JPS63240225A - Fmx stereo broadcast receiver - Google Patents
Fmx stereo broadcast receiverInfo
- Publication number
- JPS63240225A JPS63240225A JP7537087A JP7537087A JPS63240225A JP S63240225 A JPS63240225 A JP S63240225A JP 7537087 A JP7537087 A JP 7537087A JP 7537087 A JP7537087 A JP 7537087A JP S63240225 A JPS63240225 A JP S63240225A
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- Prior art keywords
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- circuit
- stereo
- level
- noise
- Prior art date
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Links
- 238000001514 detection method Methods 0.000 claims abstract description 29
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 claims description 10
- 239000003990 capacitor Substances 0.000 abstract description 3
- 230000005540 biological transmission Effects 0.000 description 7
- 239000011159 matrix material Substances 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 230000006835 compression Effects 0.000 description 4
- 238000007906 compression Methods 0.000 description 4
- 230000001360 synchronised effect Effects 0.000 description 4
- 239000002131 composite material Substances 0.000 description 3
- 230000003321 amplification Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 210000003127 knee Anatomy 0.000 description 2
- 238000003199 nucleic acid amplification method Methods 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
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- Stereo-Broadcasting Methods (AREA)
Abstract
Description
【発明の詳細な説明】
（イ）産業上の利用分野
本発明は、ＦＭＸステレオ放送を受信し得るＦＭＸステ
レオ放送受信機に関するもので、特にパルス雑音やマル
チパス雑音等に起因する受信妨害を除去し得るＦＭＸス
テレオ放送受信機に関する。Detailed Description of the Invention (a) Industrial Application Field The present invention relates to an FMX stereo broadcasting receiver capable of receiving FMX stereo broadcasting, and in particular, to a receiver capable of removing reception interference caused by pulse noise, multipath noise, etc. The present invention relates to a possible FMX stereo broadcast receiver.
（ロ）従来の技術
ＦＭステレオ放送のＳ／Ｎの改善を計り、サービスエリ
アの拡大を計ったものとしてＦＭＸステレオ放送が提案
されている。前記ＦＭＸステレオ放送の送信信号は、従
来のＦＭステレオ放送の送信信号に加えて、圧縮された
ステレオ差信号（Ｌ−Ｒ〉′を同時に送信するもので、
その送信信号を式％式％
となる。前記第（１）式から明らかな如く、圧縮された
ステレオ差信号（Ｌ−Ｒ）’は、ステレオ差信号（Ｌ−
Ｒ）に直交変調されており、ＦＭＸステレオ放送の送信
信号のスペクトラムは第２図の、如くなる。(b) Conventional technology FMX stereo broadcasting has been proposed as a way to improve the S/N ratio of FM stereo broadcasting and expand the service area. The transmission signal of the FMX stereo broadcast is such that in addition to the transmission signal of the conventional FM stereo broadcast, a compressed stereo difference signal (L-R〉') is simultaneously transmitted.
The transmitted signal is expressed as follows. As is clear from the above equation (1), the compressed stereo difference signal (L-R)' is the stereo difference signal (L-
The spectrum of the FMX stereo broadcasting signal is shown in FIG. 2.
