JPS5975727A - Data transmission system - Google Patents

Data transmission system

Info

Publication number
JPS5975727A
JPS5975727A JP57187153A JP18715382A JPS5975727A JP S5975727 A JPS5975727 A JP S5975727A JP 57187153 A JP57187153 A JP 57187153A JP 18715382 A JP18715382 A JP 18715382A JP S5975727 A JPS5975727 A JP S5975727A
Authority
JP
Japan
Prior art keywords
pulse
pulse width
data
modulated
clock
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.)
Pending
Application number
JP57187153A
Other languages
Japanese (ja)
Inventor
Teruaki Aoki
照明 青木
Mitsuo Imai
光雄 今井
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Cable Ltd
Original Assignee
Hitachi Cable Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hitachi Cable Ltd filed Critical Hitachi Cable Ltd
Priority to JP57187153A priority Critical patent/JPS5975727A/en
Publication of JPS5975727A publication Critical patent/JPS5975727A/en
Pending legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00Baseband systems
    • H04L25/38Synchronous or start-stop systems, e.g. for Baudot code
    • H04L25/40Transmitting circuits; Receiving circuits
    • H04L25/49Transmitting circuits; Receiving circuits using code conversion at the transmitter; using predistortion; using insertion of idle bits for obtaining a desired frequency spectrum; using three or more amplitude levels ; Baseband coding techniques specific to data transmission systems
    • H04L25/4906Transmitting circuits; Receiving circuits using code conversion at the transmitter; using predistortion; using insertion of idle bits for obtaining a desired frequency spectrum; using three or more amplitude levels ; Baseband coding techniques specific to data transmission systems using binary codes

Abstract

PURPOSE:To multiplex a data signal and a transmission clock with simple constitution by composing a modulator of a pulse width modulation part which synchronizes with the transmission clock and a pulse insertion part which adds a pulse between modulated pulses at specific intervals of time, and a demodulator of a pulse removal part and a data clock regeneration part. CONSTITUTION:The pulse width modulation part 31a outputs modulated wide width pulses 61 and 62 synchronously with the transmission clock ST according to the level of the data signal SD, and the pulse insertion part 31b adds a pulse 63 having less width than the modulated pulses 61 and 62 between the modulated pulses at specific intervals of time a specific time after each modulated pulse rises. This insertion, however, is avoided in a specific insertion inhibition period before each modulated pulse rises. The pulse removal part 32a of the demodulator 32 removes the pulse 63 and the data clock regeneration part 32b regenerates the data signal RD and performs frequency division according to the number of the modulated pulses 61 or 62 following the signal RD to regenerate and output the clock RT.

Description

【発明の詳細な説明】 本発明はデータ伝送システムに係り、特に光ファイバを
用いてデータ信号と送信クロックとを多重伝送するのに
好適なデータ伝送システムに関するものである。
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data transmission system, and more particularly to a data transmission system suitable for multiplex transmission of data signals and transmission clocks using optical fibers.

まず、従来技術について第1図、第2図を用いて説明す
る。第1図は従来のこの種データ伝送システムの構成図
で、11はデータ信号SDを変調する変調器、12は変
調信号を電光変換する光透 −信器、13は光ファイバ
、14は受信した光信号を光電変換する光受信器、15
は光電変換された変調信号を復調する復調器、16は受
信データ信号RDを出力する同期回路、17は受信クロ
ックRTを出力するクロック抽出回路である。
First, the prior art will be explained using FIG. 1 and FIG. 2. Fig. 1 is a configuration diagram of a conventional data transmission system of this type, in which 11 is a modulator that modulates the data signal SD, 12 is an optical transmitter that converts the modulated signal into electro-optic signals, 13 is an optical fiber, and 14 is a receiving device. Optical receiver that photoelectrically converts optical signals, 15
1 is a demodulator that demodulates a photoelectrically converted modulated signal; 16 is a synchronization circuit that outputs a received data signal RD; and 17 is a clock extraction circuit that outputs a received clock RT.

