EP2158706A2 - Apparatus for the simultaneous broadcast of an analog and digital signal - Google Patents
Apparatus for the simultaneous broadcast of an analog and digital signalInfo
- Publication number
- EP2158706A2 EP2158706A2 EP08750987A EP08750987A EP2158706A2 EP 2158706 A2 EP2158706 A2 EP 2158706A2 EP 08750987 A EP08750987 A EP 08750987A EP 08750987 A EP08750987 A EP 08750987A EP 2158706 A2 EP2158706 A2 EP 2158706A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- signal
- block
- analog
- digital
- drm
- 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.)
- Withdrawn
Links
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
- H04H20/30—Arrangements for simultaneous broadcast of plural pieces of information by a single channel
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04H—BROADCAST COMMUNICATION
- H04H20/00—Arrangements for broadcast or for distribution combined with broadcast
- H04H20/44—Arrangements characterised by circuits or components specially adapted for broadcast
- H04H20/46—Arrangements characterised by circuits or components specially adapted for broadcast specially adapted for broadcast systems covered by groups H04H20/53-H04H20/95
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04H—BROADCAST COMMUNICATION
- H04H20/00—Arrangements for broadcast or for distribution combined with broadcast
- H04H20/65—Arrangements characterised by transmission systems for broadcast
- H04H20/71—Wireless systems
- H04H20/72—Wireless systems of terrestrial networks
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04H—BROADCAST COMMUNICATION
- H04H2201/00—Aspects of broadcast communication
- H04H2201/10—Aspects of broadcast communication characterised by the type of broadcast system
- H04H2201/12—Aspects of broadcast communication characterised by the type of broadcast system digital radio mondiale [DRM]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04H—BROADCAST COMMUNICATION
- H04H2201/00—Aspects of broadcast communication
- H04H2201/10—Aspects of broadcast communication characterised by the type of broadcast system
- H04H2201/18—Aspects of broadcast communication characterised by the type of broadcast system in band on channel [IBOC]
- H04H2201/183—FM digital or hybrid
Abstract
An apparatus (10) for the simultaneous broadcast of an analog and digital radio signals, used in the frequency band of the FM (Frequency Modulation) signal, comprising a block or electronic card (12) to which one, two or more analog and/or digital audio and/or radio signals are inputted, consisting of a plurality of blocks or units for handling and processing analog audio signals, a possible RDS (Radio Digital System) and/or DARC (Data Radio Channel) signal, and a digital DRM (Digital Radio Mondiale) signal.
Description
APPARATUS FOR THE SIMULTANEOUS BROADCAST OF AN ANALOG AND DIGITAL SIGNAL
DESCRIPTION
The present invention relates to an apparatus for the simultaneous broadcast of an analog and digital signal.
More in particular, the present invention relates to an apparatus as defined above which is used in the frequency band of the FM (Frequency Modulation) signal and which additionally utilizes the DRM (Digital Radio Mondiale) digital standard.
As known, the transmission of a radio-type analog signal is often accomplished by using the
FM (Frequency Modulation) system, according to which the frequency of the transmission radio signal is modulated as a function of the frequency of the signal to be transmitted.
This type of modulation offers some advantages over amplitude modulation (AM), in that it is less sensitive to various kinds of noise and allows for higher quality transmissions.
The band amplitude used for transmitting analog radio signals (voice) is essentially comprised within a range of about 50 kHz, which is broader than the frequency band required by the AM system but such to allow to obtain a signal transmission which is less sensitive to interference or electric discharges.
The broader band available also allows to transmit stereo radio signals by using a so-called
"multiplexing" system, which allows to manipulate both audio signals of the two stereo channels, left and right (L and R), of the program to be broadcast and to transmit them as a sum signal (L + R) and a difference signal (L - R). The difference signal (L - R) is then translated, through suitable known systems, above the audible band; this provides compatibility with monophonic receivers which only reproduce the sum signal, the latter being de facto equal to the monophonic content of the signal taken into account.
The FM modulation system also supports the RDS (Radio Data System) standard, which allows to send small quantities of digital information, such as the name of the radio station, and the author and title of the track being played.
However, the transmission of the analog signal is often affected by noise which may alter the quality of the transmission itself; one of the most frequent types of noise is caused by propagation of the radio signal in the surrounding environment, with the signal being reflected by ground, buildings and local topographical features.
