Data communications system including an optical fiber data link disposed between serial bidirectional electrical data busses

• US 9,071,357 B1
• Filed: 07/11/2014
• Issued: 06/30/2015
• Est. Priority Date: 07/11/2014
• Status: Active Grant

• Current Assignee: Emcore Corporation
• Original Assignee: Emcore Corporation
• Inventors: Shi, Feng, Lee, Sang
• Primary Examiner(s): CURS, NATHAN M
• Application Number:
  US14/329,682
• Time in Patent Office: 354 Days
• Field of Search: 398/159, 398/193, 398/194, 398/208
• US Class Current: 1/1
• CPC Class Codes: H04B 10/2575 Radio-over-fibre, e.g. radio frequency signal modulated onto an optical carrier
• CPC Class Codes: H04B 10/2589 Bidirectional transmission
• CPC Class Codes: H04B 10/271 Combination of different networks, e.g. star and ring configuration in the same network or two ring networks interconnected
• CPC Class Codes: H04B 10/516 Details of coding or modulation
• CPC Class Codes: H04B 10/697 Arrangements for reducing noise and distortion

Abstract

An optical fiber data communications network in which an electro-optical transceiver couples a plurality of serial electrical data buses over a single bidirectional optical fiber link, and includes a controller that functions by oversampling the digital electrical signal on each of such buses, multiplexes them, and converts the signal into a high speed optical signal for transmission over an optical fiber.

Claims

1. A communications network comprising:

a first bidirectional serial electrical bus having a first data rate and using a predetermined electrical data protocol for coupling with a plurality of network nodes;

a first interface controller coupled to the first bidirectional serial electrical bus for sampling signals received from the first bidirectional serial electrical bus at a sampling rate at least fifty times larger than the first data rate and encoding resultant sampled data into a second digital signal for transmission at a second data rate substantially greater than the first data rate;

an electro-optical transmitter coupled to the first interface controller for converting the second digital signal into an optical signal at a first optical frequency for transmission over an optical fiber;

an optical fiber coupled to the electro-optical transmitter for transmitting the optical signal to a remote receiver;

an electro-optical receiver coupled to the optical fiber for converting the optical signal into an electrical signal; and

a second interface controller coupled to the electro-optical receiver for decoding the electrical signal from the electro-optical receiver and processing the decoded electrical signal to generate a digital signal for transmission on a second bidirectional serial electrical bus using said predetermined electrical data protocol, wherein the second interface controller comprises a pre-distorter arranged to add pre-distortion to compensate for signal distortion.

2. The communications network of claim 1, wherein the first interface controller is arranged to sample signals received from the first bidirectional serial electrical bus at a sampling rate 150 times larger than the first data rate.

3. The communication network of claim 1, wherein the signals on the first bidirectional serial electrical bus correspond to Manchester-encoded data signals.

4. The communications network of claim 3, wherein the second interface controller is arranged to recover the timing of the Manchester-encoded data signals by dynamic adjustment of a starting time reference for a decision window.

5. The communications network of claim 4, wherein the second interface controller is arranged to apply a transition window corresponding to half a Manchester code bit period.

6. The communications network of claim 1, wherein the pre-distorter is arranged to add said pre-distortion in the generation of the digital signal for transmission.

7. The communications network of claim 6, wherein the pre-distorter is operable to shift a bias level of the digital signal for transmission.

8. The communications network of claim 1, wherein the second interface controller is arranged to add a sample period extension in either positive or negative bias to adjust a DC bias of the electrical signals in the first and second bidirectional serial electrical buses.

9. The communications network of claim 1, wherein the first interface controller is implemented on a single integrated circuit device.

10. The communications network of claim 9, wherein the single integrated circuit device is a Field Programmable Gate Array.

