EP0941588B1 - Method and device for mixed analog and digital broadcast of a radio programme broadcast by the same transmitter - Google Patents
Method and device for mixed analog and digital broadcast of a radio programme broadcast by the same transmitter Download PDFInfo
- Publication number
- EP0941588B1 EP0941588B1 EP97947119A EP97947119A EP0941588B1 EP 0941588 B1 EP0941588 B1 EP 0941588B1 EP 97947119 A EP97947119 A EP 97947119A EP 97947119 A EP97947119 A EP 97947119A EP 0941588 B1 EP0941588 B1 EP 0941588B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- modulation
- signal
- spectrum
- digital
- process according
- 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
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04H—BROADCAST COMMUNICATION
- H04H20/00—Arrangements for broadcast or for distribution combined with broadcast
- H04H20/28—Arrangements for simultaneous broadcast of plural pieces of information
Definitions
- the present invention relates to a broadcasting method mixed analog and digital to ensure the transition between conventional amplitude modulation broadcasting systems, for example example, and digital broadcasting systems. It applies in particular the creation of a transmitter broadcasting in the range of short waves.
- the object of the invention is to remedy this situation.
- the invention relates to a broadcasting method mixed analog and digital broadcast radio broadcast by the same transmitter and intended to be received equally by amplitude modulation or single sideband receivers and digital type receivers suitable for multi demodulation subcarriers, characterized in that it consists in transmitting a signal composite whose frequency spectrum consists of a first analog spectrum representative of amplitude modulation or single sideband and a second spectrum composed of multi-subcarriers, the first and second spectrum occupying two bands of disjoint frequency.
- the invention has the advantage that it allows broadcasting simultaneous analog and digital by the same transmitter of a transmission can be received by a modulation receiver as well scope of trade without the need to modify or change it, only by a receiver fitted with a signal demodulator digital.
- the transmission signal is produced according to the invention by modulation of a composite signal which is the sum of the audio signal and a digital signal obtained by multi-sub-modulation of the audio signal.
- the frequency spectrum of the digital signal is formed as represented by curve A of FIG. 1 by a large number of regularly spaced subcarriers and modulated independently of each other according to a modulation method with several phase states of the type known for example under the abbreviation MAQ of Amplitude Modulation on two quadrature channels.
- the frequency spectrum obtained occupies a bandwidth B n which is the sum of the frequency spectra of all the subcarriers.
- the frequency spectrum of the digital signal as a whole appears very well delimited in the frequency space, unlike the spectrum represented by the curve B in Figure 1 which is that obtained with a digital modulation method on a single carrier.
- the analog signal is transmitted using the known methods of amplitude modulation with two sidebands or with a single sideband known by the abbreviation BLU.
- amplitude modulation still known by the English abbreviation AM for "Amplitude-Modulation”
- the analog signal is obtained by amplitude modulation of a pure carrier, taking care that the amplitude of the modulated signal is never canceled.
- a signal to be modulated S (t) gives rise at the output of a transmitter to a signal of the form cos (2 ⁇ F o t) (S o + S (t) ) where S o is a bias guaranteeing a positive amplitude and F o is the carrier frequency.
- the frequency spectrum is formed as shown in FIG.
- the power conveyed by the carrier residue represents 70% of the total power emitted, while the carrier residue does not carry any information by itself, the useful information being entirely contained in each of the spectra S (f ) .
- the spectral congestion obtained is as shown in Figure 3 reduced A half. Modulation which can be seen as modulation amplitude is filtered to let pass only one of the two halves frequency spectrum with little or no carrier residue.
- the reduction in transmission power varies depending on the fraction carrier residue. If this residue is completely eliminated, the necessary transmitting power, at equivalent range, is no longer than 15% of that required for AM amplitude modulation.
- Unfortunately as a simple commercial receiver appears unable to properly demodulate such a signal especially when the carrier residue is absent, the transmission must take place with a residue therefore of carrier, to limit the distortion which invariably can occur with an amplitude modulation receiver.
- the composite signal which is transmitted according to the invention by a single transmitter is the sum of the analog signal, of bandwidth B a and of the digital signal of bandwidth B n .
- the bandwidth of the signal S (t) is designated by B S and is close to the bandwidth B o .
- B n denotes the bandwidth necessary for the transmission of the bit rate of the digital signal associated with S (t).
- the high frequencies of the spectrum S (f) are arranged to be the closest to those of the digital signal.
- a possible involuntary reception by a commercial AM receiver of some of the frequencies contained in the digital signal can only result in a noise localized in the high frequencies, which is a lesser harm by the fact that a noise in the acute frequencies is perceptually less annoying than in the low frequencies and that in addition a receiver with amplitude modulation of the trade strongly attenuates the treble.
- the power conveyed by the digital component can be equal or even lower than that of the analog component, which amounts to saying that the total power transmitted can be close to or less than that which is necessary for a transmitter with AM amplitude modulation carrying only the analog signal.
- the difference between the frequencies F 0 and F 1 which respectively represent the frequency of the carrier residue for the analog and the central frequency of the digital is determined so that the total band of the transmitted signal, denoted B t , is compatible with the broadcasting rules in use.
- the transmission in AM amplitude modulation of the digital signal alone can occupy all the available band on its own or, as shown in the figure 6, the simultaneous transmission in amplitude modulation of analog and digital, the digital signal can then be considered as a special "signaling" located beyond the acute frequencies of the low frequency analog signal S (t) .
