JP2643543B2 - CATV transmission equalization method - Google Patents
CATV transmission equalization methodInfo
- Publication number
- JP2643543B2 JP2643543B2 JP2161617A JP16161790A JP2643543B2 JP 2643543 B2 JP2643543 B2 JP 2643543B2 JP 2161617 A JP2161617 A JP 2161617A JP 16161790 A JP16161790 A JP 16161790A JP 2643543 B2 JP2643543 B2 JP 2643543B2
- Authority
- JP
- Japan
- Prior art keywords
- signal
- catv transmission
- voltage value
- level
- transmission signal
- 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
Links
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、FDM（Frequency Division Multiplex）多
重された伝送信号に対し用いられるCATV伝送等化方式に
関する。Description: TECHNICAL FIELD The present invention relates to a CATV transmission equalization system used for FDM (Frequency Division Multiplex) multiplexed transmission signals.
従来のCATV伝送等化方式では、中継増幅器のケーブル
等化残を補償するため、周知のモップアップ等化器を使
用したり、あるいは、予等化方式を採用して、保守者が
誤差分を手動にて調整していた。In the conventional CATV transmission equalization method, a well-known mop-up equalizer is used to compensate for the cable equalization residue of the relay amplifier, or a pre-equalization method is used, so that the maintenance person can reduce the error. It was adjusted manually.
上述した従来のCATV伝送等化方式のうちモップアップ
等化器を使用する場合では、等化特性の自由度が小さ
く、誤差分を手動で行わなければならず、従って、リア
ルタイムで等化を行うことができないという欠点があ
り、予等化方式では、最大延長線路長が変わるごとに調
整しなおさなければならず手間がかかるという欠点があ
る。In the case of using the above-mentioned conventional CATV transmission equalization method using a mop-up equalizer, the degree of freedom of the equalization characteristics is small, and the error must be manually performed. Therefore, equalization is performed in real time. However, the pre-equalization method has a disadvantage in that it has to be adjusted every time the maximum extension line length changes, which is troublesome.
本発明の目的は、伝送帯域全体にわたってきめ細かに
且つリアルタイムに等化することができるCATV伝送等化
方式を提供することにある。An object of the present invention is to provide a CATV transmission equalization method capable of finely equalizing in real time over the entire transmission band.
本発明のCATV伝送等化方式は、FDM多重されたCATV伝
送信号を分岐出力し、前記分岐出力されたCATV伝送信号
と任意の発振周波数とを混合し、選択する信号が変って
も常に一定周波数を出力させる第１の手段と、 前記一定周波数を抽出，増幅した後，整流し、前記整
流された信号レベルに対する直流電圧値と予め記憶して
ある前記CATV伝送信号中の選択される信号における標準
レベルに対応する直流電圧値とを比較し、その差分電圧
値を検出する第２の手段と、 前記差分電圧値が検出されたとき、前記第２の手段か
ら前記差分電圧値を受信し、前記CATV伝送信号の選択さ
れた信号に対しそれぞれ対応して設けられる等化器に接
続してそのレベルを自動利得等化動作させる第３の手段
とを備える構成である。The CATV transmission equalization method according to the present invention branches and outputs an FDM-multiplexed CATV transmission signal, mixes the branched and output CATV transmission signal with an arbitrary oscillation frequency, and keeps a constant frequency even when a signal to be selected changes. First means for outputting the constant frequency, extracting and amplifying the fixed frequency, rectifying the rectified signal level, and a DC voltage value corresponding to the rectified signal level and a standard for a signal selected in the CATV transmission signal stored in advance. A second means for comparing a DC voltage value corresponding to a level and detecting a difference voltage value, and when the difference voltage value is detected, receiving the difference voltage value from the second means; Third means connected to an equalizer provided for each of the selected signals of the CATV transmission signal to perform an automatic gain equalization operation on the level thereof.
次に、本発明の実施例について図面を参照して説明す
る。Next, embodiments of the present invention will be described with reference to the drawings.
