Optical transceiver and method for controlling optical transceiver

A method for controlling an optical transceiver configured to receive an optical signal on which a monitoring signal encoded by Manchester encoding is superimposed and to decode the monitoring signal from an electrical signal generated from the optical signal, the method comprising steps of:

• detecting only a rising edge or a falling edge of a waveform of the electrical signal;
• measuring a first time interval between a detected first edge and a second edge detected immediately after detecting the first edge;
• measuring a second time interval between the second edge and a third edge detected immediately after detecting the second edge;
• estimating a number of clocks of the second time interval with respect to a period of a synchronized clock used in the Manchester encoding of the monitoring signal based on the ratio between the first time interval and the second time interval;
• and
• decoding the monitoring signal encoded by the Manchester encoding based on a ratio between the first time interval and the second time interval, the estimated number of clocks of the second time interval and a logical value of the monitoring signal decoded immediately before.

An optical transceiver configured to receive an optical signal on which a monitoring signal encoded by Manchester encoding is superimposed, the optical transceiver comprising:

• a decoding circuit configured to decode the monitoring signal from an electrical signal generated from the optical signal, the decoding circuit including:
• an interval measuring unit configured to detect only a rising edge or a falling edge of a waveform of the electrical signal, to measure a first time interval between a detected first edge and a second edge detected immediately after detecting the first edge, and to measure a second time interval between the second edge and a third edge detected immediately after detecting the second edge;
• and
• a decoding unit configured to decode the monitoring signal encoded by the Manchester encoding based on a ratio between the first time interval and the second time interval,
• wherein the monitoring signal encoded by the Manchester encoding and received by the decoding circuit includes a correction pattern in which a first logical value, the first logical value, a second logical value, and the first logical value sequentially appear, and
• wherein the first logical value is indicated by a rising edge or a falling edge detected by the interval measuring unit.