また、ステレオ差信号（Ｌ−Ｒ）と圧縮されたステレオ
差信号（Ｌ−Ｒ）’との関係すなわち、圧縮特性は、第
３図の如くなる。第３図において、入力信号のレベルが
小であるときは、前記信号（Ｌ−Ｒ）’がステレオ差信
号（Ｌ−Ｒ”）よりも２０ｄＢ大きくなり、入出力特性
は直線的になり、圧縮比は１：１となる。入力信号のレ
ベルが中（約−３０ｄＢ）になると、圧縮比は〜：１に
なり、入出力特性は約１０ｄＢの範囲にわたって平坦と
なる。入力信号のレベルが大になったときは、前記信号
（Ｌ−Ｒ）’が急激に減衰する。従って、ステレオ差信
号（Ｌ−Ｒ）（実線（イ））に対し、圧縮されたステレ
オ差信号（Ｌ−Ｒ）’は実線（ロ）の如くなり、前記信
号（Ｌ−Ｒ）と前記信号（Ｌ−Ｒ）’との和信号は、点
線（ハ）の如くなる。Further, the relationship between the stereo difference signal (LR) and the compressed stereo difference signal (LR)', that is, the compression characteristics, is as shown in FIG. In Figure 3, when the level of the input signal is low, the signal (L-R)' becomes 20 dB larger than the stereo difference signal (L-R''), the input/output characteristics become linear, and the compression The ratio is 1:1.When the input signal level is medium (approximately -30 dB), the compression ratio is ~:1, and the input/output characteristics are flat over a range of approximately 10 dB.When the input signal level is large When , the signal (L-R)' is rapidly attenuated. Therefore, compared to the stereo difference signal (L-R) (solid line (A)), the compressed stereo difference signal (L-R) ' is shown as a solid line (b), and the sum signal of the signal (LR) and the signal (LR)' is shown as a dotted line (c).
上述の如きＦＭＸステレオ放送の送信信号は、第４図に
示す如き受信機により受信される。第４図において、ア
ンテナ（１）に受信されたＦＭＸステレオ放送の送信信
号は、従来のＦＭステレオ受信機と同一の構成の受信回
路（２）によって受信され、ステレオ和信号（Ｌ＋Ｒ）
（以下Ｍと称す）、ステレオ差信号（Ｌ−Ｒ）（以下
Ｓと称す）、圧縮されたステレオ差信号（Ｌ−Ｒ）’（
以下Ｓ′と称す）がそれぞれ復調される。受信回路中に
含まれるＦＭ検波回路を用いて受信信号を検波すれば、
ステレオ和信号Ｍが復調され、受信回路中のＰＬＬから
得られる３８ＫＨｚ副搬送波信号を用いてステレオコン
ポジット信号を同期検波すれば、ステレオ差信号Ｓが復
調きれ、直交検波すれば、圧縮されたステレオ差信号Ｓ
′が復調される。The transmission signal of the FMX stereo broadcast as described above is received by a receiver as shown in FIG. In FIG. 4, a transmission signal of FMX stereo broadcast received by an antenna (1) is received by a receiving circuit (2) having the same configuration as a conventional FM stereo receiver, and a stereo sum signal (L+R) is generated.
(hereinafter referred to as M), stereo difference signal (L-R) (hereinafter referred to as S), compressed stereo difference signal (L-R)' (
(hereinafter referred to as S') are respectively demodulated. If the received signal is detected using the FM detection circuit included in the receiving circuit,
If the stereo sum signal M is demodulated and the stereo composite signal is synchronously detected using the 38KHz subcarrier signal obtained from the PLL in the receiving circuit, the stereo difference signal S can be demodulated, and if the quadrature detection is performed, the compressed stereo difference signal S can be demodulated. Signal S
' is demodulated.
受信回路（２）から得られるステレオ差信号Ｓと圧縮さ
れたステレオ差信号Ｓ′とは、加算回路（３）で加算さ
れた後減衰器として動作するＶＣＡ（電圧制御増幅器）
（４）に印加される。ステレオ差信号Ｓ及びＶ ＣＡ
（４）の出力信号（ｓｒｓ’）が所定レベル（ニーポイ
ント）以上のとき、スレシホールドレベルを有する第１
及び第２レベル検出回路（５）及び（６）が動作し、ス
テレオ差信号Ｓのレベルと前記Ｖ ＣＡ （４）の出力
信号（Ｓ＋Ｓ’）のレベルとが第１及び第２レベル検出
回路（５）及び（６）で検出され、比較回路（７）で比
較される。そして、前記比較回路（７〉から得、られる
レベル差に応じた信号が、整流回路（８〉で整流平滑さ
れた後制御信号としテＶ ＣＡ （４）に印加されルノ
テ、前記Ｖ ＣＡ （４）の出力信号（Ｓ＋Ｓ″）は、
ステレオ差信号Ｓのレベルと等しくなる様に制御される
。一方、前記ステレオ差信号Ｓ及びＶ ＣＡ （４）（
７）出力信号（Ｓ＋５’）がニーポイント以下のときは
、第１及び第２レベル検出回路（５）及び（６〉が動作
せず、Ｖ ＣＡ （４）における減衰量は約２０ｄＢに
固定される。The stereo difference signal S obtained from the receiving circuit (2) and the compressed stereo difference signal S' are added in an adder circuit (3), and then a VCA (voltage control amplifier) that operates as an attenuator is added.
