Multiple detector decision receiver

• US 7,209,671 B1
• Filed: 04/22/2002
• Issued: 04/24/2007
• Est. Priority Date: 04/22/2002
• Status: Expired due to Fees

• Current Assignee: Tyco Electronics Subsea Communications LLC (TE Connectivity Ltd. (United Kingdom))
• Original Assignee: Tyco Telecommunications Us Incorporated (Johnson Controls International plc)
• Inventors: Pilipetskii, Alexei N., Hayee, M. Imran, Pedersen, Bo, Lenner, Gerald E.
• Primary Examiner(s): TRAN, DZUNG D
• Application Number:
  US10/127,739
• Time in Patent Office: 1,828 Days
• Field of Search: 398202-214, 385/88
• US Class Current: 398/207
• 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

Abstract

An optical signal receiver including a plurality of threshold decision circuits configured to receive an electrical signal representative of the optical signal. Each of the threshold decision circuits is configured to sample the electrical signal and to provide an associated threshold decision circuit output in response to a comparison of the signal to an associated threshold level. The threshold decision circuit outputs are coupled to an output decision circuit, which is configured to output a signal representative of a binary state of the optical signal. An optical communication system and a method of reconstructing received data signal in an optical communication system are also provided.

Claims

1. An optical signal receiver for receiving an optical signal comprising:

a plurality of threshold decision circuits configured to receive an electrical signal representative of said optical signal, each of said threshold decision circuits being configured to sample said electrical signal and to provide an associated threshold decision circuit output in response to a comparison of said signal to an associated threshold level; and

an output decision circuit configured to receive each of said threshold decision circuit outputs and output a signal representative of a binary state of said optical signal, wherein said output decision circuit is further configured to apply a selected logic function to said threshold decision circuit outputs for providing said signal representative of said binary state of said optical signal, and wherein said output decision circuit comprises a controller and a look-up table, said controller configured to receive said threshold decision circuit outputs and provide an associated control signal representative of said selected logic function to said look-up table for storing data representative of said selected logic function in said look-up table.

2. An optical receiver of claim 1, wherein said output decision circuit is further configured to output a digital one if at least one of said threshold decision circuit outputs is a digital one.

3. A receiver according to claim 1, wherein said output decision circuit comprises an OR gate, and wherein each of said threshold decision circuit outputs is coupled to an associated input of said OR gate.

4. A receiver according to claim 1, said receiver comprising first, second, and third ones of said threshold decision circuits.

5. A receiver according to claim 1, wherein each said threshold decision circuit comprises an associated comparator circuit for performing said comparison of said signal with said associated threshold level.

6. A receiver according to claim 1, wherein said output decision circuit is further configured to apply a selected logic function to said threshold decision circuit outputs for providing said signal representative of said binary state of said optical signal.

7. A receiver according to claim 6, wherein said selected logic function comprises selecting one of said associated threshold decision circuit outputs.

8. A receiver according to claim 6, wherein said selected logic function is selected from the group consisting of:

OR, AND, and XOR.

9. A receiver according to claim 1, wherein said output decision circuit further comprises decision logic for receiving said threshold decision circuit outputs, said decision logic being configured to apply said selected logic function to said outputs in response to said data representative of said selected logic function.

10. An optical signal receiver for receiving an optical signal comprising:

a plurality of threshold decision circuits configured to receive an electrical signal representative of said optical signal, each of said threshold decision circuits being configured to sample said electrical signal and to provide an associated threshold decision circuit output in response to a comparison of said signal to an associated threshold level; and

an output decision circuit configured to receive each of said threshold decision circuit outputs and output a signal representative of a binary state of said optical signal, wherein said output decision circuit is further configured to apply a selected logic function to said threshold decision circuit outputs for providing said signal representative of said binary state of said optical signal, and wherein said optical signal comprises a predetermined teaching bit sequence, and wherein a look-up table is constructed by adding said teaching bit sequence with a transmitted data frame.

11. An optical communication system comprising:

a transmitter providing an optical signal on an optical information channel; and

a receiver coupled to said optical information channel for receiving said optical signal, said receiver comprising a plurality of threshold decision circuits configured to receive an electrical signal representative of said optical signal, each of said threshold decision circuits being configured to sample said electrical signal at a sample time within a bit time period and to provide an associated threshold decision circuit digital output in response to a comparison of said sample of said signal to an associated threshold level, wherein each of said threshold decision circuits comprises an associated delay element for establishing said sample time associated therewith, and wherein at least some of said threshold decision circuits are configured to sample said electrical signal at different sample times within said bit time period; and

an output decision circuit configured to receive each of said threshold decision circuit digital outputs and output a signal representative of a binary state of said optical signal within said bit time period and wherein said output decision circuit comprises a controller and a look-up table, said controller configured to receive said threshold decision circuit digital outputs and provide an associated control signal representative of said selected logic function to said look-up table for storing data representative of said selected logic function in said look-up table.

12. A system according to claim 11, wherein said output decision circuit is further configured to output a digital one if at least one of said threshold decision circuit digital outputs is a digital one.

13. A system according to claim 11, wherein said output decision circuit comprises an OR gate, and wherein each of said threshold decision circuit digital outputs is coupled to an associated input of said OR gate.

14. A system according to claim 11, wherein said receiver comprises first, second, and third ones of said threshold decision circuits.

15. A system according to claim 11, wherein each said threshold decision circuit comprises an associated comparator circuit for performing said comparison of said signal with said associated threshold level.

