Subscriber line driver with equalizer

1. A line driver for transforming amplitude characteristics of a communication signal, comprising:

means for detecting amplitude of a first portion of a frequency spectrum of the communication signal, the amplitude greater than a predefined specification;

means for detecting amplitude of a second portion of the frequency spectrum of the communication signal, the amplitude less than the predefined specification;

means for decreasing the amplitude of the first portion before transmission of the communication signal so that the decreased amplitude is within a predefined threshold of the predefined specification; and

means for increasing the amplitude of the second portion before transmission of the communication signal so that the increased amplitude is within the predefined threshold of the predefined specification.

2. The line driver of claim 1 , further comprising a transmitting means for transmitting said transformed communication signal onto a communication medium pursuant to the predefined specification.

3. The line driver of claim 1 , wherein said predefined specification is a power spectral distribution (PSD) standard.

4. The line driver of claim 1 , wherein said predefined specification is a fraction of a power spectral distribution (PSD) standard.

5. The line driver of claim 1 , wherein the communication signal is a digital subscriber loop (DSL) signal.

6. A line driver for transforming amplitude characteristics of a communication signal to produce a transformed communication signal, comprising a signal equalizer configured to:

decrease amplitude of a first portion of a frequency spectrum of the communication signal before transmission of the communication signal, the first portion having a first amplitude greater than a predefined specification, so that the adjusted first amplitude is within a predefined threshold of the predefined specification; and

increase amplitude of a second portion of the frequency spectrum of the communication signal before transmission of the communication signal, the second portion having a second amplitude less than the predefined specification, so that the adjusted second amplitude of the communication signal is within the predefined threshold of the predefined specification.

7. The line driver of claim 6 , further comprising a current driver, the current driver configured to receive communications from the signal equalizer so that said current driver injects the transformed communication signal into a communication system.

8. The line driver of claim 6 , further comprising a voltage driver, the voltage driver configured to receive communications from the signal equalizer so that said voltage driver injects the transformed communication signal into a communication system.

9. The line driver of claim 6 , further comprising a voltage feedback amplifier circuit wherein the inputs to the voltage feedback amplifier circuit are connected to a tip wire and a ring wire of a telephony system, and the output of the voltage feedback amplifier circuit is connected as an input to the signal equalizer.

10. The line driver of claim 1 , further comprising a means for sensing the direction of travel of said communication signal and a means for selectively operating in a transmit signal direction when the communication signal is traveling in a direction out to a communication transmission system.

11. A method for transforming characteristics of a communication signal to produce a transformed communication signal, comprising:

decreasing amplitude of a first detected portion of a frequency spectrum of the communication signal before transmission of the communication signal so that the decreased amplitude is within a predefined threshold of a predefined specification; and

increasing amplitude of a second portion of the frequency spectrum of the communication signal before transmission of the communication signal so that the increased amplitude is within the predefined threshold of the predefined specification.

12. The method of claim 11 , further comprising:

detecting amplitude of the first portion of the frequency spectrum of the communication signal, the first portion having a first amplitude greater than the predefined specification; and

detecting amplitude of the second portion of the frequency spectrum of the communication signal, the second portion having a second amplitude less than the predefined specification.

13. The method of claim 11 , wherein the decreasing further comprises decreasing amplitude of the first portion to within a predefined difference threshold.

14. The method of claim 11 , wherein the increasing further comprises increasing amplitude of the second portion to within a predefined difference threshold.

15. The method of claim 11 , further comprising:

sensing direction of travel of the communication signal; and

selectively operating in a transmit signal direction when the communication signal is traveling in a direction out to a communication transmission system.

16. The method of claim 11 , wherein said predefined specification is a power spectral distribution (PSD) standard.

17. The method of claim 15 , wherein the communication system is a digital subscriber loop (DSL).

18. The line driver of claim 1 , wherein said predefined specification includes a predefined frequency band, and further comprising:

means for detecting the frequency spectrum of the communication signal, the frequency spectrum outside the predefined frequency band; and

means for confining said communication signal to within said predefined frequency band.

19. The line driver of claim 18 , wherein said means for confining includes a filter so that said filter attenuates a third part of said communication signal, wherein said third part lies outside of said predefined frequency band.

20. The line driver of claim 18 , wherein said means for confining includes a frequency modulator so that said modulator translates a third part of said communication signal, wherein said third part lies outside of said predefined frequency band.

21. The line driver of claim 1 , wherein the amplitude of the first portion of the frequency spectrum of the communication signal is decreased so that said amplitude is within a predefined difference threshold of said predefined specification.

22. The line driver of claim 1 , wherein the amplitude of the first portion of the frequency spectrum of the communication signal is decreased by a fixed amount.

23. The line driver of claim 1 , wherein the amplitude of the second portion of the frequency spectrum of the communication signal is increased so that said amplitude is within a predefined difference threshold of said predefined specification.

24. The line driver of claim 1 , wherein the amplitude of the second portion of the frequency spectrum of the communication signal is increased by a fixed amount.

25. The line driver of claim 1 , wherein the communication signal is continuously and automatically transformed by said line driver.

