Architecture for intermediate frequency encoder

• US 6,741,650 B1
• Filed: 03/02/2000
• Issued: 05/25/2004
• Est. Priority Date: 03/02/2000
• Status: Expired due to Term

• Current Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Original Assignee: ADC Telecommunications Incorporated (TE Connectivity Limited)
• Inventors: Painchaud, Dean, Wachter, Lawrence J
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Kim, Kevin
• Application Number:
  US09/518,072
• Time in Patent Office: 1,545 Days
• Field of Search: 375/229, 375/214, 375/220, 375/240.12, 375/355, 329/306
• US Class Current: 375/240.21
• CPC Class Codes: H03M 1/1245 Details of sampling arrangements or methods
• CPC Class Codes: H04N 7/01 Conversion of standards , e.g. involving analogue television standards or digital television standards processed at pixel level

Abstract

An encoder. The encoder includes an analog-to-digital (A/D) converter that receives an analog signal. The A/D converter downconverts and digitizes the analog signal without analog mixing of the analog signal. The encoder also includes a resampler that is coupled to the A/D converter. The resampler receives the digital signal and converts the downconverted digital signal to an output signal at a data rate independent of a data rate of the digitized analog signal.

Claims

1. An encoder for encoding an analog signal for transmission over a communication link, the encoder comprising:

an input adapted to receive the analog signal;

an analog-to-digital (A/D) converter, coupled to the input, that receives the analog signal and downconverts and digitizes the analog signal without analog mixing of the analog signal;

a resampler coupled to the A/D converter that receives the downconverted digital signal and converts the downconverted digital signal to an output signal at a data rate independent of a data rate of the digitized analog signal; and

an output, coupled to the resampler, the output adapted to be coupled to the communication link for transmitting the output signal over the communication link to a remote decoder.

2. The encoder of claim 1, wherein the analog signal has a frequency bandwidth selected from the group consisting of narrowband and wideband.

3. An encoder for encoding an analog signal for transmission over a communication link, the encoder comprising:

an input adapted to receive the analog signal;

an analog-to-digital (A/D) converter, coupled to the input, that receives the analog signal that has a frequency spectrum, wherein the A/D converter lowers the frequency spectrum of the analog signal and digitizes the analog signal;

an asynchronous resampler coupled to the A/D converter that receives the digital signal and converts the digital signal to an output signal having an output data rate independent of a data rate of the digitized analog signal; and

an output, coupled to the resampler, the output adapted to be coupled to the communication link for transmitting the output signal over the communication link to a remote decoder.

4. The encoder of claim 3, wherein a ratio of the data rate of the digitized analog signal to the output data rate is non-integer based.

5. The encoder of claim 3, wherein the A/D converter comprises a wide bandwidth A/D converter.

6. The encoder of claim 4, further comprising a gain control circuitry coupled to the A/D converter, wherein the gain control circuitry scales an amplitude of the analog signal such that a maximum amplitude of the analog signal is lower than a maximum input amplitude required by the A/D converter.

7. The encoder of claim 3, wherein the A/D converter has a clock input that allows a sampling rate of the A/D converter to be adjusted.

8. The encoder of claim 3, wherein the A/D converter samples the analog signal at a rate lower than a Nyquist sampling rate.

9. An encoder for encoding an analog signal for transmission over a communication link, the encoder comprising:

an input adapted to receive the analog signal;

an analog-to-digital (A/D) converter, coupled to the input, that receives the analog signal and downconverts and digitizes the analog signal independent of an analog mixing of the analog signal, such that a sampling rate of the A/D converter is less than a Nyquist sampling rate;

a resampler coupled to the A/D converter that receives the downconverted digital signal and converts the downconverted digital signal to an output signal having a data rate independent of a data rate of the digitized analog signal; and

an output, coupled to the resampler, the output adapted to be coupled to the communication link for transmitting the output signal over the communication link to a remote decoder.