(4) is applied. Stereo difference signal S and V CA
(4) When the output signal (srs') is above a predetermined level (knee point), the first
and second level detection circuits (5) and (6) operate, and the level of the stereo difference signal S and the level of the output signal (S+S') of the V CA (4) are detected by the first and second level detection circuits ( 5) and (6), and compared in a comparison circuit (7). Then, a signal corresponding to the level difference obtained from the comparison circuit (7>) is rectified and smoothed by the rectification circuit (8>) and then applied as a control signal to the V CA (4). ) output signal (S+S'') is
The level is controlled to be equal to the level of the stereo difference signal S. On the other hand, the stereo difference signal S and V CA (4) (
7) When the output signal (S+5') is below the knee point, the first and second level detection circuits (5) and (6> do not operate, and the attenuation amount at V CA (4) is fixed at approximately 20 dB. Ru.
受信回路（２）から得られるステレオ和信号Ｍは、直接
マトリクス回路（９）に印加され、ステレオ差信号Ｓ及
びＶ ＣＡ （４）の出力信号（Ｓ＋Ｓ’）はスイッチ
（１０）を介してマトリクス回路（９）に印加される。The stereo sum signal M obtained from the receiving circuit (2) is directly applied to the matrix circuit (9), and the stereo difference signal S and the output signal (S+S') of V CA (4) are applied to the matrix circuit via the switch (10). applied to the circuit (9).
先の説明では省略したが、ＦＭＸステレオ放送の送信信
号中には、１０ＨｚのＩＤ信号が含まれており、前記Ｉ
Ｄ信号によりＦＭＸステレオ放送を従来のＦＭステレオ
放送と区別している。そして、受信回路（２）中には、
前記ＩＤ信号を検出する検出回路が内蔵されているので
、前記検出回路の出力信号により、ＦＭＸステレオ放送
であるか否かを判別出来る。スイッチ（１０）は、前記
ＩＤ信号により切換制御される。ＩＤ信号が存在する場
合には、前記スイッチ（１０）が図示の状態に切換えら
れる。その為、マトリクス回路（９）においては、ステ
レオ和信号Ｍとレベル制御されたＶＣＡ（４）の出力信
号（ｓ＋ｓ’）とがマトリクスされ、左右出力端子（１
１）及び（１２）に左右ステレオ信号り及びＲが発生す
る。また、ＩＤ信号が存在しない場合には、スイッチ（
１０）が図示と逆の状態に切換わり、マトリクス回路（
９）においてステレオ和信号Ｍとステレオ差信号Ｓとが
マトリクスされる。Although omitted in the previous explanation, the transmission signal of the FMX stereo broadcast includes a 10Hz ID signal, and the
The D signal distinguishes FMX stereo broadcasting from conventional FM stereo broadcasting. And in the receiving circuit (2),
Since a detection circuit for detecting the ID signal is built-in, it is possible to determine whether or not it is an FMX stereo broadcast based on the output signal of the detection circuit. The switch (10) is controlled by the ID signal. If an ID signal is present, said switch (10) is switched to the state shown. Therefore, in the matrix circuit (9), the stereo sum signal M and the level-controlled output signal (s+s') of the VCA (4) are matrixed, and the left and right output terminals (1
Left and right stereo signals and R are generated at 1) and (12). Also, if there is no ID signal, switch (
10) switches to the opposite state as shown, and the matrix circuit (
In 9), the stereo sum signal M and the stereo difference signal S are matrixed.
