JPH033427A - Communication system - Google Patents
Communication systemInfo
- Publication number
- JPH033427A JPH033427A JP13610189A JP13610189A JPH033427A JP H033427 A JPH033427 A JP H033427A JP 13610189 A JP13610189 A JP 13610189A JP 13610189 A JP13610189 A JP 13610189A JP H033427 A JPH033427 A JP H033427A
- Authority
- JP
- Japan
- Prior art keywords
- transmission
- white noise
- coefficient
- filter
- reception
- 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
Links
- 238000004891 communication Methods 0.000 title claims abstract description 16
- 230000005540 biological transmission Effects 0.000 claims abstract description 36
- 230000008054 signal transmission Effects 0.000 claims abstract description 3
- 238000005311 autocorrelation function Methods 0.000 claims description 7
- 238000005314 correlation function Methods 0.000 abstract 2
- 230000003044 adaptive effect Effects 0.000 abstract 1
- 230000000694 effects Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000010365 information processing Effects 0.000 description 1
- 230000002123 temporal effect Effects 0.000 description 1
Landscapes
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は伝送路を介して通信を行う通信システムに係わ
り、特に伝送路を通過するデータや音声等の振幅歪を等
化するようにした通信システムに関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a communication system that performs communication via a transmission line, and particularly to a communication system that equalizes amplitude distortion of data, voice, etc. passing through the transmission line. Regarding communication systems.
送信部から受信部に伝送路を介してデータや音声等の送
信を行うと、伝送歪が発生する。このような伝送歪を除
去するために、従来では受信部に複数個の固定等化器を
配置していた。そして、送信部と受信部との間に実際に
設置されたケーブルの長さに応じてこれら複数個の固定
等化器のうちの１つを選択して伝送歪の補償に使用して
いた。When data, voice, etc. are transmitted from a transmitter to a receiver via a transmission path, transmission distortion occurs. In order to remove such transmission distortion, conventionally, a plurality of fixed equalizers have been arranged in the receiving section. One of these fixed equalizers is selected depending on the length of the cable actually installed between the transmitting section and the receiving section, and is used to compensate for transmission distortion.
このように従来の通信システムでは、複数の等化器とこ
れらのうちの１つを選択する選択回路とによって伝送歪
の等化を行っていた。このような従来の通信システムで
は、ケーブルの特性にのみ依存する固定的な伝送歪に対
しては十分な効果・をあげることができるが、例えばイ
ンピーダンス不整合の場合のように伝送歪自体に凹凸が
存在するものや時間的な変動を伴うものに対しては、伝
送歪を打゛ち消して平坦化することができないという問
題があった。In this way, in conventional communication systems, transmission distortion is equalized using a plurality of equalizers and a selection circuit that selects one of them. In such conventional communication systems, it is possible to achieve sufficient effects against fixed transmission distortion that depends only on the characteristics of the cable. There is a problem in that it is not possible to cancel out transmission distortion and flatten the transmission distortion when it exists or is accompanied by temporal fluctuations.
そこで本発明の目的は、伝送路の振幅歪を適応的に等化
することのできる伝送歪等化回路を提供することにある
。SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a transmission distortion equalization circuit that can adaptively equalize amplitude distortion of a transmission path.
本発明の通信システムでは、（ｉ）白色雑音発生回路を
備え、実際の信号伝送に先立って白色雑音を発生する送
信部と、（ｉｉ ）この送信部から伝送路を介して送ら
れてきた白色雑音について自己相関関数を計算する自己
相関部と、この自己相関部で計算した自己相関関数を線
型予測係数分析して線形予測係数を求める線形予測係数
分析部と、送信部から伝送路を介して伝送されてくる実
際の信号に対して線形予測係数をフィルタ係数としてフ
ィルタ処理を行う逆フィルタ部とによって通信システム
を構成する。The communication system of the present invention includes (i) a transmitting section that includes a white noise generation circuit and generates white noise prior to actual signal transmission; and (ii) a white noise sent from the transmitting section via a transmission path. An autocorrelation unit that calculates an autocorrelation function for noise; a linear prediction coefficient analysis unit that analyzes the autocorrelation function calculated by the autocorrelation unit to obtain a linear prediction coefficient; A communication system is constituted by an inverse filter section that performs filter processing on an actual transmitted signal using linear prediction coefficients as filter coefficients.
そして、送信に際して白色雑音を送信部から送出させ、
逆フィルタ部のフィルタ係数を所望の値に設定し、伝送
路の振幅歪を適応的に等化させる。Then, when transmitting, white noise is sent out from the transmitter,
The filter coefficients of the inverse filter section are set to desired values, and the amplitude distortion of the transmission path is adaptively equalized.