10. The encoder of claim 9, wherein the resampler is asynchronous.

11. An encoder for encoding an analog signal for transmission over a communication link, the encoder comprising:

an input adapted to receive the analog signal;

an analog-to-digital (A/D) converter, coupled to the input, that receives the analog signal and samples the analog signal at a rate that is lower than a Nyquist sampling rate to produce a digital signal with a frequency spectrum that is lower than a frequency spectrum of the analog signal;

a resampler coupled to the A/D converter that receives the digitized signal and converts the digitized signal to an output signal having a data rate that is independent of a data rate of the sampled analog signal, such that a ratio of the data rate of the sampled analog signal to the data rate of the output signal is non-integer based; and

an output, coupled to the resampler, the output adapted to be coupled to the communication link for transmitting the output signal over the communication link to a remote decoder.

12. The encoder of claim 11, wherein the frequency spectrum of the analog signal is selected from the group consisting of narrowband and wideband.

13. An encoder comprising:

a gain control circuitry that receives an analog signal and scales an amplitude of the analog signal, wherein the analog signal has a frequency range;

an analog bandpass filter coupled to the gain control circuitry, wherein the analog bandpass filter bandpass filters the analog signal such that a bandpass band includes the frequency spectrum of the analog signal;

a frequency response equalization circuit coupled to the analog bandpass filter, wherein the frequency response equalization circuit receives the analog signal and lowers distortion in the analog signal;

an analog-to-digital (A/D) converter coupled to the frequency response circuit, wherein the A/D converter receives the analog signal and lowers a frequency spectrum of the analog signal and digitizes the analog signal;

a lowpass filter coupled to the A/D converter, wherein the lowpass filter lowpass filters the digital signal such that a lowpass band includes the frequency spectrum of the digital signal; and

a resampler coupled to the lowpass filter that receives the digital signal and converts the digital signal to a fixed data rate output signal independent of a data rate of the digitized analog signal.

14. The encoder of claim 13, wherein the lowpass filter comprises a finite impulse response filter.

15. The encoder of claim 13, wherein a sample rate of the A/D converter is programmable.

16. The encoder of claim 13, wherein the resampler is programmable.

17. A method of encoding an analog signal for transmission over a communication link, the method comprising:

receiving the analog signal;

digitizing the analog signal to generate a digital signal, wherein a frequency spectrum of the digital signal is lower than a frequency spectrum of an analog signal;

converting the digital signal to an output signal having a fixed data rate independent of a data rate of the digitized analog signal; and

transmitting the output signal over a communication link to a remote decoder.

18. The method of claim 17, wherein the frequency spectrum of the analog signal is selected from the group consisting of narrowband and wideband.

19. A method of encoding an analog signal for transmission over a communication link, the method comprising:

receiving the analog signal;

downconverting the analog signal without analog mixing;

converting the downconverted analog signal to a downconverted digital signal;

resampling the downconverted digital signal to generate an output signal having a fixed data rate that is independent of a data rate of the downconverted digital signal; and

transmitting the output signal over a communication link to a remote decoder.

20. The method of claim 19, wherein a ratio of the data rate of the downconverted digital signal to the fixed data rate of the output signal is non-integer based.

21. The method of claim 19, wherein downconverting the analog signal includes sampling at a rate that is less than a Nyquist sampling rate.

22. A method for encoding an analog signal for transmission over a communication link the method comprising:

receiving the analog signal;

digitizing the analog signal to generate a digitized signal, wherein a frequency range of the digitized signal is lower than a frequency range of the analog signal;

converting a data rate of the digital signal to an output signal with an output data rate, such that a ratio of an input data rate of the digitized analog signal to the output data rate is non-integer based; and

transmitting the output signal over a communication link to a remote decoder.

23. The method of claim 22, wherein digitizing the analog signal includes sampling the analog signal at a rate lower than a Nyquist sampling rate.

24. A method of encoding an analog signal for transmission over a communication link, the method comprising:

receiving the analog signal;

digitizing the analog signal to generate a digitized signal such that the analog signal is sampled at a rate that is lower than a Nyquist sampling rate, wherein a frequency spectrum of the digitized signal is lower than a frequency spectrum of the analog signal independent of analog mixing of the analog signal;

converting the digitized signal to an output signal having a data rate that is independent of a data rate of the digitized analog signal, such that a ratio of the data rate of the digitized analog signal to the data rate of the output signal is non-integer based, and

transmitting the output signal over a communication link to a remote decoder.

25. The method of claim 24, wherein the frequency spectrum of the analog signal is selected from the group consisting of narrowband and wideband.