本発明の一実施例を示す第１図を参照すると、CATV伝
送等化方式は大別して３つの手段によって構成され、第
１の手段は、方向性結合器５と、ミクサ６と、PLL（Pha
se Locked Loop）シンセサイザ７とから成り、第２の手
段は、CPU（Central Processing Unit）８と、帯域ろ波
器９と、増幅器10と、整流器11と、メモリ12とから成
り、第３の手段は、制御器13と、イコライザ21〜2nと、
中継増幅部３とから成る。Referring to FIG. 1 showing one embodiment of the present invention, the CATV transmission equalization system is roughly divided into three means. The first means is a directional coupler 5, a mixer 6, a PLL (Pha).
The second means comprises a CPU (Central Processing Unit) 8, a bandpass filter 9, an amplifier 10, a rectifier 11, and a memory 12, and the third means Is a controller 13, an equalizer 21-2n,
And a relay amplification unit 3.
以下に、動作を説明する。CATV伝送信号は、TV信号，
データ信号などの数十チャネルより成るFDM多重された
信号であり、入力端子１から入力され、イコライザ21,2
2……2nを介し、中継増幅部３にて増幅され、方向性結
合器５へ入力される。方向性結合器５の幹線出力は出力
端子４を介して線路へ出力され、分岐出力はミクサ６へ
入力される。ミクサ６のローカルには、CPU8の制御によ
り発振周波数を任意に順次可変するPLLシンセサイザ７
を接続し、選択するいくつかの信号が変ってもミクサ６
の出力を一定周波数にする。例えば、一定周波数を10MH
zと仮定すると、伝送信号として92MHzが入力された場合
には、発振周波数を102MHzとし、伝送信号として82MHz
が入力された場合には、発振周波数を92MHzとする。そ
して、ミクサ６の出力の一定周波数を抽出する帯域ろ波
器9,増幅器10及び整流器11により、選択した信号のレベ
ルを直流電圧値としてCPU8へ入力させる。CPU8では、こ
の直流電圧値とメモリ12に予め記憶させている選択され
る信号の標準レベルに対する直流電圧値とを比較し、そ
の差分電圧をデータとして制御器13へ送出する。制御器
13の出力ポートは、選択される信号に対応する数を有
し、イコライザ21,22,……2nへ接続される。イコライザ
21,22,……2nは、選択される信号の数に相当し、制御器
13の制御電圧により可変するネットワークであり、CPU8
の出力の差分電圧値が零となるまでフィードバックによ
るループにより自動可変する。ここで、１つ前迄制御し
ていた順次選択された信号については、収束した値で固
定しておくこととする。このように、選択された信号そ
れぞれにつき自動等化するフィードバックループを構成
する。The operation will be described below. The CATV transmission signal is a TV signal,
This is an FDM multiplexed signal composed of several tens of channels, such as a data signal.
2... 2n, the signal is amplified by the relay amplifier 3 and input to the directional coupler 5. The main line output of the directional coupler 5 is output to the line via the output terminal 4, and the branch output is input to the mixer 6. Local to the mixer 6 is a PLL synthesizer 7 that arbitrarily changes the oscillation frequency arbitrarily under the control of the CPU 8.
And the mixer 6
Output to a constant frequency. For example, a constant frequency of 10 MHz
Assuming z, when 92 MHz is input as a transmission signal, the oscillation frequency is set to 102 MHz, and the transmission signal is set to 82 MHz.
Is input, the oscillation frequency is set to 92 MHz. Then, the level of the selected signal is input to the CPU 8 as a DC voltage value by the bandpass filter 9, the amplifier 10 and the rectifier 11 for extracting a constant frequency of the output of the mixer 6. The CPU 8 compares the DC voltage value with a DC voltage value corresponding to a standard level of a selected signal stored in the memory 12 in advance, and sends the difference voltage to the controller 13 as data. Controller
Thirteen output ports have numbers corresponding to the signals to be selected and are connected to equalizers 21, 22,... 2n. equalizer
21,22, ... 2n corresponds to the number of signals to be selected
It is a network that can be changed by the control voltage of 13
Is automatically varied by a feedback loop until the output differential voltage value becomes zero. Here, the sequentially selected signals that have been controlled up to immediately before are fixed at converged values. In this way, a feedback loop for automatically equalizing each of the selected signals is formed.
