EP0691050B1 - Circuit pour la derivation de signaux de masquage de signaux audio - Google Patents

Circuit pour la derivation de signaux de masquage de signaux audio Download PDF

Info

Publication number
EP0691050B1
EP0691050B1 EP94911062A EP94911062A EP0691050B1 EP 0691050 B1 EP0691050 B1 EP 0691050B1 EP 94911062 A EP94911062 A EP 94911062A EP 94911062 A EP94911062 A EP 94911062A EP 0691050 B1 EP0691050 B1 EP 0691050B1
Authority
EP
European Patent Office
Prior art keywords
signal
signals
low
pass filter
circuit
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 - Lifetime
Application number
EP94911062A
Other languages
German (de)
English (en)
Other versions
EP0691050A1 (fr
Inventor
Djahanyar Chahabadi
Matthias Herrmann
Lothar Vogt
Jürgen KÄSSER
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Blaupunkt Werke GmbH
Original Assignee
Blaupunkt Werke GmbH
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from DE4309518A external-priority patent/DE4309518A1/de
Application filed by Blaupunkt Werke GmbH filed Critical Blaupunkt Werke GmbH
Publication of EP0691050A1 publication Critical patent/EP0691050A1/fr
Application granted granted Critical
Publication of EP0691050B1 publication Critical patent/EP0691050B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04H—BROADCAST COMMUNICATION
    • H04H40/00—Arrangements specially adapted for receiving broadcast information
    • H04H40/18—Arrangements characterised by circuits or components specially adapted for receiving
    • H04H40/27—Arrangements characterised by circuits or components specially adapted for receiving specially adapted for broadcast systems covered by groups H04H20/53 - H04H20/95
    • H04H40/36—Arrangements characterised by circuits or components specially adapted for receiving specially adapted for broadcast systems covered by groups H04H20/53 - H04H20/95 specially adapted for stereophonic broadcast receiving
    • H04H40/45—Arrangements characterised by circuits or components specially adapted for receiving specially adapted for broadcast systems covered by groups H04H20/53 - H04H20/95 specially adapted for stereophonic broadcast receiving for FM stereophonic broadcast systems receiving
    • H04H40/63—Arrangements characterised by circuits or components specially adapted for receiving specially adapted for broadcast systems covered by groups H04H20/53 - H04H20/95 specially adapted for stereophonic broadcast receiving for FM stereophonic broadcast systems receiving for separation improvements or adjustments
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04H—BROADCAST COMMUNICATION
    • H04H40/00—Arrangements specially adapted for receiving broadcast information
    • H04H40/18—Arrangements characterised by circuits or components specially adapted for receiving
    • H04H40/27—Arrangements characterised by circuits or components specially adapted for receiving specially adapted for broadcast systems covered by groups H04H20/53 - H04H20/95
    • H04H40/36—Arrangements characterised by circuits or components specially adapted for receiving specially adapted for broadcast systems covered by groups H04H20/53 - H04H20/95 specially adapted for stereophonic broadcast receiving
    • H04H40/45—Arrangements characterised by circuits or components specially adapted for receiving specially adapted for broadcast systems covered by groups H04H20/53 - H04H20/95 specially adapted for stereophonic broadcast receiving for FM stereophonic broadcast systems receiving
    • H04H40/72—Arrangements characterised by circuits or components specially adapted for receiving specially adapted for broadcast systems covered by groups H04H20/53 - H04H20/95 specially adapted for stereophonic broadcast receiving for FM stereophonic broadcast systems receiving for noise suppression
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04H—BROADCAST COMMUNICATION
    • H04H20/00—Arrangements for broadcast or for distribution combined with broadcast
    • H04H20/53—Arrangements specially adapted for specific applications, e.g. for traffic information or for mobile receivers
    • H04H20/57—Arrangements specially adapted for specific applications, e.g. for traffic information or for mobile receivers for mobile receivers

