JPH03930B2 - - Google Patents
Info
- Publication number
- JPH03930B2 JPH03930B2 JP14721785A JP14721785A JPH03930B2 JP H03930 B2 JPH03930 B2 JP H03930B2 JP 14721785 A JP14721785 A JP 14721785A JP 14721785 A JP14721785 A JP 14721785A JP H03930 B2 JPH03930 B2 JP H03930B2
- Authority
- JP
- Japan
- Prior art keywords
- received signal
- output
- band
- noise
- ssb
- 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
Links
- 238000000034 method Methods 0.000 claims description 10
- 238000001514 detection method Methods 0.000 claims description 6
- 230000001629 suppression Effects 0.000 claims description 3
- 238000001228 spectrum Methods 0.000 description 10
- 238000010586 diagram Methods 0.000 description 8
- 238000004891 communication Methods 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 210000005069 ears Anatomy 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 230000005236 sound signal Effects 0.000 description 1
Landscapes
- Noise Elimination (AREA)
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明はキヤリヤ抑圧変調方式における受信信
号の検出方式、殊にスケルチ回路制御等を目的と
した受信信号検出方式に関する。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for detecting a received signal in a carrier suppression modulation method, and particularly to a method for detecting a received signal for purposes such as squelch circuit control.
（従来技術）
キヤリヤ抑圧変調方式、例えばSSB（Sinle
Side Band）通信方式はキヤリヤ信号両側に発生
する伝送すべき情報を含んだ側帯波の一方のみを
使用するものであり、A3電波を使用するものに
比べ送信電力が１／８以下でよくかつ占有帯域が
狭く各種妨害に強い優れた特性を有する。(Prior art) Carrier suppression modulation method, such as SSB (Single
Side Band) communication method uses only one of the sideband waves that contain the information to be transmitted, which are generated on both sides of the carrier signal, and requires less than 1/8th the transmission power compared to those that use A3 radio waves, and occupies less space. It has a narrow band and has excellent characteristics that are resistant to various types of interference.
一方、受信機では受信信号が存在しない間その
復調出力には種々の原因によつて雑音が生じ、極
めて耳ざわりである。 On the other hand, in the case of a receiver, when there is no received signal, noise is generated in the demodulated output due to various causes, which is extremely unpleasant to the ears.
従つて、通常受信機にはスケルチ機能を付し受
信信号が存在しない間の前記雑音がスピーカ等に
よつて外部に出力されることを阻止するのが通常
である。 Therefore, the receiver is usually equipped with a squelch function to prevent the noise from being output to the outside through a speaker or the like while there is no received signal.
スケルチ機能を制御するには受信信号の存在の
有無を検出する必要があるが、SSBの如くキヤリ
ヤが欠落した信号でしかもFM（Freque ncy
Modutation）のように受信信号が存在しない場
合の復調雑音出力が大きくない場合の受信信号の
検出は一般に困難である。 To control the squelch function, it is necessary to detect the presence or absence of a received signal, but it is necessary to detect the presence or absence of a received signal.
It is generally difficult to detect a received signal when the demodulation noise output is not large when there is no received signal, such as in the case of modulation.
即ち、FMに於けるスケルチ方式はキヤリヤの
存在を検出するキヤリヤスケルチ、キヤリヤのな
いときの多大な復調雑音を検出するノイズスケル
チ等があるが、SSBに於いてはこのうちのキヤリ
ヤスケルチは適用できない。 In other words, squelch methods in FM include a carrier squelch that detects the presence of a carrier, and a noise squelch that detects a large amount of demodulation noise when there is no carrier, but in SSB, the carrier squelch is Not applicable.
従つて従来のSSB受信機では受信信号なき場合
の微かな復調雑音出力を検出してスケルチ機能を
制御していたため、FM方式に比して利きが悪
く、復調歪雑音によつて誤動作する等の欠陥があ
つた。 Therefore, conventional SSB receivers control the squelch function by detecting the slight demodulation noise output when there is no received signal, which is less effective than the FM method and may cause malfunctions due to demodulation distortion noise. There was a defect.