本発明は以上説明したように、CATV信号における任意
の信号を選択し、選択された信号のレベルと予め記憶し
てあるこの信号の規定レベルとを比較し、選択された信
号に対しそれぞれ対応して設けられる等化器に接続して
そのレベルが規定レベルとなるよう自動利得制御を行う
ことにより、伝送帯域全体にわたってきめ細かに且つリ
アルタイムに等化することができる。As described above, the present invention selects an arbitrary signal in a CATV signal, compares the level of the selected signal with a predetermined level of the signal stored in advance, and corresponds to each of the selected signals. By performing automatic gain control so that the level becomes a specified level by connecting to an equalizer provided by the user, equalization can be finely performed in real time over the entire transmission band.
第１図は本発明の一実施例を示す構成図である。 １……入力端子、３……中継増幅部、４……出力端子、
５……方向性結合器、６……ミクサ、７……PLLシンセ
サイザ、８……CPU、９……帯域ろ波器、10……増幅
器、11……整流器、12……メモリ、13……制御器、21,2
2,2n……イコライザ。FIG. 1 is a block diagram showing one embodiment of the present invention. 1 ... input terminal, 3 ... relay amplification section, 4 ... output terminal,
5 ... directional coupler, 6 ... mixer, 7 ... PLL synthesizer, 8 ... CPU, 9 ... bandpass filter, 10 ... amplifier, 11 ... rectifier, 12 ... memory, 13 ... Controller, 21,2
2,2n …… Equalizer.
Claims (1)
し、前記分岐出力されたCATV伝送信号と任意の発振周波
数とを混合し、選択する信号が変わっても常に一定周波
数を出力させる第１の手段と、 前記一定周波数を抽出，増幅した後，整流し、前記整流
された信号レベルに対する直流電圧値と予め記憶してあ
る前記CATV伝送信号中の選択される信号における標準レ
ベルに対応する直流電圧値とを比較し、その差分電圧値
を検出する第２の手段と、 前記差分電圧値が検出されたとき、前記第２の手段から
前記差分電圧値を受信し、前記CATV伝送信号の選択され
た信号に対しそれぞれ対応して設けられる等化器に接続
してそのレベルを自動利得等化動作させる第３の手段と
を備えたことを特徴とするCATV伝送等化方式。1. A method of branching and outputting an FDM-multiplexed CATV transmission signal, mixing the branched and output CATV transmission signal with an arbitrary oscillation frequency, and always outputting a constant frequency even when a signal to be selected changes. Means for extracting and amplifying the constant frequency, rectifying the rectified signal level, and rectifying the dc signal value with respect to the rectified signal level and the dc voltage value corresponding to a standard level in a signal selected from the CATV transmission signal stored in advance. A second means for comparing the voltage value and detecting the difference voltage value, and when the difference voltage value is detected, receiving the difference voltage value from the second means and selecting the CATV transmission signal. CATV transmission equalization method, comprising: third means for connecting equalizers provided corresponding to the respective signals to automatically perform a level equalization operation on the equalizers.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2161617A JP2643543B2 (en) | 1990-06-20 | 1990-06-20 | CATV transmission equalization method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2161617A JP2643543B2 (en) | 1990-06-20 | 1990-06-20 | CATV transmission equalization method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0451793A JPH0451793A (en) | 1992-02-20 |
| JP2643543B2 true JP2643543B2 (en) | 1997-08-20 |
Family
ID=15738581
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2161617A Expired - Lifetime JP2643543B2 (en) | 1990-06-20 | 1990-06-20 | CATV transmission equalization method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2643543B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ES2259888B1 (en) * | 2004-10-27 | 2007-10-01 | Fagor, S. Coop. | TV RECEPTION HEADER, WITH AN AUTOMATIC CONTROL CIRCUIT OF OUTPUT LEVELS. |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6125388A (en) * | 1984-07-16 | 1986-02-04 | Miharu Tsushin Kk | Mop-up equalization of catv system |
-
1990
- 1990-06-20 JP JP2161617A patent/JP2643543B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0451793A (en) | 1992-02-20 |
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