OPTICAL RECEIVER AND LIGHT RECEIVING METHOD

• US 20100092186A1
• Filed: 10/08/2009
• Published: 04/15/2010
• Est. Priority Date: 10/09/2008
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: TAKAHARA, Tomoo
• Granted Patent: US 8,326,145 B2
• Time in Patent Office: Days
• US Class Current: 398/208
• CPC Class Codes: H04B 10/695 Arrangements for optimizing the decision element in the receiver, e.g. by using automatic threshold control

Abstract

An apparatus and method includes converting an optical signal that is received into an electrical signal and outputting the electrical signal, converting the electrical signal into a data signal and outputting the data signal by comparing the electrical signal with a reference voltage, monitoring the electrical signal and output monitored information, and controlling the reference voltage based on the monitored information.

Claims

1. An apparatus, comprising:

a first converter configured to convert an optical signal that is received into an electrical signal and output the electrical signal;

a second converter configured to convert the electrical signal into a data signal and output the data signal by comparing the electrical signal with a reference voltage;

a monitor configured to monitor the electrical signal and output monitored information; and

a controller configured to control the reference voltage based on the monitored information.

2. The apparatus according to claim 1,

wherein the monitor monitors a current value of the electrical signal and outputs information about the current value as the monitored information.

3. The apparatus according to claim 2,

wherein the first converter includes a photodiode and a resistor provided between the photodiode and a bias voltage, and

wherein the monitor monitors a current value flowing through the resistor and outputs information about the current value as the monitored information.

4. The apparatus according to claim 2,

wherein the first converter includes an output terminal for the electrical signal, a load resistor connected to the output terminal, and a shunt resistor connected to the load resistor, and

wherein the monitor monitors a current value flowing through the shunt resistor and outputs information about the current value as the monitored information.

5. The apparatus according to claim 1,

wherein the monitor monitors a power of the electrical signal and outputs information about the power as the monitored information.

6. The apparatus according to claim 1,

wherein the monitor monitors a peak value of the electrical signal and outputs information about the peak value as the monitored information.

7. The apparatus according to claim 1,

wherein the monitor monitors an amplitude of the electrical signal and outputs information about the amplitude as the monitored information.

8. The apparatus according to claim 1, wherein the second converter includes:

a first analog-to-digital converter that compares the electrical signal with a reference voltage in synchronization with a clock signal to output a first data signal, and

a second analog-to-digital converter that compares the electrical signal with a reference voltage in synchronization with an inverted clock signal to output a second data signal.

9. A signal generating circuit, comprising:

a first converter for converting an optical signal that is received into an electrical signal and output the electrical signal;

a second converter for converting the electrical signal into a data signal and outputs the data signal by comparing the electrical signal with a reference voltage;

a monitor for monitoring the electrical signal and output monitored information; and

a controller for controlling the reference voltage based on the monitored information.

10. A receiving method for an apparatus, the method comprising:

receiving an optical signal;

converting the optical signal into an electrical signal;

monitoring the electrical signal to acquire monitored information;

controlling a reference voltage based on the monitored information; and

converting the electrical signal into a data signal by comparing the electrical signal with the controlled reference voltage.

11. A method of controlling a circuit, comprising:

selecting information of an electrical signal to be monitored; and

controlling the circuit by adjusting a reference voltage in accordance with a level of the electrical signal based on the monitored information.