上述の如＜、ＦＭＸステレオ放送は、ステレオ差信号Ｓ
の圧縮、伸長を行なって送受信を行なっているので、大
幅なＳ／Ｎの改善を計ることが出来、従来のＦＭモノラ
ル放送と同程度にサービスエリアを拡大することが出来
る。As mentioned above, FMX stereo broadcasting uses the stereo difference signal S
Since transmission and reception are performed by compressing and decompressing the data, it is possible to significantly improve the S/N ratio and expand the service area to the same extent as conventional FM monaural broadcasting.
尚、ＦＭＸステレオ放送の送信信号は、従来のＦＭステ
レオ受信機により正確に受信することが出来る。その場
合、圧縮されたステレオ差信号Ｓ′は、ステレオ差信号
Ｓに対して直交変調されているので、受信に対して悪影
響を与えない。Note that the transmission signal of the FMX stereo broadcast can be accurately received by a conventional FM stereo receiver. In this case, the compressed stereo difference signal S' is orthogonally modulated with respect to the stereo difference signal S, so that it does not adversely affect reception.
ＦＭＸステレオ放送については、ＪＡＳ ＪＯＵＲＮＡ
Ｌ１９８６年９月号第１１頁乃至第９月号第１１れてい
る。For FMX stereo broadcasting, please contact JAS JOURNA
L September 1986 issue, page 11 to September issue no. 11.
（ハ）発明が解決しようとする問題点
上述の如きＦＭＸステレオ放送受信機において、マルチ
パス妨害等が生じると、ステレオ差信号Ｓ及び圧縮され
たステレオ差信号Ｓ′が妨害を受け、それらのレベルが
変動する。しかして、前記両信号Ｓ及びＳ′のレベルが
変動し、しかもその変化量が互いに異なる場合には、比
較回路（７〉から異常な制御信号が発生し、ＶＣＡ（４
）における減衰量が不適なものとなる。すなわち、送信
機における圧縮量と受信機における伸張量とが一致しな
くなり、Ｖ Ｃ Ａ （４）の出力信号レベルが不所望
となる。(c) Problems to be Solved by the Invention When multipath interference occurs in the FMX stereo broadcast receiver as described above, the stereo difference signal S and the compressed stereo difference signal S' are interfered with, and their levels are changes. However, when the levels of the two signals S and S' fluctuate and the amounts of change are different from each other, an abnormal control signal is generated from the comparator circuit (7), and the VCA (4)
) becomes inappropriate. That is, the amount of compression at the transmitter and the amount of expansion at the receiver no longer match, and the output signal level of V CA (4) becomes undesirable.
（二）問題点を解決するための手段
本発明は、上述の点に鑑み成されたもので、ステレオ差
信号と圧縮ステレオ差信号との加算信号のレベルを制御
するレベル制御回路と、ステレオ差信号のレベルと前記
レベル制御回路の出力信号のレベルとを比較し、前記レ
ベル制御回路を制御する為の制御信号を発生ずる制御信
号発生回路と、受信信号中の雑音を検出する雑音検出回
路と、前記レベル制御回路と前記制御信号発生回路との
間に挿入され、前記雑音検出回路の出力信号に応じて開
閉するスイッチとを備える点を特徴とする。(2) Means for Solving the Problems The present invention has been made in view of the above-mentioned points, and includes a level control circuit that controls the level of a sum signal of a stereo difference signal and a compressed stereo difference signal, and a stereo difference signal. a control signal generation circuit that compares the level of the signal with the level of the output signal of the level control circuit and generates a control signal for controlling the level control circuit; and a noise detection circuit that detects noise in the received signal. , further comprising a switch inserted between the level control circuit and the control signal generation circuit and opened and closed according to the output signal of the noise detection circuit.
（ホ）作用
本発明に依れば、マルチパス妨害等が生じて雑音が増大
したとき、前記雑音を検出し、スイッチを開放させるの
で、制御信号発生回路の出力制御信号がレベル制御回路
に印加されなくなり、レベル制御回路が異常制御されな
くなる。(E) Effect According to the present invention, when noise increases due to multipath interference, etc., the noise is detected and the switch is opened, so that the output control signal of the control signal generation circuit is applied to the level control circuit. The level control circuit will no longer be abnormally controlled.
