Method and apparatus for optimizing decision level of signal output from optical receiver

An apparatus for optimizing a decision level of a signal output from an optical receiver, the apparatus comprising:

• a modulated frequency element extraction unit, which filters and extracts a modulated frequency signal element from various frequency elements of an electric signal output from an optical receiver;
• a signal strength detection unit, which detects the strength of the electric signal at the modulated frequency;
• a data storing unit, which stores the strength value of the electric signal;
• a reference voltage control unit, which outputs an optional reference voltage based on the strength data of the electric signal at the modulated frequency, measures the strength of the electric signal at the modulated frequency while varying the reference voltage to compare the measured strength with the stored strength value of the electric signal, and controls the reference voltage to minimize the measured strength of the electric signal;
• and
• a reference voltage generation unit, which generates and outputs the reference voltage adjusted in the reference voltage control unit.

A system for optimizing a decision level of a signal output from an optical receiver, the system comprising:

• an optical receiver, which receives an optical signal and converts into an electric signal;
• an RF spectrum analyzer, which measures the spectrum of the electric signal at a frequency region to detect a modulated frequency and measures the strength of the electric signal at the detected modulated frequency;
• and
• a reference voltage supplier, which outputs an optional reference voltage based on the strength data of the electric signal, measures the strength of the electric signal at the modulated frequency while varying the reference voltage, and adjusts and supplies the reference voltage input to the optical receiver to minimize the measured strength of the signal.

A recording medium readable in a computer that includes a program for operating a method for optimizing a decision level of a signal output from an optical receiver in a computer, wherein the method comprises:

• measuring the strength of an electric signal at a modulated frequency out of the frequency elements of the output electric signal in the optical receiver;
• generating a reference voltage based on the strength data of the electric signal;
• inputting the reference voltage to the optical receiver and measuring the strength of the electric signal output from the optical receiver, again;
• and
• adjusting the reference voltage based on the re-measured strength data of the signal,
• wherein generating the reference voltage and re-measuring the strength of the signal are repeated until the measured strength of the signal is lowered than a predetermined value.