Definitions

  • the invention relates to a circuit arrangement for deriving signals for masking audio signals in a radio receiver. Due to drops in the received field strength, the reception quality can fluctuate significantly, particularly with car radios. In order to keep the resulting interference as low as possible, measures for masking these interference in audio signals are known. For example, with low reception field strength, it is possible to reduce the stereo channel separation or to temporarily attenuate the audio signals.
  • a noise reduction circuit is known from EP 0 449 199 A, by means of which interference at the output of a receiver can be reduced. For this purpose, the field strength of the received radio signal is determined. Furthermore, a noise value is tapped at the output of the radio receiver and both signals are fed to a fuzzy circuit. On the basis of the output signal of the fuzzy circuit, an attenuation circuit is now activated, which is intended to reduce the noise level at the output of the receiver.
  • a further noise reduction circuit is known from EP 0 418 036 A, in which occurring noises are damped by a low-pass filter with a variable cut-off frequency in the differential signal after the stereo demodulator is switched on.
  • the cut-off frequency is determined as a function of a control signal which is determined on the basis of the received RF level, the multipath propagation level and the spectral content of the audio signal.
  • an FM radio system is known in which the receiver also has a noise reduction circuit. To reduce noise, both the received field strength of the received signal and the spectrum at the output of the discriminator are evaluated, with frequencies above 3 kHz being considered. In the case of weak signals or relay faults, the output signal is only attenuated if the control signal for the attenuation rises above a predetermined signal-to-noise ratio.
  • the measure according to the invention further improves interference suppression.
  • this makes it possible to reduce the stereo channel separation even in the case of relatively short field strength drops, while the signals are damped as a function of the presence of interference signals in the received signal when the field strength drops are more or less short.
  • coefficients can also be stored permanently in the circuit arrangement according to the invention
  • a further development of the invention is particularly advantageous in that the coefficient or coefficients are stored in a non-volatile memory and with the aid of a microcomputer, a display device and an operating device and with the aid of a program are changeable for operator guidance.
  • This further training means that individual copies can be adapted a larger series of radio receivers to different, for example, typical operating conditions possible.
  • the coefficients can also be changed by a service workshop or by the user.
  • a further development of the invention consists in combining the weighted field strength signals to form masking signals with auxiliary signals which indicate the presence of interference signals.
  • the combination with the auxiliary signals is preferably carried out by multiplication.
  • circuit arrangement according to the invention can be implemented in various ways. For example, individual or groups of the blocks shown can be implemented using suitable circuits, in particular integrated circuits. With a very high degree of integration, it is also possible to implement the entire digital signal processing of the receiver in an integrated circuit, signal processing steps, such as filtering or nonlinear weighting, being carried out by arithmetic operations. To implement a receiver with the circuit arrangement according to the invention, digital signal processors and other digital circuits, such as shift registers, flip-flops etc., can also be arranged together within an integrated circuit.
  • a signal H3 is fed to an input 1 which corresponds to the received field strength in is substantially proportional and is referred to below as auxiliary signal H3.
  • This is averaged in two low-pass filters 2, 3 with different time constants.
  • a changeover switch 4 forwards one of the output signals of the low-pass filters 2, 3 as a signal AMC depending on a signal DD2 to be explained later.
  • This is weighted at 5 to generate a signal AFE indicating the noise attenuation and can be removed at an output 6.
  • the signal WF with a smaller time constant is also weighted at 7 and can be taken from an output 8 as signal WF2.
  • Coefficients K1, K2 required for weighting are stored in a non-volatile memory 9 and are supplied to the circuits 5, 7 via a microcomputer 10.
  • K1 and K2 can be individual coefficients or a group of coefficients.
  • a display device 11 and an input device 12 are connected to the microcomputer 10.
  • the microcomputer 10 is provided with a program which allows the setting of the coefficients in a menu-driven manner.
  • Fig. 2 shows details of the circuit 7 (Fig. 1).
  • the signal WF can be fed to an input 15, while inputs 16, 17 are fed to coefficients K1.1 and K1.2.
  • a multiplier 18 the signal WF is multiplied by the coefficient K1.1.
  • the product is then added to the coefficient K1.2 at 19.
  • the output signal of the adder 19 is compared with the value 0 at 20 and replaced with the value 0 in the case of negative values with the aid of a changeover switch 21.
  • Fig. 3 shows an example of a circuit 5 (Fig. 1), in which the signal AMC supplied at 23 with an am Input 24 applied coefficient K2 is multiplied by 25.
  • the signal AFE can be taken from an output 26.
  • the dependence of the stereo channel separation SK shown in FIG. 4 on the reception field strength E can be set with the aid of the coefficients K1.1 and K1.2.
  • a solid and a dashed curve are shown as examples.
  • the coefficient K1.1 is essentially the slope and the coefficient K1.2 the shift on the field strength axis.
  • the curve shown includes the dependency of the stereo channel separation on the signal WF2, which is given by characteristics within the stereo decoder.
  • Fig. 5 shows the attenuation L as a function of the received field strength E for two different values of the coefficient K2.
  • Fig. 6 shows a second embodiment.
  • the auxiliary signals H1, H2 and H3 are fed to inputs 45, 46, 27.
  • the auxiliary signal H3 characterizing the reception field strength is averaged in two low-pass filters 28, 29 with different time constants.
  • a changeover switch 30 forwards one of the output signals of the low-pass filters 28, 29 as the signal AMC. This is weighted at 32 in the form of a noise curve to generate the noise attenuation AFE.
