JPS6336678A - Demodulator - Google Patents

Abstract

PURPOSE:To obtain a voice multiplex demodulation circuit with simple circuit constitution and low cost by using a tuning circuit to apply time division to >=2 voice subcarriers having different frequencies, applying frequency detection and time division to output the result to each voice circuit. CONSTITUTION:A high-frequency amplifier circuit 11 separates and amplifies a voice subcarrier from a part of an output signal subjected to video detection and inputs the result to a frequency conversion circuit 12. A higher frequency by 10.7MHz than the voice subcarrier frequency for making an intermediate frequency of 10.7MHz is fed to the circuit 12 from a local oscillation circuit 13, a pulse is fed from a time-division pulse generating circuit 18 to a switch 14, tuning voltages 1, 2 are switched to apply a rectangular wave voltage to the local oscillation circuit 13. The circuit 13 sends the voice intermediate frequency signal subjected to time division to the intermediate frequency amplifier circuit 15 to send the voice signal to the low frequency amplifier circuit of channels 1, 2 in the order of time division via a voice detection circuit 16 and analog switches 17, 17' to restore the signal to the original voice.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は音声サブキャリア一方式を用いた音声多重受信
機の復調装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a demodulation device for an audio multiplex receiver using one type of audio subcarrier.

従来の技術 近年、ＳＨＦ帯のＣバンド（３，７ＧＨ２〜４．１８Ｇ
）−１２）を用いた衛星放送において、主に８，８　Ｍ
Ｈｚ　、　ｅ−２Ｍ）ｌｚの音声サブキャリヤーを使用
した、音声多重のステレオ放送が運用されるようになっ
てきた。この音声サブキャリヤー信号はビデオ信号に、
多重されて送られて来るので、音声の復調はビデオ信号
の検波後に行なわれる。Conventional technology In recent years, SHF band C band (3.7GH2~4.18G
)-12) In satellite broadcasting using
Audio multiplexed stereo broadcasting using audio subcarriers of Hz, e-2M)lz has come into use. This audio subcarrier signal is converted into a video signal,
Since the signals are multiplexed and sent, the audio demodulation is performed after the video signal is detected.

以下図面を参照しながら、上述したような従来の音声多
重復調回路について説明を行なう。The conventional audio multiplexing and demodulating circuit as described above will be explained below with reference to the drawings.

第３図は従来例の構成を示す。FIG. 3 shows the configuration of a conventional example.

１は検波されたビデオ信号の中より、音声サブキャリヤ
ーを分離し増巾する高周波増巾回路である。２は高周波
増巾回路１で増巾された音声サブキャリヤー信号を中間
周波の１０．γＭｌ（ｚに変換する周波数変換回路であ
る。３は周波数変換回路２で中間周波を得る為の局部発
振回路で、同調電圧によって周波数を変化させ、音声サ
ブキャリヤー周波数と同調させる動作も合わせて行なう
、、４は中間周波増巾回路である。６は音声検波回路で
、１０．７　ＭＨｚの中間周波数より、音声信号を取り
出す。６は低周波増巾回路で、音声信号の増巾を行なう
。Reference numeral 1 denotes a high frequency amplification circuit that separates and amplifies audio subcarriers from the detected video signal. 2 converts the audio subcarrier signal amplified by the high frequency amplification circuit 1 into an intermediate frequency 10. γMl (This is a frequency conversion circuit that converts to z. 3 is a local oscillation circuit for obtaining an intermediate frequency in the frequency conversion circuit 2. It also performs the operation of changing the frequency by a tuning voltage and tuning it to the audio subcarrier frequency. , , 4 is an intermediate frequency amplification circuit. 6 is an audio detection circuit, which extracts an audio signal from an intermediate frequency of 10.7 MHz. 6 is a low frequency amplification circuit, which amplifies the audio signal.

この構成を１組として各音声チャンネルの数だけこの組
み合わせの構成が細組か存在する。第３図では２組図示
している。With this configuration as one set, there are sub-sets of configurations of this combination as many as the number of audio channels. In FIG. 3, two sets are shown.