26. The line driver of claim 1 , wherein the communication signal comprises analog information.

27. The line driver of claim 1 , wherein the communication signal comprises digital information.

28. The line driver of claim 2 , wherein the communication medium comprises at least one of the following: a digital subscriber loop (DSL) system, a public telephony system, a private branch exchange (PBXs), a coaxial cable system, a fiber optic system, a microwave system, or a radio communication system.

29. The line driver of claim 1 , wherein said line driver generally exhibits an infinite input impedance.

30. The line driver of claim 29 , wherein said input impedance further comprises a parallel resistor of a finite impedance connected to a tip wire and a ring wire of a telephony system.

31. The line driver of claim 29 , wherein said input impedance further comprises a first impedance for a first frequency band and a second impedance for a second frequency band.

32. The line driver of claim 6 , wherein said signal equalizer decreases said first portion so that said first amplitude is within a predefined difference threshold of said predefined specification.

33. The line driver of claim 6 , wherein said signal equalizer decreases said first portion so that said first amplitude is decreased by a fixed amount.

34. The line driver of claim 6 , wherein said signal equalizer increases said second portion so that said second amplitude is within a predefined difference threshold of said predefined specification.

35. The line driver of claim 6 , wherein said signal equalizer increases said second portion so that said second amplitude is increased by a fixed amount.

36. The line driver of claim 6 , wherein said predefined specification includes a predefined frequency band, and said signal equalizer further configured to confine said communication signal to within said predefined frequency band.

37. The line driver of claim 36 , wherein said signal equalizer includes a filter so that said filter attenuates a third part of said communication signal, wherein said third part lies outside of said predefined frequency band.

38. The line driver of claim 36 , wherein said signal equalizer includes a frequency modulator so that said modulator translates a third part of said communication signal, wherein said third part lies outside of said predefined frequency band.

39. The line driver of claim 6 , further comprising a means for sensing the direction of travel of said communication signal and a means for selectively operating in a transmit signal direction when the communication signal is traveling in a direction out to a communication transmission system.

40. The line driver of claim 6 , wherein the communication signal is continuously and automatically transformed by said line driver.

41. The line driver of claim 6 , wherein the communication signal comprises analog information.

42. The line driver of claim 6 , wherein the communication signal comprises digital information.

43. The line driver of claim 7 , wherein the communication system comprises at least one selected from a group consisting of a digital subscriber loop (DSL) system, a public telephony system, a private branch exchange (PBXs), a coaxial cable system, a fiber optic system, a microwave system or a radio communication system.

44. The line driver of claim 8 , wherein the communication system comprises at least one of the following: a digital subscriber loop (DSL) system, a public telephony system, a private branch exchange (PBXs), a coaxial cable system, a fiber optic system, a microwave system, or a radio communication system.

45. The method of claim 11 , wherein the decreasing further comprises decreasing amplitude of the first portion by a fixed amount.

46. The method of claim 11 , wherein the increasing further comprises increasing amplitude of the second portion by a fixed amount.

47. The method of claim 11 , wherein said predefined specification includes a predefined frequency band, and further comprising:

detecting the frequency spectrum of the communication signal, the frequency spectrum outside the predefined frequency band; and

confining said communication signal to within said predefined frequency band.

48. The method of claim 47 , wherein the confining further comprises filtering to attenuate a third part of said communication signal, wherein said third part lies outside of said predefined frequency band.

49. The method of claim 47 , wherein the confining further comprises frequency modulation to translate a third part of said communication signal, wherein said third part lies outside of said predefined frequency band.

50. The method of claim 15 , wherein the communication transmission system comprises at least one of the following: a digital subscriber loop (DSL) system, a public telephony system, a private branch exchange (PBXs), a coaxial cable system, a fiber optic system, a microwave system, or a radio communication system.

51. A line driver for transforming amplitude characteristics of a communication signal, comprising:

means for detecting a frequency spectrum of the communication signal, the frequency spectrum outside a predefined frequency band of a predefined specification; and

means for confining the communication signal to within the predefined frequency band.

52. The line driver of claim 51 , wherein said means for confining includes a filter so that said filter attenuates a third part of said communication signal, wherein said third part lies outside of said predefined frequency band.

53. The line driver of claim 51 , wherein said means for confining includes a frequency modulator so that said modulator translates a third part of said communication signal, wherein said third part lies outside of said predefined frequency band.

54. The line driver of claim 51 , further comprising:

means for detecting amplitude of a first portion of the frequency spectrum of the communication signal, the amplitude greater than a predefined specification;

means for detecting amplitude of a second portion of the frequency spectrum of the communication signal, the amplitude less than the predefined specification;

means for decreasing the amplitude of the first portion before transmission of the communication signal so that the decreased amplitude is within a predefined threshold of the predefined specification; and

means for increasing the amplitude of the second portion before transmission of the communication signal so that the increased amplitude is within a predefined threshold of the predefined specification.

55. The line driver of claim 51 , further comprising a transmitting means for transmitting said transformed communication signal onto a communication medium pursuant to the predefined specification.

56. The line driver of claim 51 , wherein said predefined specification is a power spectral distribution (PSD) standard.

57. The line driver of claim 51 , wherein the communication system is a digital subscriber loop (DSL).