- the emission of the analog signal in AM amplitude modulation or in modulation known by the English abbreviation VSB (Vestigial Side Band) to limit the distortion in the low frequencies and the digital in upper or lower sideband.
- a device for implementing the method previously described is shown in Figure 8.
- This includes a circuit adder 1 coupled by a first input to a first channel of modulation composed of an audio frequency coder 2, a multiplexer 3 of data supplied by the encoder 2, and of service data and auxiliaries, and a multi-sub modulator 4 linked together in this serial order.
- the summator 1 is also coupled by a second modulation input to a second compound channel essentially by a low pass filter 5.
- the output of the summing circuit 1 is coupled to the input of a modulation device 6 composed by a modulator with AM amplitude modulation or with a single BLU sideband.
- the modulated signal supplied by the modulation device 6 is filtered by a side band selector filter 7.
- a control device 8 is coupled between the output of the low pass filter 5 to regulate the level of residual carrier provided by the modulation device 6 This is made up as shown in figure 9 of two ways.
- a first channel comprises a device for estimating the minima of the signal S (t) coupled to a first input of a subtractor circuit 10 via a low pass filter 11.
- a second channel is composed of a circuit with delay 12 of a determined duration T corresponding to the duration of the processing of the signal S (t) in the first channel, coupled to a second input of the subtractor circuit 10 via a multiplier circuit 13 by a set value 9 .
- the output of the subtractor circuit 10 is connected to a control input of the modulation device 6 of FIG. 8.
- the signal S (t) is applied according to this configuration simultaneously to the respective inputs of the device for estimating minima 9 and of the device delay 12.
- the regulating device 8 makes it possible to limit the waste of energy represented by a strong carrier residue, by continuously adjusting this residue as a function of the instantaneous power of the signal S (t) .
- the distortion is perfectly negligible.
- the other values of the signal S (t) the distortion is brought to an acceptable level.
- the minima of the signal S (t) are permanently estimated and filtered by the low-pass filter 11 whose cut-off frequency is for example 10 Hz so as to be inaudible and the value obtained is delayed by the delay T and is affected by a gain g less than 1 before being subtracted from the signal S (t) .
- the frequency spectrum of the resulting analog signal transmitted at the output of the selector filter 7 then has the form shown in FIG. 10, the carrier residue being modulated with a very small bandwidth.
- FIGS. 11 a , 11 b and 11 c Temporal waveforms of the carrier without and with modulation of the residue are shown in FIGS. 11 a , 11 b and 11 c as a function of the amplitude of the signal S (t).
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Transmitters (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Abstract
Description
La présente invention concerne un procédé de radiodiffusion mixte analogique et numérique permettant d'assurer la transition entre les systèmes de radiodiffusion classiques à modulation d'amplitude, par exemple, et les systèmes de radiodiffusion numérique. Elle s'applique notamment à la réalisation d'émetteur diffusant dans la gamme des ondes courtes.The present invention relates to a broadcasting method mixed analog and digital to ensure the transition between conventional amplitude modulation broadcasting systems, for example example, and digital broadcasting systems. It applies in particular the creation of a transmitter broadcasting in the range of short waves.
Pour des raisons à la fois d'ordre technique, politique, ou économique les émetteurs de radiodiffusion actuellement utilisés pour la radiodiffusion de programmes en modulation d'amplitude ne peuvent pas être du jour au lendemain adaptés pour la diffusion de programmes en numérique. Ceci suggère, pendant une période transitoire plus ou moins longue, la coexistence de deux systèmes l'un numérique l'autre analogique qui diffusent les mêmes programmes. Cette solution apparaít fort coûteuse et peu souhaitable car elle laisse supposer qu'à la fin de cette période transitoire, la moitié des émetteurs utilisés pour la transmission analogique devront être supprimés.For technical, political or other reasons economical broadcasting transmitters currently used for the amplitude modulation broadcasting cannot be suitable overnight for broadcasting programs in digital. This suggests, during a more or less transitional period long, the coexistence of two systems one digital the other analog that broadcast the same programs. This solution appears very expensive and undesirable because it suggests that at the end of this transitional period, half of the transmitters used for the analog transmission will need to be removed.
Le but de l'invention est de remédier à cette situation.The object of the invention is to remedy this situation.
A cet effet, l'invention a pour objet un procédé de radiodiffusion mixte en analogique et en numérique d'émission radiophonique diffusée par un même émetteur et destinée à être reçue indifféremment par des récepteurs à modulation d'amplitude ou à bande latérale unique et des récepteurs de type numérique adaptés pour la démodulation de multi sous-porteuses, caractérisé en ce qu'il consiste à émettre un signal composite dont le spectre de fréquence se compose d'un premier spectre analogique représentatif de la modulation d'amplitude ou de la bande latérale unique et d'un deuxième spectre composé des multi sous-porteuses, les premier et deuxième spectre occupant deux bandes de fréquence disjointes.To this end, the invention relates to a broadcasting method mixed analog and digital broadcast radio broadcast by the same transmitter and intended to be received equally by amplitude modulation or single sideband receivers and digital type receivers suitable for multi demodulation subcarriers, characterized in that it consists in transmitting a signal composite whose frequency spectrum consists of a first analog spectrum representative of amplitude modulation or single sideband and a second spectrum composed of multi-subcarriers, the first and second spectrum occupying two bands of disjoint frequency.
