Low complexity high-speed communications transceiver

1. A serial/deserializer transmission system, comprising:

a plurality of demodulators, each of the plurality of demodulators receiving signals from one of a plurality of transmission bands that are transmitted on a single electrically differential conductive pair, at least one of the plurality of demodulators comprising:

an analog down converter that converts an input signal from the one of the plurality of transmission bands to a base band;

a filter coupled to receive signals from the down converter, the filter substantially filtering out signals not in the base band;

an analog-to-digital converter coupled to receive signals from the filter and generate digitized signals;

an equalizer coupled to receive the digitized signals; and

a decoder coupled to receive signals from the equalizer and generate recreated data, the recreated data being substantially the same data transmitted by a corresponding modulator,

wherein the plurality of demodulators recover a plurality of bits synchronously distributed across the plurality of transmission bands in the serial/deserializer transmission system, the plurality of demodulators being synchronous to each other.

2. The system of claim 1 , wherein the analog down-converter creates an in-phase signal and a quadrature signal, the in-phase signal being the input signal multiplied by a cosine function at the frequency of the one of the plurality of transmission bands and the quadrature signal being the input signal multiplied by a sine function at the frequency of the one of the plurality of transmission bands corresponding to that one of the plurality of demodulators.

3. The system of claim 2 , wherein the filter includes an in-phase filter filtering the in-phase signal and a quadrature filter filtering the quadrature signal.

4. The system of claim 3 , further including an offset block coupled between the down-converter and the filter, the offset block offsetting the in-phase signal and the quadrature signal such that signals output from the analog-to-digital converter averages zero.

5. The system of claim 2 , further including an amplifier coupled between the filter and the analog-to-digital converter, the amplifier amplifying an in-phase filtered signal from the in-phase filter and a quadrature filter signal from the quadrature filter such that the analog-to-digital converter is filled.

6. The system of claim 5 , wherein an in-phase gain of the amplifier and the quadrature gain of the amplifier are adaptively chosen in an automatic gain controller.

7. The system of claim 6 , wherein the automatic gain controller sets the in-phase gain and the quadrature gain based on the digitized signals from the analog to digital converters.

8. The system of claim 7 , wherein the in-phase gain and the quadrature gain are equal.

9. The system of claim 2 , wherein the analog-to-digital converter includes a first analog-to-digital converter coupled to receive signals from the in-phase filter and a second analog-to-digital converter coupled to receive signals from the quadrature filter.

10. The system of claim 9 , further including a correction circuit coupled between the analog-to-digital converter and the equalizer.

11. The system of claim 10 , wherein the correction circuit includes an adjustment to correct phases between the in-phase signal and the quadrature signal.

12. The system of claim 11 , wherein a small portion of one of the in-phase signal and the quadrature signal are added to the opposite one of the in-phase signal and the quadrature signal.

13. The system of claim 12 , wherein a second portion of the opposite one of the in-phase signal and the quadrature signal is added to the opposite one of the in-phase signal and the quadrature signal.

14. The system of claim 13 , wherein the small portion and the second portion are adaptively chosen.

15. The system of claim 14 , wherein the small portion is a function of in-phase and quadrature output signals from the correction circuit.

16. The system of claim 14 , wherein the second portion is a function of the ratio between in-phase and quadrature signals from the correction circuit.

17. The system of claim 2 , wherein a phase rotator circuit is coupled between the analog-to-digital converter and the equalizer.

18. The system of claim 17 , wherein a parameter of the phase rotator circuit is adaptively chosen.

19. The system of claim 2 , wherein an amplifier is coupled between the equalizer and the decoder.

20. The system of claim 19 , wherein a quadrature correction is coupled between the amplifier and the decoder.

21. The system of claim 20 , wherein an offset circuit is coupled between the quadrature correction and the decoder.

22. The system of claim 19 , wherein an in-phase gain and a quadrature gain of the amplifier are adaptively chosen from error signals calculated from sliced values.

