JPH0691556B2 - Digital transmission method for paired cables - Google Patents
Digital transmission method for paired cablesInfo
- Publication number
- JPH0691556B2 JPH0691556B2 JP63011374A JP1137488A JPH0691556B2 JP H0691556 B2 JPH0691556 B2 JP H0691556B2 JP 63011374 A JP63011374 A JP 63011374A JP 1137488 A JP1137488 A JP 1137488A JP H0691556 B2 JPH0691556 B2 JP H0691556B2
- Authority
- JP
- Japan
- Prior art keywords
- transmission line
- polarity
- pulse
- pair cable
- circuit
- 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 - Lifetime
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Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明はペアケーブル用ディジタル伝送方式、特にペア
ケーブルを用いて多値符号形式のディジタル信号を伝送
するためのペアケーブル用ディジタル伝送方式に関す
る。Description: TECHNICAL FIELD The present invention relates to a pair cable digital transmission system, and more particularly to a pair cable digital transmission system for transmitting a digital signal of a multi-level code format using the pair cable.
公衆通信網などにおける伝送方式のディジタル化の進展
に伴って、ペアケーブルを用いてディジタル信号を伝送
するペアケーブル用ディジタル伝送方式が実用化されつ
つある。従来のペアケーブル用ディジタル伝送方式は主
として、パルス符号変調（PCM）信号を所定のフォーマ
ットをもつフレーム構成にして、正および負極性のパル
スが交互に現れるようにしたAMI符号形式で伝送するも
のである。通信時には、まずペアケーブルの終端装置の
受信部に設けてある波形歪等化用の等化器をトレーニン
グするためのトレーニング信号を含んだフレームを転送
して、等化器トレーニングおよびフレーム同期確立を実
行したあと、終端装置間での通信に移行する。Along with the progress of digitization of transmission methods in public communication networks and the like, digital transmission methods for pair cables, which transmit digital signals using pair cables, are being put to practical use. The conventional digital transmission system for paired cables mainly transmits a pulse code modulation (PCM) signal in the AMI code format in which a frame structure having a predetermined format is used and positive and negative polarity pulses appear alternately. is there. At the time of communication, first transfer the frame containing the training signal for training the equalizer for waveform distortion equalization provided in the receiving unit of the terminating device of the pair cable, and perform equalizer training and frame synchronization establishment. After the execution, shift to communication between the end devices.
一方、通信回線を構成しているペアケーブルは、いわゆ
るチップ側およびリング側の線対が両端間において反転
無しで正しく接続されているとは限らない。従って、通
信時にペアケーブルを介して接続された両終端装置の一
方から送信したディジタル信号のパルス極性は、他方に
おける受信時に反転してしまうことがある。上述した従
来の伝送方式では、AMI符号形式を使用しており、その
パルス極性自体は復号時において全く無視でき、上述の
ようなパルス極性の反転の有無にかかわらず通信可能で
ある。On the other hand, in the paired cables forming the communication line, the so-called tip side and ring side line pairs are not always correctly connected between both ends without inversion. Therefore, the pulse polarity of the digital signal transmitted from one of the two terminal devices connected via the pair cable during communication may be inverted when the other terminal receives the signal. In the above-mentioned conventional transmission method, the AMI code format is used, the pulse polarity itself can be ignored at the time of decoding, and communication can be performed regardless of whether or not the pulse polarity is inverted as described above.
しかし、伝送効率の向上を図るために3B−2Tや4B−3Tな
どの３値の符号形式を使用する場合には、或る２値ワー
ドを３値符号化したディジタル信号のパルス極性が反転
すると、元の２値ワードに復号化できなくなる。従って
この場合、パルス極性を無視した復号は不可能であり、
チップ側およびリング側が両端で反転せずに接続してい
るペアケーブルと反転して接続しているペアケーブルと
が混在している通信回線に対し、従来の伝送方式をその
まま適用するのは不可能であるという問題点がある。However, when using a ternary code format such as 3B-2T or 4B-3T in order to improve the transmission efficiency, if the pulse polarity of a digital signal obtained by ternary encoding a certain binary word is inverted, , The original binary word cannot be decoded. Therefore, in this case, decoding that ignores the pulse polarity is impossible,
It is impossible to apply the conventional transmission method as it is to a communication line in which a pair cable in which the tip side and the ring side are connected without being inverted at both ends and a pair cable which is inverted and connected are mixed There is a problem that is.