16. A system according to claim 11, wherein said output decision circuit is further configured to apply a selected logic function to said threshold decision circuit outputs for providing said signal representative of said binary state of said optical signal.

17. An optical communication system comprising:

a transmitter providing an optical signal on an optical information channel; and

a receiver coupled to said optical information channel for receiving said optical signal, said receiver comprising a plurality of threshold decision circuits configured to receive an electrical signal representative of said optical signal, each of said threshold decision circuits being configured to sample said electrical signal and to provide an associated threshold decision circuit output in response to a comparison of said signal to an associated threshold level; and

an output decision circuit configured to receive each of said threshold decision circuit outputs and output a signal representative of a binary state of said optical signal, wherein said output decision circuit is further configured to apply a selected logic function to said threshold decision circuit outputs for providing said signal representative of said binary state of said optical signal, and wherein said output decision circuit comprises a controller and a look-up table, said controller configured to receive said threshold decision circuit outputs and provide an associated control signal representative of said selected logic function to said look-up table for storing data representative of said selected logic function in said look-up table.

18. A system according to claim 17, wherein said output decision circuit further comprises decision logic for receiving said threshold decision circuit outputs, said decision logic being configured to apply said selected logic function to said outputs in response to said data representative of said selected logic function.

19. A system according to claim 17, wherein said selected logic function comprises selecting one of said associated threshold decision circuit outputs.

20. A system according to claim 17, wherein said selected logic function is selected from the group consisting of:

OR, AND, and XOR.

21. An optical communication system comprising:

a transmitter providing an optical signal on an optical information channel; and

a receiver coupled to said optical information channel for receiving said optical signal, said receiver comprising a plurality of threshold decision circuits configured to receive an electrical signal representative of said optical signal, each of said threshold decision circuits being configured to sample said electrical signal and to provide an associated threshold decision circuit output in response to a comparison of said signal to an associated threshold level; and

an output decision circuit configured to receive each of said threshold decision circuit outputs and output a signal representative of a binary state of said optical signal, wherein said output decision circuit is further configured to apply a selected logic function to said threshold decision circuit outputs for providing said signal representative of said binary state of said optical signal,

and wherein said output decision circuit comprises a controller and a look-up table, said controller configured to receive said threshold decision circuit outputs and provide an associated control signal representative of said selected logic function to said look-up table for storing data representative of said selected logic function in said look-up table.

22. The optical communication system according to claim 21, wherein

said output decision circuit is configured to receive each of said threshold decision circuit outputs and output a digital one if at least one of said threshold decision circuit outputs is a digital one.

23. The optical communication system according to claim 21, wherein said output decision circuit comprises an OR gate, and wherein each of said threshold decision circuit outputs is coupled to an associated input of said OR gate.

24. The optical communication system according to claim 21, wherein said controller further comprises a first-in-first-out buffer.

25. The optical communication system according to claim 21, wherein each said threshold decision circuit comprises an associated delay element for establishing said sample time associated therewith.

26. The optical communication system according to claim 21, wherein each said threshold decision circuit comprises an associated comparator circuit for performing said comparison of said signal with said associated threshold level.

27. An optical signal receiver for receiving an optical signal comprising:

a plurality of threshold decision circuits configured to receive an electrical signal representative of said optical signal, each of said threshold decision circuits being configured to sample said electrical signal and to provide an associated threshold decision circuit output in response to a comparison of said signal to an associated threshold level; and

an output decision circuit configured to receive said associated threshold decision circuit outputs and apply a selected logic function to said threshold decision circuit outputs for providing an output signal representative of a binary state of said optical signal, said output decision circuit comprising a controller and a look-up table, said controller configured to receive said threshold decision circuit outputs and provide an associated control signal representative of said selected logic function to said look-up table for storing data representative of said selected logic function in said look-up table.

28. A receiver according to claim 27, wherein said output decision circuit further comprises decision logic for receiving said threshold decision circuit outputs, said decision logic being configured to apply said selected logic function to said outputs for providing said output signal representative of a binary state of said optical signal.

29. A receiver according to claim 27, wherein said selected logic function comprises selecting one of said associated threshold decision circuit outputs.

30. A receiver according to claim 27, wherein said selected logic function is selected from the group consisting of:

OR, AND, and XOR.

31. A method of reconstructing a received data signal in an optical communication system, said method comprising:

sampling said data signal at a plurality of sample times within a bit time period;

providing a threshold decision digital output associated with each of said sample times in response to a comparison of said data signal with an associated threshold level; and

coupling each said threshold decision digital outputs to an output decision circuit having a controller and a look-up table, said controller configured to provide an associated control signal representative of a selected logic function to said look-up table for storing data representative of said selected logic function in said look-up table.

32. A method according to claim 31, wherein said output decision circuit is configured to apply a logic function to said threshold decision digital outputs for providing said output signal.

33. A method according to claim 32, wherein said logic function is an OR function.

34. A method according to claim 32 further comprising the step of

comparing individual bits of a predetermined teaching bit sequence with said threshold decision outputs for determining an optimal read strategy in response to said teaching bit sequence.

35. A method according to claim 32, wherein

a first one of said sample times is established by adjusting said first sample time until the error rate performance of said system is optimized.

36. A method according to claim 35, wherein

a second one of said plurality of sample times is established after said first sample time by adjusting a second sampling time until the error rate performance of said system is optimized.

37. A method according to claim 34, wherein a third one of said plurality of sample times is established after said first and second sample times by adjusting said third sample time until the error rate performance of said system is optimized.