JPH0322713A - Receiver with c/n display - Google Patents
Receiver with c/n displayInfo
- Publication number
- JPH0322713A JPH0322713A JP15709989A JP15709989A JPH0322713A JP H0322713 A JPH0322713 A JP H0322713A JP 15709989 A JP15709989 A JP 15709989A JP 15709989 A JP15709989 A JP 15709989A JP H0322713 A JPH0322713 A JP H0322713A
- Authority
- JP
- Japan
- Prior art keywords
- level
- frequency
- display
- signal
- receiver
- 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
- 238000001514 detection method Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 4
- 230000005684 electric field Effects 0.000 description 3
- 238000012935 Averaging Methods 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
Landscapes
- Superheterodyne Receivers (AREA)
- Noise Elimination (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、受信帯域のＣ／Ｎ （キャリア／ノイズ）比
を表示する機能を付加した受信機に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a receiver having an added function of displaying a C/N (carrier/noise) ratio of a reception band.
八木アンテナ等の通常のアンテナでＦＭ，ＡＭ、ＴＶ等
の放送を受信する受信機では、第３図に示すように、そ
の受信帯域内のノイズが小さいので、入力電界強度（中
間周波信号レベル）をそのまま表示させても、充分に実
用に供することができる．〔発明が解決しようとする課
題〕
ところが、コンバータにＬＮＡ （ローノイズアンプ〉
を使用する衛星放送受信機や、ブースクを使用する共同
受信機等では、そのＬＮＡやブースタの通過帯域内にお
いて信号或分と共にノイズ威分が大きく増幅されるので
、第４図に示す特性となり、その後段において検出した
入力電界強度を表示すると、そこに相当量のノイズが含
まれ、実際の受信状態と表示した入力電界強度との関係
が一致しないという問題がある。As shown in Figure 3, in a receiver that receives FM, AM, TV, etc. broadcasts using a normal antenna such as a Yagi antenna, the noise within the reception band is small, so the input electric field strength (intermediate frequency signal level) Even if it is displayed as is, it can be put to practical use. [Problem to be solved by the invention] However, the converter is equipped with an LNA (low noise amplifier).
In satellite broadcasting receivers that use , and community receivers that use booths, the signal and noise components are greatly amplified within the passband of the LNA and booster, so the characteristics shown in Figure 4 are obtained. When the input electric field strength detected at a subsequent stage is displayed, it contains a considerable amount of noise, and there is a problem that the relationship between the actual reception state and the displayed input electric field strength does not match.
本発明はこのような点に鑑みてなされたものであり、そ
の目的は、ＬＮＡやブースタをもつ受信機においても、
容易に実際の受信状態を表示できるようしたＣ／Ｎ表示
付き受信機を提供することである。The present invention has been made in view of the above points, and its purpose is to provide a receiver with an LNA or a booster.
To provide a receiver with a C/N display that can easily display the actual reception state.
このために本発明は、目標周波数の信号レベルを記憶す
る手段と、該目標周波数から離れた無信号周波数のレベ
ルを記憶する手段と、両レベルを比較する手段と、該比
較手段の出力を表示するＣ／Ｎ表示手段とを具備するよ
うにした。To this end, the present invention provides means for storing the signal level of the target frequency, means for storing the level of the no-signal frequency distant from the target frequency, means for comparing both levels, and displaying the output of the comparing means. C/N display means is provided.
上記比較手段が電源投入時及び目標周波数変化時に上記
両レベルを比較し、上記Ｃ／Ｎ表示手段の表示内容を更
新するようにすることができる。The comparison means may compare the two levels when the power is turned on and when the target frequency changes, and update the display contents of the C/N display means.
以下、本発明の実施例について説明する。第１図はその
一実施例の受信機の受信回路を示す図である。入力端子
１に印加した入力電圧はチューナ２において、ＰＬＬ回
路３に制御される局部発振回路４からの周波数信号によ
り選局される。なお、ＰＬＬ回路３はマイクロコンピュ
ータからなる制御回路５で制御される。そして、チュー
ナ２で得られた中間周波信号が検波回路６で検波され、
オーディオ／ビデオ回路７に出力される。Examples of the present invention will be described below. FIG. 1 is a diagram showing a receiving circuit of a receiver according to one embodiment. An input voltage applied to an input terminal 1 is tuned in a tuner 2 by a frequency signal from a local oscillation circuit 4 controlled by a PLL circuit 3. Note that the PLL circuit 3 is controlled by a control circuit 5 consisting of a microcomputer. Then, the intermediate frequency signal obtained by the tuner 2 is detected by the detection circuit 6,
It is output to the audio/video circuit 7.
本実施例ではこのような基本的な構戒に加えて、ＩＦレ
ベル検出・Ａ／Ｄ回路８を設けて、中間周波レベルを検
出すると共に、それをデジタル信号に変換し、そのデジ
タル信号を制御回路５に加えて、ここで第２図に示すプ
ログラムにより処理してＣ／Ｎ表示器９でＣ／Ｎ表示す
る。In addition to this basic structure, this embodiment also includes an IF level detection/A/D circuit 8 to detect the intermediate frequency level, convert it into a digital signal, and control the digital signal. In addition to the circuit 5, processing is performed by the program shown in FIG. 2, and the C/N is displayed on the C/N display 9.