しかし、この場合、データ信号は送受信間であらかじめ
決められた信号速度で送る必要があり、さらに、It 
II+とパ0 ′の境目で反転するNRZ(Non R
eturn  to Zero )等の符号形成をとる
場合には、同一符号が長く続かないように、データ形態
を工夫する必要があった。(同一符号が長く続くとクロ
ック抽出が困難になる。) 一方、同期式の光データ伝送の場合は、光ファイ・この
広帯域性と耐雑音性が良好であることを利用して、送信
データ信号と送信クロックとを多重化して伝送する方式
がいくつか提案されている。
However, in this case, the data signal needs to be sent at a predetermined signal speed between the transmitter and the receiver, and
NRZ (Non R
When using a code formation such as (eturn to zero), it was necessary to devise a data format so that the same code does not continue for a long time. (If the same code continues for a long time, it becomes difficult to extract the clock.) On the other hand, in the case of synchronous optical data transmission, the transmission data signal is Several methods have been proposed for multiplexing and transmitting the clock and the transmission clock.

その中でデータ信号と送信クロックとを高速サンプリン
グして直列符号化して多重化する方式は、データ信号の
信号速度を任意に選べるという点ですぐれている。
Among these methods, a method in which data signals and transmission clocks are sampled at high speed, serially encoded, and multiplexed is superior in that the signal speed of the data signal can be arbitrarily selected.

第2図はこの方式の場合の送信データ信号と送信クロッ
クとの多重化方法を説明するだめのタイムチャートで、
第2図(a)は送信データ信号8Dの波形、同図(b)
は送信クロックSTの波形をそれぞれ示し、同図(c)
は直列多重化データを示す。なお、第2図のFSはスタ
ートビット、SDはデータ信号SDのサンプリングデー
タ、STはクロックSTのサンシリングデータ、FPは
ストップビットを示す。
Figure 2 is a time chart for explaining the method of multiplexing the transmission data signal and the transmission clock in this method.
Figure 2(a) shows the waveform of the transmitted data signal 8D, and Figure 2(b) shows the waveform of the transmitted data signal 8D.
(c) shows the waveform of the transmission clock ST, respectively.
indicates serially multiplexed data. In FIG. 2, FS indicates a start bit, SD indicates sampling data of the data signal SD, ST indicates sampling data of the clock ST, and FP indicates a stop bit.

しかし、この方式は、データ信号SDの信号速度に対し
て光ファイ・ζ13中の多重化信号は大体10数倍〜3
0倍程度の速さを必要とし、さらに、回路がかなり複雑
化するという欠点をもっている。
However, in this method, the multiplexed signal in the optical fiber ζ13 is about 10 to 3 times faster than the signal speed of the data signal SD.
It requires about 0 times the speed, and has the disadvantage that the circuit is considerably complicated.

まだ、単に送信データ信号SDにあらかじめ一定の・パ
ルス幅変調を施し、このときの変調・パルスの立ち上が
りまだは立ち下がりの一方をデータ信号と送信クロック
の立ち上がりと立ち下がりに一致させるようにする方式
もあるが、この方式には、信号速度が極めて遅くなった
場合に、DC状態が長時間継続することになり、符号誤
りを発生しやすくなるという欠点がある。
However, there is still a method in which the transmitted data signal SD is simply subjected to a certain pulse width modulation in advance, and the rising edge or falling edge of the modulated pulse at this time is made to match the rising and falling edges of the data signal and the transmitting clock. However, this method has the disadvantage that when the signal speed becomes extremely slow, the DC state continues for a long time, making code errors more likely to occur.

本発明は上記に鑑みてなされたもので、その目的とする
ところは、データ信号と送信クロックとを多重化して伝
送することができ、しかも、構成が簡単なデータ伝送シ
ステムを提供することにある。
The present invention has been made in view of the above, and an object of the present invention is to provide a data transmission system that can multiplex and transmit data signals and transmission clocks, and that has a simple configuration. .