本発明の目的は、上述の問題点を解決し伝送媒体におけ
るパルス極性反転の有無にかかわらず正しい復号が可能
なペアケーブル用ディジタル伝送方式を提供することに
ある。An object of the present invention is to solve the above-mentioned problems and to provide a digital transmission system for a pair cable, which enables correct decoding regardless of the presence or absence of pulse polarity inversion in the transmission medium.
本発明によれば、伝送路の基準端に正極性パルスおよび
負極性パルスを含む多値パルス波形を前記伝送路に送信
するラインドライバ回路と、前記多値パルス波形に重畳
すべき極性を固定した直流電流を発生する直流電圧源ま
たは直流電流源とを備え、前記伝送路の受信端にこの伝
送路を通して到来した多値パルス波形を受信するレシー
バ回路と、前記伝送路との接続端子と前記レシーバ回路
との間の接続を前記伝送路の接続端子間に設けた直流ル
ープを流れる電流方向に応じて正相または逆相に切り替
える切替回路とを備えることを特徴とするペアケーブル
用ディジタル伝送方式が得られる。According to the present invention, a line driver circuit for transmitting a multilevel pulse waveform including a positive polarity pulse and a negative polarity pulse to the transmission line at the reference end of the transmission line, and a polarity to be superimposed on the multilevel pulse waveform are fixed. A receiver circuit that includes a DC voltage source or a DC current source that generates a DC current, and that receives a multi-valued pulse waveform that has arrived through the transmission line at the receiving end of the transmission line, a connection terminal with the transmission line, and the receiver. A digital transmission system for a pair cable, characterized by comprising a switching circuit for switching between a circuit and a positive phase or a negative phase in accordance with a direction of a current flowing through a DC loop provided between the connection terminals of the transmission line. can get.
次に、本発明について図面を参照して説明する。 Next, the present invention will be described with reference to the drawings.
第１図は本発明のペアケーブル用ディジタル伝送方式の
一実施例を示すブロック図、第２図は第１図における切
替回路の他の例を示す回路図である。FIG. 1 is a block diagram showing an embodiment of the digital transmission system for a pair cable of the present invention, and FIG. 2 is a circuit diagram showing another example of the switching circuit in FIG.
第１図において、ペアケーブル１の一端は基準端２の接
続端子4,5に、他端は受信端３の接続端子6,7に結線され
ている。ペアケーブル１のチップ側およびリング側の種
別に直流電圧の極性を用いる。ペアケーブル１の基準端
２において、例えばチップ側を正極性とし、リング側を
負極性とするように直流電圧源（または直流電流源）を
固定接続する。すなわち、基準端２では、接続端子４
（チップ側）は直流電圧源（以下DC）21の正極に接続
し、接続端子５（リング側）はDC21の負極の接続される
とともに、接続端子4,5にはラインドライバ回路（以下L
DV）22の出力を接続する。LDV22は4B−3T,3B−2T符号な
どパルス極性にも意味を持つパルス列をペアケーブル１
へ送出する機能を有する。ここで4B−3T,3B−2T符号
は、接続端子４側を正極性とし、接続端子５側を負極性
とするようにLDV22の出力と接続端子4,5との接続を構成
すると、DC21の極性とLDV22からのパルス波形の極性と
が一致して利用し易い。In FIG. 1, one end of the pair cable 1 is connected to the connection terminals 4 and 5 of the reference end 2, and the other end is connected to the connection terminals 6 and 7 of the reception end 3. The polarity of the DC voltage is used for the type of the tip side and the ring side of the pair cable 1. At the reference end 2 of the pair cable 1, for example, a DC voltage source (or a DC current source) is fixedly connected so that the tip side has a positive polarity and the ring side has a negative polarity. That is, at the reference end 2, the connection terminal 4
The (chip side) is connected to the positive electrode of a DC voltage source (hereinafter DC) 21, the connection terminal 5 (ring side) is connected to the negative electrode of DC21, and the line driver circuit (hereinafter L
DV) 22 output is connected. LDV22 is a pair cable 1 that uses pulse trains such as 4B-3T and 3B-2T codes that also have meanings for pulse polarity.
