JP3514642B2 - Optical receiving circuit and optical transmission system using the same - Google Patents
Optical receiving circuit and optical transmission system using the sameInfo
- Publication number
- JP3514642B2 JP3514642B2 JP31430298A JP31430298A JP3514642B2 JP 3514642 B2 JP3514642 B2 JP 3514642B2 JP 31430298 A JP31430298 A JP 31430298A JP 31430298 A JP31430298 A JP 31430298A JP 3514642 B2 JP3514642 B2 JP 3514642B2
- Authority
- JP
- Japan
- Prior art keywords
- output
- adder
- outputs
- circuit
- amplifier
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Manipulation Of Pulses (AREA)
- Dc Digital Transmission (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、光受信回路に係わ
り、特にダイナミックレンジが広く、波形歪みの変動の
少ない光受信回路に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical receiver circuit, and more particularly to an optical receiver circuit having a wide dynamic range and less fluctuation in waveform distortion.
【０００２】[0002]
【従来の技術】図１および図２を用いて従来の技術を説
明しよう。ここで、図１は、従来のバースト光受信回路
の構成を説明するブロック図である。また、図２は、こ
のバースト光受信回路の各端子部での電圧波形を説明す
る図である。図１のバースト光受信回路は、受光素子
１、変換増幅器２、基準電圧源３、差動増幅器５、レベ
ルシフト回路７、コンパレータ８で構成される。次に、
この従来のバースト光受信回路の動作の概要を説明す
る。入力光レベルに応じた電流信号が受光素子１から出
力され、変換増幅器２にて電流信号を電圧信号２１に変
換、増幅する。基準電圧源３は、光入力なしの時の電圧
信号２１のレベル、すなわちＬＯＷレベルに相当する電
圧３１を出力する。この信号２１と電圧３１を差動増幅
器５で増幅、正相信号５１と逆相信号５２を出力する。
逆相信号５２には、レベルシフト回路７によりオフセッ
トが印加され信号７２として出力される。更に、この信
号５１、７２を比較、出力するコンパレータ８により、
最終的に出力信号８２を出力する構成となっている。2. Description of the Related Art A conventional technique will be described with reference to FIGS. Here, FIG. 1 is a block diagram illustrating a configuration of a conventional burst optical receiving circuit. Further, FIG. 2 is a diagram for explaining the voltage waveform at each terminal of the burst light receiving circuit. The burst light receiving circuit of FIG. 1 includes a light receiving element 1, a conversion amplifier 2, a reference voltage source 3, a differential amplifier 5, a level shift circuit 7, and a comparator 8. next,
An outline of the operation of this conventional burst light receiving circuit will be described. A current signal corresponding to the input light level is output from the light receiving element 1, and the conversion amplifier 2 converts the current signal into a voltage signal 21 for amplification. The reference voltage source 3 outputs the voltage 31 corresponding to the level of the voltage signal 21 when there is no light input, that is, the LOW level. The signal 21 and the voltage 31 are amplified by the differential amplifier 5, and the positive phase signal 51 and the negative phase signal 52 are output.
An offset is applied to the negative phase signal 52 by the level shift circuit 7 and is output as a signal 72. Further, by the comparator 8 which compares and outputs the signals 51 and 72,
Finally, the output signal 82 is output.
【０００３】図２（ａ）は、ＨＩＧＨレベルとＬＯＷレ
ベルの光を交互に入力した場合の変換増幅器出力２１、
（ｂ）はＬＯＷレベルを出力する基準電圧源出力３１、
（ｃ）はコンパレータの入力である差動増幅器正相出力
５１および破線で示すレベルシフト回路出力７２、
（ｄ）は差動増幅器逆相出力５２、（ｅ）はレベルシフ
ト回路出力７２、（ｆ）はコンパレータ出力８２であ
り、それぞれ、縦軸は電圧軸、横軸は時間軸である。こ
のような構成とする事で、小型化困難な大容量コンデン
サを用いて交流結合で設計する必要なく、光入力部から
信号出力まで全段直流結合が可能となり、バースト信号
を再生することが出来る。FIG. 2 (a) shows a conversion amplifier output 21 when light of HIGH level and light of LOW level are alternately input.
(B) is a reference voltage source output 31 that outputs a LOW level,
(C) is a differential amplifier positive phase output 51 which is an input of the comparator and a level shift circuit output 72 shown by a broken line,
(D) is the differential amplifier negative phase output 52, (e) is the level shift circuit output 72, and (f) is the comparator output 82, and the vertical axis is the voltage axis and the horizontal axis is the time axis. With such a configuration, it is not necessary to design with AC coupling using a large-capacity capacitor that is difficult to miniaturize, and all stages of DC coupling can be performed from the optical input section to the signal output, and burst signals can be reproduced. .
【０００４】この種の回路に関して、例えば特公昭５９
−１９６６３６号公報がある。Regarding this type of circuit, for example, Japanese Patent Publication No. 59
-196636 is available.
【０００５】長距離伝送後の小信号レベルから短距離伝
送後の大信号レベルまで受信する受光ダイナミックレン
ジの広い場合、従来のバースト光受信回路では、図２
（ｆ）の信号波形８２に示すように、入力波形２１と比
べてデューティが変動し、波形歪みが生じている。ディ
ジタル信号伝送において、このような波形歪みは符号誤
りの原因となり、極力少ないことが望まれる。In the case of a wide dynamic range of light reception for receiving from a small signal level after long-distance transmission to a large signal level after short-distance transmission, a conventional burst optical receiving circuit is shown in FIG.