Elle a également pour objet un dispositif pour la mise en oeuvre
de procédé précité selon la revendication 9.It also relates to a device for the implementation
The above method according to
L'invention a pour avantage qu'elle permet une radiodiffusion simultanée analogique et numérique par un même émetteur d'une émission pouvant être reçue aussi bien par un récepteur à modulation d'amplitude du commerce sans qu'il soit nécessaire de le modifier ou de le changer, que par un récepteur muni d'un démodulateur de signaux numériques.The invention has the advantage that it allows broadcasting simultaneous analog and digital by the same transmitter of a transmission can be received by a modulation receiver as well scope of trade without the need to modify or change it, only by a receiver fitted with a signal demodulator digital.
D'autres caractéristiques et avantages de l'invention apparaítront
dans le description qui suit faite en regard des dessins annexés qui
représentent :
Pour assurer une radiodiffusion simultanée par un émetteur unique d'un même programme pouvant être reçu aussi bien par des postes radio analogique que des postes radio numérique le signal d'émission est réalisée selon l'invention par une modulation d'un signal composite qui est la somme du signal audiofréquence et d'un signal numérique obtenu par une modulation multi sous-porteuses du signal audiofréquence. Le spectre en fréquence du signal numérique est formé de la façon représentée par la courbe A de la figure 1 par un grand nombre de sous-porteuses régulièrement espacées et modulées indépendamment les unes des autres selon un procédé de modulation à plusieurs états de phase de type connu par exemple sous l'abréviation MAQ de Modulation d'Amplitude sur deux voies en quadrature. Le spectre en fréquence obtenu occupe une largeur de bande Bn qui est la somme des spectres en fréquence de toutes les sous-porteuses. Grâce à l'étroitesse du spectre en fréquence des sous-porteuses individuelies, le spectre en fréquence du signal numérique dans son ensemble apparaít très bien délimité dans l'espace fréquentiel, contrairement au spectre représenté par la courbe B sur la figure 1 qui est celui obtenu avec un procédé de modulation numérique sur porteuse unique.To ensure simultaneous broadcasting by a single transmitter of the same program which can be received both by analog radio stations and digital radio stations, the transmission signal is produced according to the invention by modulation of a composite signal which is the sum of the audio signal and a digital signal obtained by multi-sub-modulation of the audio signal. The frequency spectrum of the digital signal is formed as represented by curve A of FIG. 1 by a large number of regularly spaced subcarriers and modulated independently of each other according to a modulation method with several phase states of the type known for example under the abbreviation MAQ of Amplitude Modulation on two quadrature channels. The frequency spectrum obtained occupies a bandwidth B n which is the sum of the frequency spectra of all the subcarriers. Thanks to the narrowness of the frequency spectrum of the individual subcarriers, the frequency spectrum of the digital signal as a whole appears very well delimited in the frequency space, unlike the spectrum represented by the curve B in Figure 1 which is that obtained with a digital modulation method on a single carrier.
Le signal analogique est transmis en utilisant les procédés connus de modulation d'amplitude à deux bandes latérales ou à bande latérale unique connu sous l'abréviation BLU. Dans le cas d'une modulation d'amplitude encore connue sous l'abréviation anglo-saxonne AM de "Amplitude-Modulation", le signal analogique est obtenu par modulation d'amplitude d'une porteuse pure, en prenant bien garde que l'amplitude du signal modulé ne s'annule jamais. Suivant ce type de modulation, un signal à moduler S(t) donne naissance à la sortie d'un émetteur à un signal de la forme cos (2π Fot) (So + S(t)) où So est un biais garantissant une amplitude positive et Fo est la fréquence de la porteuse. Le spectre en fréquence est formé comme le montre la figure 2 par deux bandes de fréquence représentant chacune le spectre S(f) du signal S(t) et disposées symétriquement par rapport à la fréquence Fo. Dans ce procédé, la puissance véhiculée par le résidu de porteuse représente 70% de la puissance totale émise, alors que le résidu de porteuse ne véhicule par lui-même aucune information, l'information utile étant entièrement contenue dans chacun des spectres S(f).The analog signal is transmitted using the known methods of amplitude modulation with two sidebands or with a single sideband known by the abbreviation BLU. In the case of amplitude modulation still known by the English abbreviation AM for "Amplitude-Modulation", the analog signal is obtained by amplitude modulation of a pure carrier, taking care that the amplitude of the modulated signal is never canceled. According to this type of modulation, a signal to be modulated S (t) gives rise at the output of a transmitter to a signal of the form cos (2π F o t) (S o + S (t) ) where S o is a bias guaranteeing a positive amplitude and F o is the carrier frequency. The frequency spectrum is formed as shown in FIG. 2 by two frequency bands each representing the spectrum S (f) of the signal S (t) and arranged symmetrically with respect to the frequency F o . In this method, the power conveyed by the carrier residue represents 70% of the total power emitted, while the carrier residue does not carry any information by itself, the useful information being entirely contained in each of the spectra S (f ) .
