulating said intermediate frequency signal output from said tuning portion into a baseband signal in which the frequency and phase are locked, and outputting an AFC signal;
a first local oscillator receiving said AFC signal and forming a frequency signal which can be varied from a reference frequency to a specific frequency, and outputting the thus-formed frequency signal to said demodulator/FPLL; and
a VSB filter for VSB-filtering said baseband signal output from said demodulator/FPLL.
2. An HDTV receiver as claimed in claim 1 , wherein said tuning portion comprises:
a second local oscillator for outputting a fixed frequency signal;
a tuner for first demodulating one of a plurality of RF signals received according to an input channel tuning signal and a delayed AGC signal, and second demodulating said first demodulated RF signal according to a frequency signal output from said second local oscillator;
a SAW filter for band-rejection-filtering a baseband the intermediate frequency signal output from said tuner; and
an IF amplifier for automatically gain-controlling said baseband intermediate frequency signal output from said SAW filter.
3. An HDTV receiver as claimed in claim 2 , wherein said second local oscillator outputs a frequency signal fixed at 876 MHz.
4. An HDTV receiver as claimed in claim 2 , wherein said SAW filter band-rejection-filters said baseband intermediate frequency signal output from said tuner through a frequency band containing a guard band with the transmission band of said VSB filter.
5. An HDTV receiver as claimed in claim 4 , wherein said guard band is set by the maximum according to the difference between the oscillating frequency generated from the channel tuning signal and the frequency of said second local oscillator.
6. An HDTV receiver as claimed in claim 4 , wherein said SAW filter band-rejection-filters said baseband intermediate frequency signal output from said tuner through 6 MHZ±300 KHz.
7. An HDTV receiver as claimed in claim 1 , wherein said first local oscillator forms a frequency signal which can be varied from a 46.69 MHz reference frequency to±300 KHz according to the AFC signal output from said demodulator/FPLL, and outputting said thus formed frequency signal to said demodulator/FPLL.
8. An HDTV receiver as claimed in claim 1 , wherein said VSB filter comprises:
an ADC portion for A/D converting said baseband signal output from said demodulator/FPLL by dividing said baseband signal into I-channel and Q-channel signals;
an SRC filter portion for SRC-filtering said I-channel and Q-channel signals output from said ADC portion; and
a subtractor for subtracting a signal output from said SRC filter portion and outputting a VSB-filtered signal.
9. An HDTV receiver as claimed in claim 8 , wherein said ADC portion consists of two first and second ADCs for A/D converting said I-channel and Q-channel signals, respectively.
10. An HDTV receiver as claimed in claim 8 , wherein said SRC filter portion comprises:
an SRC filter for SRC-filtering said I-channel signal output from said ADC portion with the coefficient of the real-number axis; and
an SRC filter for SRC-filtering said Q-channel signal output from said ADC portion with the coefficient of the imaginary-number axis.
11. An HDTV receiver as claimed in claim 9 , wherein said first and second ADCs establish their sampling frequency at the symbol rate.
12. An HDTV receiver as claimed in claim 11 , wherein said first and second ADCs have 10.76 MHz as their sampling frequency.
13. A digital television receiver comprising:
a tuning portion, including
a fixed local oscillator providing a fixed frequency signal, and
a tuner receiving a channel tuning signal and the fixed frequency signal and in response thereto selecting one of a plurality of RF signals received, and converting a selected RF signal into an intermediate frequency signal;
a demodulator/FPLL for demodulating said intermediate frequency signal output from said tuning portion into a baseband signal in which the frequency and phase are locked, and outputting an AFC signal; and
a variable local oscillator receiving said AFC signal and forming a frequency signal which can be varied from a reference frequency to a specific frequency, and outputting the thus - formed frequency signal to the demodulator/FPLL.
14. A VSB receiving system for a digital television comprising:
a tuning portion including a tuner for selecting one of a plurality of signals received, and converting a selected signal into an intermediate frequency signal, the tuning portion including a fixed local oscillator providing a first fixed frequency signal to the tuner;
a demodulator including an FPLL for demodulating said intermediate frequency signal output from said tuning portion into a baseband signal, the demodulator outputting an AFC signal; and
a variable local oscillator receiving the AFC signal and providing a frequency signal that can be varied from a reference frequency to a specific frequency and outputting a second frequency signal to the demodulator.