26. A communication system, comprising:

a modulator that receives an analog signal and modulates the analog signal onto a carrier signal;

a first transmission device coupled to the modulator that receives the carrier signal, the first transmission device includes an encoder that includes;

an analog-to-digital (A/D) converter that receives the carrier signal and downconverts and digitizes the analog signal without analog mixing of the analog signal; and

a resampler coupled to the A/D converter that receives the downconverted digital signal and converts the downconverted digital signal to an output signal at a data rate independent of a data rate of the digitized analog signal; and

a second transmission device coupled to the first transmission device that receives the output signal and generates a reconstructed analog signal from the digital signal, wherein the reconstructed analog signal is approximately equal to the analog signal.

27. The communication system of claim 26, wherein the first transmission device is coupled to the second transmission device through a fiberoptic line.

28. The communication system of claim 26, wherein digitizing the analog signal includes sampling the analog signal at a rate lower than a Nyquist sampling rate.

29. The communication system of claim 26, wherein a sample rate of the A/D converter is programmable.

30. The communication system of claim 26, wherein the resampler is programmable.

31. A system for encoding and transmitting an analog signal, comprising:

a modulator that receives the analog signal and modulates the analog signal onto a carrier signal;

a first transmission device coupled to the modulator that receives the carrier signal, wherein the first transmission device includes an encoder that includes;

an analog-to-digital (A/D) converter that receives the analog signal that has a frequency spectrum, wherein the A/D converter lowers the frequency spectrum of the analog signal and digitizes the analog signal; and

an asynchronous resampler coupled to the A/D converter that receives the digital signal and converts the digital signal to an output signal having an output data rate, such that a ratio of the input data rate to the output data rate is non-integer based; and

a second transmission device coupled to the first transmission device that receives the output signal and generates a reconstructed analog signal from the digital signal, wherein the reconstructed analog signal is approximately equal to the analog signal.

32. The system of claim 31, wherein the analog signal has a frequency bandwidth selected from the group consisting of narrowband and wideband.

33. A system for encoding and transmitting an analog signal, the system comprising:

a modulator that receives the analog signal and modulates the analog signal onto a carrier signal; and

a first transmission device coupled to the modulator that receives the carrier signal, wherein the first transmission device includes an encoder that includes;

an analog-to-digital (A/D) converter that receives the analog signal and downconverts and digitizes the analog signal independent of a frequency band of the analog signal;

a resampler coupled to the A/D converter that receives the downconverted digital signal and converts the downconverted digital signal to an output signal at a data rate independent of a data rate of the digitized analog signal; and

a second transmission device coupled to the first transmission device that receives the output signal and generates a reconstructed analog signal from the digital signal, wherein the reconstructed analog signal is approximately equal to the analog signal.

34. The system of claim 33, wherein the A/D converter comprises a wide bandwidth A/D converter.

35. The system of claim 34, further comprising a gain control circuitry coupled to the A/D converter, wherein the gain control circuitry scales an amplitude of the analog signal such that a maximum amplitude of the analog signal is lower than a maximum input amplitude required by the front end of the A/D converter.

36. The system of claim 33, wherein the A/D converter samples the analog signal at a rate lower than a Nyquist sampling rate.

37. A system for encoding and transmitting an analog signal, the system comprising:

a modulator that receives the analog signal and modulates the analog signal onto a carrier signal; and

a first transmission device coupled to the modulator that receives the carrier signal, wherein the first transmission device includes an encoder that includes;

an analog-to-digital (A/D) converter that receives the analog signal and digitizes the analog signal to generate a digitized signal such that the analog signal is sampled at a rate that is lower than a Nyquist sampling rate, wherein a frequency spectrum of the digitized signal is lower than a frequency spectrum of the analog signal independent of analog mixing of the analog signal;

a resampler coupled to the A/D converter that receives the digitized signal and converts the digitized signal to an output signal having a data rate that is independent of a data rate of the digitized signal, such that a ratio of the data rate of the digitized signal to the data rate of the output signal is non-integer based; and

a second transmission device coupled to the first transmission device that receives the output signal and generates a reconstructed analog signal from the digital signal, wherein the reconstructed analog signal is approximately equal to the analog signal.