As shown in the signal waveform 82 of (f), the duty fluctuates compared to the input waveform 21 and waveform distortion occurs. In digital signal transmission, such waveform distortion causes a code error and is desired to be as small as possible.
【０００６】この波形歪みの原因を図２（ｃ）と（ｆ）
とを対比して説明する。差動増幅器正相出力５１とレベ
ルシフト回路出力７２の直流電位差が信号振幅に対し無
視できない場合、言い換えると、コンパレータ正相入力
信号とコンパレータ逆相入力信号間の直流電位差が信号
振幅に対し無視できずＨＩＧＨレベルをＨＩＧＨレベル
ＬＯＷレベルをＬＯＷレベルとして識別する時間に大き
な差がある場合、コンパレータ出力のＨＩＧＨレベルと
ＬＯＷレベルのパルス幅が異なり大きくデューティが変
動する。一般に、コンパレータ正相入力信号の直流レベ
ルがコンパレータ逆相入力信号の直流レベルより高い場
合はコンパレータ出力信号は図示の通りＨＩＧＨレベル
の時間が長くなる。一方、コンパレータ正相入力信号の
直流レベルがコンパレータ逆相入力信号の直流レベルよ
り低い場合ＬＯＷレベルの時間が長くなる。これに対し
信号振幅がその直流電位差に対し十分に無視できる場合
はデューティ変動は小さい。上述した従来例では、特に
伝送距離が異なる端末からスターカプラ等を介して受信
する場合、その受信点では小信号から大信号まで入力光
レベルが変動するため、波形歪みが大きく変動する問題
があった。The cause of this waveform distortion is shown in FIGS. 2 (c) and 2 (f).
Will be explained in contrast with. When the DC potential difference between the differential amplifier positive phase output 51 and the level shift circuit output 72 cannot be ignored with respect to the signal amplitude, in other words, the DC potential difference between the comparator positive phase input signal and the comparator negative phase input signal can be ignored with respect to the signal amplitude. When there is a large difference in the time for identifying the HIGH level as the HIGH level and the LOW level as the LOW level, the pulse widths of the HIGH level and the LOW level of the comparator output are different, and the duty varies greatly. Generally, when the direct current level of the comparator positive phase input signal is higher than the direct current level of the comparator negative phase input signal, the comparator output signal becomes high for a long time as illustrated. On the other hand, when the DC level of the comparator positive phase input signal is lower than the DC level of the comparator negative phase input signal, the LOW level time becomes longer. On the other hand, when the signal amplitude is sufficiently negligible with respect to the DC potential difference, the duty fluctuation is small. In the above-mentioned conventional example, especially when receiving from a terminal having a different transmission distance via a star coupler or the like, there is a problem that the waveform distortion greatly fluctuates because the input light level fluctuates from a small signal to a large signal at the receiving point. It was
【０００７】[0007]
【発明が解決しようとする課題】光受信回路の受光素子
出力直後の増幅部出力波形の立ち上がり時間ｔｒと立ち
下がり時間ｔｆが大きくなる原因は、光ファイバの伝送
長、受光素子の帯域、増幅器等の帯域等に依存するため
である。この結果、波形歪みやデューティ劣化を生じさ
せてしまう。Causes the rise time t r and the fall time t f becomes larger of the amplifier output waveform immediately after the light-receiving element output of the optical receiver circuit The object of the invention is to solve the above-transmission length of the optical fiber, the bandwidth of the light receiving element, This is because it depends on the band of the amplifier and the like. As a result, waveform distortion and duty deterioration occur.
【０００８】さらに、送信受信一対一の伝送ではなく、
スターカプラ等を用いて一つの光受信器で複数の光送信
信号を受信する場合、光ファイバ長に依存して入力光レ
ベルが異なるため、増幅部出力の電気信号振幅に大小の
振幅変動が生じる。この結果、波形歪み変動やデューテ
ィ変動が生じ、符号誤りのため受信不具合となってしま
う。Furthermore, instead of transmission / reception one-to-one transmission,
When multiple optical transmission signals are received by a single optical receiver using a star coupler, etc., the input optical level differs depending on the optical fiber length, so the amplitude of the electrical signal at the output of the amplification unit fluctuates. . As a result, a waveform distortion variation and a duty variation occur, and a reception error occurs due to a code error.
【０００９】例えば、１：３２分岐のスターカプラ（挿
入損失：−１５ｄB）、光送信器の平均出力レベルが３
２台とも一律−５ｄBｍ、光ファイバの伝送損失０．３
５ｄB／ｋｍ、光受信器の平均最小入力光レベル−３３
ｄBｍ、コネクタ結合損失・経年劣化等のマージン６ｄB
とする。この時、入力光レベルは最短距離の場合−２６
ｄBｍ（＝−５−１５−６）、一方距離２０ｋｍの場合
は−３３ｄBｍ（＝−５−１５−６−２０＊０．３５）
となる。つまり入力光レベル差７ｄB（＝−２６−（−
３３））を一つの光受信器でカバーすることが必要であ
る。For example, a 1:32 branch star coupler (insertion loss: -15 dB), the average output level of the optical transmitter is 3
Both are uniformly -5 dBm, optical fiber transmission loss 0.3
5 dB / km, average minimum input optical level of optical receiver -33
dBm, margin for connector coupling loss, deterioration over time 6 dB
And At this time, the input light level is -26 when the shortest distance.
dBm (= -5-15-6), on the other hand, when the distance is 20 km, -33 dBm (= -5-15-6-20 * 0.35)
Becomes That is, the input light level difference is 7 dB (= -26-(-
It is necessary to cover 33)) with one optical receiver.