In the presence of such noise, the frequency response of the radio signal undergoes non- negligible deformations, due to destructive interference phenomena and/or phase displacements; such signal deformations may even lead to cancellation of some frequencies and, for narrow-band transmissions, to total signal loss. If the receiving apparatus is moving (e.g. on board of a moving car), this type of noise may occur together with other noise caused by the so-called "Doppler effect". This association has now become particularly important, for FM radio programs are nowadays mostly listened to by a large number of users when moving on board of public and/or private transportation vehicles. A further drawback of mobile reception of FM radio broadcasting is due to the fact that the antennas used for receiving radio signals are typically quite small and may therefore imply poor reception quality.
Another drawback of the FM analog signal is its poor flexibility; in fact, FM radio signal broadcasting allows to transmit only one type of information, i.e. analog information. In order to send data information, the FM system needs to use the RDS or DARC (Data Radio Channel) systems, thus requiring the use of a device capable of supporting said standard types.
A digital system called DRM has recently become widespread for transmitting audio and data information, which system so far uses different frequency bands from those used for FM signal broadcasting; this transmission system has allowed to overcome some of the typical drawbacks of FM transmission. In fact, the DRM system is an international digital transmission standard for short, medium and long waves which uses the same frequencies and the same wavelength as the corresponding current transmissions, except that, while offering an audio quality comparable to that of FM transmission, in addition to the audio signal it also allows to transmit text and data to be visualized on a display.
The DRM transmission system however suffers from some drawbacks as well, which are related to the fact that in many countries (among which Italy) there are no frequencies available for the application of such a system to the FM transmission band, which is generally quite congested. In addition, should there be any frequencies available in the FM band, high costs and a long time would be required for creating ex novo the network infrastructures needed for DRM broadcasting and for replacing the users' current receiving apparatuses. The object of . the present invention is therefore to overcome the above-mentioned
drawbacks.
More in particular, it is the object of the present invention to provide an apparatus for the simultaneous broadcast of an analog and digital signal which allows to introduce the DRM digital standard into the FM transmission frequency band.
It is a further object of the present invention to provide an apparatus which allows to adopt the DRM digital transmission standard within the FM transmission band without requiring any modifications to or replacements of the receiving and/or transmitting apparatuses currently in use, said receiving apparatuses remaining capable of receiving FM transmissions.
It is a further object of the present invention to provide an apparatus adapted to ensure an
FM transmission which is noise-free and flexible, and which allows for sending digital data in addition to the audio signal.
It is a further object of the present invention to provide operators and users with an apparatus for the simultaneous broadcast of an analog and digital signal which is adapted to ensure a high level of robustness and reliability over time, and which can be manufactured easily and economically.
These and other objects are achieved by the apparatus for the simultaneous broadcast of an analog and digital signal according to the present invention, which comprises a block or electronic card to which one, two or more analog and/or digital audio or radio signals are inputted, consisting of a plurality of blocks or units for handling and processing analog audio signals, a possible RDS (Radio Digital System) signal, and digital DRM (Digital
Radio Mondiale) signals.
The construction and functional characteristics of the apparatus for the simultaneous broadcast of an analog and digital signal according to the present invention will become apparent from the following detailed description, in which reference will be made to the annexed drawing representing a preferred but non-limiting embodiment thereof, wherein:
Fig. 1 is a circuit block diagram of the apparatus for the simultaneous broadcast of an analog and digital signal according to the present invention.
With reference to the above-mentioned figure, the apparatus for the simultaneous broadcast of an analog and digital signal according to the present invention, designated as a whole by reference numeral 10, consists of an electronic block or card 12 which receives one, two or more signals and processes them as described below in order to obtain an output signal which is then sent to a transmitter device of a known type, which hence will not be
described any further.
The analog signals inputted to block 12 are defined by a left signal 14 and a right signal 16 (respectively designated by arrows La and Ra in Fig. 1), which are the analog audio signals of a stereophonic transmission. Said left signal 14 and right signal 16 are sent to an adder block 18, which outputs a sum signal 20.
Sum signal 20 outputted by adder block 18 is then sent to a block or filter 22, which converts sum signal 20 into a sum signal 20' including only those components with a 15kHz frequency band, i.e. the frequency band of the monophonic sum signal. However, if sum signal 20 has already been filtered appropriately, block or filter 22 may be overridden by the user; in such a case, the signals 20 and 20' will be the same.
The sum signal 20' thus obtained is subsequently sent to a block 24, or decision-making block, the function of which will be described later on. The signal inputted to block or electronic card 12 may also be a multiplexing signal 26 (designated by arrow MPX in Fig. 1), i.e. a signal consisting of several signals sent simultaneously; as mentioned above, multiplexing allows for sending the sum signal and difference signal of the stereophonic channels as well as any RX)S and/or DARC signals. Multiplexing signal 26 is filtered by a filter unit 28, which lets through and outputs sum signal 30 or (A+B) signal, the single A and B signals (of the two stereophonic channels), and any RDS signal 32. All of these signals are obtained from input MPX signal 26, and are therefore related to said signal.