15. The VSB receiving system as claimed in claim 14 , wherein said fixed local oscillator outputs a frequency signal fixed at 876 MHZ.
16. The VSB receiving system as claimed in claim 14 , wherein said variable local oscillator forms a frequency signal which can be varied from a 46 . 69 MHZ reference frequency to +/− 300 KHz according to the AFC signal output from said demodulator, and outputting said thus formed frequency signal to said demodulator.
17. A VSB receiving system for a digital television comprising:
a tuner selecting one of a plurality of signals received, and converting a selected signal into an intermediate frequency signal;
a fixed local oscillator providing a first fixed frequency signal to the tuner;
a filter receiving the intermediate frequency signal and performing a band pass filtering to produce a filtered signal;
an amplifier amplifying the filtered signal;
a demodulator including an FPLL for demodulating said filtered signal output from the amplifier and outputting an AFC signal; and
a variable local oscillator receiving the AFC signal and providing a frequency signal that can be varied from a reference frequency to a specific frequency and outputting a second frequency signal to the demodulator,
wherein the demodulator outputs a baseband signal.
18. The VSB receiving system as claimed in claim 17 , wherein said fixed local oscillator outputs a frequency signal fixed at 876 MHZ.
19. The VSB receiving system as claimed in claim 17 wherein said variable local oscillator forms a frequency signal which can be varied form a 46 . 69 MHZ reference frequency to +/− 300 KHz according to the AFC signal output from said demodulator, and outputting said thus formed frequency signal to said demodulator.
20. A method of processing a transmitted digital television signal at a VSB receiving system for a digital television, the method comprising the steps of:
selecting one of a plurality of signals received, and converting a selected signal into an intermediate frequency signal in response to a first fixed frequency signal generated from a fixed local oscillator;
generating an AFC signal in response to the intermediate frequency signal;
generating a second frequency signal that can be varied from a reference frequency to a specific frequency in response to the AFC signal; and
demodulating the intermediate frequency signal and generating a baseband signal from the intermediate frequency signal in response to the step of generating the second frequency signal.
21. The method of claim 20 , wherein said first fixed frequency signal is 876 MHz.
22. The method of claim 20 , wherein said second frequency signal can be varied from a 46 . 69 MHz reference frequency to +/− 300 kHz according to the AFC signal.
23. A method for processing a transmitted digital television signal at a VSB receiving system for a digital television, the method comprising the steps of:
selecting through a tuner one of a plurality of signals received, and converting a selected signal into an intermediate frequency signal;
generating through a first fixed local oscillator a first fixed frequency signal to the tuner;
band pass filtering the intermediate frequency signal to produce a filtered signal;
amplifying the filtered signal;
demodulating the filtered signal output from the amplifier and generating an AFC signal;
generating a frequency signal that can be varied from a reference frequency to a specific frequency and outputting a second frequency signal to the demodulator; and
generating a baseband signal in response to the step of generating the frequency signal that can be varied.
24. The method of claim 23 , wherein the first fixed frequency is 876 MHz.
25. The method of claim 23 , wherein said second frequency signal can be varied from a 46 . 69 MHz reference frequency to +/− 300 kHz according to the AFC signal.
26. A VSB receiving system for a digital television, comprising:
a tuning portion including a tuner for selecting one of a plurality of signals received, and converting a selected signal into an intermediate frequency signal, the tuning portion including a local oscillator providing a fixed frequency signal to the tuner, and further including an intermediate frequency filter for filtering said intermediate frequency signal to produce a filtered intermediate frequency signal;
a demodulator including an FPLL for demodulating said filtered intermediate frequency signal output from said tuning portion into a baseband signal, the demodulator outputting an AFC signal; and
a variable local oscillator receiving the AFC signal and providing a second frequency signal that can be varied from a reference frequency to a specific frequency to the demodulator.