It has the function of sending to. Here, 4B-3T, 3B-2T codes, when the connection between the output of the LDV22 and the connection terminals 4 and 5 is configured so that the connection terminal 4 side is positive and the connection terminal 5 side is negative, DC21 of The polarity matches the polarity of the pulse waveform from the LDV22 and is easy to use.
次に受信端３は、接続端子6,7を通してペアケーブル１
から到来したパルス波形を受信するレシーブ回路（以下
REC）32と、接続端子6,7とREC32との間に挿入接続され
た切替回路31とを備える。切替回路31は４個のダイオー
ド（以下D1,〜D4）で構成されたブリッジ回路とその出
力側にループ接続された抵抗（以下Ｒ）とから構成され
る。Next, the receiving end 3 passes through the connection terminals 6 and 7 and the pair cable 1
Receive circuit that receives the pulse waveform coming from
REC) 32, and a switching circuit 31 inserted and connected between the connection terminals 6 and 7 and the REC 32. The switching circuit 31 is composed of a bridge circuit composed of four diodes (hereinafter, D 1 to D 4 ) and a resistor (hereinafter, R) loop-connected to the output side thereof.
続いて本実施例の動作について説明する。Next, the operation of this embodiment will be described.
ペアケーブル１によって実線図示のように接続端子４と
６が結線され、接続端子５と７が結線されると、DC21の
電圧により切替回路31にはD1,R,D2を通して電流i1が流
れ、LDV22から送出されたパルス波形はペアケーブル1,
切替回路31を通してREC32にパルス極性を正常に維持し
た状態で到達する。When the connecting terminals 4 and 6 are connected and the connecting terminals 5 and 7 are connected by the pair cable 1 as shown by the solid line, a current i 1 is applied to the switching circuit 31 by the voltage of DC21 through D 1 , R, D 2. The pulse waveform sent from the LDV22 is the pair cable 1,
The signal reaches the REC 32 through the switching circuit 31 while maintaining the normal pulse polarity.
次に、ペアケーブル１内の接続混乱により、破線図示の
ように接続端子４と７が結線され、接続端子５と６が結
線され、つまり前例とは反転した接続になると、DC21の
電圧により切替回路31にはD3,R,D4を通して電流i2が流
れる。この状態では、LDV22から送出されたパルス波形
は接続端子6,7には極性が反転して到達するが、切替回
路31により正，負極性情報が再反転されてREC32に入力
される。つまりLDV22から送出されるパルス極性は正常
に復帰されてREC32に入力される。Next, due to connection confusion in the paired cable 1, the connection terminals 4 and 7 are connected and the connection terminals 5 and 6 are connected as shown by the broken line. A current i 2 flows through the circuit 31 through D 3 , R and D 4 . In this state, the pulse waveform transmitted from the LDV 22 arrives at the connection terminals 6 and 7 with their polarities inverted, but the switching circuit 31 re-inverts the positive and negative polarity information and inputs it to the REC 32. That is, the polarity of the pulse sent from the LDV22 is restored to normal and input to the REC32.
なお、切替回路31内のＲは伝送路終端インピーダンスで
あるとともに直流バイアス電流のループを形成するもの
である。In addition, R in the switching circuit 31 is a transmission line termination impedance and forms a loop of a DC bias current.