（へ）実施例
第１図は、本発明の一実施例を示す回路図で、（１３）
はアンテナ（１）に受信された信号をＩＦ（中間周波）
信号に変換するフロントエンド、（１４）は前記ＩＦ倍
信号増幅するＩＦ増幅回路、（１５）は該ＩＦ増幅回路
（１４）の出力信号を検波するＦＭ検波回路、（１６）
は該ＦＭ検波回路（１５）の出力信号（コンポジット信
号）中に含まれるステレオ差信号Ｓを同期検波する同期
検波回路、（１７）は前記コンポジット信号中に含まれ
る圧縮されたステレオ差信号Ｓ′を検波する直交検波回
路、（１８〉は比較回路（７）の出力端に接続されたス
イッチ、（１９）はＦＭ検波回路（１５）の出力信号中
に含まれる高域雑音を検出する雑音検出回路、及び（２
０〉は該雑音検出回路（１９〉の出力信号に応じて適切
なタイミングでスイッチ（１８）を開閉する開閉信号発
生回路である。(f) Embodiment FIG. 1 is a circuit diagram showing an embodiment of the present invention, (13)
is the signal received by antenna (1) as IF (intermediate frequency)
(14) is an IF amplification circuit that amplifies the IF multiplied signal; (15) is an FM detection circuit that detects the output signal of the IF amplification circuit (14); (16)
is a synchronous detection circuit that synchronously detects the stereo difference signal S included in the output signal (composite signal) of the FM detection circuit (15), and (17) is the compressed stereo difference signal S' included in the composite signal. (18) is a switch connected to the output terminal of the comparison circuit (7), (19) is a noise detection circuit that detects high-frequency noise contained in the output signal of the FM detection circuit (15). circuit, and (2
0> is an opening/closing signal generation circuit that opens and closes the switch (18) at appropriate timing according to the output signal of the noise detection circuit (19).
尚、第１図において、第４図と同一の回路素子には同一
の符号を付し説明を省略する。In FIG. 1, circuit elements that are the same as those in FIG. 4 are designated by the same reference numerals, and their explanations will be omitted.
ＦＭＸステレオ放送受信時には、ＦＭ検波回路（１５〉
の出力端にステレオ和信号Ｍが、同期検波回路（１６〉
の出力端にステレオ差信号Ｓが、直交検波回路（１７）
の出力端に圧縮されたステレオ差信号Ｓ′がそれぞれ発
生する。前記ステレオ差信号Ｓと圧縮されたステレオ差
信号Ｓ゛とは、加算回路（３）で加算され、ＶＣＡ（４
）でレベル制御されてスイッチ（１０）の端子に導出さ
れる。その際、ｖＣＡ（４）には第１及び第２レベル検
出回路（５）及び（６）と比較回路（７）とによって作
られる制御信号がスイッチ（１８）及び整流回路（８）
を介して印加されるので、前記Ｖ Ｃ Ａ （４）の出
力信号レベルは、ステレオ差信号Ｓのレベルに応じたも
のとなる。そして、ＶＣＡ（４）の出力信号は、スイッ
チ（１０）を介してマトリクス回路（９）に印加され、
ステレオ和信号Ｍとマトリクスされるので、前記マトリ
クス回路（９）の出力端子（１１）及び（１２）には、
左右ステレオ信号り及びＲが得られる。When receiving FMX stereo broadcasts, the FM detection circuit (15)
The stereo sum signal M is output to the output terminal of the synchronous detection circuit (16).
The stereo difference signal S is output to the output terminal of the quadrature detection circuit (17).
A compressed stereo difference signal S' is generated at the output end of each. The stereo difference signal S and the compressed stereo difference signal S' are added in an adder circuit (3), and then sent to a VCA (4).