Suivant le type de modulation à bande latérale unique, l'encombrement spectral obtenu est comme le montre la figure 3 réduit de moitié. La modulation qui peut être vue comme de la modulation d'amplitude est filtrée pour ne laisser passer que l'une des deux moitiés du spectre en fréquence avec peu ou pas du tout de résidu de porteuse. La réduction de la puissance d'émission varie en fonction de la fraction de résidu de la porteuse. Si ce résidu est éliminé totalement, la puissance d'émission nécessaire, à portée équivalente, n'est alors plus que de 15% de celle nécessaire à une modulation d'amplitude AM. Malheureusement, comme un récepteur simple du commerce apparaít incapable de démoduler correctement un tel signal notamment lorsque le résidu de porteuse est absent, l'émission doit avoir lieu avec un résidu de porteuse conséquent, pour limiter la distorsion qui invariablement peut se produite avec un récepteur à modulation d'amplitude.Depending on the type of single sideband modulation, the spectral congestion obtained is as shown in Figure 3 reduced A half. Modulation which can be seen as modulation amplitude is filtered to let pass only one of the two halves frequency spectrum with little or no carrier residue. The reduction in transmission power varies depending on the fraction carrier residue. If this residue is completely eliminated, the necessary transmitting power, at equivalent range, is no longer than 15% of that required for AM amplitude modulation. Unfortunately, as a simple commercial receiver appears unable to properly demodulate such a signal especially when the carrier residue is absent, the transmission must take place with a residue therefore of carrier, to limit the distortion which invariably can occur with an amplitude modulation receiver.
Comme le montrent les figures 4 à 7 le signal composite, qui est émis selon l'invention par un émetteur unique est la somme du signal analogique, de largeur de bande Ba et du signal numérique de largeur de bande Bn. Dans les différentes variantes envisagées, la largeur de bande du signal S(t) est désignée par BS et est voisine de la largeur de bande Bo. Bn désigne la largeur de bande nécessaire à la transmission du débit du signal numérique associé à S(t). Dans toutes les variantes des combinaisons spectrales envisagées, les fréquences aiguës du spectre S(f) sont disposées pour être les plus proches de celles du signal numérique. Ainsi, une possible réception involontaire par un récepteur AM du commerce de quelques unes des fréquences contenues dans le signal numérique ne peut se traduire que par un bruit localisé dans les fréquences aiguës, ce qui est un moindre mal par le fait qu'un bruit dans les fréquences aiguës est perceptuellement moins gênant que dans les fréquences graves et qu'en plus un récepteur à modulation d'amplitude du commerce atténue fortement les aigus.As shown in FIGS. 4 to 7, the composite signal which is transmitted according to the invention by a single transmitter is the sum of the analog signal, of bandwidth B a and of the digital signal of bandwidth B n . In the various variants envisaged, the bandwidth of the signal S (t) is designated by B S and is close to the bandwidth B o . B n denotes the bandwidth necessary for the transmission of the bit rate of the digital signal associated with S (t). In all the variants of the spectral combinations envisaged, the high frequencies of the spectrum S (f) are arranged to be the closest to those of the digital signal. Thus, a possible involuntary reception by a commercial AM receiver of some of the frequencies contained in the digital signal can only result in a noise localized in the high frequencies, which is a lesser harm by the fact that a noise in the acute frequencies is perceptually less annoying than in the low frequencies and that in addition a receiver with amplitude modulation of the trade strongly attenuates the treble.
Sachant par ailleurs que, pour une même portée d'émission, le rapport signal/bruit nécessaire à une transmission numérique est nettement inférieur à celui nécessaire pour une transmission analogique, la puissance véhiculée par la composante numérique peut être égale ou même inférieure à celle de la composante analogique, ce qui revient à dire que la puissance totale émise peut être voisine ou inférieure à celle qu'il est nécessaire à un émetteur à modulation d'amplitude AM ne véhiculant que le signal analogique. Sur les figures 4 à 7 l'écart entre les fréquence F0 et F1 qui représentent respectivement la fréquence du résidu de porteuse pour l'analogique et la fréquence centrale du numérique est déterminé pour que la bande totale du signal émis, notée Bt, soit compatible des règles de radiodiffusion en usage. Knowing moreover that, for the same transmission range, the signal / noise ratio necessary for a digital transmission is much lower than that necessary for an analog transmission, the power conveyed by the digital component can be equal or even lower than that of the analog component, which amounts to saying that the total power transmitted can be close to or less than that which is necessary for a transmitter with AM amplitude modulation carrying only the analog signal. In FIGS. 4 to 7, the difference between the frequencies F 0 and F 1 which respectively represent the frequency of the carrier residue for the analog and the central frequency of the digital is determined so that the total band of the transmitted signal, denoted B t , is compatible with the broadcasting rules in use.
Il est aussi possible d'envisager comme le montre la figure 5 que dans une période transitoire, l'émission en modulation d'amplitude AM du signal numérique seul, puisse occuper à lui seul toutes la bande disponible ou encore, comme le montre la figure 6, l'émission simultanée en modulation d'amplitude de l'analogique et du numérique, le signal numérique pouvant alors être considéré comme une "signalisation" spéciale localisée au-delà des fréquences aiguës du signal basse fréquence analogique S(t). Selon encore une autre variante représentée à la figure 7 l'émission du signal analogique en modulation d'amplitude AM ou en modulation connue sous l'abréviation anglo-saxonne VSB de (Vestigial Side Band) pour limiter la distorsion dans les fréquences basses et du numérique en bande latérale supérieure ou inférieure.It is also possible to envisage as shown in FIG. 5 that in a transitional period, the transmission in AM amplitude modulation of the digital signal alone, can occupy all the available band on its own or, as shown in the figure 6, the simultaneous transmission in amplitude modulation of analog and digital, the digital signal can then be considered as a special "signaling" located beyond the acute frequencies of the low frequency analog signal S (t) . According to yet another variant shown in FIG. 7, the emission of the analog signal in AM amplitude modulation or in modulation known by the English abbreviation VSB (Vestigial Side Band) to limit the distortion in the low frequencies and the digital in upper or lower sideband.