【００１０】本発明の課題は、上記波形歪みを無くし、
長距離伝送後の小信号レベルから短距離伝送後の大信号
レベルまで受信可能な、光信号受信回路、光伝送装置、
光伝送システムを提供することにある。An object of the present invention is to eliminate the above waveform distortion,
Optical signal receiving circuit, optical transmission device, capable of receiving from small signal level after long distance transmission to large signal level after short distance transmission
It is to provide an optical transmission system.
【００１１】[0011]
【課題を解決するための手段】上記目的を達成するため
に、微分回路と増幅器および加算器とを用いてコンパレ
ータ入力波形の立ち上がり時間ｔｒ、立ち下り時間ｔｆ
を小さくすることで、上記課題を解決することが出来
る。つまり、信号波形の立ち上がり立ち下がりの変化点
を抽出し、その変化量を出力できる微分回路と、微分回
路出力と信号波形を加える加算器によって、信号波形の
立ち上がりと立ち下がりを急峻にすることができる。こ
の時、急峻になった信号波形のオーバーシュートとアン
ダーシュートはコンパレータで識別されるので問題な
い。To achieve the above object, according to the Invention The rise time t r of the comparator input waveform using the differential circuit and the amplifier and the adder, fall time t f
The problem can be solved by reducing In other words, it is possible to make the rising and falling edges of the signal waveform steep by using a differentiating circuit that can extract the changing points of the rising and falling edges of the signal waveform and output the amount of change, and an adder that adds the differentiating circuit output and the signal waveform. it can. At this time, there is no problem because the comparator discriminates overshoot and undershoot of the steep signal waveform.
【００１２】[0012]
【発明の実施の形態】以下本発明の実施の形態を図面を
用いて説明する。まず、本発明の実施の形態である光受
信回路の実施例を図４、図５を用いて説明しよう。ここ
で、図４は、本発明の光受信回路の構成を説明するブロ
ック図である。また、図５は、この光受信回路の各端子
部での電圧波形を説明する図である。図４のバースト光
受信回路は、受光素子１、変換増幅器２、基準電圧源
３、微分回路４、差動増幅器５、差動増幅器６、レベル
シフト回路７、コンパレータ８、加算器９、加算器１
０、加算器１１で構成された光受信回路である。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. First, an example of the optical receiving circuit according to the embodiment of the present invention will be described with reference to FIGS. Here, FIG. 4 is a block diagram for explaining the configuration of the optical receiving circuit of the present invention. Further, FIG. 5 is a diagram for explaining voltage waveforms at the respective terminal parts of the optical receiving circuit. The burst light receiving circuit of FIG. 4 includes a light receiving element 1, a conversion amplifier 2, a reference voltage source 3, a differentiating circuit 4, a differential amplifier 5, a differential amplifier 6, a level shift circuit 7, a comparator 8, an adder 9, and an adder. 1
It is an optical receiving circuit composed of 0 and an adder 11.
【００１３】入力光レベルに応じた電流信号が受光素子
１から出力され、変換増幅器２にて電流信号を電圧信号
２１に変換、増幅する。基準電圧源３は、光入力なしの
時の電圧信号２１のレベル、すなわちＬＯＷレベルに相
当する電圧３１を出力する。この信号２１と電圧３１を
差動増幅器５で増幅、正相信号５１と逆相信号５２を出
力する。一方、微分回路４は、信号２１を微分し出力す
る。この微分出力と電圧３１を加算した第１の加算器出
力４１と電圧３１とを入力とする差動増幅器６は正相信
号６１と逆相信号６２を出力する。信号５２と信号６２
は第２の加算器で加算され、信号５３として出力され
る。信号５１と信号６１も第３の加算器で加算されて信
号５４として出力され、更にレベルシフト回路７にて直
流オフセットを印加されて信号７１として出力される。
この信号５３、７１を比較、出力するコンパレータ８に
より、最終的に出力信号８１を出力する構成となってい
る。A current signal corresponding to the input light level is output from the light receiving element 1, and the conversion amplifier 2 converts the current signal into a voltage signal 21 for amplification. The reference voltage source 3 outputs the voltage 31 corresponding to the level of the voltage signal 21 when there is no light input, that is, the LOW level. The signal 21 and the voltage 31 are amplified by the differential amplifier 5, and the positive phase signal 51 and the negative phase signal 52 are output. On the other hand, the differentiating circuit 4 differentiates the signal 21 and outputs it. The differential amplifier 6 which receives the first adder output 41 obtained by adding the differential output and the voltage 31 and the voltage 31 outputs the positive phase signal 61 and the negative phase signal 62. Signal 52 and signal 62
Are added by the second adder and output as a signal 53. The signal 51 and the signal 61 are also added by the third adder and output as a signal 54. Further, a DC offset is applied by the level shift circuit 7 and output as a signal 71.
The output signal 81 is finally output by the comparator 8 which compares and outputs the signals 53 and 71.
