Adaptive equalizer and method of controlling the same

• US 9,300,500 B2
• Filed: 09/25/2014
• Issued: 03/29/2016
• Est. Priority Date: 09/26/2013
• Status: Active Grant

• Current Assignee: Industry Academic Cooperation Foundation, Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Hojung, Cho, Seongho, Kim, Wangsoo, Youn, Jinsung, Choi, Wooyoung, Yang, Moonseung
• Primary Examiner(s): VARNDELL, ROSS E
• Application Number:
  US14/496,499
• Publication Number:
  US 20150085912A1
• Time in Patent Office: 551 Days
• US Class Current: 1/1
• CPC Class Codes: H04L 25/03885 adaptive
• CPC Class Codes: H04L 7/0337 Selecting between two or more discretely delayed clocks or selecting between two or more discretely delayed received code signals
• CPC Class Codes: H04W 52/0287 changing the clock frequency of a controller in the equipment
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Provided are an adaptive equalizer for adaptively controlling an equalization coefficient until two comparators outputs a same value, after generating a sensitivity difference between signals at a front end of each comparator for performing sampling, and a method of controlling the adaptive equalizer.

Claims

1. An adaptive equalizer comprising:

an equalizing unit configured to equalize an input signal based on an equalization coefficient;

a plurality of sampling units configured to, generate a plurality of adjusted signals from the equalized input signal, each of the plurality of sampling units having a sensitivity that varies independently, and the plurality of sampling units configured to sample a respective one of the plurality of adjusted signals; and

an error detection unit configured to vary the equalization coefficient based on sampled signals until an error is not present between the sampled signals,

wherein each of the plurality of sampling units includes,

a pre-driver configured to generate an adjusted sensitivity signal by adjusting the sensitivity of a respective one of the plurality of sampling units to the equalized input signal, and

a comparator configured to output a logic low or a logic high based on sampling the adjusted sensitivity signal.

2. The adaptive equalizer of claim 1, wherein the plurality of sampling units comprises:

a first sampling unit configured to generate a first signal by adjusting a sensitivity of the first sampling unit to the equalized input signal, and to sample the first signal; and

a second sampling unit configured to generate a second signal by adjusting a sensitivity of the second sampling unit to the equalized input signal, and to sample the second signal.

3. The adaptive equalizer of claim 1, further comprising:

an adjustment unit configured to adjust the sensitivity of the respective one of the plurality of sampling units based on the plurality of sampled signals by updating a gain or a common mode voltage of the pre-driver.

4. The adaptive equalizer of claim 3, wherein the adjustment unit comprises:

an edge counter configured to count a number of edges associated with the sampled signals; and

an adjustment signal determination unit configured to update the gain or the common mode voltage of the pre-driver based on the number of edges, until a threshold level of error is generated between the sampled signals.

5. The adaptive equalizer of claim 4, wherein,

if the counted number of edges corresponds to a first number, the adjustment signal determination unit is configured to modify the gain or the common mode voltage of the pre-driver and,

if the threshold level of error is generated, the adjustment signal determination unit is configured to maintain the gain or the common mode voltage of the pre-driver.

6. The adaptive equalizer of claim 1, wherein the error detection unit comprises:

an error determination unit configured to detect that the error is present if the sampled signals are different from each other;

an error counter configured to count a number of times that the error determination unit detects the error as a number of errors; and

an equalization coefficient determination unit configured to control the equalization coefficient of the equalizing unit based on the number of errors.

7. The adaptive equalizer of claim 6, wherein,

if the number of errors corresponds to a second number, the equalization coefficient determination unit is configured to update the equalization coefficient, and

if the number of errors does not correspond to the second number, the equalization coefficient determination unit is configured to maintain the equalization coefficient.

8. A method of controlling an adaptive equalizer, the method comprising:

equalizing an input signal, based on an equalization coefficient;

generating a plurality of adjusted signals from the equalized input signal, the adjusted signals having different sensitivities to the equalized input signal,

sampling the plurality of adjusted signals; and

varying the equalization coefficient based on sampled signals until an error is not present between the sampled signals, wherein

the generating each of the plurality of the adjusted signals includes generating, by a pre-driver, the adjusted sensitivity signal by adjusting the sensitivity of a respective one of a plurality of sampling units to the equalized input signal, and

the sampling each of the plurality of the adjusted signals includes outputting a logic low or high based on sampling the adjusted sensitivity signal.

9. The method of claim 8, wherein the generating of the plurality of the adjusted signals comprises:

generating, by a first sampling unit, a first signal by adjusting a sensitivity of the first sampling unit to the equalized input signal; and

generating, by a second sampling unit, a second signal by adjusting a sensitivity of the second sampling unit to the equalized input signal, wherein the sampling includes,

sampling the first signal, and

sampling the second signal.

10. The method of claim 8, further comprising:

adjusting the sensitivity of the respective one of the plurality of sampling units based on the sampled signals by updating a gain or a common mode voltage of the pre-driver.

11. The method of claim 10, wherein the adjusting the sensitivity comprises:

counting a number of edges associated with the sampled signals; and

updating the gain or the common mode voltage of the pre-driver based on the number of edges, until a threshold level of error is generated between the plurality of sampled signals.

12. The method of claim 11, wherein,

if the counted number of edges corresponds to a first number, the updating modifies the gain or the common mode voltage of the pre-driver and,

if the threshold level of error is generated, the updating maintains the gain or the common mode voltage of the pre-driver.

13. The method of claim 8, wherein the varying of the equalization coefficient comprises:

detecting that the error is present, if the sampled signals are different from each other;

counting a number of times that the detecting detects the error as a number of errors; and

controlling the equalization coefficient based on the number of errors.

14. The method of claim 13, wherein,

if the number of errors corresponds to a second number, the controlling of the equalization coefficient includes updating the equalization number and,

if the number of the errors does not correspond to the second number, the controlling of the equalization coefficient includes maintaining the equalization coefficient.

15. A non-transitory computer-readable storage medium having stored thereon a computer program, which when executed by a computer, performs the method of claim 8.