) is level-controlled and led out to the terminal of the switch (10). At that time, the control signal generated by the first and second level detection circuits (5) and (6) and the comparison circuit (7) is sent to the vCA (4) by the switch (18) and the rectifier circuit (8).
, the output signal level of the V CA (4) corresponds to the level of the stereo difference signal S. The output signal of the VCA (4) is applied to the matrix circuit (9) via the switch (10),
Since it is matrixed with the stereo sum signal M, the output terminals (11) and (12) of the matrix circuit (9) have the following:
Left and right stereo signals and R are obtained.
同期検波回路（１６）の出力端に得られる出力信号中に
雑音が含まれていない場合には、雑音検出回路（１９）
の出力が発生せず、開閉信号発生回路（２０）の出力も
発生しない。その為、スイッチ（１８）は開成状態を保
ち、比較回路（７）の出力信号はスイ・ンチ（１８）及
び整流回路（８）を介してＶ Ｃ Ａ （４）に印加さ
れ、正常なレベル制御が行なわれる。If the output signal obtained at the output end of the synchronous detection circuit (16) does not contain noise, the noise detection circuit (19)
No output is generated, and no output from the switching signal generation circuit (20) is generated either. Therefore, the switch (18) remains open, and the output signal of the comparator circuit (7) is applied to VCA (4) via the switch (18) and the rectifier circuit (8), and the output signal is maintained at the normal level. Control takes place.
いま、マルチパス妨害等に起因して同期検波回路（１６
）の出力端に所定レベル以上の雑音が発生したとすれば
、雑音検出回路（１９）によって前記雑音が検出され、
開閉信号発生回路（２０）の出力信号が発生し、スイッ
チ（１８）が図示の開放状態となる。Currently, due to multipath interference, etc., the synchronous detection circuit (16
), the noise is detected by the noise detection circuit (19),
An output signal from the open/close signal generation circuit (20) is generated, and the switch (18) is placed in the open state shown in the figure.
その為、比較回路（７）の出力信号が遮断され、ＶＣＡ
（４）は整流回路（８）内のコンデンサ（図示せず）
の端子電圧に応じて制御される様になる。前記コンデン
サの端子電圧は、スイッチ（１８〉が開放する直前の値
を保持しているので、開閉信号発生回路（２０）の出力
信号のパルス幅を適切に設定すれば、スイッチ（１８）
の開放が行なわれても、ＶＣＡ（４）は正常にかつ連続
的に制御される。Therefore, the output signal of the comparator circuit (7) is cut off, and the VCA
(4) is a capacitor (not shown) in the rectifier circuit (8)
It comes to be controlled according to the terminal voltage of. Since the terminal voltage of the capacitor maintains the value immediately before the switch (18) opens, if the pulse width of the output signal of the switching signal generation circuit (20) is appropriately set, the terminal voltage of the switch (18)
Even if the VCA (4) is opened, the VCA (4) is normally and continuously controlled.
従って、第１図の如く、雑音の発生時に比較回路（７）
の出力信号を遮断すれば、Ｖ ＣＡ （４）が異常制御
されず、該Ｖ ＣＡ （４）の出力信号が異常に大とな
ったり、歪が発生するのを防止出来る。Therefore, as shown in Figure 1, when noise occurs, the comparator circuit (7)
By cutting off the output signal of the V CA (4), the V CA (4) is not controlled abnormally, and the output signal of the V CA (4) can be prevented from becoming abnormally large and generating distortion.
（ト）発明の効果
以上述べた如く、本発明に依れば、マルチパス妨害等に
起因する雑音により妨害を受けないＦＭＸステレオ放送
受信機を提供出来る。特に、レベル制御回路の出力信号
の大幅なレベル変化を防止し得るので、歪の発生やセパ
レーションの悪化を防止することが出来る。(g) Effects of the Invention As described above, according to the present invention, it is possible to provide an FMX stereo broadcast receiver that is not interfered with by noise caused by multipath interference or the like. In particular, since it is possible to prevent a large level change in the output signal of the level control circuit, it is possible to prevent the occurrence of distortion and deterioration of separation.