Un dispositif pour la mise en oeuvre du procédé précédemment
décrit est représenté à la figure 8. Celui-ci comprend, un circuit
sommateur 1 couplé par une première entrée à une première voie de
modulation composée d'un codeur audiofréquence 2, d'un multiplexeur
3 de données fournies par le codeur 2, et de données de service et
auxiliaires, et d'un modulateur multi sous-porteuses 4 reliés entre eux
dans cet ordre en série. Le sommateur 1 est d'autre part couplé par une
deuxième entrée de modulation à une deuxième voie composée
essentiellement par un filtre passe bas 5.A device for implementing the method previously
described is shown in Figure 8. This includes a circuit
adder 1 coupled by a first input to a first channel of
modulation composed of an
La sortie du circuit sommateur 1 est couplée à l'entrée d'un
dispositif de modulation 6 composé par un modulateur à modulation
d'amplitude AM ou à bande latérale unique BLU. Le signal modulé fourni
par le dispositif de modulation 6 est filtré par un filtre sélecteur de
bandes latérales 7. Un dispositif de régulation 8 est couplé entre la sortie
du filtre passe bas 5 pour réguler le niveau de porteuse résiduelle fourni
par le dispositif de modulation 6. Celui-ci se compose de la façon
représentée à la figure 9 de deux voies. Une première voie comprend un
dispositif d'estimation des minima du signal S(t) couplé à une première
entrée d'un circuit soustracteur 10 par l'intermédiaire d'un filtre passe
bas 11. Une deuxième voie est composée d'un circuit à retard 12 d'une
durée déterminée T correspondant à la durée du traitement du signal S(t)
dans la première voie, couplé à une deuxième entrée du circuit
soustracteur 10 par l'intermédiaire d'un circuit multiplieur 13 par une
valeur de consigne 9.The output of the summing circuit 1 is coupled to the input of a
La sortie du circuit soustracteur 10 est reliée à une entrée de
commande du dispositif de modulation 6 de la figure 8. Le signal S(t) est
appliqué suivant cette configuration simultanément sur les entrées
respectives du dispositif d'estimation des minima 9 et du dispositif à
retard 12. Le dispositif de régulation 8 permet de limiter le gaspillage
d'énergie que représente un fort résidu de porteuse, en ajustant en
permanence ce résidu en fonction de la puissance instantanée du signal
S(t). Quand le niveau de puissance du signal S(t) est de faible puissance,
la distorsion est parfaitement négligeable. Pour les autres valeurs du
signal S(t) la distorsion est amenée à un niveau acceptable. Pour cela les
minima du signal S(t) sont estimés en permanence et filtrés par le filtre
passe-bas 11 dont la fréquence de coupure est par exemple de 10 Hz de
façon à être inaudible et la valeur obtenue est retardée du retard T et est
affectée d'un gain g inférieur à 1 avant d'être soustraite du signal S(t).The output of the
Le spectre en fréquence du signal analogique résultant émis à la sortie du filtre sélecteur 7 a alors la forme représentée à la figure 10, le résidu de porteuse étant modulé avec une très faible largeur de bande.The frequency spectrum of the resulting analog signal transmitted at the output of the selector filter 7 then has the form shown in FIG. 10, the carrier residue being modulated with a very small bandwidth.
Des formes d'onde temporelles de la porteuse sans et avec modulation du résidu sont représentées aux figures 11a, 11b et 11c en fonction de l'amplitude du signal S(t).Temporal waveforms of the carrier without and with modulation of the residue are shown in FIGS. 11 a , 11 b and 11 c as a function of the amplitude of the signal S (t).
Claims (10)
- Process of mixed analogue and digital radiobroadcasting of a radiophonic transmission broadcast by one and the same transmitter and intended to be received either by amplitude-modulation receivers or single-sideband receivers and digital type receivers adapted for the demodulation of multi-subcarriers, characterized in that it consists in transmitting a composite signal whose frequency spectrum (Bt) is composed of a first analogue spectrum (Ba) representative of the amplitude modulation or of the single sideband and of a second spectrum (Bn) composed of the multi-subcarriers, the first and second spectra occupying two disjoint frequency bands.
- Process according to Claim 1, characterized in that the spectrum of the analogue signal (Ba) is that of an amplitude-modulated signal.
- Process according to Claim 1, characterized in that the spectrum (Ba) of the analogue signal is that of a single-sideband-modulated signal.
- Process according to Claim 1, characterized in that the spectrum (Ba) of the analogue signal is that of a VSB modulated signal.
- Process according to any one of Claims 1 to 4, characterized in that the spectrum (Bn) of the digital signal is composed of a specified number of regularly spaced subcarriers which are modulated independently of one another according to a multiple phase state modulation process.
- Process according to any one of Claims 1 to 5, characterized in that it consists in placing the spectrum of the digital signal in a frequency band (Bn) alongside the frequencies corresponding to the high-pitched frequencies of the original analogue frequency band.
- Process according to Claim 6, characterized in that it consists in simultaneously transmitting the analogue and digital signals using amplitude modulation.
- Process according to Claim 6, characterized in that it consists in simultaneously transmitting the analogue signal using amplitude modulation and the digital signal using single sideband.
- Device for implementing the process according to any one of Claims 1 to 8, characterized in that it comprises a summator circuit (1) which is coupled by a first input to a first modulation path composed of an audiofrequency coder (2), of a multiplexer (3) and of a multi-subcarrier modulator (4) which are linked in this order in series, and is coupled by a second input to a second path comprising a low-frequency filter (5), the output of the summator circuit (1) being coupled to the input of a modulation device (6) made up of an amplitude-modulation or single-sideband modulator.