以下、実施例につき本発明の詳細な説明する。 Hereinafter, the present invention will be described in detail with reference to Examples.
第１図は本発明の一実施例の通信システムを表わしたも
のである。FIG. 1 shows a communication system according to an embodiment of the present invention.
この通信システムで、送信部１１には送信回路１２と白
色雑音発生回路１３およびこれらの出力を切り替えるた
めの切替器１４が備えられている。In this communication system, a transmitting section 11 is equipped with a transmitting circuit 12, a white noise generating circuit 13, and a switch 14 for switching the outputs of these circuits.
切替器１４の出力側は伝送路１５の送信側に接続されて
いる。伝送路１５の受信側には受信部１６が接続されて
いる。受信部１６に受信された信号は逆フィルタ１７と
自己相関部１８の双方に人力されるようになっている。The output side of the switch 14 is connected to the transmission side of the transmission line 15. A receiving section 16 is connected to the receiving side of the transmission path 15 . The signal received by the receiving section 16 is manually input to both the inverse filter 17 and the autocorrelation section 18.
自己相関部１８は自己相関関数Ｒ（ｉ）（ただしｉ＝０
．１．・・・・・・ｐ）を求め、ＬＰＧ （線形予測係
数）分析部１９に供給するようになっている。ＬＰＣ分
析部１９はＬＰＣ係数αｋ （ただしに＝０．１．・・
・・・・ｐ）を求める部分であり、制御パス２１を介し
て逆フィルタ１７に接続されている。逆フィルタ１７は
制御パス２１によって与えられたＬＰＧ係数α、によっ
て最適の振幅特性に設定されるようになっており、これ
によって等化された信号が受信回路２２に伝達するよう
になっている。The autocorrelation unit 18 has an autocorrelation function R(i) (where i=0
．． 1. . . . p) is determined and supplied to an LPG (linear prediction coefficient) analysis section 19. The LPC analysis unit 19 calculates the LPC coefficient αk (where = 0.1...
. . p), and is connected to the inverse filter 17 via the control path 21. The inverse filter 17 is set to have an optimum amplitude characteristic by the LPG coefficient α given by the control path 21, so that an equalized signal is transmitted to the receiving circuit 22.
このような構成の通信システムで、送信部１１は送信に
先立って一定の時間Ｔ秒だけその切替器１４を白色雑音
発生回路１３側に接続する。これにより、白色雑音発生
回路１３から１秒の間、白色雑音が伝送路１５を通じて
受信部１６に伝送される。In the communication system having such a configuration, the transmitter 11 connects the switch 14 to the white noise generation circuit 13 for a certain period of time T seconds prior to transmission. As a result, white noise is transmitted from the white noise generating circuit 13 to the receiving section 16 via the transmission path 15 for one second.
この１秒間にわたって、受信部１６では自己相関部１８
によって自己相関関数Ｒ（ｉ）を求める。During this one second, the autocorrelation unit 18 in the receiving unit 16
The autocorrelation function R(i) is determined by
ＬＰＧ分析１１９では、この自己相関関数Ｒ（ｉ）を基
にして、次の（１）式によりＬＰＧ係数α３を求める。In the LPG analysis 119, based on this autocorrelation function R(i), the LPG coefficient α3 is determined by the following equation (1).
Σ αｋＲ（＋−，ｋ） ＝ Ｒ（＋ ）
・・・・・・ （１）予測誤差の自乗平均を最小にする
ような線形予測係数がこの（１）式で示したような連豆
Ｐ元−次方程式の解として求められることは、例えば斎
藤収三、中田和男著の「音声情報処理の基礎」（オーム
社、１９８１年発行）等に記載されているところである
。Σ αkR(+-,k) = R(+)
...... (1) The linear prediction coefficient that minimizes the root mean square of the prediction error can be found as a solution to the P-dimensional equation shown in equation (1), for example. This is described in books such as ``Fundamentals of Speech Information Processing'' (Ohmsha, published in 1981) by Shuzo Saito and Kazuo Nakata.
ＬＰＧ分析部１９で得られたＬＰＧ係数α工は、前記し
たように逆フィルタ１７の係数として与えられる。この
逆フィルタ１７は、次の（２〉式で示すような伝達関数
Ｈ（Ｚ）を有している。The LPG coefficient α obtained by the LPG analysis section 19 is given as a coefficient of the inverse filter 17 as described above. This inverse filter 17 has a transfer function H(Z) as shown in the following equation (2>).
したがって、逆フィルタ１７はこのフィルタ係数に設定
される。Therefore, the inverse filter 17 is set to this filter coefficient.