（発明の目的）
本発明はこのような事情に鑑みてなされたもの
であつて、キヤリヤが欠落し又受信信号がないと
きの復調雑音出力が比較的少ないSSB変調方式に
於けるスケルチ機能制御等に効果的な受信信号検
出方式を提供することを目的とする。(Object of the Invention) The present invention has been made in view of the above circumstances, and provides squelch function control, etc. in the SSB modulation method, in which demodulation noise output is relatively small when a carrier is missing or there is no received signal. The purpose of this research is to provide an effective received signal detection method.
（発明の概要）
このため本発明では受信信号の通過帯内の一つ
又は複数の周波数を夫々通過域とする帯域フイル
タを介して得る夫々の周波成分レベルを比較し
て、これら周波数成分レベルが受信信号の有無に
より異なることを利用してその存在を検出するよ
う構成する。(Summary of the Invention) For this reason, the present invention compares the levels of each frequency component obtained through a band filter whose passband is one or more frequencies within the passband of the received signal, and calculates the level of these frequency components. The configuration is configured to detect the presence of a received signal by utilizing the fact that it differs depending on the presence or absence of the received signal.
（実施例）
以下本発明を図示した実施例に基づいて詳細に
説明する。(Example) The present invention will be described in detail below based on an illustrated example.
第１図は本発明の一実施例を示すブロツク図で
ある。同図に於いて１は従来のSSB受信機であつ
て、この内部はSSB受信機２、低周波増幅器３及
びこれに接続したスピーカ４とから構成され、
SSB受信部２の出力５は復調信号である。 FIG. 1 is a block diagram showing one embodiment of the present invention. In the figure, 1 is a conventional SSB receiver, which is internally composed of an SSB receiver 2, a low frequency amplifier 3, and a speaker 4 connected to it.
The output 5 of the SSB receiver 2 is a demodulated signal.
この実施例は復調信号の周波数成分を監視する
ことによつて受信信号の有無を検出する場合を示
す。 This embodiment shows a case where the presence or absence of a received signal is detected by monitoring the frequency components of a demodulated signal.
即ち、前記SSB受信部２の復調信号の一部を
夫々通過域周波数の異る３つの帯域フイルタ
（BPF）６，７、及び８に並列に入力する。 That is, a part of the demodulated signal from the SSB receiver 2 is input in parallel to three bandpass filters (BPF) 6, 7, and 8, each having a different passband frequency.
又これら３つのBPF出力は夫々整流回路９，
１０，１１により直流化したのち比較回路
（COMP）１２に入力し該比較回路出力によつて
前記低周波増幅器３の動作を制御するよう構成す
る。 In addition, these three BPF outputs are connected to rectifier circuits 9 and 9, respectively.
10 and 11, the signal is converted into a direct current, and then input to a comparator circuit (COMP) 12, and the operation of the low frequency amplifier 3 is controlled by the output of the comparator circuit.
以下、このように構成した回路の動作を、各回
路要素の具体例を掲げて詳細に説明する。 The operation of the circuit configured as described above will be described in detail below, citing specific examples of each circuit element.
第２図ａは無線回線を介して伝送する音声信号
の一般的な周波数スペクトル図であつて、周知の
通り0.3KHzから2.7KHzを通過帯域とする他、通
常ほぼ0.8KHz近傍にピークをもつた三角波形を
程する。 Figure 2a is a general frequency spectrum diagram of an audio signal transmitted via a wireless line, and as is well known, the passband ranges from 0.3KHz to 2.7KHz, and usually has a peak around 0.8KHz. Adjust the triangular waveform.
前記SSB受信部の復調出力にはこのような音声
スペクトルが現れるが、受信信号がない場合には
同図ｂ示すように0.3KHzから2.7KHzの通過全域
にわたつてほぼ均等な白色ノイズが発生する。尚
このノイズレベルはSSB受信部全体の増幅度、特
にSSB受信機ではAGC（Automatic Gain
Control）を付加するのが一般的であるからこの
制御量によつて、或は復調回路の利得によつても
変化する。 Such a sound spectrum appears in the demodulated output of the SSB receiver, but when there is no received signal, almost uniform white noise is generated over the entire pass range from 0.3KHz to 2.7KHz, as shown in Figure b. . This noise level is determined by the amplification level of the entire SSB receiver, especially the AGC (Automatic Gain) of the SSB receiver.
Since it is common to add a control amount, it changes depending on this control amount or the gain of the demodulation circuit.
