System and method for the adjustment of offset compensation applied to a signal

• US 7,764,757 B2
• Filed: 05/24/2007
• Issued: 07/27/2010
• Est. Priority Date: 05/30/2006
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Hidaka, Yasuo
• Primary Examiner(s): Ahn; Sam K
• Application Number:
  US11/753,101
• Publication Number:
  US 20070280341A1
• Time in Patent Office: 1,160 Days
• Field of Search: 375229-236, 333/18, 333/28.R, 708/300, 708/322, 708/323, 379/340, 379/398
• US Class Current: 375/354
• CPC Class Codes: G01D 21/00 Measuring or testing not otherwise provided for
• CPC Class Codes: H04L 25/03057 with a recursive structure H04L25/03031 takes precedence
• CPC Class Codes: H04L 25/061 providing hard decisions only; arrangements for tracking or suppressing unwanted low frequency components, e.g. removal of dc offset removal of dc offset in coupling arrangements H04L25/029, H04L25/0296
• CPC Class Codes: H04L 25/068 by sampling faster than the nominal bit rate

Abstract

In one embodiment of the present invention, a method for adjusting a signal includes receiving an input data signal and applying an offset compensation to the input data signal to generate an output signal. The method also includes, using a clock signal, sampling the output signal to generate a plurality of boundary values, each value comprising either a high value or a low value based on the sampling of the output signal. The method further includes, based at least on the high or low value of a boundary value, adjusting the offset compensation applied to the input data signal.

Claims

1. A method for adjusting a signal at a receiver of a digital signal transmission system, comprising:

receiving an input data signal at a receiver of a digital signal transmission system;

using the receiver, applying an offset compensation to the input data signal to generate an output signal;

using a clock signal, sampling the output signal at the receiver to generate a plurality of boundary values, each boundary value comprising either a high value or a low value based on the sampling of the output signal;

using the receiver, comparing the number of boundary values comprising a high value and the number of boundary values comprising a low value;

using the receiver, determining whether the number of boundary values comprising a high value is greater or less than the number of boundary values comprising a low value by a pre-determined number or ratio; and

if the number of boundary values comprising a high value is greater or less than the number of boundary values comprising a low value by the pre-determined number or ratio, adjusting by the receiver the offset compensation applied to the input data signal based on the comparison of the number of boundary values comprising a high value and the number of boundary values comprising a low value.

2. The method of claim 1, wherein the offset compensation applied to the input data signal is adjusted based only on the high or low value of the boundary value.

3. The method of claim 1, wherein:

the output signal is further sampled using the clock signal to generate a plurality of data values; and

the offset compensation applied to the input data signal is adjusted based on the high or low value of a boundary value not corresponding to a transition in value between two successive data values.

4. The method of claim 1, wherein the clock signal is associated with the output signal.

5. The method of claim 1, further comprising:

using the clock signal, further sampling the output signal to generate a plurality of data values;

if the number of boundary values comprising a high value is not greater or less than the number of boundary values comprising a low value by the pre-determined number or ratio, adjusting the offset compensation applied to the input data signal based on the high or low value of a boundary value between two successive data values comprising a transition in value.

6. The method of claim 1, further comprising:

using the clock signal, further sampling the output signal to generate a plurality of data values;

determining whether the number of data and boundary values comprising a high value is not greater or less than the number of data and boundary values comprising a low value by a pre-determined number or ratio; and

if the number of data and boundary values comprising a high value is not greater or less than the number of data and boundary values comprising a low value by the pre-determined number or ratio, adjusting the offset compensation applied to the input data signal based on the high or low value of a boundary value between two successive data values comprising a transition in value.

7. The method of claim 1, further comprising:

using the clock signal, further sampling the output signal to generate a plurality of data values;

comparing the number of received data values comprising a high value and the number of received data values comprising a low value; and

based at least on the comparison, adjusting the offset compensation applied to the input data signal.

8. The method of claim 7, further comprising:

determining whether the number of received data values comprising a high value is greater or less than the number of received data values comprising a low value by a pre-determined number or ratio; and

if the number of received data values comprising a high value is greater or less than the number of received data values comprising a low value by the pre-determined number or ratio, adjusting the offset compensation applied to the input data signal based on the comparison of the number of received data values comprising a high value and the number of received data values comprising a low value.