前記した１秒が経過すると、切替器１４は送信回路１２
の出力側を選択する。これにより送信画ｖＩ１１２から
伝送路１５を介して送られてきた信号は、逆フィルタ１
７に入力され、前記したフィルタ係数に固定された逆フ
ィルタによって等化された信号が受信回路２２に供給さ
れることになる。When the one second described above has elapsed, the switch 14 switches the transmission circuit 12
Select the output side. As a result, the signal sent from the transmission image vI 112 via the transmission path 15 is filtered through the inverse filter 1.
7 and equalized by the inverse filter fixed to the above-mentioned filter coefficients is supplied to the receiving circuit 22.
すなわち、信号の送信の直前における伝送路１５の特性
に応じて振幅歪が打ち消され平坦化された信号が受信さ
れることになる。That is, a signal whose amplitude distortion is canceled and is flattened according to the characteristics of the transmission line 15 immediately before the signal is transmitted is received.
以上説明したように、本発明によれば送信部と受信部が
通信を行うたびに、その時点での伝送路の振幅歪に合っ
た係数に逆フィルタ部が設定されるので、適応的な等化
が可能になり、固定的な特性しか等化することのできな
かった従来の通信システムに比べて特性の大幅な改善を
図ることができる。As explained above, according to the present invention, each time the transmitting section and the receiving section communicate, the inverse filter section is set to coefficients that match the amplitude distortion of the transmission path at that time. This makes it possible to significantly improve the characteristics compared to conventional communication systems in which only fixed characteristics could be equalized.
第１図は本発明の一実施例における通信システムの概要
を示すブロック図である。
１１・・・・・・送信部、１２・・・・・・送信回路、
１３・・・・・・白色雑音発生回路、１４・・・・・・
切替器、１５・・・・・・伝送路、１６・・・・・・受
信部、１７・・・・・・逆フィルタ、１８・・・・・・
自己相関部、１９・・・・・・ＬＰＣ分析部、２２・・
・・・・受信回路。FIG. 1 is a block diagram showing an overview of a communication system in an embodiment of the present invention. 11... Transmission unit, 12... Transmission circuit,
13... White noise generation circuit, 14...
Switching device, 15... Transmission line, 16... Receiving section, 17... Inverse filter, 18...
Autocorrelation section, 19...LPC analysis section, 22...
...Reception circuit.
Claims (1)
色雑音を発生する送信部と、 この送信部から伝送路を介して送られてきた白色雑音に
ついて自己相関関数を計算する自己相関部と、この自己
相関部で計算した自己相関関数を線型予測係数分析して
線形予測係数を求める線形予測係数分析部と、前記送信
部から伝送路を介して伝送されてくる実際の信号に対し
て前記線形予測係数をフィルタ係数としてフィルタ処理
を行う逆フィルタ部とを備えた受信部 とを具備することを特徴とする通信システム。[Claims] A transmitting section that is equipped with a white noise generation circuit and generates white noise prior to actual signal transmission, and calculates an autocorrelation function for the white noise sent from the transmitting section via a transmission path. a linear prediction coefficient analysis unit that analyzes the autocorrelation function calculated by the autocorrelation unit to obtain a linear prediction coefficient; A communication system comprising: a receiving section including an inverse filter section that performs filter processing on a signal using the linear prediction coefficient as a filter coefficient.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13610189A JPH033427A (en) | 1989-05-31 | 1989-05-31 | Communication system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13610189A JPH033427A (en) | 1989-05-31 | 1989-05-31 | Communication system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH033427A true JPH033427A (en) | 1991-01-09 |
Family
ID=15167299
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13610189A Pending JPH033427A (en) | 1989-05-31 | 1989-05-31 | Communication system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH033427A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04328915A (en) * | 1991-04-30 | 1992-11-17 | Matsushita Electric Ind Co Ltd | Data receiver |
| US6628352B1 (en) | 1998-04-17 | 2003-09-30 | Sharp Kabushiki Kaisha | Liquid crystal display apparatus and electronic device incorporating the same wherein the optical guide having particular periodic structure |
-
1989
- 1989-05-31 JP JP13610189A patent/JPH033427A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04328915A (en) * | 1991-04-30 | 1992-11-17 | Matsushita Electric Ind Co Ltd | Data receiver |
| US6628352B1 (en) | 1998-04-17 | 2003-09-30 | Sharp Kabushiki Kaisha | Liquid crystal display apparatus and electronic device incorporating the same wherein the optical guide having particular periodic structure |
| US6882381B2 (en) | 1998-04-17 | 2005-04-19 | Sharp Kabushiki Kaisha | Liquid crystal display apparatus and electronic device incorporating the same |
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