Optical receiving apparatus

• US 5,612,810 A
• Filed: 09/12/1995
• Issued: 03/18/1997
• Est. Priority Date: 09/12/1994
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Inami, Daijiro, Sato, Yuichi
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): NEGASH, KINFE MICHAEL
• Application Number:
  US08/527,036
• Time in Patent Office: 553 Days
• Field of Search: 359/189, 359/194, 359/154, 250/214 A, 330/59, 330/308
• US Class Current: 398/202
• CPC Class Codes: H04B 10/695 Arrangements for optimizing the decision element in the receiver, e.g. by using automatic threshold control

Abstract

An optical receiving apparatus of the present invention comprises an opto-electric conversion element for converting an optical signal into an electric signal, a differential type preamplifier for sending a non-inverting phase signal and a inverting phase signal of the electric signal and a first and second peak hold circuits for holding peak values of the respective non-inverting and inverting phase signals. Further, the optical receiving apparatus of the present invention comprises a first adder for adding the inverting phase signal to the non-inverting phase peak signal from the first peak hold circuit and a second adder for adding the non-inverting phase signal to the inverting phase peak signal from the second peak hold circuit. Further, the optical receiving apparatus comprises a main amplifier including a differential amplifier having inputs supplied with outputs of the first and second adders and a comparator for outputting a binary signal correspondingly to a high and low levels of two output signals of the differential amplifier. The peak values of the non-inverting and inverting phase signals of the receiving signal are held and added by a feedforward connection.

Claims

1. An optical receiving apparatus comprising:

peak value detection means for detecting a peak value of an input signal and a peak value region including the peak value;

offset removing means for removing an offset from a reference value of the input signal and outputting the input signal without offset;

amplitude amplification means for converting a bottom region of the input signal into the peak value and a inverting value obtained by inverting the peak value about the reference value, amplifying then and outputting an amplitude amplified signal; and

duty detection means for detecting a duty of the amplitude amplified signal in the reference value.

2. An optical receiving apparatus comprising:

signal sending means for sending a non-inverting phase signal and a inverting phase signal of an input signal;

first peak value holding means for holding a peak value of the non-inverting phase signal and outputting a non-inverting phase peak value signal;

second peak value holding means for holding a peak value of the inverting phase signal and outputting a non-inverting phase peak value signal;

first adder means for adding the inverting phase signal to the non-inverting phase peak value signal and outputting a non-inverting phase sum signal;

second adder means for adding the non-inverting phase signal to the inverting phase peak value signal and outputting a inverting phase sum signal;

differential amplifier means for differentially amplifying the non-inverting phase sum signal and the inverting phase sum signal and sending a differentially amplified signal; and

duty detection means for detecting a duty of the differentially amplified signal.

3. The optical receiving apparatus claimed in claim 2, wherein the input signal is an optical signal, and further comprising an opto-electric conversion means for converting the optical signal into an electric signal.

4. The optical receiving apparatus claimed in claim 3, wherein the input signal is a burst signal.

5. An optical receiving apparatus comprising:

opto-electric conversion means for converting an optical signal into an electric signal;

preamplifier means for sending a non-inverting phase signal and a inverting phase signal of the electric signal;

at least one first peak hold means for detecting and holding a peak value of the inverting phase signal and outputting a non-inverting phase peak signal;

at least one second peak hold means for detecting and holding a peak value of the inverting phase signal and outputting a inverting phase peak signal;

first adder means for adding the inverting phase signal to the non-inverting phase peak signal and outputting a inverting phase sum signal;

second adder means for adding the non-inverting phase signal to the inverting phase peak signal and outputting a non-inverting phase sum signal;

differential amplifier means for differentially amplifying the positive phase sum signal and the inverting phase sum signal and outputting a differentially amplified signal; and

comparing means for outputting a binary signal correspondingly to a high and low levels of the differentially amplified signal.

6. The optical receiving apparatus claimed in claim 5, wherein said first adder means comprising a first resistor having one end connected to an output terminal of said first peak hold means and a second resistor having one end connected to an output terminal of said preamplifier means and said second adder means comprising a first resistor having one end connected to an output terminal of said second peak hold means and a second resistor having one end connected to said output terminal of said preamplifier means, and further comprising means for connecting the other terminals of said first and second resistors to respective input terminals of said differential amplifier means.

7. The optical receiving apparatus claimed in claim 5, wherein said first adder means comprises a third resistor for connecting an output terminal of said differential amplifier means to one of said input terminal thereof and said second adder means comprises a third resistor for connecting an output terminal of said differential amplifier means to the other input terminal thereof.

8. The optical receiving apparatus claimed in claim 5, wherein said first peak hold means comprises a non-inverting peak hold means for holding a non-inverting peak value and a inverting peak hold means for holding a inverting peak value and said second peak hold means comprises a positive peak hold means for holding a non-inverting peak value and a inverting peak hold means for holding a inverting peak value.

9. The optical receiving apparatus claimed in claim 5, wherein said differential amplifier means comprises a plurality of series connected amplifier stages and a last amplifier stage is connected to said comparing means.