- Device according to Claim 9, characterized in that it comprises a regulating device (8) coupled between the output of the low-pass filter (5) and the output of the multi-subcarrier modulator (4) so as to regulate the residual-carrier level provided by the modulation device (6).
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR9614686A FR2756686B1 (en) | 1996-11-29 | 1996-11-29 | METHOD AND DEVICE FOR ANALOG AND DIGITAL MIXED BROADCASTING OF RADIO TRANSMISSION BROADCASTED BY THE SAME TRANSMITTER |
FR9614686 | 1996-11-29 | ||
PCT/FR1997/002109 WO1998024201A1 (en) | 1996-11-29 | 1997-11-21 | Method and device for mixed analog and digital broadcast of a radio programme broadcast by the same transmitter |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0941588A1 EP0941588A1 (en) | 1999-09-15 |
EP0941588B1 true EP0941588B1 (en) | 2003-02-05 |
Family
ID=9498189
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP97947119A Expired - Lifetime EP0941588B1 (en) | 1996-11-29 | 1997-11-21 | Method and device for mixed analog and digital broadcast of a radio programme broadcast by the same transmitter |
Country Status (7)
Country | Link |
---|---|
US (1) | US6418300B1 (en) |
EP (1) | EP0941588B1 (en) |
JP (1) | JP4131483B2 (en) |
AT (1) | ATE232342T1 (en) |
DE (1) | DE69718930T2 (en) |
FR (1) | FR2756686B1 (en) |
WO (1) | WO1998024201A1 (en) |
Families Citing this family (36)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6091940A (en) | 1998-10-21 | 2000-07-18 | Parkervision, Inc. | Method and system for frequency up-conversion |
US7515896B1 (en) | 1998-10-21 | 2009-04-07 | Parkervision, Inc. | Method and system for down-converting an electromagnetic signal, and transforms for same, and aperture relationships |
US6694128B1 (en) | 1998-08-18 | 2004-02-17 | Parkervision, Inc. | Frequency synthesizer using universal frequency translation technology |
US6061551A (en) | 1998-10-21 | 2000-05-09 | Parkervision, Inc. | Method and system for down-converting electromagnetic signals |
US7039372B1 (en) | 1998-10-21 | 2006-05-02 | Parkervision, Inc. | Method and system for frequency up-conversion with modulation embodiments |
US6813485B2 (en) | 1998-10-21 | 2004-11-02 | Parkervision, Inc. | Method and system for down-converting and up-converting an electromagnetic signal, and transforms for same |
US6061555A (en) | 1998-10-21 | 2000-05-09 | Parkervision, Inc. | Method and system for ensuring reception of a communications signal |
US6370371B1 (en) | 1998-10-21 | 2002-04-09 | Parkervision, Inc. | Applications of universal frequency translation |
US6049706A (en) | 1998-10-21 | 2000-04-11 | Parkervision, Inc. | Integrated frequency translation and selectivity |
US6542722B1 (en) | 1998-10-21 | 2003-04-01 | Parkervision, Inc. | Method and system for frequency up-conversion with variety of transmitter configurations |
US6560301B1 (en) | 1998-10-21 | 2003-05-06 | Parkervision, Inc. | Integrated frequency translation and selectivity with a variety of filter embodiments |
US7236754B2 (en) | 1999-08-23 | 2007-06-26 | Parkervision, Inc. | Method and system for frequency up-conversion |
US6704549B1 (en) | 1999-03-03 | 2004-03-09 | Parkvision, Inc. | Multi-mode, multi-band communication system |
US6704558B1 (en) | 1999-01-22 | 2004-03-09 | Parkervision, Inc. | Image-reject down-converter and embodiments thereof, such as the family radio service |
US6879817B1 (en) | 1999-04-16 | 2005-04-12 | Parkervision, Inc. | DC offset, re-radiation, and I/Q solutions using universal frequency translation technology |
US6853690B1 (en) | 1999-04-16 | 2005-02-08 | Parkervision, Inc. | Method, system and apparatus for balanced frequency up-conversion of a baseband signal and 4-phase receiver and transceiver embodiments |
US7065162B1 (en) | 1999-04-16 | 2006-06-20 | Parkervision, Inc. | Method and system for down-converting an electromagnetic signal, and transforms for same |
US7110444B1 (en) | 1999-08-04 | 2006-09-19 | Parkervision, Inc. | Wireless local area network (WLAN) using universal frequency translation technology including multi-phase embodiments and circuit implementations |
US7693230B2 (en) | 1999-04-16 | 2010-04-06 | Parkervision, Inc. | Apparatus and method of differential IQ frequency up-conversion |
US8295406B1 (en) | 1999-08-04 | 2012-10-23 | Parkervision, Inc. | Universal platform module for a plurality of communication protocols |
US7010286B2 (en) | 2000-04-14 | 2006-03-07 | Parkervision, Inc. | Apparatus, system, and method for down-converting and up-converting electromagnetic signals |
US7454453B2 (en) | 2000-11-14 | 2008-11-18 | Parkervision, Inc. | Methods, systems, and computer program products for parallel correlation and applications thereof |
US7072427B2 (en) | 2001-11-09 | 2006-07-04 | Parkervision, Inc. | Method and apparatus for reducing DC offsets in a communication system |
FR2832879B1 (en) * | 2001-11-23 | 2006-08-18 | Thales Sa | METHOD AND EQUALIZATION BY DATA SEGMENTATIONS |
FR2832877B1 (en) * | 2001-11-23 | 2006-08-18 | Thales Sa | BLOCK EQUALIZATION METHOD AND DEVICE WITH IMPROVED INTERPOLATION |
FR2832880B1 (en) * | 2001-11-23 | 2004-04-09 | Thales Sa | BLOCK EQUALIZATION METHOD AND DEVICE WITH ADAPTATION TO THE TRANSMISSION CHANNEL |
US7460584B2 (en) | 2002-07-18 | 2008-12-02 | Parkervision, Inc. | Networking methods and systems |
