Adaptive reception techniques for over-sampled receivers

• US 20070071153A1
• Filed: 09/28/2005
• Published: 03/29/2007
• Est. Priority Date: 09/28/2005
• Status: Active Grant

• Current Assignee: Genesis Microchip Inc. (STMicroelectronics NV)
• Original Assignee: Genesis Microchip Inc. (STMicroelectronics NV)
• Inventors: Eglit, Alexander
• Granted Patent: US 7,801,257 B2
• Time in Patent Office: Days
• US Class Current: 375/355
• CPC Class Codes: H04L 25/0216 with estimation of channel length
• CPC Class Codes: H04L 25/03019 adaptive, i.e. capable of adjustment during data reception
• CPC Class Codes: H04L 7/0054 Detection of the synchronisation error by features other than the received signal transition by means of signal transition H04L7/033
• CPC Class Codes: H04L 7/0338 the correction of the phase error being performed by a feed forward loop

Abstract

An over-sampled sequence detector operates on sampled data and tracks the detection reliability of the sampled data. The detector separately analyzes sample sequences for different sampling phases and then picks a sample sequence that allows for the most reliable detection. For the different sampling phases, the detector inspects some amount of look-behind and look-ahead information in order to improve upon simple symbol-by-symbol detection. The over-sampled information is used to further improve detection performance.

Claims

1. A method for receiving data over a digital transmission link, comprising:

receiving a sequence of samples generated to represent an over-sampled sequence of symbols;

detecting a first and second symbol from the first and second sample streams; and

estimating a channel response length.

2. A method as recited in claim 1, wherein the estimating comprises tracking a minimum symbol width or an average symbol width, wherein symbol width is represented by number of samples per symbol.

3. A method as recited in claim 2, further comprising:

adjusting an equalizer when the number of symbols comprising fewer than L samples (narrow symbols) exceeds a threshold, thereby reducing the number of narrow symbols.

4. A method as recited in claim 3, wherein the adjusting comprises making an upward adjustment to an equalization parameter and a downward adjustment to the equalization parameter in order to determine in which direction equalization improves.

5. A method for receiving data over a digital transmission link, comprising:

receiving a sequence of samples generated to represent a sequence of over-sampled symbols, the sequence of samples comprising a first and second sample stream according to a first and second phase of the sequence of samples;

detecting a first and second symbol from the first and second sample streams; and

examining a first synchronization data field in the first sample stream and a second synchronization data field in the second sample stream in order to estimate a first and second detection reliability of the first and second symbols.

6. A method as recited in claim 5, wherein the first and second synchronization data fields comprise a DVI retrace interval or an HDMI retrace interval.

7. A method for receiving data over a digital transmission link, comprising:

receiving a sequence of samples generated to represent a sequence of over-sampled symbols, the sequence of samples comprising a first and second sample stream according to a first and second phase of the sequence of samples;

detecting a first and second symbol from the first and second sample streams, wherein the detecting proceeds according to a dynamically updated table associating one or more detection patterns Pattern_i to one or more flags Flag_i, wherein Flag_i has a value indicating a difference between a width of the symbol associated with Pattern_i and an over-sampling rate L used to produce the sequence of samples; and

adjusting one or more equalizer parameters in order to reduce the flag values.

8. An apparatus for receiving data over a digital transmission link, comprising:

a receiver for;

(a) receiving a sequence of samples generated to represent an over-sampled sequence of symbols;

(b) detecting a first and second symbol from the first and second sample streams; and

(c) estimating a channel response length.

9. An apparatus as recited in claim 8, wherein the estimating comprises tracking a minimum symbol width or an average symbol width, wherein symbol width is represented by number of samples per symbol.

10. An apparatus as recited in claim 9, the receiver further for:

(d) adjusting an equalizer when the number of symbols comprising fewer than L samples (narrow symbols) exceeds a threshold, thereby reducing the number of narrow symbols.

11. An apparatus as recited in claim 10, wherein the adjusting comprises making an upward adjustment to an equalization parameter and a downward adjustment to the equalization parameter in order to determine in which direction equalization improves.

12. An apparatus for receiving data over a digital transmission link, comprising:

a receiver for;

(a) receiving a sequence of samples generated to represent a sequence of over-sampled symbols, the sequence of samples comprising a first and second sample stream according to a first and second phase of the sequence of samples;

(b) detecting a first and second symbol from the first and second sample streams, and

(c) examining a first synchronization data field in the first sample stream and a second synchronization data field in the second sample stream in order to estimate a first and second detection reliability of the first and second symbols.

13. An apparatus as recited in claim 12, wherein the first and second synchronization data fields comprise a DVI retrace interval or an HDMI retrace interval.

14. An apparatus for receiving data over a digital transmission link, comprising:

a receiver for;

(a) receiving a sequence of samples generated to represent a sequence of over-sampled symbols, the sequence of samples comprising a first and second sample stream according to a first and second phase of the sequence of samples;

(b) detecting a first and second symbol from the first and second sample streams, wherein the detecting proceeds according to a dynamically updated table associating one or more detection patterns Pattern_i to one or more flags Flag_i, wherein Flag_i has a value indicating a difference between a width of the symbol associated with Pattern_i and an over-sampling rate L used to produce the sequence of samples; and

(c) adjusting one or more equalizer parameters in order to reduce the flag values.

15. A computer-readable medium having computer-executable instructions recorded thereon for enabling a processor of a computer system to process incoming data over a digital transmission link, the computer-executable instructions comprising:

receiving a sequence of samples generated to represent an over-sampled sequence of symbols;

detecting a first and second symbol from the first and second sample streams; and

estimating a channel response length.

16. A computer-readable medium as recited in claim 15, wherein the estimating comprises tracking a minimum symbol width or an average symbol width, wherein symbol width is represented by number of samples per symbol.

17. A computer-readable medium as recited in claim 16, the computer-executable instructions further comprising:

adjusting an equalizer when the number of symbols comprising fewer than L samples (narrow symbols) exceeds a threshold, thereby reducing the number of narrow symbols.

18. A computer-readable medium as recited in claim 17, wherein the adjusting comprises making an upward adjustment to an equalization parameter and a downward adjustment to the equalization parameter in order to determine in which direction equalization improves.

19. A computer-readable medium having computer-executable instructions recorded thereon for enabling a processor of a computer system to process incoming data over a digital transmission link, the computer-executable instructions comprising:

receiving a sequence of samples generated to represent a sequence of over-sampled symbols, the sequence of samples comprising a first and second sample stream according to a first and second phase of the sequence of samples;

detecting a first and second symbol from the first and second sample streams; and

examining a first synchronization data field in the first sample stream and a second synchronization data field in the second sample stream in order to estimate a first and second detection reliability of the first and second symbols.

20. A computer-readable medium as recited in claim 19, wherein the first and second synchronization data fields comprise a DVI retrace interval or an HDMI retrace interval.

21. A computer-readable medium having computer-executable instructions recorded thereon for enabling a processor of a computer system to process incoming data over a digital transmission link, the computer-executable instructions comprising:

receiving a sequence of samples generated to represent a sequence of over-sampled symbols, the sequence of samples comprising a first and second sample stream according to a first and second phase of the sequence of samples;

detecting a first and second symbol from the first and second sample streams, wherein the detecting proceeds according to a dynamically updated table associating one or more detection patterns Pattern_i to one or more flags Flag_i, wherein Flag_i has a value indicating a difference between a width of the symbol associated with Pattern_i and an over-sampling rate L used to produce the sequence of samples; and

adjusting one or more equalizer parameters in order to reduce the flag values.