【００１４】図５（ａ）はＨＩＧＨレベルとＬＯＷレベ
ルの光を交互に入力した場合の変換増幅器出力２１、
（ｂ）はＬＯＷレベルを出力する基準電圧源出力３１、
（ｃ）は第１の加算器出力４１、（ｄ）は差動増幅器正
相出力５１、（ｅ）は差動増幅器逆相出力５２、（ｆ）
は差動増幅器正相出力６１、（ｇ）は差動増幅器逆相出
力６２、（ｈ）は第３の加算器出力５３および破線で示
したレベルシフト回路出力７１、（ｉ）は第２の加算器
出力５４、（ｊ）はレベルシフト回路出力７１、（ｋ）
はコンパレータ出力８１であり、それぞれ、縦軸は電圧
軸、横軸は時間軸である。図５中のf（ｔ）は直流成分
を持たない信号関数、ＡからＤは適当な直流成分を表わ
す定数、Ｖｒｅｆは基準レベル発生回路出力値、ａとｂ
は増幅率を表わす定数、Ｖｏｆｆｓｅｔはオフセット電
圧値として表現する。このように、コンパレータ８の入
力信号５３，７１の立ち上がり時間、立ち下がり時間を
小さくすることで、コンパレータ正相入力信号とコンパ
レータ逆相入力信号間の直流電位差が信号振幅に対し無
視できなくてもＨＩＧＨレベルとＬＯＷレベルを識別す
る時間に大きな差がなくなるため、コンパレータ出力の
デューティ変動が小さく、波形歪みを抑えることが出来
る。また、図４では二つの差動増幅器の逆相出力を加算
した後にレベルシフト回路で直流オフセットを加えた
が、二つの差動増幅器の正相出力を加算後レベルシフト
回路で直流オフセットを加えても同様であることは明ら
かである。さらに図３に示すように図４のレベルシフト
回路7をレベルシフト回路１２に変更して相対的に直流
オフセットを加えても同様である。FIG. 5 (a) shows a conversion amplifier output 21 when light of HIGH level and light of LOW level are alternately input.
(B) is a reference voltage source output 31 that outputs a LOW level,
(C) is the first adder output 41, (d) is the differential amplifier positive phase output 51, (e) is the differential amplifier negative phase output 52, (f)
Is the differential amplifier positive phase output 61, (g) is the differential amplifier negative phase output 62, (h) is the third adder output 53 and the level shift circuit output 71 shown by the broken line, and (i) is the second Adder output 54, (j) is level shift circuit output 71, (k)
Is a comparator output 81, and the vertical axis is the voltage axis and the horizontal axis is the time axis. In FIG. 5, f (t) is a signal function having no DC component, A to D are constants representing an appropriate DC component, Vref is a reference level generator output value, and a and b.
Is a constant that represents an amplification factor, and Voffset is an offset voltage value. In this way, by reducing the rise time and fall time of the input signals 53 and 71 of the comparator 8, even if the DC potential difference between the comparator positive-phase input signal and the comparator negative-phase input signal cannot be ignored with respect to the signal amplitude. Since there is no large difference in the time for distinguishing between the HIGH level and the LOW level, the duty fluctuation of the comparator output is small and the waveform distortion can be suppressed. In addition, in FIG. 4, the DC offset is added by the level shift circuit after adding the negative phase outputs of the two differential amplifiers, but the DC offset is added by the level shift circuit after adding the positive phase outputs of the two differential amplifiers. Obviously the same is true for. Further, as shown in FIG. 3, the level shift circuit 7 of FIG.
【００１５】次に、本発明の他の実施例を図６を用いて
説明する。図６は、本発明の光受信回路の構成を説明す
る回路図である。この光受信回路は、微分回路４、差動
増幅器５、差動増幅器６、レベルシフト回路７、コンパ
レータ８で構成されている。Next, another embodiment of the present invention will be described with reference to FIG. FIG. 6 is a circuit diagram illustrating the configuration of the optical receiving circuit of the present invention. This optical receiving circuit is composed of a differentiating circuit 4, a differential amplifier 5, a differential amplifier 6, a level shift circuit 7, and a comparator 8.
【００１６】変換増幅器、基準電圧源、コンパレータは
ごく一般的な回路で構成可能である。差動増幅器５は抵
抗２つ、トランジスタ２つ、定電流源１つで構成される
ごく一般的な回路である。微分回路４はコンデンサ１
つ、抵抗１つで構成され、加算機能も有し、例えば、１
５５Ｍｂｉｔ／ｓの信号の場合、コンデンサは１〜２０
ｐＦ、抵抗は１００〜２０００Ω程度である。差動増幅
器６も差動増幅器５と同じく抵抗２つ、トランジスタ２
つ、定電流源１つで構成されるごく一般的な回路である
が、抵抗は差動増幅器５と共用することで加算機能を同
時に実現できる。レベルシフト回路は抵抗１つと直流電
流源１つで構成されるが、この抵抗も差動増幅器と共用
できる。The conversion amplifier, the reference voltage source, and the comparator can be constructed by a general circuit. The differential amplifier 5 is a very general circuit including two resistors, two transistors, and one constant current source. Differentiating circuit 4 is a capacitor 1
, One resistor, and also has an adding function, for example, 1
For 55 Mbit / s signal, the capacitor is 1-20
The pF and resistance are about 100 to 2000Ω. Like the differential amplifier 5, the differential amplifier 6 has two resistors and a transistor 2.
Although it is a very general circuit composed of one constant current source, the addition function can be realized at the same time by sharing the resistor with the differential amplifier 5. The level shift circuit is composed of one resistor and one DC current source, but this resistor can also be used as a differential amplifier.
【００１７】尚、本実施例ではレベルシフト回路７が差
動増幅器５とコンパレータ８の間に有るが、基準電圧３
出力３１と差動増幅器５の入力との間に有っても同様な
効果が得られ、更に、両方に有っても良い。In this embodiment, the level shift circuit 7 is provided between the differential amplifier 5 and the comparator 8, but the reference voltage 3
The same effect can be obtained even if it is provided between the output 31 and the input of the differential amplifier 5, and further, it may be provided at both.