US7379883B2 (en) | 2002-07-18 | 2008-05-27 | Parkervision, Inc. | Networking methods and systems |
FR2847400B1 (en) * | 2002-11-15 | 2005-01-21 | Thales Sa | SYSTEM AND METHOD FOR PRESENCE DETECTION AND SYNCHRONIZATION OF A SIGNAL FOR A FREQUENCY HOPPING SYSTEM OPERATING IN A PERTURBE ENVIRONMENT |
FR2854994B1 (en) * | 2003-05-16 | 2005-07-01 | Thales Sa | DEVICE AND METHOD FOR SELF-ADAPTIVE INTERFERENCE REJECTION |
WO2010018235A2 (en) | 2009-11-17 | 2010-02-18 | Phonak Ag | Hearing assistance system and method |
US8737651B2 (en) | 2009-11-17 | 2014-05-27 | Phonak Ag | Hearing assistance system and method |
US20160197669A1 (en) | 2014-12-11 | 2016-07-07 | Tesla Wireless Company LLC | Communication method and system that uses low latency/low data bandwidth and high latency/high data bandwidth pathways |
EP3176954B1 (en) | 2015-12-02 | 2018-09-26 | etatronix GmbH | Method for the transmission of analog and digital information in the transmission of energy |
GB2581930B (en) * | 2017-10-24 | 2023-03-22 | Skywave Networks Llc | Clock synchronization when switching between broadcast and data transmission modes |
CN118400244A (en) * | 2024-05-24 | 2024-07-26 | 湘潭大学 | Digital-analog mixed signal modulation method and modulation method |
Family Cites Families (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4686705A (en) * | 1984-01-27 | 1987-08-11 | Alpha-Omega Engineering, Inc. | Special vestigial sideband signal for use in communication systems |
WO1988003342A1 (en) * | 1986-10-31 | 1988-05-05 | Motorola, Inc. | Ssb communiction system with fm data capability |
US4882725A (en) * | 1987-01-30 | 1989-11-21 | Hitachi, Ltd. | Multiplex transmission method and apparatus |
US5038402A (en) * | 1988-12-06 | 1991-08-06 | General Instrument Corporation | Apparatus and method for providing digital audio in the FM broadcast band |
DE4111855C2 (en) * | 1991-04-11 | 1994-10-20 | Inst Rundfunktechnik Gmbh | Method for the radio transmission of a digitally coded data stream |
US5162763A (en) * | 1991-11-18 | 1992-11-10 | Morris Keith D | Single sideband modulator for translating baseband signals to radio frequency in single stage |
DE4210069A1 (en) * | 1992-03-27 | 1993-09-30 | Asea Brown Boveri | Amplitude-modulated radio transmitter for various types of modulation, especially DSB, SSB and ISB |
US5465396A (en) * | 1993-01-12 | 1995-11-07 | Usa Digital Radio Partners, L.P. | In-band on-channel digital broadcasting |
US5588022A (en) * | 1994-03-07 | 1996-12-24 | Xetron Corp. | Method and apparatus for AM compatible digital broadcasting |
CA2144596A1 (en) * | 1994-04-05 | 1995-10-06 | Richard Prodan | Modulator/demodulator using baseband filtering |
WO1996021291A1 (en) * | 1995-01-03 | 1996-07-11 | Northrop Grumman Corporation | Method and apparatus for improving am compatible digital broadcast analog fidelity |
DE19601161A1 (en) * | 1995-05-27 | 1996-11-28 | Deutsche Telekom Ag | Additional information transmission method esp. for television channels |
US5694419A (en) * | 1995-11-07 | 1997-12-02 | Hitachi America, Ltd. | Shared resource modulator-demodulator circuits for use with vestigial sideband signals |
US5930687A (en) * | 1996-09-30 | 1999-07-27 | Usa Digital Radio Partners, L.P. | Apparatus and method for generating an AM-compatible digital broadcast waveform |
-
1996
- 1996-11-29 FR FR9614686A patent/FR2756686B1/en not_active Expired - Fee Related
-
1997
- 1997-11-21 JP JP52435298A patent/JP4131483B2/en not_active Expired - Fee Related
- 1997-11-21 US US09/308,651 patent/US6418300B1/en not_active Expired - Fee Related
- 1997-11-21 WO PCT/FR1997/002109 patent/WO1998024201A1/en active IP Right Grant
- 1997-11-21 DE DE69718930T patent/DE69718930T2/en not_active Expired - Lifetime
- 1997-11-21 EP EP97947119A patent/EP0941588B1/en not_active Expired - Lifetime
- 1997-11-21 AT AT97947119T patent/ATE232342T1/en active
Also Published As
Publication number | Publication date |
---|---|
US6418300B1 (en) | 2002-07-09 |
FR2756686B1 (en) | 1999-02-19 |
ATE232342T1 (en) | 2003-02-15 |
FR2756686A1 (en) | 1998-06-05 |
EP0941588A1 (en) | 1999-09-15 |
DE69718930T2 (en) | 2003-11-13 |
WO1998024201A1 (en) | 1998-06-04 |
DE69718930D1 (en) | 2003-03-13 |
JP4131483B2 (en) | 2008-08-13 |
JP2001505017A (en) | 2001-04-10 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0941588B1 (en) | Method and device for mixed analog and digital broadcast of a radio programme broadcast by the same transmitter | |
EP0709980B1 (en) | Frequency synchronisation for OFDM system | |
CA2096942C (en) | Process for digital transmission and direct conversion receiver | |
EP0624959B1 (en) | FM receiver with an oversampling circuit | |
EP0580216B1 (en) | System and receiver for orthogonal frequency division multiplexed signals provided with a frequency synchronisation circuit | |
EP0950306B1 (en) | Method and device for formatting a clipping noise in a multicarrier modulation | |
EP0033256A1 (en) | Radioelectric diversity transmission system of simple and economic structure | |
EP0433198B1 (en) | Amplitude modulation transmission system with suppressed carrier maintaining the polarity of the transmitted signal | |
FR2512295A1 (en) | STEREOPHONIC RECEIVER WITH MULTI-SYSTEM AMPLITUDE MODULATION | |
FR2767429A1 (en) | DEVICE FOR MATCHING DELAYS IN A POWER AMPLIFIER | |
EP0199410A1 (en) | System for the secret transmission of audio signals, and television set for receiving such signals | |