そこで、前記帯域フイルタ６，７，８の通過周
波数を例えば0.4KHz，0.8KHz，2.5KHzと設定す
れば、受信信号の有無によつて夫々の帯域フイル
タ出力が変化する。 Therefore, if the pass frequencies of the band filters 6, 7, and 8 are set to, for example, 0.4 KHz, 0.8 KHz, and 2.5 KHz, the output of each band filter changes depending on the presence or absence of the received signal.
今、例えば復調音声スペクトル１３と受信信号
がない場合の復調ノイズスペクトル１４とが第２
図ｃに示すようなレベル関係にあると仮定すれ
ば、各周波数点に位置する３つの帯域フイルタ
６，７，８の通過域１５，１６，１７によつて抽
出される夫々のレベルが異なることが容易に理解
できよう。 Now, for example, the demodulated voice spectrum 13 and the demodulated noise spectrum 14 when there is no received signal are the second
Assuming that the level relationship is as shown in Figure c, the levels extracted by the passbands 15, 16, and 17 of the three band filters 6, 7, and 8 located at each frequency point are different. can be easily understood.
即ち、受信信号がない場合の白色ノイズ１４に
対しては帯域フイルタすべての出力はほぼ等しい
が、受信信号の存在により出力する音声スペクト
ル１３に対しては帯域フイルタ７（BPF２）の
出力が最も大きくかつ他の２つの帯域フイルタ６
及び８（BPF１，BPF３）は共にレベルが小さ
い。 That is, the outputs of all the band filters are almost equal for the white noise 14 when there is no received signal, but the output of the band filter 7 (BPF2) is the largest for the audio spectrum 13 output due to the presence of the received signal. and the other two band filters 6
and 8 (BPF1, BPF3) both have low levels.
従つて、これらの帯域フイルタの出力を整流し
て得る直流電圧値として比回路１２入力し互相比
較して帯域フイルタ７（BPF２）のレベルが他
のものより所定以上大きいとき受信信号が存在す
るものとして低周波増幅器を駆動してスピーカ４
に対し復調信号を出力すればよい。 Therefore, the DC voltage values obtained by rectifying the outputs of these bandpass filters are input to the ratio circuit 12 and compared with each other, and when the level of the bandpass filter 7 (BPF2) is higher than the other ones by a predetermined value or more, a received signal is present. drive the low frequency amplifier as speaker 4.
It is only necessary to output a demodulated signal for the
尚、前記比較回路１２としては例えば第３図に
示すように２つの差動増幅器１８，１９の夫々の
負極入力端に共通に整流回路１０の出力を又整流
回路９及び１１の出力を差動増幅器１８及び１９
の夫々の正極入力端に入力するよう構成すれば、
受信信号が存在するときのみ、即ち0.8KHz近傍
のレベルが0.4KHz及び2.5KHzより大きいときの
みAND回路２０の出力に高電位げ生ずるから、
これにより前記低周波増幅器３を駆動すればよ
い。 As shown in FIG. 3, the comparator circuit 12 may be configured such that the output of the rectifier circuit 10 is commonly connected to the negative input terminals of the two differential amplifiers 18 and 19, and the outputs of the rectifier circuits 9 and 11 are differentially connected to the negative input terminals of the two differential amplifiers 18 and 19. Amplifiers 18 and 19
If configured to input to each positive input terminal of
A high potential is generated at the output of the AND circuit 20 only when there is a received signal, that is, when the level near 0.8 KHz is greater than 0.4 KHz and 2.5 KHz.
This may drive the low frequency amplifier 3.
尚本発明の実施にあたつては、上述したように
復調したのちその周波数成分を比較したが、高周
波信号の段階で周波数分離を行うことも可能であ
る。 In implementing the present invention, the frequency components were compared after demodulating as described above, but it is also possible to perform frequency separation at the high frequency signal stage.
又、使用する帯域フイルタは３個に限らず２個
あるいは４個以上であつてもよいことは明らかで
あろう。 Furthermore, it is clear that the number of bandpass filters to be used is not limited to three, but may be two, four or more.
更には、本発明の受信信号検出方式スケルチ動
作の制御のみならず、その他の目的例えば中継装
置の制御或は他の通信機の話中表示等広く応用可
能なること説明を要しない。 Further, it is not necessary to explain that the present invention can be widely applied not only to controlling the squelch operation of the received signal detection method but also to other purposes such as controlling a relay device or indicating that another communication device is busy.