以上説明したように、本実施例によればペアケーブル１
内のチップ側，リング側の識別が乱れて接続混乱が起き
ている場合にも、LDV22出力の極性を維持して受信する
ことができる。従って、受信端における4B−3T,3B−2T
等の復号のようにパルス極性の情報が重要となる符号を
用いてもペアケーブル１内のチップ・リング誤接続が全
く問題とならない。As described above, according to this embodiment, the pair cable 1
Even when the chip side and ring side in the inside are disturbed and the connection is confused, the LDV22 output polarity can be maintained and received. Therefore, 4B-3T, 3B-2T at the receiving end
Even if a code in which the information on the pulse polarity is important is used as in the decoding such as the above, the misconnection of the chip ring in the pair cable 1 does not pose any problem.
上記の切替回路31の代わりに第２図に示す切替回路36を
用いても同等の効果が得られることは明らかである。す
なわち、切替回路36は４個のホトダイオード（以下PD1,
PD2,PD3,PD4）とそのそれぞれに対応するスイッチ素子
（以下SW1,SW2,SW3,SW4）から構成される４組のホトカ
プラとでブリッジを組みPDブリッジの入力を接続端子6,
7に接続し、出力をＲに接続し、SWブリッジの出力をREC
32の入力に接続している。このように構成すると、接続
端子6,7の極性がLDV22（第１図に図示）の出力パルスの
極性と一致しているときはSW1,SW2がオンし、また不一
致のときはSW3,SW4がオンしてREC32へは常に正常な極性
で入力される。さらに、切替回路36の動作時にその直流
ループの瞬断は起こらない。It is obvious that the same effect can be obtained by using the switching circuit 36 shown in FIG. 2 instead of the switching circuit 31. That is, the switching circuit 36 includes four photodiodes (hereinafter PD 1 ,
PD 2 , PD 3 , PD 4 ) and switch elements (hereinafter SW 1 , SW 2 , SW 3 , SW 4 ) corresponding to each of them form a bridge with 4 pairs of photocouplers and connect the inputs of PD bridge. Terminal 6,
Connect to 7 and output to R, REC output of SW bridge
Connected to 32 inputs. With this configuration, SW 1 and SW 2 are turned on when the polarities of the connection terminals 6 and 7 match the polarity of the output pulse of the LDV 22 (shown in FIG. 1), and when they do not match, SW 3 , SW 4 turns on and REC 32 is always input with normal polarity. Furthermore, when the switching circuit 36 is operating, the DC loop is not interrupted.
以上説明したように本発明のペアケーブル用ディジタル
伝送方式は、伝送路の基準端に正極性パルスおよび負極
性パルスを含む多値パルス波形を前記伝送路に送信する
ラインドライバ回路と、前記多値パルス波形に重畳すべ
き極性を固定した直流電流を発生する直流電圧源または
直流電流源とを備え、前記伝送路の受信端にこの伝送路
を通して到来した多値パルス波形を受信するレシーバ回
路と、前記伝送路との接続端子と前記レシーバ回路との
間の接続を前記伝送路の接続端子間に設けた直流ループ
を流れる電流方向に応じて正相または逆相に切り替える
切替回路とを備えることにより、切替回路の切替え時に
伝送路の直流ループの瞬断を伴わずに、かつ伝送路にお
けるパルス極性反転の有無にかかわらず、パルス極性に
重要な意味を有する多値符号の正しい復号が可能となる
効果がある。As described above, the digital transmission method for a pair cable of the present invention includes a line driver circuit that transmits a multilevel pulse waveform including a positive polarity pulse and a negative polarity pulse to the transmission line at the reference end of the transmission line, and the multilevel signal. A receiver circuit that includes a DC voltage source or a DC current source that generates a DC current with a fixed polarity to be superimposed on the pulse waveform, and a receiver circuit that receives a multi-valued pulse waveform that has arrived through this transmission path at the receiving end of the transmission path, By providing a switching circuit that switches the connection between the connection terminal with the transmission line and the receiver circuit to the positive phase or the negative phase according to the direction of the current flowing through the DC loop provided between the connection terminals of the transmission line. , The pulse polarity has an important meaning without instantaneous interruption of the DC loop of the transmission line when switching the switching circuit, and regardless of the presence or absence of pulse polarity reversal in the transmission line. The effect of correct decoding of the multi-level code is possible.