EP0169093B1 (en) | Receiver for time division multiplexed television transmission comprising a frequency demodulator | |
EP0150880B1 (en) | Demodulator using phase-locked loop | |
FR2498853A1 (en) | FM BROADCASTING SYSTEM WITH TRANSMITTER CHARACTERIZATION | |
FR2517141A1 (en) | METHOD AND APPARATUS FOR AUTOMATIC GAIN CONTROL FOR FREQUENCY MODULATION TRANSMISSION | |
FR2666709A1 (en) | GAIN ADJUSTMENT ASSEMBLY FOR RADIOTELEPHONE. | |
EP1627479B1 (en) | Method and simultaneous radio broadcast transmitter using a pre-filtering of the multi-carrier digital signal | |
EP0731588B1 (en) | Multiresolution phase modulation, for multicarrier systems | |
FR2757725A1 (en) | Hierarchical transmission process for digital broadcast short wave signals | |
EP0086525A1 (en) | Television transmission method, transmitter and receiver with a plurality of sound channels | |
EP0944979B1 (en) | Method for digital transmission or radio broadcast | |
KR100941823B1 (en) | Drm/am simulcast | |
JPS60501086A (en) | Simultaneous transmission of voice and data over analog channels | |
CH406296A (en) | Installation for transmitting a signal by means of a frequency modulated wave | |
FR2573266A1 (en) | Device for decoding coded television transmissions, intended in particular for an installation with communal antenna |
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: 19990531 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT CH DE FI FR GB IT LI |
|
17Q | First examination report despatched |
Effective date: 20000613 |
|
RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: THALES |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
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 |
Designated state(s): AT CH DE FI FR GB IT LI |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D Free format text: NOT ENGLISH |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP |
|
REF | Corresponds to: |
Ref document number: 69718930 Country of ref document: DE Date of ref document: 20030313 Kind code of ref document: P |
|
GBT | Gb: translation of ep patent filed (gb section 77(6)(a)/1977) |
Effective date: 20030501 |
|
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 |
Effective date: 20031106 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: TP |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: AT Payment date: 20101110 Year of fee payment: 14 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FI Payment date: 20101110 Year of fee payment: 14 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R082 Ref document number: 69718930 Country of ref document: DE Representative=s name: DREISS PATENTANWAELTE, DE |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R082 Ref document number: 69718930 Country of ref document: DE Representative=s name: DREISS PATENTANWAELTE PARTG MBB, DE Effective date: 20111004 Ref country code: DE Ref legal event code: R081 Ref document number: 69718930 Country of ref document: DE Owner name: PL TECHNOLOGIES AG, CH Free format text: FORMER OWNER: THALES, PARIS, FR Effective date: 20111004 |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: 732E Free format text: REGISTERED BETWEEN 20120705 AND 20120711 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20111121 |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: MM01 Ref document number: 232342 Country of ref document: AT Kind code of ref document: T Effective date: 20111121 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: TP Owner name: PL TECHNOLOGIES AG, CH Effective date: 20121207 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: AT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20111121 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: CH Payment date: 20121123 Year of fee payment: 16 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 20121029 Year of fee payment: 16 Ref country code: IT Payment date: 20121124 Year of fee payment: 16 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20121217 Year of fee payment: 16 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20130123 Year of fee payment: 16 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R119 Ref document number: 69718930 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R079 Ref document number: 69718930 Country of ref document: DE Free format text: PREVIOUS MAIN CLASS: H04H0001000000 Ipc: H04H0020000000 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20131121 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CH Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20131130 Ref country code: LI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20131130 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST Effective date: 20140731 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R119 Ref document number: 69718930 Country of ref document: DE Effective date: 20140603 Ref country code: DE Ref legal event code: R079 Ref document number: 69718930 Country of ref document: DE Free format text: PREVIOUS MAIN CLASS: H04H0001000000 Ipc: H04H0020000000 Effective date: 20140722 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20131121 Ref country code: DE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20140603 |
|
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: 20131121 Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20131202 |