9. The method of claim 7, further comprising:

determining whether the number of received data values comprising a high value is greater or less than the number of received data values comprising a low value by a pre-determined number or ratio; and

if the number of received data values comprising a high value is not greater or less than the number of received data values comprising a low value by the pre-determined number or ratio, adjusting the offset compensation applied to the input data signal based on the high or low value of a boundary value between two successive data values comprising a transition in value.

10. The method of claim 7, wherein the clock signal is associated with the output signal.

11. A receiver, comprising:

an input port configured to receive an input data signal;

an amplifier configured to apply an offset compensation to the input data signal to generate an output signal;

a sampler configured to;

receive the output signal and a clock signal; and

using the clock signal, sample the output signal to generate a plurality of boundary values, each boundary value comprising either a high value or a low value based on the sampling of the output signal; and

a controller configured to;

compare the number of boundary values comprising a high value and the number of boundary values comprising a low value;

determine whether the number of boundary values comprising a high value is greater or less than the number of boundary values comprising a low value by a pre-determined number or ratio; and

if the number of boundary values comprising a high value is greater or less than the number of boundary values comprising a low value by the pre-determined number or ratio, adjust the offset compensation applied to the input data signal based on the comparison of the number of boundary values comprising a high value and the number of boundary values comprising a low value.

12. The receiver of claim 11, wherein the offset compensation applied to the input data signal is adjusted based only on the high or low value of the boundary value.

13. The receiver of claim 11, wherein:

the sampler is further configured to sample the output signal using the clock signal to generate a plurality of data values; and

the offset compensation applied to the input data signal is adjusted based on the high or low value of a boundary value not corresponding to a transition in value between two successive data values.

14. The receiver of claim 11, wherein the clock signal is associated with the output signal.

15. The receiver of claim 11, wherein:

the sampler is further configured to sample the output signal using the clock signal to generate a plurality of data values; and

the controller is further configured to;

if the number of boundary values comprising a high value is not greater or less than the number of boundary values comprising a low value by the pre-determined number or ratio, adjust the offset compensation applied to the input data signal based on the high or low value of a boundary value between two successive data values comprising a transition in value.

16. The receiver of claim 11, wherein:

the sampler is further configured to sample the output signal using the clock signal to generate a plurality of data values; and

the controller is further configured to;

determine whether the number of data and boundary values comprising a high value is not greater or less than and the number of data and boundary values comprising a low value by a pre-determined number or ratio; and

if the number of data and boundary values comprising a high value is not greater or less than the number of data and boundary values comprising a low value by the pre-determined number or ratio, adjust the offset compensation applied to the input data signal based on the high or low value of a boundary value between two successive data values comprising a transition in value.

17. The receiver of claim 11, wherein:

the sampler is further configured to sample the output signal using the clock signal to generate a plurality of data values; and

the controller is further configured to;

compare the number of received data values comprising a high value and the number of received data values comprising a low value; and

based at least on the comparison, adjust the offset compensation applied to the input data signal.

18. The receiver of claim 17, wherein the controller is further configured to:

determine whether the number of received data values comprising a high value is greater or less than the number of received data values comprising a low value by a pre-determined number or ratio; and

if the number of received data values comprising a high value is greater or less than the number of received data values comprising a low value by the pre-determined number or ratio, adjust the offset compensation applied to the input data signal based on the comparison of the number of received data values comprising a high value and the number of received data values comprising a low value.

19. The receiver of claim 17, wherein the controller is further configured to:

determine whether the number of received data values comprising a high value is greater or less than the number of received data values comprising a low value by a pre-determined number or ratio; and

if the number of received data values comprising a high value is not greater or less than the number of received data values comprising a low value by the pre-determined number or ratio, adjust the offset compensation applied to the input data signal based on the high or low value of a boundary value between two successive data values comprising a transition in value.

20. The receiver of claim 17, wherein the clock signal is associated with the output signal.