【００１８】尚、本図はＮＰＮ型バイポーラトランジス
タでの構成例を示したが、ＰＮＰ型バイポーラトランジ
スタやＦＥＴで構成した場合でも同様な効果が得られ
る。Although this figure shows an example of the structure of the NPN type bipolar transistor, the same effect can be obtained even when the structure is composed of the PNP type bipolar transistor or the FET.
【００１９】また、上述したすべての実施例は、バース
ト光受信回路だけでなく、単に入力波形立ち上がり時
間、立ち下がり時間を小さくすると効果がある一般的な
増幅器や論理回路にも適用出来る。Further, all of the above-described embodiments can be applied not only to the burst optical receiving circuit but also to general amplifiers and logic circuits where it is effective to simply reduce the input waveform rise time and fall time.
【００２０】本発明の他の実施の形態である光伝送装置
の実施例を図７を用いて説明する。図７は、本発明の光
伝送装置のブロック図および接続例である。スターカプ
ラ４０００及び光ファイバ３０００を伝送してきた光信
号は光受信回路１２００によって電気信号に変換され
る。変換された電気信号は多重・分離部１３００にてク
ロック及びその他の制御信号とデータ信号に分離されイ
ンタフェース部１４００によって信号は後段の処理装置
等１６００に伝えられる。光受信回路部と多重・分割部
とインタフェース部とこれらを制御する制御部１５００
によって伝送装置１１００は構成される。なお、図７に
於いては、一方向の伝送系を示しているが、実際は、伝
送装置１１００側に光送信回路が備えられることによ
り、双方向の伝送系が構成される。また前記光受信器と
前記光送信器の伝送路側に光合分波器等を用いることに
より、一心双方向の伝送系が構成される。An embodiment of an optical transmission device which is another embodiment of the present invention will be described with reference to FIG. FIG. 7 is a block diagram and connection example of the optical transmission device of the present invention. The optical signal transmitted through the star coupler 4000 and the optical fiber 3000 is converted into an electric signal by the optical receiving circuit 1200. The converted electric signal is separated into a clock and other control signals and a data signal by the multiplexer / demultiplexer 1300, and the signal is transmitted to the subsequent processing device 1600 by the interface 1400. Optical receiving circuit unit, multiplexing / division unit, interface unit, and control unit 1500 for controlling these
The transmission device 1100 is configured by the above. Although FIG. 7 shows a unidirectional transmission system, actually, a bidirectional transmission system is configured by providing an optical transmission circuit on the transmission device 1100 side. A one-core bidirectional transmission system is configured by using an optical multiplexer / demultiplexer or the like on the transmission path side of the optical receiver and the optical transmitter.
【００２１】次に本発明の他の実施の形態であるバース
ト伝送システムを図８を用いて説明する。図８は、本発
明の実施例のバースト光伝送システムのブロック図であ
る。中央局１０００は、光ファイバ３０００及びスター
カプラ４０００を介して、端末２０００Ａ、２０００
Ｂ、２０００Ｃと接続されている。中央局１０００内に
は、光伝送の制御をする伝送装置１１００が備えられて
おり、伝送装置１１００内には、光ファイバ３０００を
通して端末から送信されてくるデジタル光信号を受信す
る光受信回路１２００が備えられている。光受信回路１
２００は、図３または図４で説明した構成になってい
る。また、端末２０００Ａ内には、中央局１０００との
光伝送を制御する終端装置２１００Ａが備えられてお
り、終端装置２１００Ａ内には、デジタル信号を光信号
に変換して送信する光送信回路２２００Ａが備えられて
いる。他の端末２０００Ｂ、２０００Ｃも、端末２００
０Ａと同様の構成となっている。Next, a burst transmission system according to another embodiment of the present invention will be described with reference to FIG. FIG. 8 is a block diagram of a burst optical transmission system according to an embodiment of the present invention. The central office 1000 receives the terminals 2000A, 2000 via the optical fiber 3000 and the star coupler 4000.
B and 2000C are connected. A transmission device 1100 for controlling optical transmission is provided in the central office 1000, and an optical receiving circuit 1200 for receiving a digital optical signal transmitted from a terminal through an optical fiber 3000 is provided in the transmission device 1100. It is equipped. Optical receiver circuit 1
200 has the configuration described in FIG. 3 or FIG. Further, a terminal device 2100A that controls optical transmission with the central office 1000 is provided in the terminal 2000A, and an optical transmission circuit 2200A that converts a digital signal into an optical signal and transmits the optical signal is provided in the terminal device 2100A. It is equipped. The other terminals 2000B and 2000C are also the terminals 200
It has the same configuration as 0A.
【００２２】端末２０００Ａの光送信回路２２００Ａか
ら送信された光信号は、スターカプラ４０００及び光フ
ァイバ３０００を介して、中央局１０００の光受信回路
１２００によって受信される。尚、図８に於いては、一
方向の伝送系を示しているが、実際は、中央局１０００
側にも光送信回路が備えられ、端末２０００側にも光受
信回路が備えられることにより、双方向の伝送系が構成
される。また前記光受信器と前記光送信器の伝送路側に
光合分波器等を用いことにより、一心双方向の伝送系が
構成される。The optical signal transmitted from the optical transmission circuit 2200A of the terminal 2000A is received by the optical reception circuit 1200 of the central office 1000 via the star coupler 4000 and the optical fiber 3000. Although FIG. 8 shows a one-way transmission system, in reality, the central office 1000
The optical transmission circuit is also provided on the side and the optical receiving circuit is provided on the terminal 2000 side, so that a bidirectional transmission system is configured. A one-core bidirectional transmission system is configured by using an optical multiplexer / demultiplexer or the like on the transmission path side of the optical receiver and the optical transmitter.