発明が解決しようとする問題点 １７かしながら上記のような構成では、各音声チヤンネ
ル毎に復調装置が１組必要で、回路が複雑になる事と、
コスト高になるという問題点を有していた。Problem 17 to be Solved by the Invention However, with the above configuration, one set of demodulators is required for each audio channel, which makes the circuit complicated.
This has the problem of high cost.

本発明は上記問題点に鑑み、回路構成が簡単で、かつ低
コストの音声多重復調回路を提供するものである。In view of the above-mentioned problems, the present invention provides an audio multiplexing demodulation circuit with a simple circuit configuration and low cost.

問題点を解決するだめの手段 この目的を達成するために本発明の音声多重復調回路は
、同調回路の同調電圧を時分割して、それぞれの音声チ
ャンネルの同調を行ない、音声検波後、同調時の時分割
のタイミングに合わせて再度分割し、各音声のチャンネ
ルへ出力する事によって、音声サブキャリヤー分離部よ
り音声検波部までを共用化することを特徴とする。Means for Solving the Problem In order to achieve this object, the audio multiplex demodulation circuit of the present invention time-divisionally tunes the tuning voltage of the tuning circuit to tune each audio channel, and after audio detection, at the time of tuning. This feature is characterized in that by re-dividing the signal in accordance with the time division timing of , and outputting it to each audio channel, the sections from the audio subcarrier separation unit to the audio detection unit can be shared.

作用 同調電圧を時分割して、それぞれの音声サブキャリヤー
周波数に同調し、音声検波後に再度時分割して、各音声
をチャンネルごとに分離することによって音声サブキャ
リヤーの分離部より音声検波部までを共用出来ることと
なり、構成の簡素化。The working tuning voltage is time-divided to tune to each audio subcarrier frequency, and after audio detection, it is time-divided again to separate each audio channel for each channel. It can be shared, simplifying the configuration.

低コスト化が可能となる。Cost reduction becomes possible.

実施例 以下本発明の一実施例について図面を参照しながら説明
する。EXAMPLE An example of the present invention will be described below with reference to the drawings.

第１図は本発明の一実施例における音声多重復調装置の
構成図を示す物で、図において、１１はビデオ検波出力
信号の中より音声サブキャリヤーの分離及び増巾を行う
高周波増巾回路、１２は周波数変換部、１３は局部発振
回路部、１４は同調電圧切替用のアナログスイッチ、１
６は中間周波増巾回路、１６は音声検波回路部、１７　
、１７’は低周波増巾回路、１８は時分割用のパルス発
生回路、１９は音声信号切替用のアナログスイッチを示
すものである。FIG. 1 shows a configuration diagram of an audio multiplexing and demodulating device according to an embodiment of the present invention. In the figure, 11 is a high frequency amplification circuit that separates and amplifies audio subcarriers from a video detection output signal; 12 is a frequency conversion section, 13 is a local oscillation circuit section, 14 is an analog switch for switching the tuning voltage, 1
6 is an intermediate frequency amplification circuit, 16 is an audio detection circuit section, 17
, 17' is a low frequency amplification circuit, 18 is a pulse generation circuit for time division, and 19 is an analog switch for switching audio signals.

第２図は、第１図のタイムチャート及び各部の波形を示
すものである。FIG. 2 shows the time chart of FIG. 1 and waveforms of various parts.

以上のように構成された音声多重復調回路について、以
下その動作について説明する。The operation of the audio multiplexing and demodulation circuit configured as described above will be described below.

まず、高周波増巾回路１１により、ビデオ検波された出
力信号の一部より、音声サブキャリヤーを分離、増巾し
、周波数変換回路１２へ入力する。First, the high frequency amplification circuit 11 separates and amplifies audio subcarriers from a portion of the video-detected output signal, and inputs the separated and amplified audio subcarriers to the frequency conversion circuit 12 .