27. The VSB receiving system as claimed in claim 26 , wherein said first frequency signal is 876 MHZ.
28. The VSB receiving system as claimed in claim 26 , wherein said variable local oscillator forms a frequency signal which can be varied from a 46 . 69 MHZ reference frequency to +/− 300 KHz according to the AFC signal output from said demodulator, and outputting said thus formed frequency signal to said demodulator.
29. A VSB receiving system for a digital television, comprising:
a tuner selecting one of a plurality of signals received, and converting a selected signal into an intermediate frequency signal;
a local oscillator providing a fixed frequency signal to the tuner;
a SAW filter receiving the intermediate frequency signal and performing a band pass filtering to produce a filtered signal;
an amplifier amplifying the filtered signal;
a demodulator including an FPLL for demodulating said filtered signal output from the amplifier and outputting an AFC signal; and
a variable local oscillator receiving the AFC signal and providing a frequency signal that can be varied from a reference frequency to a specific frequency and outputting a second frequency signal to the demodulator,
wherein the demodulator outputs a baseband signal.
30. The method of claim 29 , wherein said fixed frequency signal is 876 MHz.
31. The VSB receiving system as claimed in claim 29 , wherein said variable local oscillator forms a frequency signal which can be varied from a 46 . 69 MHZ reference frequency to +/− 300 KHz according to the AFC signal output from said demodulator, and outputting said thus formed frequency signal to said demodulator.
32. A method for processing a transmitted digital television signal at a VSB receiving system for a digital television, the method comprising the steps of:
selecting one of a plurality of signals received, and converting a selected signal into an intermediate frequency signal in response to a fixed frequency signal generated from a local oscillator, the selecting step including band pass filtering the intermediate frequency signal;
generating an AFC signal in response to the intermediate frequency signal;
generating a frequency signal that can be varied from a reference frequency to a specific frequency in response to the AFC signal and generating a second frequency signal; and
demodulating the intermediate frequency signal and generating a baseband signal from the intermediate frequency signal in response to the step of generating the frequency signal.
33. The method of claim 20 , wherein said fixed frequency signal is 876 MHz.
34. The method of claim 32 , wherein said second frequency signal can be varied from a 46 . 69 MHz reference frequency to +/− 300 kHz according to the AFC signal.
35. A method for processing a transmitted digital television signal at a VSB receiving system for a digital television, the method comprising the steps of:
selecting through a tuner one of a plurality of signals received, and converting a selected signal into an intermediate frequency signal;
generating through a first local oscillator a fixed frequency signal to the tuner;
saw filtering the intermediate frequency signal to produce a filtered signal;
amplifying the filtered signal;
demodulating the filtered signal output from the amplifier and generating an AFC signal;
generating a second frequency signal that can be varied from a reference frequency to a specific frequency and outputting the second frequency signal to the demodulator; and
generating a baseband signal in response to the step of generating the frequency signal that can be varied.
36. The method of claim 35 , wherein said fixed local oscillator outputs a frequency signal fixed at 876 MHz.
37. The method of claim 35 , wherein said second frequency signal can be varied from a 46 . 69 MHz reference frequency to +/− 300 kHz according to the AFC signal.
38. A VSB receiving system for a digital television, comprising:
a tuning portion including a tuner for selecting one of a plurality of signals received, and converting a selected signal into an intermediate frequency signal, the tuning portion including a local oscillator providing a first frequency signal to the tuner;
a first bandpass filter coupled to the tuner for receiving the intermediate frequency signal and outputting a bandpass filtered signal;
a second filter coupled to the first bandpass filter, the second filter including a VSB signal matching filter.
39. The VSB receiving system as claimed in claim 38 , wherein said local oscillator outputs a frequency signal at 876 MHZ.
40. A VSB receiving system for a digital television receiver comprising:
a tuning portion including a tuner for selecting one of a plurality of signals received, and converting a selected signal into an intermediate frequency signal, the tuning portion including a local oscillator providing a first frequency signal to the tuner;
a first bandpass filter coupled to the tuner for receiving the intermediate frequency signal and outputting a bandpass filtered signal;
a demodulator coupled to the first bandpass filter and producing a baseband signal from the bandpass filtered signal; and
a second bandpass filter coupled to the demodulator, the second bandpass filter including a VSB signal matching filter.