11. An integrated circuit device comprising:

a first interface controller for sampling signals received from a serial bidirectional electrical bus at a sampling rate, wherein the received signals are at a first data rate and the sampling rate is at least fifty times larger than the first data rate, and encoding the sampled data into a second digital signal for transmission at a second data rate substantially greater than the first data rate, and

a second interface controller coupled for decoding an electrical signal at the second data rate and processing the decoded electrical signal to generate a digital signal for transmission on the bidirectional serial electrical bus using a predetermined electrical data protocol, wherein the second interface controller is arranged to recover the timing of Manchester-encoded digital data by dynamic adjustment of a starting time reference for a decision window, and wherein the second interface controller is arranged to apply a transition window corresponding to half a Manchester code bit period.

12. The integrated circuit device of claim 11, wherein the sampling rate is at least 150 times larger than the first data rate.

13. The integrated circuit device of claim 11, wherein the second interface controller comprises a pre-distorter arranged to introduce pre-distortion to compensate for distortion generated on transmission to the serial bidirectional electrical bus.

14. The integrated circuit device of claim 13, wherein the pre-distorter is operable to shift a bias level of the digital signal for transmission.

15. A non-volatile storage medium comprising instructions for programming a programmable apparatus to sample signals received from a serial bidirectional electrical bus at a sampling rate, wherein the received signals are at a first data rate and the sampling rate is at least fifty times larger than the first data rate, and to encode the sampled data into a second digital signal for transmission at a second data rate substantially greater than the first data rate;

and further comprising (i) instructions for decoding an electrical signal received at the second data rate and processing the decoded electrical signal to generate a digital signal for transmission on the bidirectional serial electrical bus using a predetermined electrical data protocol; and

(ii) instructions for introducing pre-distortion to compensate for distortion generated on transmission of the digital signal on the serial electrical bus, wherein the instructions for introducing pre-distortion include instructions to shift a bias level of the digital signal for transmission.

16. A communications network comprising:

a first bidirectional serial electrical bus having a first data rate and using a predetermined electrical data protocol for coupling with a plurality of network nodes;

a first interface controller coupled to the first bidirectional serial electrical bus for sampling signals received from the first bidirectional serial electrical bus at a sampling rate at least fifty times larger than the first data rate and encoding resultant sampled data into a second digital signal for transmission at a second data rate substantially greater than the first data rate;

an electro-optical transmitter coupled to the first interface controller for converting the second digital signal into an optical signal at a first optical frequency for transmission over an optical fiber;

an optical fiber coupled to the electro-optical transmitter for transmitting the optical signal to a remote receiver;

an electro-optical receiver coupled to the optical fiber for converting the optical signal into an electrical signal; and

a second interface controller coupled to the electro-optical receiver for decoding the electrical signal from the electro-optical receiver and processing the decoded electrical signal to generate a digital signal for transmission on a second bidirectional serial electrical bus using said predetermined electrical data protocol,

wherein the signals on the first bidirectional serial electrical bus correspond to Manchester-encoded data signals, wherein the second interface controller is arranged to recover the timing of the Manchester-encoded data signals by dynamic adjustment of a starting time reference for a decision window, and wherein the second interface controller is arranged to apply a transition window corresponding to half a Manchester code bit period.

17. The communications network of claim 16, wherein the first interface controller is arranged to sample signals received from the first bidirectional serial electrical bus at a sampling rate 150 times larger than the first data rate.

18. An integrated circuit device comprising:

a first interface controller for sampling signals received from a serial bidirectional electrical bus at a sampling rate, wherein the received signals are at a first data rate and the sampling rate is at least fifty times larger than the first data rate, and encoding the sampled data into a second digital signal for transmission at a second data rate substantially greater than the first data rate, and

a second interface controller coupled for decoding an electrical signal at the second data rate and processing the decoded electrical signal to generate a digital signal for transmission on the bidirectional serial electrical bus using a predetermined electrical data protocol, wherein the second interface controller comprises a pre-distorter arranged to introduce pre-distortion to compensate for distortion generated on transmission to the serial bidirectional electrical bus.

19. The integrated circuit device of claim 18, wherein the pre-distorter is operable to shift a bias level of the digital signal for transmission.

20. The integrated circuit device of claim 18, wherein the second interface controller is arranged to recover the timing of Manchester-encoded digital data by dynamic adjustment of a starting time reference for a decision window.