周波数変換回路１２へは局部発振回路１３よシ、１０．
７　Ｍｌ−１７の中間周波を作る為の音声サブキャリヤ
ー周波数より１０．７　Ｍ）ｌｚ高い周波数が加わるが
、アナログスイッチ１４へ、時分割用パルス発生回路１
８より、第２図に示すパルスｆが加わり、同調電圧１，
２を切替え第２図Ｃの様な電圧を局部発振回路１３へ加
える。局部発振回路１３は、第２図Ｃの電圧に応じて発
振周波数がそれぞれ変化し、周波数変換回路１２では見
掛上それぞれの音声サブキャリヤーに交互に同調して中
間周波増巾回路１６へ時分割された音声中間周波信号を
送り出す。音声中間周波信号は中間周波増巾回路１５で
、増巾された後音声検波回路１６で、検波されて時分割
によって合成された音声信号が取り出され、アナログス
イッチ１９へ加わる。アナログスイッチ１９のコントロ
ール部へは、時分割用パルス発生回路１８より、コント
ロールパルスｆが加わり、音声信号を時分割した順にチ
ャンネル１゜チャンネル２の低周波増巾回路１７　、１
７’へ送り出し、元の音にもどす事が出来、本来の目的
を達成出来る。The local oscillation circuit 13 is connected to the frequency conversion circuit 12, 10.
7 A frequency 10.7 M)lz higher than the audio subcarrier frequency to create the intermediate frequency of Ml-17 is added to the analog switch 14, and the time division pulse generation circuit 1
8, the pulse f shown in FIG. 2 is added, and the tuning voltage 1,
2 and apply a voltage as shown in FIG. 2C to the local oscillation circuit 13. The local oscillation circuit 13 changes its oscillation frequency depending on the voltage shown in FIG. It sends out an audio intermediate frequency signal. The audio intermediate frequency signal is amplified by an intermediate frequency amplification circuit 15, then detected by an audio detection circuit 16, and an audio signal synthesized by time division is extracted and applied to an analog switch 19. A control pulse f is applied from the time division pulse generation circuit 18 to the control section of the analog switch 19, and the low frequency amplification circuits 17, 1 of channel 1 and channel 2 are applied in the order in which the audio signal is time divided.
7' and return it to the original sound, achieving the original purpose.

発明の効果 以上のように本発明によれば、同調時に時分割して複数
の音声チャンネルを同調合成して、音声検波後、分離し
各音声チャンネルに分割する事により、従来の構成の音
声多重復調回路に比較して、２チヤンネル目以降の音声
サブキャリヤー分離より音声検波回路までが不要となり
、回路の簡素化。Effects of the Invention As described above, according to the present invention, a plurality of audio channels are time-divisionally tuned and synthesized at the time of tuning, and after audio detection, they are separated and divided into individual audio channels, thereby improving the audio multiplexing of the conventional configuration. Compared to the demodulation circuit, the circuit is simplified because it eliminates the need for audio subcarrier separation from the second channel onwards, as well as the audio detection circuit.

低コスト化等がはかれ、その実用的効果は大なるものが
ある。The cost can be reduced, and the practical effects are great.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明の一実施例における復調装置の構成図、
第２図は第１図のタイムチャート及び出力波形図、第３
図は従来例の回路構成図である。 １１・・・・・・高周波増巾回路、１２・・・・・・周
波数変換回路、１３・・・・・・局部発振回路、１４．
１９・・・・・・アナログスイッチ、１５・・・・・・
中間周波増巾回路、１６・・・・・・音声検波回路、１
７　、１７’・・・・・・低周波増巾回路、１８・・・
・・時分割用パルス発生回路。FIG. 1 is a configuration diagram of a demodulator in an embodiment of the present invention;
Figure 2 is the time chart and output waveform diagram of Figure 1, and Figure 3 is the time chart and output waveform diagram of Figure 1.
The figure is a circuit configuration diagram of a conventional example. 11... High frequency amplification circuit, 12... Frequency conversion circuit, 13... Local oscillation circuit, 14.
19...Analog switch, 15...
Intermediate frequency amplification circuit, 16...Audio detection circuit, 1
7, 17'...Low frequency amplification circuit, 18...
...Time division pulse generation circuit.

Claims (1)

【特許請求の範囲】[Claims] 周波数の異なる、２つ以上の音声サブキャリヤーを同調
回路で時分割して同調し、音声検波後、時分割して各音
声回路へ出力することを特徴とする復調装置。A demodulation device characterized in that two or more audio subcarriers having different frequencies are time-divisionally tuned by a tuning circuit, and after audio detection, the demodulator is time-divisionally tuned and output to each audio circuit.