【００２３】ここで、スターカプラ４０００と端末２０
００との距離は、一定ではなくそれぞれ異なるため、中
央局１０００に含まれる光受信回路１２００は、受光ダ
イナミックレンジの広い光受信回路を用いる必要があ
る。例えば、中央局１０００と端末２０００Ａとの通信
距離が短く、中央局１０００と端末２０００Ｂとの通信
距離が長いように、端末との距離に応じて光受信回路１
２００で受信する入力光レベルが大きく異なるような場
合にも、精度良く端末からの光情報を検出することが出
来る。Here, the star coupler 4000 and the terminal 20
Since the distance to 00 is not constant but different from each other, the optical receiving circuit 1200 included in the central office 1000 needs to use an optical receiving circuit having a wide light receiving dynamic range. For example, the optical receiving circuit 1 is arranged according to the distance between the central office 1000 and the terminal 2000A so that the communication distance between the central office 1000 and the terminal 2000A is short and the communication distance between the central office 1000 and the terminal 2000B is long.
Even when the input light levels received by the 200 are significantly different, the optical information from the terminal can be accurately detected.
【００２４】尚、図８では端末が３つの例を示したが、
３つに限定しなくても良いことは言うまでもない。Although FIG. 8 shows an example with three terminals,
It goes without saying that the number is not limited to three.
【００２５】[0025]
【発明の効果】本発明によって、簡単な回路で、波形歪
みが少なく、広範囲な入力光レベルに対応可能な光受信
回路、光伝送装置、光伝送システムを得ることができ
た。According to the present invention, it is possible to obtain an optical receiving circuit, an optical transmission device, and an optical transmission system which have a simple circuit and a small waveform distortion and can cope with a wide range of input light levels.
【図１】従来のバースト光受信回路のブロック図であ
る。FIG. 1 is a block diagram of a conventional burst light receiving circuit.
【図２】従来のバースト光受信回路の各端子部での電圧
波形を説明する図である。FIG. 2 is a diagram illustrating voltage waveforms at respective terminal portions of a conventional burst light receiving circuit.
【図３】本発明の実施例の光受信回路ブロック図であ
る。FIG. 3 is a block diagram of an optical receiver circuit according to an embodiment of the present invention.
【図４】本発明の実施例の光受信回路ブロック図であ
る。FIG. 4 is a block diagram of a light receiving circuit according to an embodiment of the present invention.
【図５】本発明の実施例のバースト光受信回路の各端子
部での電圧波形を説明する図である。FIG. 5 is a diagram illustrating a voltage waveform at each terminal of the burst light receiving circuit according to the embodiment of the present invention.
【図６】本発明の他の実施例の光受信回路のブロック図
である。FIG. 6 is a block diagram of an optical receiving circuit according to another embodiment of the present invention.
【図７】本発明の実施例のバースト光伝送装置のブロッ
ク図および接続例である。FIG. 7 is a block diagram and a connection example of a burst optical transmission device according to an embodiment of the present invention.
【図８】本発明の実施例のバースト光伝送システムのブ
ロック図である。FIG. 8 is a block diagram of a burst optical transmission system according to an embodiment of the present invention.
１…受光素子、２…変換増幅器、３…基準電圧源、４…
微分回路、５…差動増幅器、６…差動増幅器、７…レベ
ルシフト回路、８…コンパレータ、９…加算器、１０…
加算器、１１…加算器、１２…レベルシフト回路、１０
００…中央局、１１００…伝送装置、１２００…光受信
回路、１３００…多重・分離部、１４００…インタフェ
ース部、１５００…制御部、１６００…処理装置等、２
０００…端末、２１００…終端装置、２２００…光送信
回路、３０００…光ファイバ、３００１…光ファイバ、
３００２…光ファイバ、３００３…光ファイバ、４００
０…スターカプラ。1 ... Light receiving element, 2 ... Conversion amplifier, 3 ... Reference voltage source, 4 ...
Differentiator circuit, 5 ... Differential amplifier, 6 ... Differential amplifier, 7 ... Level shift circuit, 8 ... Comparator, 9 ... Adder, 10 ...
Adder, 11 ... Adder, 12 ... Level shift circuit, 10
00 ... Central office, 1100 ... Transmission device, 1200 ... Optical receiving circuit, 1300 ... Multiplexing / demultiplexing unit, 1400 ... Interface unit, 1500 ... Control unit, 1600 ... Processing device, etc., 2
000 ... Terminal, 2100 ... Termination device, 2200 ... Optical transmission circuit, 3000 ... Optical fiber, 3001 ... Optical fiber,
3002 ... Optical fiber, 3003 ... Optical fiber, 400
0 ... Star coupler.