23. The system of claim 22 , wherein the sliced values are determined from input signals to the decoder.

24. The system of claim 20 , wherein a parameter of the quadrature correction is adaptively chosen.

25. The system of claim 21 , wherein a parameter of the offset circuit is adaptively chosen.

26. The system of claim 1 , wherein C k x (0) is one and C k y (0) is zero.

27. The system of claim 26 , wherein the parameters C k x (−1) is one and C k y (−1) are fixed.

28. The system of claim 27 , wherein the parameter C k x (−1) is about −0.3125.

29. The system of claim 27 , wherein the parameter C k y (−1) is about −0.015625.

30. A method of receiving data in a serial/deserializer system, comprising:

receiving an input signal into a plurality of demodulators coupled to a single conducting differential pair, each of the plurality of demodulators receiving signals from one of a plurality of transmission bands synchronously with others of the plurality of demodulators, a plurality of bits of the received input signal having been synchronously encoded and transmitted across the plurality of transmission bands, each of the plurality of demodulators performing the functions of:

analog down-converting the input signal to obtain a base band signal corresponding to one of the respective plurality of transmission bands;

filtering the base band signal to remove signals not in the base band;

digitizing the filtered base band signal to obtain a digitized signal;

equalizing the digitized signal, wherein equalizing is accomplished using a complex equalizer executing a transfer function, the transfer function having parameters C k x (j) and C k y (j), where x, y, k, and j are integers; wherein the parameters C k x (0) and C k y (0) are fixed to avoid interaction with an adaptation of gain coefficients used in an amplifier and a carrier phase rotation performed in a phase rotator; and

decoding the equalized signal to recover data that is substantially the same as that transmitted by a corresponding modulator in a transmitter, wherein the plurality of bits synchronously transmitted across the plurality of transmission bands of the serial/deserializer system is recovered,

wherein operating parameters of at least one of the down-converting, the filtering, the digitizing and equalizing are adaptively chosen.

31. The method of claim 30 , wherein down-converting the input signal includes:

multiplying the input signal by a cosine function at the frequency of the one of the plurality of transmission bands to obtain an in-phase signal; and

multiplying the input signal by a sine function at the frequency of the one of the plurality of transmission bands to obtain a quadrature signal,

wherein the base band signal includes the in-phase signal and the quadrature signal.

32. The method of claim 30 , further including:

offsetting the base band signal so that the averaged digitized signal is zero; and

amplifying the base band signal so that a full range of the digitized signal is obtained.

33. The method of claim 31 , further including adjusting the phase between the in-phase signal and the quadrature signal of the base band signal.

34. The method of claim 31 , further including providing a quadrature correction.

35. The method of claim 31 , further including slicing recovered data.

36. The method of claim 30 , further including adaptively choosing at least one operating parameter.

37. A receiver system in a serial/deserializer system, comprising: means for receiving an input signal from a single conductive differential pair, the input signal including a plurality of transmission bands; and for each of the plurality of transmission band:

means for down-converting the input signal to a base-band signal;

means for obtaining a digital signal from the base-band signal;

means for equalizing the digital signal, wherein equalizing is accomplished using a complex equalizer executing a transfer function, the transfer function having parameters C k x (j) and C k y (j), where x, y, k, and j are integers; wherein the parameters C k x (0) and C k y (0) are fixed to avoid interaction with an adaptation of gain coefficients used in an amplifier and a carrier phase rotation performed in a phase rotator; and

means for decoding the equalized signal to recover data transmitted by a corresponding modulator in a transmitter coupled to the single conductive differential pair,

wherein a plurality of bits that were synchronously transmitted across the plurality of transmission bands is recovered, and the means for down-converting, means for obtaining, and means for equalizing, and means for decoding for each of the plurality of transmission bands are synchronous to each other; and

wherein operating parameters of at least one of the means for down-converting, the means for filtering, the means for obtaining a digital signal, and means for equalizing are adaptively chosen.