The set of signals outputted by filter unit 28 defines the input of a DRM signal encoding block 34, which processes the DRM signal corresponding to the signals coming from filter 28 with a band centre frequency tendentially equal to 38 kHz. As an alternative to the multiplexing signals, encoding block 34 may receive left signal 14 and right signal 16 inputted to block 12.
Encoding block 34 may receive one or more pairs of additional analog audio signals (consisting of a monophonic signal, or a right channel signal and a left channel signal), which may even be unrelated to the signals described so far; in the preferred embodiment, said additional signals preferably consist of two pairs of left and right signals Ll, Rl and L2, R2.
Encoding block 34 therefore provides high flexibility in choosing among the input signals thereof, and outputs a DRM type digital signal 36 which is sent to an additional adder block
38.
Instead of defining a signal inputted to the encoding block 34, the sum signal or (A+B) signal 30 may alternatively be sent to the decision-making block 24, as shown diagrammatically in Fig. 1.
5 Decision-making block 24 allows to choose which signal between sum signal 20', coming from filter 22, and (A+B) signal 30, coming from filter block 30, will define the input sent to additional adder block 38 on the basis of publishing, non-technical choices. RDS signal 32 possibly outputted by filter unit 28 is sent to a possible additional decision- making block 40.
0 A further possible RDS signal 42, inputted to block or electronic card 12 from a traditional RDS signal source, is sent to a filter unit 44 adapted to let through only the components of the RDS signal itself, i.e. an RDS signal 42'. However, if RDS signal 42 has already been filtered appropriately, block or filter 44 may be overridden by the user; in such a case, signals 42 and 42' will be the same.
5 RDS signal 42' outputted by filter unit 44 is sent, just like any RDS signal 32, to additional decision-making block 40.
The RDS signal outputted by additional decision-making block 40, if present, is inputted to additional adder block 38. Together with the RDS signal, additional adder block 38 also receives the above-defined
O DRM signal 36 and the sum signal outputted by decision-making block 24; said signals are added together, thus outputting a multiplexing signal 46 (designated MPX out in the diagram).
Multiplexing signal 46 outputted by block or electronic card 12 is defined, as schematized in diagram 48, by an analog sum signal (A+B), a digital DRM signal and a possible RDS
£5 signal; said multiplexing signal is then sent to a known conventional transmission device or apparatus.
The sum signal (A+B) and any FM transmission RDS signal are received unchanged by both monophonic and stereophonic analog receivers. In fact, analog receivers are equipped with a filter which is capable of removing audio signal
50 components at frequencies higher than 15 kHz, while letting through the typical frequency bands of RDS and DARC signals. Stereophonic receivers detect the absence of the 19kHz pilot tone indicating stereo broadcasting, and use a filter which is capable of removing audio signal components at frequencies higher than 15 kHz, while letting through the typical
frequency bands of RDS and DARC signals. DRM signal 36 is not therefore recognized by traditional analog receivers which, as aforementioned, will only receive the monophonic sum signal (A+B) and any information sent by means of an RDS or DARC signal. In an alternative embodiment, in the event that the DRM signal is characterized by a band centre frequency tendentially equal to 12 kHz, or anyway different from 38 kHz, the apparatus according to the invention may also comprise, in addition to encoding block 34, a shift block adapted to change the band centre frequency of the DRM signal from 12 kHz, or from the band centre frequency of the generated DRM signal, to 38 kHz. The results attained by the invention are apparent from the above description. The apparatus for the simultaneous broadcast of an analog and digital signal according to the present invention allows to introduce the DRM standard into the FM transmission frequency band, thus allowing analog and digital signals to be broadcast simultaneously. A further advantage is that the apparatus according to the invention allows to adopt the DRM digital transmission standard within the FM transmission band without requiring any modifications to or replacements of the receiving and/or transmitting apparatuses currently in use, said receiving apparatuses remaining capable of receiving FM transmissions. A further advantage is that the apparatus according to the invention ensures more noise- resistant FM transmission and allows digital data to be transmitted along with the audio signal; furthermore, the apparatus is made flexible by the possibility of receiving radio signals of different types from different sources.
The apparatus according to the invention may be advantageously equipped with a detector of remote control signals which, whether said remote control signals are sent separately to the same apparatus by means of another communication line or are contained in that portion of the signal 26 which is normally reserved for the difference of signal (A-B), will allow the apparatus to be controlled remotely for the purpose of including into MPX out signal 46 components of the analog and/or digital signal coming from different inputs of the same apparatus on a day and/or time basis, while also changing the composition and bit rate of the digital signal. This will provide, for example, easy and low-cost broadcasting of local programs within the context of a national program, only on certain days and/or within certain time intervals.
