Closed loop module control for communication
The present invention is directed to communication systems and methods. According to an embodiment, a receiving optical transceiver determines signal quality for signals received from a transmitting optical transceiver. Information related to the signal quality is embedded into back-channel data and sent to the transmitting optical transceiver. The transmitting optical transceiver detects the presence of the back-channel data and adjusts one or more of its operating parameters based on the back-channel data. There are other embodiments as well.
1. An optical transceiver apparatus comprising:
an optical receiver for converting incoming optical signals to incoming electrical signals;
a digital signal processor (DSP) configured to analyze the incoming electrical signals and to generate a first signal quality value characterizing the incoming electrical signals;
a forward-error correction (FEC) module configured to process the incoming electrical signals and to generate a second signal quality value characterizing an error rate associated with the incoming electrical signals;
a control module configured to generate back-channel data based at least on the first signal quality value and the second signal quality value, the control module further being configured to insert the back-channel data to an outgoing data stream, the back channel data segment being positioned at a predetermined location of an encoded data frame for processing by a compatible device; and
an optical transmitter for generating output optical signals based on the outgoing data stream,
wherein the outgoing data stream indicates a first pulse amplitude modulation (PAM) parameter adjustment comprising lane skew.
2. The apparatus of claim 1 wherein the FEC module is configured to decode the incoming electrical signals.
3. The apparatus of claim 1 wherein the FEC module is configured to encapsulate the back-channel data and a portion of the outgoing data stream into an FEC frame.
4. The apparatus of claim 1 wherein the first signal quality value comprises a signal-to-noise ratio.
5. The apparatus of claim 1 wherein the first signal quality value is associated with a histogram.
6. The apparatus of claim 1 wherein the first signal quality value comprises an optical eye diagram.
7. The apparatus of claim 1 wherein the error rate comprises an overall bit-error rate (BER).
8. The apparatus of claim 1 the second quality value is associated with a bit-transition error matrix.
9. The apparatus of claim 1 wherein the optical transmitter comprises a laser device.
10. The apparatus of claim 9 wherein the control module is configured to change one or more settings for the laser device based on received back-channel data embedded in the incoming electrical signals.
11. The apparatus of claim 10 wherein the one or more settings include a laser wavelength.
12. The apparatus of claim 1 wherein the optical transmitter comprises a modulator.
13. The apparatus of claim 12 wherein the control module is configured to change one or more settings for the modulator based on received back-channel data embedded in the incoming electrical signals.
14. The apparatus of claim 1 wherein the optical transmitter comprises a multiplexer, the control module being configured to change one or more settings for the multiplexer based on received back-channel data embedded in the incoming electrical signals.
15. The apparatus of claim 14 wherein the multiplexer comprises a delay line interferometer (DLI), the DLI being configured to operate at a tuning parameter based on back-channel data and/or near-end data.