フロントページの続き (56)参考文献 特開 昭63−10941（ＪＰ，Ａ) 特開 昭63−31338（ＪＰ，Ａ) 特開 平９−162931（ＪＰ，Ａ) 特開 平６−17834（ＪＰ，Ａ) 特開 平８−84160（ＪＰ，Ａ) 特開 平６−315011（ＪＰ，Ａ) 特開 昭59−196636（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) H04L 25/03 H03K 5/08 H03K 5/12 Continuation of front page (56) Reference JP-A-63-10941 (JP, A) JP-A-63-31338 (JP, A) JP-A-9-162931 (JP, A) JP-A-6-17834 (JP , A) JP-A-8-84160 (JP, A) JP-A-6-315011 (JP, A) JP-A-59-196636 (JP, A) (58) Fields investigated (Int.Cl. 7 , DB) Name) H04L 25/03 H03K 5/08 H03K 5/12
Claims (5)
受光素子と、 前記受光素子が出力する電気信号を増幅する第１の増幅
器と、 基準レベル発生器と、 前記第１の増幅器出力と前記基準レベル発生器出力を比
較増幅する第２の増幅器と、 前記第１の増幅器出力の信号の変化分を検出し出力する
変化分検出器と、 前記変化分検出器出力と前記基準レベル発生器出力を加
算する第１の加算器と、 前記第１の加算器出力と前記基準レベル発生器出力を比
較増幅する第３の増幅器と、 前記第２および第３の二つの増幅器の出力を加算し出力
する第２の加算器と、 前記第２の加算器出力を入力とするレベル判定器と、 から構成されることを特徴とする光受信回路。1. A light receiving element that outputs an electric signal according to an input light level, a first amplifier that amplifies an electric signal output by the light receiving element, a reference level generator, and the first amplifier output. A second amplifier for comparing and amplifying the reference level generator output; a change amount detector for detecting and outputting a change amount of the signal of the first amplifier output; the change amount detector output and the reference level generator A first adder for adding outputs, a third amplifier for comparing and amplifying the first adder output and the reference level generator output, and outputs for the second and third two amplifiers An optical receiving circuit comprising: a second adder that outputs and a level determiner that receives the output of the second adder as an input.
受光素子と、 前記受光素子が出力する電流信号を電圧信号に変換増幅
する変換増幅器と、 入力光がオフの時の前記変換増幅器出力電圧に相当する
基準電圧を出力する基準電圧源と、 前記変換増幅器出力と前記基準電圧源出力を比較増幅す
る第１の差動増幅器と、 前記変換増幅器出力を微分する微分回路と、 前記微分回路出力と前記基準電圧源出力を加算する第１
の加算器と、 前記第１の加算器出力と前記基準電圧源出力を比較増幅
する第２の差動増幅器と、 前記第１および第２の二つの差動増幅器の逆相出力を加
算し出力する第２の加算器と、 前記第１および第２の二つの差動増幅器の正相出力を加
算し出力する第３の加算器と、 前記第２および第３の加算器出力を入力として前記第２
および第３の加算器出力間に直流オフセット電圧を印加
し正相および逆相信号を出力するレベルシフト回路と、 前記レベルシフト回路の正相および逆相出力を入力とす
るコンパレータと、 から構成されることを特徴とする光受信回路。2. A light receiving element that outputs a current signal according to the input light level, a conversion amplifier that converts and amplifies the current signal output by the light receiving element into a voltage signal, and the conversion amplifier output when the input light is off. A reference voltage source that outputs a reference voltage corresponding to a voltage, a first differential amplifier that compares and amplifies the conversion amplifier output and the reference voltage source output, a differentiation circuit that differentiates the conversion amplifier output, and the differentiation circuit A first for adding the output and the reference voltage source output
Adder, a second differential amplifier that compares and amplifies the output of the first adder with the output of the reference voltage source, and outputs the negative-phase outputs of the first and second differential amplifiers. And a third adder for adding and outputting the positive phase outputs of the first and second differential amplifiers, and the second and third adder outputs as inputs. Second
And a level shift circuit for applying a DC offset voltage between the outputs of the third adder and outputting the positive and negative phase signals, and a comparator for inputting the positive and negative phase outputs of the level shift circuit. An optical receiving circuit characterized by the above.
受光素子と、 前記受光素子が出力する電流信号を電圧信号に変換増幅
する変換増幅器と、 入力光がオフの時の前記変換増幅器出力電圧に相当する
基準電圧を出力する基準電圧源と、 前記変換増幅器出力と前記基準電圧源出力を比較増幅す
る第１の差動増幅器と、 前記変換増幅器出力を微分する微分回路と、 前記微分回路出力と前記基準電圧源出力を加算する第１
の加算器と、 前記第１の加算器出力と前記基準電圧源出力を比較増幅
する第２の差動増幅器と、 前記第１および第２の二つの差動増幅器の逆相出力を加
算し出力する第２の加算器と、 前記第２の加算器出力に直流オフセット電圧を印加する
レベルシフト回路と、 前記第１および第２の二つの差動増幅器の正相出力を加
算する第３の加算器と、 前記第３の加算器出力と前記レベルシフト回路出力を入
力とするコンパレータと、 から構成されることを特徴とする光受信回路。3. A light-receiving element that outputs a current signal according to the input light level, a conversion amplifier that converts and amplifies the current signal output by the light-receiving element into a voltage signal, and the conversion amplifier output when the input light is off. A reference voltage source that outputs a reference voltage corresponding to a voltage, a first differential amplifier that compares and amplifies the conversion amplifier output and the reference voltage source output, a differentiation circuit that differentiates the conversion amplifier output, and the differentiation circuit A first for adding the output and the reference voltage source output
Adder, a second differential amplifier that compares and amplifies the output of the first adder with the output of the reference voltage source, and outputs the negative-phase outputs of the first and second differential amplifiers. A second adder, a level shift circuit for applying a DC offset voltage to the output of the second adder, and a third adder for adding the positive phase outputs of the first and second differential amplifiers. And a comparator that receives the output of the third adder and the output of the level shift circuit as an input.