第２図において、まず、電源が投入されると、周波数を
変化させ、無信号の周波数においてノイズレベルを検知
して、同様にメモリにそのレベルＮが記憶される。次に
、その時の受信周波数（通常は信号を受信する特定の目
標周波数にセントされた状態で電源オフされるので、電
源オン時にはその目標周波数が受信される）での受信信
号レベル（中間周波レベル）が取り込まれ、制御回路５
内のメモリにそのレベルＣが記憶される。次に、上記目
標信号受信レベルＣとノイズレベルＮが比較演算されて
、その結果が表示器９で表示される。In FIG. 2, first, when the power is turned on, the frequency is changed, the noise level is detected at the no-signal frequency, and the level N is similarly stored in the memory. Next, the received signal level (intermediate frequency level ) is taken in, and the control circuit 5
The level C is stored in the internal memory. Next, the target signal reception level C and the noise level N are compared and calculated, and the result is displayed on the display 9.
この表示器９としては、例えば７セグメント素子でなる
表示素子が使用され、例えばｒｃＮ１４ｄＢＪのように
表示される。As this display 9, a display element consisting of, for example, a 7-segment element is used, and displays, for example, rcN14 dBJ.
上記第２図では電源投入時について説明したが、周波数
変化（チャンネル変化）時にも同様に処理され、受信周
波数（目標周波数）のレベルとそこから離れた無信号周
波数（予め設定したダミーチャンネル等）とが比較され
て、Ｃ／Ｎ表示が行われる。In Figure 2 above, we explained the case when the power is turned on, but the same process is performed when the frequency changes (channel changes), and the level of the reception frequency (target frequency) and the no-signal frequency (preset dummy channel, etc.) separated from it are processed in the same way. are compared and a C/N display is performed.
つまり、目標周波数変化毎に目標信号受信レベルＣとノ
イズレベルＮの比較結果が更新され、これに基づいてＣ
／Ｎ表示器９における表示内容が更新される。In other words, each time the target frequency changes, the comparison result between the target signal reception level C and the noise level N is updated, and based on this, the
/N The display content on the display 9 is updated.
なお、無信号周波数（叉はダミーチャンネル）の検出は
、１個に限らず複数個にし、それらの受信レベルを平均
してノイズレベルＮとすることもできる。Note that the detection of a no-signal frequency (or dummy channel) is not limited to one, but a plurality of detections, and the noise level N can be obtained by averaging the reception levels of the detection.
また、ノイズ検出は、映像出力にノイズが出ないように
速く行なうか、或いはその間映像ミュートを行う。Further, noise detection is performed quickly so that noise does not appear in the video output, or the video is muted during that time.
以上のように本発明によれば、目標周波数と無信号周波
数のレベルを比較して表示するようにしたので、微弱信
号を増幅するＬＮＡやブースタを含む受信機においても
、実際の受信状態を示す適切なＣ／Ｎの表示が行われる
ようになるという利点がある。また、このＣ／Ｎ表示用
の信号を使用すれば、受信周波数をシークする機構に適
用して、良好な受信周波数選局を行わせることもできる
。As described above, according to the present invention, the levels of the target frequency and the no-signal frequency are compared and displayed, so that even in a receiver including an LNA or a booster that amplifies weak signals, the actual reception status is displayed. This has the advantage that an appropriate C/N ratio can be displayed. Further, by using this signal for C/N display, it is possible to apply it to a mechanism for seeking the reception frequency and perform good reception frequency tuning.
第１図は本発明の一実施例の受信機のブロック図、第２
図はその受信機の制御回路の動作のプログラムのフロー
チャート、第３図は一般的な受信機の受信信号特性図、
第４図はＬＮＡやブースタを具備する受信機の受信信号
特性図である。FIG. 1 is a block diagram of a receiver according to an embodiment of the present invention, and FIG.
The figure is a flowchart of the operation program of the control circuit of the receiver, and Figure 3 is a diagram of received signal characteristics of a general receiver.
FIG. 4 is a received signal characteristic diagram of a receiver equipped with an LNA and a booster.
Claims (2)
目標周波数から離れた無信号周波数のレベルを記憶する
手段と、両レベルを比較する手段と、該比較手段の出力
を表示するＣ／Ｎ表示手段とを具備することを特徴とす
るＣ／Ｎ表示付き受信機。(1) means for storing a signal level of a target frequency, means for storing a level of a no-signal frequency distant from the target frequency, means for comparing both levels, and a C/C/ 1. A receiver with a C/N display, comprising: N display means.
化時に上記両レベルを比較して上記Ｃ／Ｎ表示手段の表
示内容を更新することを特徴とする特許請求の範囲第１
項記載のＣ／Ｎ表示付き受信機。(2) The first aspect of the present invention is characterized in that the comparison means compares the two levels when the power is turned on and when the target frequency changes and updates the display contents of the C/N display means.
Receiver with C/N display as described in section.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15709989A JPH0322713A (en) | 1989-06-20 | 1989-06-20 | Receiver with c/n display |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15709989A JPH0322713A (en) | 1989-06-20 | 1989-06-20 | Receiver with c/n display |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0322713A true JPH0322713A (en) | 1991-01-31 |
Family
ID=15642219
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15709989A Pending JPH0322713A (en) | 1989-06-20 | 1989-06-20 | Receiver with c/n display |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0322713A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6506335B1 (en) | 1995-03-03 | 2003-01-14 | Sumitomo Chemical Company, Limited | Mold for production of hollow thermoplastic resin molded article, and process for production of hollow thermoplastic resin molded article using the same |
-
1989
- 1989-06-20 JP JP15709989A patent/JPH0322713A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6506335B1 (en) | 1995-03-03 | 2003-01-14 | Sumitomo Chemical Company, Limited | Mold for production of hollow thermoplastic resin molded article, and process for production of hollow thermoplastic resin molded article using the same |
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