  • the field strength signal with the smaller time constant is also weighted at 31 (signal WF2). This is multiplied at 33 by a signal AT1 to form the control signal D, which is available at the output 34.
  • auxiliary signals H2 and H3 are used to generate the signal DD2, the generation of which is explained in more detail in connection with FIG. 7.
  • the auxiliary signal H1 representing the spectral components above the useful range of the stereo multiplex signal is first squared at 35, thereby forming a measure of the energy content of these components. This is passed through a threshold value detector at 36, so that a signal AHD arises which indicates the presence of spectral components with an energy lying above a predetermined threshold.
  • the auxiliary signal H2 formed from the symmetry signal SY (FIG. 1) is passed via a threshold value detector 37 ', the output signal ASD of which thus indicates asymmetries which exceed a predetermined threshold.
  • Such asymmetries indicate, among other things, the presence of adjacent channel interference.
  • both detectors 36, 37 are provided, the output signals AHD and ASD of which are routed via a controllable logic network 38.
  • this has the advantage that, in the case of pure mono broadcasts in which no carrier-frequency stereo signal is transmitted, the signal DD2 is derived from the auxiliary signal H1. It is also possible to derive the DD2 signal using stereo signal transmission methods that deviate from the European standard - for example, the FMX method in the USA.
  • the logical network 38 enables a selection or a logical combination of the two signals AHD and ASD to the signal DD1.
  • the logical network 38 can be formed in a simple manner from a controllable four-way switch, the inputs of which are the signals AHD and ASD, an OR combination of these signals and an AND combination these signals can be fed.
  • the signal DD1 is then available at the output of the controllable changeover switch and is fed to a pulse width discriminator 39. This ensures that the signal DD2 only indicates a fault when the signal DD1 is active for an adjustable minimum time.
  • the signal DD2 serves as a trigger signal for two asymmetrical integrators 40, 41. These essentially each contain a counter which jumps to 0 or another predetermined value at the moment of triggering and retains it as long as the signal DD2 is at 0. If the signal DD2 then assumes the logic level 1, the output signals AT1 and AMU of the asymmetrical integrators 40, 41 increase linearly to a maximum value with adjustable time constants.
  • the signal AT1 is fed to a multiplier 33 together with the field strength signal WF2 weighted at 32.
  • the output signal AMU of the asymmetrical integrator 41 is multiplied at 42 by the signal AFE, which results in a signal AFE_AMU which effects an attenuation of the audio signals by means of the multipliers 9, 10 (FIG. 1) by a maximum of 33 dB. This signal can be found in the circuit at output 43.
  • the exemplary embodiments explained with reference to FIGS. 1 to 6 are parts of a radio receiver with digital signal processing, for which an exemplary embodiment is shown in FIG. 7.
  • the signal received via an antenna 51 is amplified, selected and demodulated in a receiving part (tuner) 52 in a manner known per se.
  • a stereo multiplex signal MPX1 with a sampling rate of 456 kHz is available at an output 53 of the receiving part 52.
  • a low-pass filter 55 is provided before the sampling rate reduction 54.
  • a low-pass filter with a flat frequency response in the pass band is required for proper further processing of the stereo multiplex signal.
  • a simpler low-pass filter with a decreasing frequency response is provided in the exemplary embodiment.
  • the drop in frequency response is compensated in a subsequent compensation filter 56.
  • the stereo multiplex signal MPX2 is then routed via a circuit 57 for automatic interference suppression, which repeats the sample values before the start of the interference until the end of the interference, in particular when spark interference occurs.
  • This circuit is followed by a stereo decoder 58, which generates two audio signals L, R, which are passed to outputs 61, 62 via multipliers 59, 60. From there, the audio signals are fed to the loudspeakers via NF amplifiers.
  • a signal is generated from the stereo multiplex signal MPX1 with the aid of a high pass 63 and a decimation circuit 64 which contains signal components above the useful frequency range of the stereo multiplex signal, but which are folded into a lower frequency range by the decimation.
  • This signal MPX3 indicates various faults, for example the faults caused by spark from vehicles. It is used on the one hand to control the circuit 57 for automatic interference suppression and on the other hand to form the auxiliary signal H1 by decimation of the sampling rate to 9.5 kHz at 65.
  • the auxiliary signal H2 whose sampling rate is also 9.5 kHz is formed by low-pass filtering at 66 and decimation at 67 from a symmetry signal SY. This in turn is shaped in the stereo decoder 58. It is known that the stereo subcarrier is amplitude-demodulated to form the differential signal LR. This is done by multiplying the subcarrier by a subcarrier of the same phase position regenerated in the radio receiver. In the stereo decoder 58, the stereo subcarrier is additionally multiplied by a carrier rotated by 90 ° with respect to the reference carrier, thereby producing a signal which is 0 for symmetrical sidebands of the stereo subcarrier and deviates from 0 accordingly for asymmetries. The further auxiliary signal H2 is formed from this signal by low-pass filtering at 66 and decimation at 67.
  • the receiving part 52 emits a signal AM, which is produced by amplitude demodulation of the FM intermediate frequency signal.
  • this likewise has a sampling rate of 456 kHz and is decimated by a factor of 48 after a low-pass filtering 69 at 70, so that the resulting third auxiliary signal H3 has a sampling rate of 9.5 kHz.
  • control signals D and AFE_AMU the sampling rate of which is initially 9.5 kHz, but is increased to 228 kHz at 72 and 73. This is done by interpolating 24 samples each, which in the simplest case consists in repeating each sample 24 times.
  • the control signal D is fed to a control input of the stereo decoder 58 and is used there to switch over to mono operation in the event of a disturbed reception.
  • the signal AFE_AMU is fed to the multipliers 59 and 60, as a result of which the volume (masking) is reduced when there are faults.

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Noise Elimination (AREA)
  • Stereo-Broadcasting Methods (AREA)

Abstract

Dans un circuit servant à la dérivation de signaux de masquage de signaux audio dans un récepteur radio, un signal sensiblement proportionnel à l'intensité du champ de réception est transmis à travers un filtre passe-bas puis pondéré par une fonction prédéterminée.

Claims (7)

  1. Circuit pour la dérivation de signaux servant à masquer des signaux audio dans un récepteur radio, dans lequel un signal (H3) sensiblement proportionnel à l'intensité du champ de la réception est amené à un premier filtre passe-bas (2),
    circuit caractérisé en ce que
    le signal (H3), sensiblement proportionnel à l'intensité du champ de la réception est amené à un second filtre passe-bas (3), le signal de sortie du premier filtre passe-bas (2) est pondéré dans un premier circuit (7) par un premier coefficient prédéfini et peut être utilisé pour former un signal de masquage servant à réduire la séparation des canaux stéréo (7) en ce que le signal de sortie du premier filtre passe-bas (2) est également pondéré dans un deuxième circuit (5) par un deuxième coefficient prédéfini et peut être utilisé pour former un signal de masquage servant à amortir les signaux audio, et en cas de parasites dans le signal audio, on amène à la place du signal de sortie du premier filtre passe-bas (2) le signal de sortie du second filtre passe-bas (3) pour former le signal de masquage qui sert à amortir les signaux audio du second circuit (5).
  2. Circuit selon la revendication 1,
    caractérisé en ce que
    les coefficients sont déposés dans une mémoire non volatile (9) et peuvent être modifiés à l'aide d'un micro-ordinateur (10), d'un dispositif d'affichage (11), d'un dispositif de commande (12) et d'un programme servant à guider l'utilisateur.
  3. Circuit selon la revendication 1 ou 2,
    caractérisé en ce que
    les signaux pondérés de sortie du premier ou du deuxième filtre passe-bas qui servent à former les signaux de masquage, sont combinés à des signaux auxiliaires, qui sont dérivés à partir des parasites dans le signal audio.
  4. Circuit selon la revendication 3,
    caractérisé en ce que
    la combinaison des signaux pondérés de sortie du premier ou du second filtre passe-bas avec les signaux auxiliaires a lieu au moyen d'une multiplication.
  5. Circuit selon l'une des revendications 1 à 4,
    caractérisé en ce que
    l'on détermine un parasite dans le signal audio quand des fractions du spectre du signal audio, qui se trouvent au-dessus de la zone utile du signal multiplex stéréo, dépassent un seuil prédéfini au-delà d'une plage prédéfinie de temps.
  6. Circuit selon l'une des revendications 1 à 5,
    caractérisé en ce que
    le signal proportionnel pondéré de l'intensité du champ de la réception est limité à une valeur maximale.
  7. Circuit selon l'une des revendications 1 à 6,
    caractérisé en ce que
    le signal de masquage qui sert à réduire la séparation des canaux stéréo est limité à une valeur non négative.
EP94911062A 1993-03-24 1994-03-22 Circuit pour la derivation de signaux de masquage de signaux audio Expired - Lifetime EP0691050B1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE4309518A DE4309518A1 (de) 1993-03-24 1993-03-24 Schaltungsanordnung zur Ableitung mindestens eines von der Qualität eines empfangenen Signals abhängigen Qualitätssignals
DE4309518 1993-03-24
PCT/DE1994/000321 WO1994022229A1 (fr) 1993-03-24 1994-03-22 Circuit pour la derivation de signaux de masquage de signaux audio

Publications (2)

Publication Number Publication Date
EP0691050A1 EP0691050A1 (fr) 1996-01-10
EP0691050B1 true EP0691050B1 (fr) 1996-12-18

Family

ID=38729052

Family Applications (1)

Application Number Title Priority Date Filing Date
EP94911062A Expired - Lifetime EP0691050B1 (fr) 1993-03-24 1994-03-22 Circuit pour la derivation de signaux de masquage de signaux audio

Country Status (5)

Country Link
US (1) US5661810A (fr)
EP (1) EP0691050B1 (fr)
JP (1) JP3676363B2 (fr)
DE (1) DE59401348D1 (fr)
WO (1) WO1994022229A1 (fr)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4434451A1 (de) * 1994-09-27 1996-03-28 Blaupunkt Werke Gmbh Amplitudendemodulator
DE59509187D1 (de) * 1995-11-25 2001-05-17 Micronas Gmbh Signalmodifikationsschaltung
DE19630395C1 (de) * 1996-07-26 1997-10-02 Sgs Thomson Microelectronics Elektrische Stummsteuerschaltung
US6856925B2 (en) * 2001-10-26 2005-02-15 Texas Instruments Incorporated Active removal of aliasing frequencies in a decimating structure by changing a decimation ratio in time and space
DE10224699A1 (de) * 2002-06-04 2003-12-24 Bosch Gmbh Robert Verfahren und Schaltungsanordnung zum Beeinflussen der Höhenwiedergabe eines Audiosignals
DE102010001548A1 (de) 2009-11-18 2011-05-19 Robert Bosch Gmbh Schaltungsanordnung für einen Empfänger
KR20130115286A (ko) * 2010-11-05 2013-10-21 세미컨덕터 아이디어스 투 더 마켓트(아이톰) 비.브이. 스테레오 신호에 포함된 잡음을 줄이는 방법, 이 방법을 사용하는 스테레오 신호 처리 디바이스 및 fm 수신기

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5757051A (en) * 1980-09-22 1982-04-06 Nippon Gakki Seizo Kk Fm stereo receiver
US4497063A (en) * 1981-06-26 1985-01-29 Pioneer Electronic Corporation FM stereo demodulator
JPS61263327A (ja) * 1985-05-17 1986-11-21 Pioneer Electronic Corp 音声多重受信機
MX161741A (es) * 1987-08-28 1990-12-20 Motorola Inc Sistema mejorado de comunicaciones de frecuencia modulada
US4901350A (en) * 1989-04-20 1990-02-13 Delco Electronics Corporation Closed-loop audio attenuator
CA2025012A1 (fr) * 1989-09-11 1991-03-12 William R. Short Systeme de reduction des bruits audibles
US5027402A (en) * 1989-12-22 1991-06-25 Allegro Microsystems, Inc. Blend-on-noise stereo decoder
US5201062A (en) * 1990-03-28 1993-04-06 Pioneer Electronic Corporation Noise reducing circuit
US5257312A (en) * 1991-05-03 1993-10-26 U.S. Philips Corporation Time-discrete stereo decoder
US5249233A (en) * 1992-04-06 1993-09-28 Ford Motor Company Multipath noise minimizer for radio receiver
US5432854A (en) * 1993-02-25 1995-07-11 Chrysler Corporation Stereo FM receiver, noise control circuit therefor
DE4311933A1 (de) * 1993-04-10 1994-10-13 Blaupunkt Werke Gmbh Schaltungsanordnung zur Erzeugung eines Stopp-Signals für einen Sendersuchlauf

Also Published As

Publication number Publication date
US5661810A (en) 1997-08-26
EP0691050A1 (fr) 1996-01-10
JP3676363B2 (ja) 2005-07-27
DE59401348D1 (de) 1997-01-30
JPH08508143A (ja) 1996-08-27
WO1994022229A1 (fr) 1994-09-29

Similar Documents

Publication Publication Date Title
EP0497115B1 (fr) Procédé de shuntage des interruptions de signaux audio
DE4237692C1 (de) Empfänger für ein digitales Rundfunksignal
EP0617519B1 (fr) Méthode pour dériver au moins un signal indiquant la qualité d'un signal reçu
EP0783794B1 (fr) Procédé de Démodulation d'Amplitude
EP0691050B1 (fr) Circuit pour la derivation de signaux de masquage de signaux audio
EP0642715B1 (fr) Recepteur radio a traitement numerique de signaux
EP0642714B1 (fr) Recepteur radio a traitement numerique de signaux
DE4323015C2 (de) Stereophoner Rundfunkempfänger
DE60037722T2 (de) AM Empfänger
EP0653850B1 (fr) Circuit pour reconnaítre l'interférence d'un canal adjacent
EP0345843B1 (fr) Méthode de réception et système d'antenne de réception pour réception mobile
DE69937018T2 (de) RDS Demodulator für den Empfang von Rundfunkprogrammen die Radiodatensignalen und Autofahrer Rundfunkinformationsignalen (ARI) enthalten, mit einer digitalen Filtervorrichtung die eine hohe Dämpfung des ARI Signals bewirkt
EP1804396B1 (fr) Récepteur et procédé de démodulation et décodage optimisés de signaux radio numériques
EP0642712B1 (fr) Circuit pour la derivation d'un signal indicateur d'interferences dans un signal multiplex stereo de reception
EP0691049B1 (fr) Methode pour la derivation d'un signal de qualite dependant de la qualite d'un signal multiplex de reception
DE2653508C2 (de) Schaltungsanordnung zur Störimpulsaustastung mit Momentanwertspeicherung bei Stereo-Rundfunkempfängern
DE19722385C2 (de) Verfahren zur Erkennung von Multipathstörungen beim FM-Rundfunkempfang und Schaltungsanordnung zur Durchführung des Verfahrens
DE2826524A1 (de) Schaltungsanordnung zur stoerverminderung in einem fm-radioempfaenger
DE19925868A1 (de) Diversity-TV-Empfangssystem
EP0642713B1 (fr) Circuit pour la derivation d'un signal indicateur d'interferences dans un signal stereo multiplex de reception
EP0818078B1 (fr) Filtre numerique
WO1998038835A1 (fr) Procede pour influer sur l'espacement des voies stereo d'un signal audio et dispositif correspondant
DE4133197A1 (de) Fm-stereoempfangsanordnung
DE10131456A1 (de) Funkempfänger
DE10202638A1 (de) Verfahren zum Umblenden von Stereo-auf Mono-und von Mono-auf Stereowiedergabe in einem Stereorundfunkempfänger sowie Stereorundfunkempfänger

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19951024

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB IT

17Q First examination report despatched

Effective date: 19960205

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT

REF Corresponds to:

Ref document number: 59401348

Country of ref document: DE

Date of ref document: 19970130

ET Fr: translation filed
ITF It: translation for a ep patent filed

Owner name: 0403;07MIFSTUDIO JAUMANN

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 19970227

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20100331

Year of fee payment: 17

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20100324

Year of fee payment: 17

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20100327

Year of fee payment: 17

Ref country code: DE

Payment date: 20100512

Year of fee payment: 17

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20110322

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20111130

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20110331

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20111001

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 59401348

Country of ref document: DE

Effective date: 20111001

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20110322

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20110322