第１図は、本発明の、一実施例を示す回路図、第２図は
ＦＭＸステレオ放送信号のスペクトラムを示す特性図、
第３図はステレオ差信号と圧縮されたステレオ差信号と
の関係を示す特性図、及び第４図は従来のＦＭＸステレ
オ放送受信機を示す回路図である。
（４〉・・・ＶＣＡ、 （７）・・・比較回路、 （８
）・・・整流回路、 （１８）・・・スイッチ、 （１
９）・・・雑音検出回路。FIG. 1 is a circuit diagram showing an embodiment of the present invention, FIG. 2 is a characteristic diagram showing the spectrum of an FMX stereo broadcast signal,
FIG. 3 is a characteristic diagram showing the relationship between a stereo difference signal and a compressed stereo difference signal, and FIG. 4 is a circuit diagram showing a conventional FMX stereo broadcast receiver. (4>...VCA, (7)...comparison circuit, (8)
)... Rectifier circuit, (18)... Switch, (1
9)...Noise detection circuit.
Claims (1)
れたステレオ差信号を同時に送信するＦＭＸステレオ放
送を受信するＦＭＸステレオ放送受信機において、検波
されたステレオ差信号と圧縮されたステレオ差信号との
加算信号のレベルを制御するレベル制御回路と、前記ス
テレオ差信号のレベルと前記加算信号のレベルとを比較
し、前記レベル制御回路の制御信号を発生する制御信号
発生回路と、受信信号中に含まれる雑音を検出する雑音
検出回路と、前記制御信号発生回路と前記レベル制御回
路との間に挿入され、前記雑音検出回路の出力信号に応
じて開閉するスイッチとを備えるＦＭＸステレオ放送受
信機。(1) In an FMX stereo broadcast receiver that receives an FMX stereo broadcast that simultaneously transmits a compressed stereo difference signal together with a stereo sum signal and a stereo difference signal, the detected stereo difference signal and the compressed stereo difference signal are added together. a level control circuit that controls the level of the signal; a control signal generation circuit that compares the level of the stereo difference signal with the level of the addition signal and generates a control signal for the level control circuit; and a control signal generation circuit that is included in the received signal. An FMX stereo broadcast receiver comprising: a noise detection circuit for detecting noise; and a switch inserted between the control signal generation circuit and the level control circuit and opened and closed according to an output signal of the noise detection circuit.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7537087A JPS63240225A (en) | 1987-03-27 | 1987-03-27 | Fmx stereo broadcast receiver |
| US07/170,908 US4916741A (en) | 1987-03-27 | 1988-03-21 | FM/FMX stereophonic receiver |
| AU13707/88A AU601560B2 (en) | 1987-03-27 | 1988-03-24 | Fm/fmx stereophonic receiver |
| EP19880104869 EP0284101A3 (en) | 1987-03-27 | 1988-03-25 | Fm/fmx stereophonic receiver |
| CA000562583A CA1287115C (en) | 1987-03-27 | 1988-03-25 | Fm/fmx stereophonic receiver |
| KR1019880003328A KR880012033A (en) | 1987-03-27 | 1988-03-26 | Stereo broadcast receiver |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7537087A JPS63240225A (en) | 1987-03-27 | 1987-03-27 | Fmx stereo broadcast receiver |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63240225A true JPS63240225A (en) | 1988-10-05 |
| JPH0542184B2 JPH0542184B2 (en) | 1993-06-25 |
Family
ID=13574258
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7537087A Granted JPS63240225A (en) | 1987-03-27 | 1987-03-27 | Fmx stereo broadcast receiver |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63240225A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02135829A (en) * | 1988-11-16 | 1990-05-24 | Sanyo Electric Co Ltd | Signal discrimination circuit |
-
1987
- 1987-03-27 JP JP7537087A patent/JPS63240225A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02135829A (en) * | 1988-11-16 | 1990-05-24 | Sanyo Electric Co Ltd | Signal discrimination circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0542184B2 (en) | 1993-06-25 |
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