受光素子と、 前記受光素子が出力する電流信号を電圧信号に変換増幅
する変換増幅器と、 入力光がオフの時の前記変換増幅器出力電圧に相当する
基準電圧を出力する基準電圧源と、 前記変換増幅器出力と前記基準電圧源出力を比較増幅す
る第１の差動増幅器と、 前記変換増幅器出力を微分する微分回路と、前記微分回
路出力と前記基準電圧源出力を加算する第１の加算器
と、 前記第１の加算器出力と前記基準電圧源出力を比較増幅
する第２の差動増幅器と、 前記第１および第２の二つの差動増幅器の逆相出力を加
算し出力する第２の加算器と、 前記第２の加算器出力に直流オフセット電圧を印加する
レベルシフト回路と、 前記第１および第２の二つの差動増幅器の正相出力を加
算する第３の加算器と、 前記第３の加算器出力と前記レベルシフト回路出力を入
力とするコンパレータと、 から構成される光受信回路と、 光送信回路とを有し、前記光受信回路と光送信回路の送
受信信号を制御／処理する中央局と、前記光受信回路と
光送信回路を有する複数の端末との間を光ファイバによ
り接続して、前記端末と前記中央局間でデータを伝送す
ることを特徴とする光伝送システム。4. A light receiving element for outputting a current signal according to an input light level, a conversion amplifier for converting and amplifying a current signal output by the light receiving element into a voltage signal, and the conversion amplifier output when the input light is off. A reference voltage source that outputs a reference voltage corresponding to a voltage, a first differential amplifier that compares and amplifies the conversion amplifier output and the reference voltage source output, a differentiation circuit that differentiates the conversion amplifier output, and the differentiation circuit A first adder for adding an output and the reference voltage source output, a second differential amplifier for comparing and amplifying the first adder output and the reference voltage source output, and the first and second two A second adder for adding and outputting negative-phase outputs of two differential amplifiers; a level shift circuit for applying a DC offset voltage to the output of the second adder; and two differential circuits of the first and second differential amplifiers. Add positive phase output of amplifier A third adder, and a comparator that receives the output of the third adder and the output of the level shift circuit as an input, and an optical transmitter circuit. An optical fiber is used to connect a central station that controls / processes transmission / reception signals of an optical transmission circuit and a plurality of terminals having the optical reception circuit and the optical transmission circuit, and transmit data between the terminal and the central station. An optical transmission system characterized by:
とする請求項４記載の光伝送システム。5. The optical transmission system according to claim 4 , wherein the communication signal is a burst signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31430298A JP3514642B2 (en) | 1998-11-05 | 1998-11-05 | Optical receiving circuit and optical transmission system using the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31430298A JP3514642B2 (en) | 1998-11-05 | 1998-11-05 | Optical receiving circuit and optical transmission system using the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000151722A JP2000151722A (en) | 2000-05-30 |
| JP3514642B2 true JP3514642B2 (en) | 2004-03-31 |
Family
ID=18051734
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31430298A Expired - Fee Related JP3514642B2 (en) | 1998-11-05 | 1998-11-05 | Optical receiving circuit and optical transmission system using the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3514642B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4691127B2 (en) * | 2008-03-28 | 2011-06-01 | 日本電信電話株式会社 | Amplifier circuit |
-
1998
- 1998-11-05 JP JP31430298A patent/JP3514642B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2000151722A (en) | 2000-05-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5822426A (en) | Balanced hybrid circuit | |
| US5432817A (en) | Vehicle communications network transceiver, ground translation circuit therefor | |
| JP2656734B2 (en) | Optical receiving circuit | |
| JPH07154337A (en) | Optical data communication network | |
| JP5305932B2 (en) | Preamplifier | |
| JP3514993B2 (en) | Optical receiving circuit and optical module using the circuit | |
| EP0868038B1 (en) | Burst mode digital optical receiver | |
| US5838731A (en) | Burst-mode digital receiver | |
| JP4536770B2 (en) | Burst mode receiver for generating on-chip reset signal and burst mode receiving method | |
| JP2007036329A (en) | Amplifier circuit and transimpedance amplifier | |
| JPH0818429A (en) | Optical receiver | |
| JP3606143B2 (en) | Offset control circuit, optical receiver using the same, and optical communication system | |
| JP3514642B2 (en) | Optical receiving circuit and optical transmission system using the same | |
| EP1481488B1 (en) | TRANSMITTER/RECEIVER FOR BIDIRECTIONAL COMMUNICATIONS | |
| JP3313273B2 (en) | Optical signal receiver | |
| JP3230574B2 (en) | Optical receiving circuit | |
| US6519069B1 (en) | Optoelectric converter | |
| JPH11205263A (en) | Device for coupling and amplifying two broad band signals | |
| JPH114265A (en) | Amplifier, identification device, optical receiver and burst optical transmission system | |
| JP3400286B2 (en) | Receiver circuit | |
| JP3612147B2 (en) | Optical receiver circuit and optical transmission system | |
| JPS6223224A (en) | Dc restoration circuit for digital repeater | |
| JP2536178B2 (en) | Optical transceiver | |
| JP2837209B2 (en) | Optical receiver and optical communication system including the optical receiver | |
| JPH0837501A (en) | Optical receiver |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20040106 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20040113 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080123 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090123 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090123 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100123 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110123 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110123 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120123 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120123 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130123 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130123 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140123 Year of fee payment: 10 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |