JPH04259121A - Radio reception system - Google Patents
Radio reception systemInfo
- Publication number
- JPH04259121A JPH04259121A JP4055491A JP4055491A JPH04259121A JP H04259121 A JPH04259121 A JP H04259121A JP 4055491 A JP4055491 A JP 4055491A JP 4055491 A JP4055491 A JP 4055491A JP H04259121 A JPH04259121 A JP H04259121A
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- Japan
- Prior art keywords
- intermediate frequency
- signal
- frequency
- filter
- radio reception
- 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.)
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- 230000002452 interceptive effect Effects 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 5
- 238000004519 manufacturing process Methods 0.000 abstract 1
- 238000003079 width control Methods 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 10
- 230000002159 abnormal effect Effects 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 239000000919 ceramic Substances 0.000 description 2
- 238000001514 detection method Methods 0.000 description 1
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
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- Superheterodyne Receivers (AREA)
- Noise Elimination (AREA)
- Circuits Of Receivers In General (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明はラジオ受信方式に係わり
、特に中間周波フィルタの中心周波数を入力信号である
中間周波信号の瞬時周波数に追従させるラジオ受信方式
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio reception system, and more particularly to a radio reception system in which the center frequency of an intermediate frequency filter follows the instantaneous frequency of an input intermediate frequency signal.
【０００２】0002
【従来の技術】低周波信号を復調する復調回路の出力を
利用して、中間周波フィルタの中心周波数や帯域幅の広
狭を入力信号（中間周波信号）の瞬時周波数に追従して
制御するラジオ受信方式がある。[Prior Art] Radio reception that uses the output of a demodulation circuit that demodulates low-frequency signals to control the center frequency and bandwidth of an intermediate-frequency filter in accordance with the instantaneous frequency of an input signal (intermediate-frequency signal). There is a method.
【０００３】図４はかかるラジオ受信方式を採用したＦ
Ｍラジオ受信機の要部構成図であり、１１はアンテナ、
１２は１０．７ＭＨｚの中間周波信号を出力するフロン
トエンド、１３は中間周波帯域幅を設定するセラミック
フィルタで、２００ＫＨｚ間隔で局周波数が定められて
いる場合、周波数特性は図５のＣＦＦのように設定され
る。１４は１０ＭＨｚの局部発振器、１５は混合器であ
り、狭帯域フィルタを構成しやすいように１０．７ＭＨ
ｚの中間周波数を７００ＫＨｚに変換するものである。FIG. 4 shows an F using such a radio reception system.
It is a main part configuration diagram of the M radio receiver, 11 is an antenna,
12 is a front end that outputs a 10.7 MHz intermediate frequency signal, and 13 is a ceramic filter that sets the intermediate frequency bandwidth. When the local frequency is set at 200 KHz intervals, the frequency characteristics are as shown in the CFF in Figure 5. Set. 14 is a 10MHz local oscillator, 15 is a mixer, and 10.7MHz is used to easily configure a narrowband filter.
This converts the intermediate frequency of z to 700KHz.
【０００４】１６は帯域幅や中心周波数ｆ０を可変可能
な中間周波フィルタ、１７は中間周波信号より低周波信
号を復調する復調回路であり、中間周波数７００ＫＨｚ
からの周波数変調度（偏移）が大きくなる程出力は大き
くなる。１８はフィルタ制御信号発生部であり、復調出
力に基づいて、換言すれば中間周波信号の周波数偏移（
中間周波信号の瞬時周波数）１に従って図５の１ａ〜１
ｃに示すように、中間フィルタ１６の中心周波数ｆ０を
移動させ、かつ帯域幅の広狭を制御する。尚、図５にお
いて２、３は希望局と隣接妨害局の周波数スペクトルで
ある。かかるラジオ受信方式によれば、隣接局妨害が小
さい場合には、ひずみが少ない良好な音質でラジオ受信
ができる長所がある。16 is an intermediate frequency filter whose bandwidth and center frequency f0 can be varied, and 17 is a demodulation circuit that demodulates a lower frequency signal than the intermediate frequency signal, and has an intermediate frequency of 700 KHz.
The output increases as the degree of frequency modulation (deviation) from . 18 is a filter control signal generator, which generates the frequency deviation of the intermediate frequency signal (based on the demodulated output).
1a to 1 in Fig. 5 according to 1 (instantaneous frequency of intermediate frequency signal) 1
As shown in c, the center frequency f0 of the intermediate filter 16 is moved and the width of the bandwidth is controlled. In FIG. 5, numerals 2 and 3 are the frequency spectra of the desired station and the adjacent interfering station. This radio reception system has the advantage that when adjacent station interference is small, radio reception can be performed with good sound quality and little distortion.
【０００５】[0005]
【発明が解決しようとする課題】しかし、上記ラジオ受
信方式は中間周波フィルタの中心周波数を周波数偏移に
応じて移動させるものであるため、図６の点線で示すよ
うに隣接妨害局の変調度が高く、且つ電波が希望局より
強い場合、中間周波フィルタが隣接妨害局側に引き込ま
れ一瞬混信を起こし、バリバリというような不快な雑音
を発生する問題があった。[Problems to be Solved by the Invention] However, since the above radio reception system moves the center frequency of the intermediate frequency filter according to the frequency shift, the modulation degree of the adjacent interfering station changes as shown by the dotted line in FIG. When the signal is high and the radio waves are stronger than the desired station, the intermediate frequency filter is drawn into the adjacent interfering station, causing momentary interference, which causes an unpleasant crunching noise.
【０００６】以上から、本発明の目的は隣接妨害局の変
調度が高く、且つ電波が希望局より強い場合であっても
、雑音の発生を防止できるラジオ受信方式を提供するこ
とである。SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a radio reception system that can prevent the generation of noise even when the modulation degree of an adjacent interfering station is high and the radio waves are stronger than the desired station.
【０００７】[0007]
【課題を解決するための手段】上記課題は、隣接妨害信
号の変調度が大きく強度が設定レベル以上であることを
識別する手段、中間周波フィルタの中心周波数を中間周
波帯域の中心に固定する手段、隣接妨害信号の強度に応
じて中間周波フィルタの帯域幅を可変する手段とにより
達成される。[Means for Solving the Problems] The above-mentioned problems are a means for identifying that the degree of modulation of an adjacent interference signal is large and the intensity is above a set level, and a means for fixing the center frequency of an intermediate frequency filter to the center of the intermediate frequency band. , and means for varying the bandwidth of the intermediate frequency filter depending on the strength of the adjacent interference signal.
【０００８】[0008]
【作用】低周波信号を復調する復調回路の出力に基づい
て中間周波フィルタの中心周波数を入力信号（中間周波
信号）の瞬時周波数に追従させてラジオ受信する。かか
るラジオ受信において、隣接妨害信号の変調度が大きく
て強度が設定レベル以上になった時、中間周波フィルタ
の中心周波数を中間周波帯域の中心に固定すると共に、
隣接妨害信号が強くなる程、中間周波フィルタの帯域幅
を狭くする。このようにすれば、隣接妨害局の変調度が
高く、且つ電波が希望局より強い場合であっても、隣接
妨害局と混信を起こすことが無く雑音の発生を防止でき
る[Operation] Radio reception is performed by making the center frequency of the intermediate frequency filter follow the instantaneous frequency of the input signal (intermediate frequency signal) based on the output of the demodulation circuit that demodulates the low frequency signal. In such radio reception, when the degree of modulation of the adjacent interference signal is large and the intensity exceeds a set level, the center frequency of the intermediate frequency filter is fixed at the center of the intermediate frequency band, and
The stronger the adjacent interference signal, the narrower the bandwidth of the intermediate frequency filter. In this way, even if the modulation degree of the adjacent jamming station is high and the radio wave is stronger than the desired station, interference with the adjacent jamming station will not occur and noise generation can be prevented.
【０００９】又、低周波信号を復調する復調回路の出力
に基づいて中間周波フィルタの中心周波数を入力信号（
中間周波信号）の瞬時周波数に追従させる第１のラジオ
受信モ−ドと、中間周波フィルタの中心周波数を入力信
号（中間周波信号）の瞬時周波数に追従させない第２の
ラジオ受信モ−ドを設け、通常第１のラジオ受信モ−ド
で受信し、隣接妨害信号の変調度が大きくて強度が設定
レベル以上になったら、第２のラジオ受信モ−ドに切り
換えて受信するようにする。このようにすれば、隣接妨
害によって起こるＳ／Ｎの劣化や異音の発生を防止でき
る。Furthermore, the center frequency of the intermediate frequency filter is determined based on the output of the demodulation circuit that demodulates the low frequency signal.
A first radio reception mode in which the center frequency of the intermediate frequency filter does not follow the instantaneous frequency of the input signal (intermediate frequency signal) is provided. Normally, the first radio reception mode is used for reception, and when the degree of modulation of the adjacent interference signal is large and the intensity exceeds a set level, the next radio reception mode is switched to the second radio reception mode for reception. In this way, it is possible to prevent S/N deterioration and abnormal noise caused by adjacent interference.
【００１０】0010
【実施例】（ａ） 第１の実施例
全体の構成
図１は本発明に係わるラジオ受信方式を採用したＦＭラ
ジオ受信機の要部構成図であり、１１はアンテナ、１２
は１０．７ＭＨｚの中間周波信号を出力するフロントエ
ンド、１３は中間周波帯域幅を設定するセラミックフィ
ルタ、１４は１０ＭＨｚの局部発振器、１５は１０．７
ＭＨｚの中間周波数を７００ＫＨｚに変換する混合器、
１６は帯域幅や中心周波数ｆ０を可変可能な中間周波フ
ィルタ、１７は中間周波信号より低周波信号を復調する
復調回路、１８はフィルタ制御信号発生部であり、復調
出力に基づいてフィルタ制御信号ＦＣＮを発生し、中間
周波フィルタ１６の中心周波数ｆ０を中間周波信号の周
波数偏移（換言すれば中間周波信号の瞬時周波数）に従
って移動させる。[Embodiment] (a) Overall configuration of the first embodiment Fig. 1 is a diagram showing the main part configuration of an FM radio receiver that adopts the radio reception system according to the present invention.
is a front end that outputs a 10.7 MHz intermediate frequency signal, 13 is a ceramic filter that sets the intermediate frequency bandwidth, 14 is a 10 MHz local oscillator, and 15 is 10.7
a mixer that converts an intermediate frequency of MHz to 700KHz;
16 is an intermediate frequency filter whose bandwidth and center frequency f0 can be varied, 17 is a demodulation circuit that demodulates a lower frequency signal than the intermediate frequency signal, and 18 is a filter control signal generator, which generates a filter control signal FCN based on the demodulated output. is generated, and the center frequency f0 of the intermediate frequency filter 16 is moved according to the frequency shift of the intermediate frequency signal (in other words, the instantaneous frequency of the intermediate frequency signal).
【００１１】尚、以上の構成は図４の従来例の構成と同
一であるが、（１） フィルタ制御信号発生部１８が後
述フィルタ制御指令ＦＣＳにより、中間周波フィルタ１
６の中心周波数を中間周波帯域の中心に固定する機能を
備えている点、及び（２） 中間周波フィルタ１６が後
述する先鋭度切換信号ＱＳＷにより帯域幅を広狭に制御
される点で異なる。The above configuration is the same as the configuration of the conventional example shown in FIG.
The difference is that the intermediate frequency filter 16 has a function of fixing the center frequency of 6 at the center of the intermediate frequency band, and (2) the intermediate frequency filter 16 is controlled to widen or narrow the bandwidth by a sharpness switching signal QSW, which will be described later.
【００１２】２１は隣接妨害信号の変調度が大きく強度
が設定レベル以上であることを識別する隣接妨害識別部
であり、復調回路１７の復調出力が入力される１００Ｋ
Ｈｚのハイパスフィルタ２１ａと、ハイパスフィルタ２
１ａの出力が設定レベルＶＳ１以上であるか比較し、設
定レベル以上の場合にはフィルタ制御停止指令ＦＣＳを
出力するレベル比較器２１ｂを有している。Reference numeral 21 denotes an adjacent interference identification unit which identifies that the degree of modulation of the adjacent interference signal is large and the intensity is higher than a set level, and the demodulation output of the demodulation circuit 17 is inputted to the adjacent interference identification unit.
Hz high pass filter 21a and high pass filter 2
It has a level comparator 21b which compares whether the output of 1a is higher than the set level VS1 and outputs a filter control stop command FCS if it is higher than the set level.
【００１３】２２は隣接妨害信号の変調度が大きく強度
が設定レベル以上の時、隣接妨害信号の強度に応じて中
間周波フィルタ１６の帯域幅を制御する帯域広狭制御部
であり、例えばハイパスフィルタ２１ａの出力が設定レ
ベルＶＳ２（＞ＶＳ１）以上であるか比較し、設定レベ
ルＶＳ２以上の場合には共振尖鋭度切換信号ＱＳＷを出
力する。中間周波フィルタ１６は切換信号ＱＳＷにより
抵抗値を変えて共振尖鋭度Ｑを上げて帯域幅を狭める。
尚、ハイパスフィルタ２１ａの出力電圧に応じて数段階
にわたって中間周波フィルタ１６の抵抗値を変えて帯域
幅を制御するように構成することもできる。Reference numeral 22 denotes a band wide/narrow control section which controls the bandwidth of the intermediate frequency filter 16 according to the intensity of the adjacent interference signal when the degree of modulation of the adjacent interference signal is large and the intensity exceeds a set level. It is compared whether the output of is equal to or higher than a set level VS2 (>VS1), and if it is equal to or higher than the set level VS2, a resonance sharpness switching signal QSW is output. The intermediate frequency filter 16 changes its resistance value in response to the switching signal QSW to increase the resonance sharpness Q and narrow the bandwidth. Note that it is also possible to configure the bandwidth to be controlled by changing the resistance value of the intermediate frequency filter 16 over several stages depending on the output voltage of the high-pass filter 21a.
【００１４】中間周波フィルタの構成
図２は帯域幅を広狭２段階に制御される中間周波フ
ィルタ１６の構成図であり、帯域の広狭の選択は切換信
号ＱＳＷに基づいてスイッチＳＷをオン・オフして抵抗
Ｒを共振回路ＲＮＣに並列に接続するかしないかにより
行ない、中心周波数（共振周波数）はバリキャップＶＣ
に印加するフィルタ制御信号ＦＣＮの電圧値に基づいて
制御する。Configuration of Intermediate Frequency Filter FIG. 2 is a configuration diagram of an intermediate frequency filter 16 whose bandwidth is controlled in two stages, wide and narrow.The selection of the wide or narrow band is made by turning on and off the switch SW based on the switching signal QSW. The center frequency (resonant frequency) is determined by whether or not the resistor R is connected in parallel with the resonant circuit RNC.
The control is performed based on the voltage value of the filter control signal FCN applied to the filter control signal FCN.
【００１５】全体の動作
通常は、低周波信号を復調する復調回路１７の出力
に応じた電圧値を有するフィルタ制御信号ＦＣＮをフィ
ルタ制御信号発生部１８から発生し、該フィルタ制御信
号ＦＣＮに従って、換言すれば中間周波信号の周波数偏
移に従って、中間周波フィルタ１６の中心周波数ｆ０を
移動させる。Overall operation Normally, a filter control signal FCN having a voltage value corresponding to the output of the demodulation circuit 17 for demodulating a low frequency signal is generated from the filter control signal generating section 18, and according to the filter control signal FCN, Then, the center frequency f0 of the intermediate frequency filter 16 is moved according to the frequency shift of the intermediate frequency signal.
【００１６】かかるラジオ受信状態において、隣接妨害
信号の変調度が大きくて強度が設定レベルＶＳ１以上に
なると、レベル比較器２１ｂはフィルタ制御停止指令Ｆ
ＣＳを発生する。これにより、フィルタ制御信号発生部
１８はフィルタ制御信号ＦＣＮをバイス電圧に固定し（
交流分を零にし）、中間周波フィルタ１６の中心周波数
を中間周波帯域の中心に固定する（図５の１ａ参照）。
以上により、隣接妨害局の電波が強い場合であっても、
混信を起こすことが無く雑音の発生を防止できる。In such a radio reception state, when the degree of modulation of the adjacent interference signal is large and the intensity exceeds the set level VS1, the level comparator 21b issues a filter control stop command F.
Generate CS. As a result, the filter control signal generator 18 fixes the filter control signal FCN to the bias voltage (
(the AC component is made zero), and the center frequency of the intermediate frequency filter 16 is fixed at the center of the intermediate frequency band (see 1a in FIG. 5). As a result of the above, even when the radio waves of adjacent interfering stations are strong,
Noise generation can be prevented without causing interference.
【００１７】又、隣接妨害局の妨害電波強度が強くなっ
てハイパスフィルタ２１ａの出力が設定レベルＶＳ２以
上になれば、帯域広狭制御部２２は尖鋭度切換信号ＱＳ
Ｗを発生して中間周波フィルタ１６の共振尖鋭度Ｑを上
昇して帯域を狭める（図５の１ａ′参照）。この結果、
希望局信号の音質が若干劣化するが妨害局と混信するこ
とが無くなり雑音の発生を防止できる。[0017] Furthermore, when the interference radio wave intensity of the adjacent jamming station becomes strong and the output of the high-pass filter 21a exceeds the set level VS2, the band wide/narrow control section 22 changes the sharpness switching signal QS.
W is generated to increase the resonance sharpness Q of the intermediate frequency filter 16 and narrow the band (see 1a' in FIG. 5). As a result,
Although the sound quality of the desired station signal is slightly degraded, there is no interference with the interfering station, and the generation of noise can be prevented.
【００１８】（ｂ） 第２の実施例
図３は本発明のラジオ受信方式の別の実施例構成図であ
り、図１と同一部分には同一符号を付している。図中、
１１はアンテナ、１２はフロントエンド、２１は隣接妨
害信号の変調度が大きく強度が設定レベル以上であるこ
とを識別する隣接妨害検出部であり、１００ＫＨｚのハ
イパスフィルタ２１ａと、ハイパスフィルタ２１ａの出
力が設定レベルＶＳ１以上であるか比較し、設定レベル
以上の場合には受信モ−ド切換信号ＲＭＳを出力するレ
ベル比較器２１ｂを有している。(b) Second Embodiment FIG. 3 is a block diagram of another embodiment of the radio reception system of the present invention, and the same parts as in FIG. 1 are given the same reference numerals. In the figure,
11 is an antenna, 12 is a front end, 21 is an adjacent interference detection unit that identifies when the modulation degree of the adjacent interference signal is large and the intensity is higher than a set level, and a 100 KHz high-pass filter 21a and an output of the high-pass filter 21a are connected to each other. It has a level comparator 21b which compares whether it is higher than a set level VS1 and outputs a reception mode switching signal RMS if it is higher than the set level.
【００１９】３１は第１のラジオ受信部であり、中間周
波フィルタの中心周波数を中間周波信号の瞬時周波数に
追従させて受信するもので、図４の点線で囲んだ部分と
同一の構成を有している。Reference numeral 31 denotes a first radio receiving section, which receives the intermediate frequency signal by making the center frequency of the intermediate frequency filter follow the instantaneous frequency of the intermediate frequency signal, and has the same configuration as the part surrounded by the dotted line in FIG. are doing.
【００２０】３２は第２のラジオ受信部であり、中間周
波フィルタの中心周波数を中間周波信号の瞬時周波数に
追従させない通常のラジオ受信を行なうもの、３３は受
信モ−ド切換信号ＲＭＳに基づいて所定のラジオ受信部
からの信号を選択して出力するセレクタである。Reference numeral 32 denotes a second radio reception section, which performs normal radio reception in which the center frequency of the intermediate frequency filter is not made to follow the instantaneous frequency of the intermediate frequency signal; 33, the reception mode is changed based on the reception mode switching signal RMS This is a selector that selects and outputs a signal from a predetermined radio receiving section.
【００２１】通常、セレクタ３３は第１のラジオ受信部
３１からの信号を選択して出力している。すなわち、通
常は中間周波信号の周波数偏移に従って中間周波フィル
タの中心周波数ｆ０を移動させてラジオを受信している
。Normally, the selector 33 selects and outputs the signal from the first radio receiving section 31. That is, radio is normally received by moving the center frequency f0 of the intermediate frequency filter according to the frequency shift of the intermediate frequency signal.
【００２２】かかるラジオ受信状態において、隣接妨害
信号の変調度が大きくなって強度が設定レベルＶＳ１以
上になると、隣接妨害識別部２１のレベル比較器２１ｂ
は受信モ−ド切換信号ＲＭＳを出力する。In such a radio reception state, when the degree of modulation of the adjacent interference signal increases and its intensity exceeds the set level VS1, the level comparator 21b of the adjacent interference identification section 21
outputs a reception mode switching signal RMS.
【００２３】受信モ−ド切換信号ＲＭＳの発生により、
セレクタ３３は第２のラジオ受信部３２からの信号を選
択して出力する。この結果、以後中間周波フィルタの中
心周波数を中間周波信号の瞬時周波数に追従させない第
２のラジオ受信モ−ドでラジオ受信する。By generating the reception mode switching signal RMS,
The selector 33 selects and outputs the signal from the second radio receiving section 32. As a result, radio reception is subsequently performed in the second radio reception mode in which the center frequency of the intermediate frequency filter is not made to follow the instantaneous frequency of the intermediate frequency signal.
【００２４】以後、第２のラジオ受信モ−ドでラジオ受
信を継続し、隣接妨害信号の変調度が小さくなって強度
が設定レベルＶＳ１以下になると再び第１のラジオ受信
モ−ドに切り替わってラジオ受信が行なわれる。このよ
うにすれば、隣接妨害によって起こるＳ／Ｎの劣化や異
音の発生を防止できる。Thereafter, radio reception continues in the second radio reception mode, and when the degree of modulation of the adjacent interfering signal becomes smaller and the intensity becomes less than the set level VS1, the mode switches to the first radio reception mode again. Radio reception is performed. In this way, it is possible to prevent S/N deterioration and abnormal noise caused by adjacent interference.
【００２５】以上、本発明を実施例により説明したが、
本発明は請求の範囲に記載した本発明の主旨に従い種々
の変形が可能であり、本発明はこれらを排除するもので
はない。The present invention has been explained above using examples, but
The present invention can be modified in various ways according to the gist of the present invention as described in the claims, and the present invention does not exclude these modifications.
【００２６】[0026]
【発明の効果】以上本発明によれば、隣接妨害信号の変
調度が大きくて強度が設定レベル以上になった時、中間
周波フィルタの中心周波数を中間周波帯域の中心に固定
すると共に、隣接妨害信号の強度に応じて中間周波フィ
ルタの帯域幅を可変するように構成したから、隣接妨害
局と混信を起こすことが無く雑音の発生を防止できる。According to the present invention, when the degree of modulation of the adjacent interference signal is large and the intensity exceeds the set level, the center frequency of the intermediate frequency filter is fixed at the center of the intermediate frequency band, and the adjacent interference signal is fixed at the center of the intermediate frequency band. Since the bandwidth of the intermediate frequency filter is configured to be variable according to the strength of the signal, it is possible to prevent noise from occurring without causing interference with adjacent interfering stations.
【００２７】又、本発明によれば、低周波信号を復調す
る復調回路の出力に基づいて中間周波フィルタの中心周
波数を入力信号（中間周波信号）の瞬時周波数に追従さ
せる第１のラジオ受信モ−ドと、中間周波フィルタの中
心周波数を入力信号（中間周波信号）の瞬時周波数に追
従させない第２のラジオ受信をモ−ドを設け、通常第１
のラジオ受信モ−ドで受信し、隣接妨害信号の変調度が
大きくて強度が設定レベル以上になったら、第２のラジ
オ受信モ−ドに切り換えて受信するように構成したから
、隣接妨害によって起こるＳ／Ｎの劣化や異音の発生を
防止できる。Further, according to the present invention, the first radio receiving module causes the center frequency of the intermediate frequency filter to follow the instantaneous frequency of the input signal (intermediate frequency signal) based on the output of the demodulation circuit that demodulates the low frequency signal. - mode and a second radio reception mode in which the center frequency of the intermediate frequency filter does not follow the instantaneous frequency of the input signal (intermediate frequency signal).