本発明の特徴は、データ信号と送信クロックとを変調す
る変調器は、上記送信クロックの立ち上がりおよび立ち
下がりに同期して上記データ信号がII O”レベルの
ときは、aルス幅が狭い変調パルスに、“1″レベルの
ときは・ξルス幅が広い変調・パルスにパルス幅変調す
る・パルス幅変調部と、上記それぞれの変調・パルス間
に上記各変調・パルスのノξルス幅に比較してノξルス
幅が狭いノξルスを上記各変調・パルスの立ち上がりか
ら所定時間経過した後にあらかじめ定めた上記各変調・
パルスの立ち上がり前の挿入禁止期間を除いて所定時間
毎に付加する・パルス挿入部とより構成し、光受信器で
光電変換後の変調信号を復調する復調器は、上記変調信
号から上記各変調・パルスより・ξルス幅が狭い・パル
スを除去する・パルス除去部と、このパルス除去部の出
力からデータ信号を再生するとともにこのデータ信号を
引き続く上記パルス幅が狭い変調・パルスの数寸だけ上
記ノξルス幅が広い変調ノξルスの数に応じて分周して
送信クロックを再生するデータ・クロック再生部とより
構成した点にある。
A feature of the present invention is that a modulator that modulates a data signal and a transmission clock generates a modulation pulse with a narrow pulse width when the data signal is at the II O'' level in synchronization with the rising and falling edges of the transmission clock. When the level is "1", ・Modulation with a wide ξ pulse width ・Pulse width modulation on the pulse ・Pulse width modulation section and each of the above modulations ・Each modulation between the pulses ・Comparison with the ξ pulse width of the pulse After a predetermined period of time has elapsed from the rise of each modulation pulse, the pulse ξ with a narrow pulse width is
The demodulator, which consists of a pulse insertion section that adds pulses at predetermined intervals except during the insertion prohibited period before the rise of the pulse, demodulates the modulated signal after photoelectric conversion in the optical receiver, converts the modulated signal into each of the modulated signals.・Narrower ξ pulse width than the pulse ・Remove the pulse ・Regenerate the data signal from the pulse removal section and the output of this pulse removal section and continue this data signal by modulating the above pulse width with a narrow width ・Only a few dimensions of the pulse The present invention is comprised of a data/clock regenerating section that regenerates a transmission clock by dividing the frequency according to the number of modulation noises ξ having a wide noise width.

以下本発明を第3図に示した実施例および第4図〜第6
図を用いて詳細に説明する。
The embodiment of the present invention shown in FIG. 3 and FIGS. 4 to 6 are as follows.
This will be explained in detail using figures.

第3図は本発明のデータ伝送システムの一実施例を示す
構成図である。第3図において、31はデータ信号SD
と送信クロックSTとを人力して変調する変調器、12
は変調信号を電光変換する光送信器、13は光ファイバ
、14は受信した光信号を光電変換する光受信器、32
は光電変換された変調信号を復調する復調器で、デー・
夕信号RDとクロックRTとを出力する。
FIG. 3 is a block diagram showing an embodiment of the data transmission system of the present invention. In FIG. 3, 31 is the data signal SD
a modulator for manually modulating the and transmission clock ST; 12;
13 is an optical fiber; 14 is an optical receiver that converts the received optical signal into electricity; 32
is a demodulator that demodulates the photoelectrically converted modulated signal.
The evening signal RD and clock RT are output.

第4図〜第6図はそれぞれ第3図における変調方式を説
明するための異なる例のタイムチャートで、第4図、第
5図、第6図の順に信号速度が遅くなる。第4図〜第6
図の(a)はデータ信号SDの波形、(b)は送信クロ
ックSTの波形、(C)は変調信号の波形を示している
4 to 6 are time charts of different examples for explaining the modulation method in FIG. 3, and the signal speed becomes slower in the order of FIG. 4, FIG. 5, and FIG. 6. Figures 4 to 6
In the figure, (a) shows the waveform of the data signal SD, (b) shows the waveform of the transmission clock ST, and (C) shows the waveform of the modulation signal.

第3図の変調器31は、第4図〜第6図に示すように、
送信クロックSTの立上がりおよび立ち下がりに同期し
てデータ信号SDが′0 ″レベルのときは・ξルス幅
が狭い変調パルス61に、寸だ、”1”レベルのときは
ノξルス幅が広い変調ノ?ルス62に・ξルス幅変調す
る・ξルス幅変調部31aと、それぞれの変調パルス6
’l、62間(変調)ξシス61と61の間、61と6
2の間、62と62の間等がある。)に変調・ξシス6
1,62の・ξルス幅に比較してパルス幅が狭いパルス
63を各変調パルスの立ち上がり(立ち下がりでもよい
。)から所定時間経過した後に所定時間毎に付加する・
ξシス挿入部3 ]、 bとよシ構成しである。ただし
、・ξシス挿入部31bは、各変調ノξルス61,62
の立ち上がり前のあらかじめ定めた挿入禁止期間におい
ては、・ξルス63を付加しないようになっている。
The modulator 31 in FIG. 3 is, as shown in FIGS. 4 to 6,
When the data signal SD is at the 0'' level in synchronization with the rising and falling edges of the transmission clock ST, the modulation pulse 61 has a narrow ξ pulse width, and when it is at the 1 level, the ξ pulse width is wide. The modulation pulse 62 modulates the ξ pulse width.The ξ pulse width modulator 31a and each modulating pulse 6
'l, between 62 (modulation) ξ cis between 61 and 61, 61 and 6
2, between 62 and 62, etc. ) modulated to ξcis6
A pulse 63 whose pulse width is narrower than the pulse width of 1 and 62 is added at a predetermined time interval after a predetermined time has elapsed from the rise (or fall) of each modulation pulse.
ξ cis insertion part 3 ], b. However, the ξ cis insertion unit 31b has the modulation noise ξ 61, 62
During the predetermined insertion prohibition period before the rising edge of , the .xi. pulse 63 is not added.

また、復調器32は、光受信器14で受信した光信号が
光覗変換された変調信号から各変調・ξシス61,62
よりノξルス幅が狭いノξルス63を除去する・ξシス
除去部32aと、・ξシス除去部32aの出力からデー
タ信号RDを再生して出力するとともに、このデータ信
号RDを引き続く変調・ξシス61の数まだは62の数
に応じ分周してクロックRTを再生して出力するデータ
・クロック再生部32bとより構成しである。
In addition, the demodulator 32 converts the optical signal received by the optical receiver 14 into a modulated signal obtained by optically converting the optical signal to each modulation/ξ system 61, 62.
The ξ cis removal unit 32a removes the ξ noise 63 having a narrower ξ noise width, and the data signal RD is reproduced and output from the output of the ξ cis removal unit 32a, and this data signal RD is subjected to subsequent modulation. The data/clock reproducing section 32b divides the frequency according to the number of .xi.systems 61 and reproduces and outputs the clock RT.

したがって、第4図〜第6図の(c)に示しだ変調信号
が光送信器12で光信号に変換され、光ファイバ13を
通して伝送され、光受信器14で受信されて、その光信
号が再び電気信号に変換されて変調信号が得られ、これ
より変調器32でデータ信号RDとクロックRTとが再
生されて出力される。
Therefore, the modulated signal shown in FIGS. 4 to 6 (c) is converted into an optical signal by the optical transmitter 12, transmitted through the optical fiber 13, and received by the optical receiver 14, and the optical signal is The signal is converted into an electric signal again to obtain a modulated signal, from which a data signal RD and a clock RT are regenerated by a modulator 32 and output.

上記したように、本発明によれば、データ信号と送信ク
ロックとを多重化して伝送することができ、しかも、構
成が簡単なものにできるという効果がある。
As described above, according to the present invention, data signals and transmission clocks can be multiplexed and transmitted, and the configuration can be simplified.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は従来のデータ伝送システムの構成図、第2図は
従来のデータ信号と送信クロックとの多重化方法を説明
するだめのタイムチャート、第3図は本発明のデータ伝
送システムの一実施例を示す構成図、第4図〜第6図は
それぞれ第3図における変調方式を説明するだめの異な
る例のタイムチャートである。 12 ・光送信器、13・・光ファイバ、14・・・光
受信器、3I・・・変調器、31a・・パルス幅変調部
、311〕 ・・eルス挿入部、32 ・復調器、32
a・・eルス除去部、321)・・・データ・クロック
再生部。 1F 第 1 日
Fig. 1 is a configuration diagram of a conventional data transmission system, Fig. 2 is a time chart for explaining the conventional multiplexing method of data signals and transmission clocks, and Fig. 3 is an implementation of the data transmission system of the present invention. The configuration diagrams illustrating examples and FIGS. 4 to 6 are time charts of different examples for explaining the modulation method in FIG. 3, respectively. 12 - Optical transmitter, 13... Optical fiber, 14... Optical receiver, 3I... Modulator, 31a... Pulse width modulation unit, 311]... e-rus insertion unit, 32 - Demodulator, 32
a...e Lux removal unit, 321)...Data/clock recovery unit. 1F 1st day