41. The VSB receiving system as claimed in claim 40 , wherein said local oscillator outputs a frequency signal at 876 MHZ.
42. A VSB receiving system for a digital television comprising:
a tuning portion including a tuner for selecting one of a plurality of signals received, and converting a selected signal into an intermediate frequency signal;
a filter having a guard band value (α) , receiving the intermediate frequency from the tuner and performing a bandpass filtering to produce a filtered intermediate frequency signal;
a demodulator including an FPLL for demodulating said filtered intermediate frequency signal output from said filter into a baseband signal, the demodulator outputting an AFC signal; and
a variable local oscillator receiving the AFC signal and generating a frequency signal that can be varied from a reference frequency to a specific frequency corresponding to the guard band value (α) and outputting said frequency signal to the demodulator.
43. A VSB receiving system as claimed in claim 42 , wherein said guard band value (α) is no greater than +/− 300 kHz.
44. A VSB receiving system for a digital television comprising:
a tuner selecting one of a plurality of signals received, and converting a selected signal into an intermediate frequency signal;
a filter having guard band value (α) , receiving the intermediate frequency signal and performing a band pass filtering to produce a filtered intermediate frequency signal;
an amplifier amplifying the filtered intermediate frequency signal;
a demodulator including an FPLL for demodulating the filtered intermediate frequency signal output from the amplifier and outputting an AFC signal; and
a variable local oscillator receiving the AFC signal and generating a frequency signal that can be varied from a reference frequency to a specific frequency corresponding to the guard band value (α) and outputting said frequency signal to the demodulator.
45. A VSB receiving system as claimed in claim 42 , wherein said guard band value (α) is no greater than +/− 300 kHz.
46. A method for processing a transmitted digital television signal in a VSB receiving system for a digital television, the method comprising:
selecting one of a plurality of signals received, and converting a selected signal into an intermediate frequency signal;
band pass filtering the intermediate frequency signal with a filter having a guard band value (α) and producing a filtered intermediate frequency signal;
generating an AFC signal in response to the filtered intermediate frequency signal;
generating a frequency signal that can be varied from a reference frequency to a specific frequency corresponding to the guard band value (α) in response to the AFC signal; and
demodulating the filtered intermediate frequency signal and generating a baseband signal from the filtered intermediate frequency signal in response to the step of generating the frequency signal.
47. The VSB receiving system as claimed in claim 46 , wherein said guard band value (α) is no greater than +/− 300 kHz.
48. A method for processing a transmitted digital television signal in a VSB receiving system for a digital television, the method comprising:
selecting through a tuner one of a plurality of signals received, and converting a selected signal into an intermediate frequency signal;
band pass filtering the intermediate frequency signal with a filter having guard band value (α) , and producing a filtered intermediate frequency signal;
amplifying the filtered intermediate frequency signal;
demodulating the filtered intermediate frequency signal output from the amplifier and generating an AFC signal;
generating a frequency signal that can be varied from a reference frequency to a specific frequency corresponding to the guard band value (α) and outputting said frequency signal to the demodulator; and
generating a baseband signal in response to the step of generating the frequency signal that can be varied.
49. The VSB receiving system as claimed in claim 48 , wherein said guard band value (α) is no greater than +/− 300 kHz.
50. A VSB receiving system for a digital television receiver comprising:
a tuning portion including a tuner for selecting one of a plurality of signals received, and converting a selected signal into an intermediate frequency signal,
a first band pass filter having a guard band value (α) coupled to the tuner for receiving the intermediate frequency signal and outputting a bandpass filtered signal;
a demodulator coupled to the first band pass filter and producing a baseband signal from the bandpass filtered signal and;
a variable local oscillator receiving the AFC signal and generating a frequency signal that can be varied from a reference frequency to a specific frequency corresponding to guard band value (α) and outputting said frequency signal to the demodulator and;
a second band pass filter coupled to the demodulator, the second band pass filter including a signal matching filter.
51. The VSB receiving system as claimed in claim 50 , wherein said guard band value (α) is no greater than +/− 300 kHz.Cited by (0)
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