第１図は本発明のペアケーブル用ディジタル伝送方式の
一実施例を示すブロック図、第２図は第１図における切
替回路の他の例を示す回路図である。 １……ペアケーブル、２……基準端、３……受信端、4,
5,6,7……接続端子、21……直流電圧源（DC）、22……
ラインドライバ回路（LDV）、31,36……切替回路、32…
…レシーバ回路（REC）、PD1,〜PD4……ホトダイオー
ド、Ｒ……抵抗、SW1,〜SW4……スイッチ素子。FIG. 1 is a block diagram showing an embodiment of the digital transmission system for a pair cable of the present invention, and FIG. 2 is a circuit diagram showing another example of the switching circuit in FIG. 1 ... pair cable, 2 ... reference end, 3 ... reception end, 4,
5,6,7 …… Connection terminals, 21 …… DC voltage source (DC), 22 ……
Line driver circuit (LDV), 31,36 ... Switching circuit, 32 ...
... Receiver circuit (REC), PD 1 , ... PD 4 ... Photodiode, R ... Resistor, SW 1 , ... SW 4 ... Switch element.
Claims (1)
性パルスを含む多値パルス波形を前記伝送路に送信する
ラインドライバ回路と、前記多値パルス波形に重畳すべ
き極性を固定した直流電流を発生する直流電圧源または
直流電流源とを備え、前記伝送路の受信端にこの伝送路
を通して到来した多値パルス波形を受信するレシーバ回
路と、前記伝送路との接続端子と前記レシーバ回路との
間の接続を前記伝送路の接続端子間に設けた直流ループ
を流れる電流方向に応じて正相または逆相に切り替える
切替回路とを備えることを特徴とするペアケーブル用デ
ィジタル伝送方式。1. A line driver circuit for transmitting a multi-valued pulse waveform including a positive polarity pulse and a negative polarity pulse to the transmission line at a reference end of the transmission line, and a direct current having a fixed polarity to be superimposed on the multi-level pulse waveform. A receiver circuit that includes a DC voltage source or a DC current source that generates a current, and that receives a multi-valued pulse waveform that has arrived at the receiving end of the transmission line through the transmission line, a connection terminal for the transmission line, and the receiver circuit. And a switching circuit for switching the connection between the positive and negative phases in accordance with the direction of the current flowing through the DC loop provided between the connection terminals of the transmission line.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63011374A JPH0691556B2 (en) | 1988-01-19 | 1988-01-19 | Digital transmission method for paired cables |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63011374A JPH0691556B2 (en) | 1988-01-19 | 1988-01-19 | Digital transmission method for paired cables |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01185052A JPH01185052A (en) | 1989-07-24 |
| JPH0691556B2 true JPH0691556B2 (en) | 1994-11-14 |
Family
ID=11776240
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63011374A Expired - Lifetime JPH0691556B2 (en) | 1988-01-19 | 1988-01-19 | Digital transmission method for paired cables |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0691556B2 (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1143332B (en) * | 1981-01-30 | 1986-10-22 | Olivetti & Co Spa | TELEGRAPHIC COMMUNICATION SYSTEM WITH AUTOMATIC MANAGEMENT OF CONNECTION IRREGULARITIES |
| JPS58194447A (en) * | 1982-05-07 | 1983-11-12 | Nec Corp | Polarity controlling system for burst transmission |
-
1988
- 1988-01-19 JP JP63011374A patent/JPH0691556B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01185052A (en) | 1989-07-24 |
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