Claims (1)

【特許請求の範囲】[Claims] 1、 データ信号と送信クロックとを変調器で・ξルス
幅変調し、光送信器で電光変換を行って光ファイバを用
いて伝送し、光受信器で光電変換後後調器で復調するよ
うにしてなるデータ伝送システムにおいて、前記変調器
は、前記送信クロックの立ち上りおよび立ち下がりに同
期して前記データ信号が゛°0′″レベルのときは・ξ
ルス幅が狭い変調・ξルスに tt 1nレベルのトキ
ハノξルス幅が広い変調ノξルスにノξルス幅変調する
ノξルス幅変調部と、前記それぞれの変調・ξルス間に
前記各変調パルスの・ξルス幅に比較してパルス幅が狭
い・にルスを、前記各変調・ξルスの立ち上がりから所
定時間経過した後に、あらかじめ定めた前記各変調ノξ
ルスの立ち上がり前の挿入禁止期間を除いて所定時間毎
に付加する・ξルス挿入部とよりなり、前記復調器は、
前記光受信器からの変調信号から前記各変調パルスよシ
パルス幅が狭い・ξルスを除去する・ξルス除去部と、
該ノξルス除去部の出力からデータ信号を再生するとと
もに該データ信号を引き続く前記・qルス幅が狭い変調
パルスの数または前記・ξルス幅が広い変調・ξルスの
数に応じて分周して送信クロックを再生するデータ・ク
ロック再生部とよりなることを特徴とするデータ伝送シ
ステム。
1. The data signal and the transmission clock are pulse-width modulated by a modulator, electrical-to-optical conversion is performed by an optical transmitter, and transmitted using an optical fiber. After photoelectric conversion by an optical receiver, demodulation is performed by a post-modulator. In the data transmission system, when the data signal is at ゛°0'' level in synchronization with rising and falling edges of the transmission clock, the modulator transmits
A ξ pulse width modulation unit that modulates the ξ pulse width to a modulation/ξ pulse with a narrow pulse width, and a ξ pulse width modulation unit that modulates the pulse width to a modulation pulse with a wide pulse width; After a predetermined period of time has elapsed from the rising edge of each modulation ξ, the pulse width is narrower than the ξ pulse width of the pulse.
The demodulator consists of a ξ pulse insertion section that adds pulses at predetermined time intervals except during the insertion prohibited period before the rise of the pulse;
a ξ rus removal unit that removes ξ rus having a narrow pulse width than each of the modulated pulses from the modulated signal from the optical receiver;
Reproducing a data signal from the output of the ξ pulse removal section, and dividing the data signal according to the number of subsequent modulated pulses with a narrow pulse width or the number of modulated pulses with a wide pulse width. What is claimed is: 1. A data transmission system comprising: a data clock regenerating section that regenerates a transmission clock using a data clock regenerating section.
JP57187153A 1982-10-25 1982-10-25 Data transmission system Pending JPS5975727A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP57187153A JPS5975727A (en) 1982-10-25 1982-10-25 Data transmission system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP57187153A JPS5975727A (en) 1982-10-25 1982-10-25 Data transmission system

Publications (1)

Publication Number Publication Date
JPS5975727A true JPS5975727A (en) 1984-04-28

Family

ID=16201045

Family Applications (1)

Application Number Title Priority Date Filing Date
JP57187153A Pending JPS5975727A (en) 1982-10-25 1982-10-25 Data transmission system

Country Status (1)

Country Link
JP (1) JPS5975727A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5430707A (en) * 1990-06-01 1995-07-04 Siemens Aktiengesellschaft Method and apparatus for communicating operating information between centralized and decentralized equipment of a communication system
WO2008007240A2 (en) * 2006-06-19 2008-01-17 Koninklijke Philips Electronics N.V. An optical recording apparatus

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5430707A (en) * 1990-06-01 1995-07-04 Siemens Aktiengesellschaft Method and apparatus for communicating operating information between centralized and decentralized equipment of a communication system
WO2008007240A2 (en) * 2006-06-19 2008-01-17 Koninklijke Philips Electronics N.V. An optical recording apparatus
WO2008007240A3 (en) * 2006-06-19 2008-04-17 Koninkl Philips Electronics Nv An optical recording apparatus

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