The configuration is configured so that when the adjacent interference signal is received in the second radio reception mode and the modulation degree of the adjacent interference signal is large and the intensity exceeds the set level, it is switched to the second radio reception mode and received. It is possible to prevent S/N deterioration and abnormal noise from occurring.
【図１】本発明に係わるラジオ受信方式を採用したＦＭ
ラジオ受信機の要部構成図である。[Figure 1] FM using the radio reception method according to the present invention
FIG. 2 is a configuration diagram of main parts of a radio receiver.
【図２】中間周波フィルタの構成図である。FIG. 2 is a configuration diagram of an intermediate frequency filter.
【図３】本発明の別の実施例構成図である。FIG. 3 is a configuration diagram of another embodiment of the present invention.
【図４】従来のＦＭラジオ受信機の構成図である。FIG. 4 is a configuration diagram of a conventional FM radio receiver.
【図５】従来のラジオ受信方式の説明図である。FIG. 5 is an explanatory diagram of a conventional radio reception system.
【図６】従来のラジオ受信方式の問題点説明図である。FIG. 6 is an explanatory diagram of problems in the conventional radio reception system.
１６・・中間周波フィルタ １７・・復調回路 １８・・フィルタ制御信号発生部 ２１・・隣接妨害識別部 ２２・・帯域広狭制御部 16...Intermediate frequency filter 17... Demodulation circuit 18... Filter control signal generation section 21...Adjacent interference identification unit 22... Bandwidth wide/narrow control section
Claims (2)
ィルタの中心周波数を入力信号の瞬時周波数に追従させ
るラジオ受信方式において、隣接妨害信号の変調度が大
きくて強度が設定レベル以上の時、中間周波フィルタの
中心周波数を中間周波帯域の中心に固定すると共に、隣
接妨害信号の強度に応じて中間周波フィルタの帯域幅を
可変することを特徴とするラジオ受信方式。Claim 1. In a radio reception system in which the center frequency of an intermediate frequency filter follows the instantaneous frequency of an input signal based on the output of a demodulation circuit, when the degree of modulation of an adjacent interference signal is large and the intensity is above a set level, A radio receiving system characterized in that the center frequency of a frequency filter is fixed at the center of an intermediate frequency band, and the bandwidth of the intermediate frequency filter is varied according to the strength of an adjacent interfering signal.
ィルタの中心周波数を入力信号の瞬時周波数に追従させ
る第１のラジオ受信方式と、中間周波フィルタの中心周
波数を入力信号の瞬時周波数に追従させない第２のラジ
オ受信方式を備えたラジオ受信方式において、隣接妨害
信号の変調度が小さくて強度が設定レベル以下の時、第
１のラジオ受信方式で受信し、隣接妨害信号の変調度が
大きくて強度が設定レベル以上の時、第２のラジオ受信
方式で受信することを特徴とするラジオ受信方式。[Claim 2] A first radio reception method in which the center frequency of the intermediate frequency filter follows the instantaneous frequency of the input signal based on the output of the demodulation circuit, and the center frequency of the intermediate frequency filter does not follow the instantaneous frequency of the input signal. In a radio reception system equipped with a second radio reception system, when the modulation degree of the adjacent interference signal is small and the intensity is below the set level, it is received using the first radio reception system, and when the modulation degree of the adjacent interference signal is large, A radio reception method characterized in that when the intensity is above a set level, reception is performed using a second radio reception method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4055491A JPH04259121A (en) | 1991-02-13 | 1991-02-13 | Radio reception system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4055491A JPH04259121A (en) | 1991-02-13 | 1991-02-13 | Radio reception system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04259121A true JPH04259121A (en) | 1992-09-14 |
Family
ID=12583671
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4055491A Withdrawn JPH04259121A (en) | 1991-02-13 | 1991-02-13 | Radio reception system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04259121A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009071574A (en) * | 2007-09-13 | 2009-04-02 | Pioneer Electronic Corp | Receiver and receiving method |
-
1991
- 1991-02-13 JP JP4055491A patent/JPH04259121A/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009071574A (en) * | 2007-09-13 | 2009-04-02 | Pioneer Electronic Corp | Receiver and receiving method |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Application deemed to be withdrawn because no request for examination was validly filed |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 19980514 |