（発明の効果）
本発明は以上説明したように構成し機能するも
のであるから、SSB変調方式の如くキヤリヤが抑
圧されかつ受信信号がないときの受信帯域雑音レ
ベルが少ない受信機に於いて受信信号の有無の検
出を行ううえで極めて効果的である。(Effects of the Invention) Since the present invention is constructed and functions as explained above, it is possible to receive signals in a receiver with a low reception band noise level when a carrier is suppressed and there is no received signal, such as in the SSB modulation method. This is extremely effective in detecting the presence or absence of a signal.
第１図は本発明を応用してスケルチ機能を付加
したSSB受信機の一実施例を示すブロツク図、第
２図は本発明の原理及び前記第１図の動作を説明
するための図であつて、ａは音声スペクトル図、
ｂはノイズスペクトル図、ｃは前記第１図のSSB
受信部の復調出力信号スペクトルと帯域フイルタ
通過域との関係を説明する図、第３図は前記比較
回路の一実施例を示すブロツク図である。
１……従来のSSB受信機、２……SSB受信部、
３……低周波増幅器、４……スピーカ、５……復
調出力信号、６，７及び８……帯域フイルタ、
９，１０及び１１……整流器、１２……比較回
路、１３……音声スペクトル、１４……ノイズス
ペクトル、１５，１６及び１７……帯域フイルタ
６，７及び８の夫々の通過帯域特性、１８，１９
……差動増幅器、２０……AND回路。
FIG. 1 is a block diagram showing an embodiment of an SSB receiver to which the present invention is applied and a squelch function is added, and FIG. 2 is a diagram for explaining the principle of the present invention and the operation of FIG. 1. , a is the audio spectrum diagram,
b is the noise spectrum diagram, and c is the SSB in Figure 1 above.
FIG. 3 is a diagram illustrating the relationship between the demodulated output signal spectrum of the receiving section and the bandpass filter passband, and is a block diagram showing one embodiment of the comparison circuit. 1... Conventional SSB receiver, 2... SSB receiver,
3...Low frequency amplifier, 4...Speaker, 5...Demodulated output signal, 6, 7 and 8...Band filter,
9, 10 and 11... Rectifier, 12... Comparison circuit, 13... Audio spectrum, 14... Noise spectrum, 15, 16 and 17... Pass band characteristics of band filters 6, 7 and 8, respectively, 18. 19
...Differential amplifier, 20...AND circuit.
Claims (1)
に於いて、受信信号帯域内の一つ又は複数の周波
数成分を抽出する帯域フイルタを設け、夫々の抽
出成分レベルの相対比を検出することによつて受
信信号到来の有無を検出したことを特徴とする受
信信号検出方式。 ２ 前記帯域フイルタを設ける部位が受信高周波
段であることを特徴とした特許請求の範囲１項記
載の受信信号検出方式。 ３ 前記帯域フイルタを設ける部位が復調段以降
であることを特徴とした特許請求の範囲１項記載
の受信信号検出方式。[Claims] 1. In a receiver that employs the carrier suppression amplitude modulation method, a band filter is provided to extract one or more frequency components within the received signal band, and the relative ratio of the level of each extracted component is determined. A received signal detection method characterized in that the presence or absence of the arrival of a received signal is detected by detection. 2. The received signal detection method according to claim 1, wherein the part where the bandpass filter is provided is a receiving high frequency stage. 3. The received signal detection method according to claim 1, wherein the bandpass filter is provided at a portion after a demodulation stage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14721785A JPS627224A (en) | 1985-07-04 | 1985-07-04 | Reception signal detecting system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14721785A JPS627224A (en) | 1985-07-04 | 1985-07-04 | Reception signal detecting system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS627224A JPS627224A (en) | 1987-01-14 |
| JPH03930B2 true JPH03930B2 (en) | 1991-01-09 |
Family
ID=15425216
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14721785A Granted JPS627224A (en) | 1985-07-04 | 1985-07-04 | Reception signal detecting system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS627224A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2867900B2 (en) * | 1994-11-30 | 1999-03-10 | 日本電気株式会社 | Facsimile control device |
| JP4742859B2 (en) * | 2005-12-27 | 2011-08-10 | 株式会社ケンウッド | Radio, control method and program |
-
1985
- 1985-07-04 JP JP14721785A patent/JPS627224A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS627224A (en) | 1987-01-14 |
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