Since the signal has already been appropriately filtered, block or filter 44 can be overridden by the user; in this case, signals 42 and 42' will be the same.
RDS signal 42' outputted by filter unit 44 is sent, just like any RDS signal 32, to additional
decision-making block 40.
The RDS signal outputted by additional decision-making block 40, if present, is inputted to additional adder block 38.
Together with the RDS signal, additional adder block 38 also receives the above-defined DRM signal 36 and the sum signal outputted by decision-making block 24; said signals are added together, thus outputting a multiplexing signal 46 (designated MPX out in the diagram).
Multiplexing signal 46 outputted by block or electronic card 12 is defined, as schematized in diagram 48, by an analog sum signal (A+B), a digital DRM signal and a possible RDS signal; said multiplexing signal is then sent to a known conventional transmission device or apparatus.
The sum signal (A+B) and any FM transmission RDS signal are received unchanged by both monophonic and stereophonic analog receivers. In fact, analog receivers are equipped with a filter which is capable of removing audio signal components at frequencies higher than 15 kHz, while letting through the typical frequency bands of RDS and DARC signals. Stereophonic receivers detect the absence of the 19kHz pilot tone indicating stereo broadcasting, and use a filter which is capable of removing audio signal components at frequencies higher than 15 kHz, while letting through the typical frequency bands of RDS and DARC signals. DRM signal 36 is not therefore recognized by traditional analog receivers which, as aforementioned, will only receive the monophonic sum signal (A+B) and any information sent by means of an RDS or DARC signal. In an alternative embodiment, in the event that the DRM signal is characterized by a band centre frequency tendentially equal to 12 kHz, or anyway different from 38 kHz, the apparatus according to the invention may also comprise, in addition to encoding block 34, a shift block adapted to change the band centre frequency of the DRM signal from 12 kHz, or from the band centre frequency of the generated DRM signal, to 38 kHz. The results attained by the invention are apparent from the above description. The apparatus for the simultaneous broadcast of an analog and digital signals according to the present invention allows to introduce the DRM standard into the FM transmission frequency band, thus allowing analog and digital signals to be broadcast simultaneously.
A further advantage is that the apparatus according to the invention allows to adopt the DRM digital transmission standard within the FM transmission band without requiring any modifications to or replacements of the receiving and/or transmitting apparatuses currently
in use, said receiving apparatuses remaining capable of receiving FM transmissions. A further advantage is that the apparatus according to the invention ensures more noise- resistant FM transmission and allows digital data to be transmitted along with the audio signal; furthermore, the apparatus is made flexible by the possibility of receiving radio signals of different types from different sources.
The apparatus according to the invention may be advantageously equipped with a detector of remote control signals which, whether said remote control signals are sent separately to the same apparatus by means of another communication line or are contained in that portion of the signal 26 which is normally reserved for the difference of signal (A-B), will allow the apparatus to be controlled remotely for the purpose of including into MPX out signal 46 components of the analog and/or digital signal coming from different inputs of the same apparatus on a day and/or time basis, while also changing the composition and bit rate of the digital signal. This will provide, for example, easy and low-cost broadcasting of local programs within the context of a national program, only on certain days and/or within certain time intervals.
Even though the invention has been described herein with reference to an explanatory, non- limiting embodiment, it will be apparent to those skilled in the art that it may be subject to many changes or variations. Therefore, the present invention is meant to embrace any changes or variations falling within the spirit and scope of the appended claims.
Claims
1. Apparatus (10) for the simultaneous broadcast of an analog and digital radio signals, used in the frequency band of the FM (Frequency Modulation) signal, characterized by comprising a block or electronic card (12) to which one, two or more audio and/or radio signals are inputted, and which consists of a plurality of blocks or units for handling and processing analog audio signals, a possible RDS (Radio Digital System) and/or DARC (Data Radio Channel) signal, and a digital DRM (Digital Radio Mondiale) signal.
2. Apparatus according to claim 1, characterized in that the audio and/or radio signals inputted to the block or electronic card (12) are defined by an analog left signal (14) and an analog right signal (16) and related to a stereophonic transmission.
3. Apparatus according to claim 1, characterized in that the signal inputted to the block (12) is defined by a multiplexing signal (26).
4. Apparatus according to claim 1, characterized by comprising an input RDS signal (42).
5. Apparatus according to one or more of the preceding claims, characterized by comprising an adder block (18) adapted to add up the left signal (14) and the right signal (16), thus obtaining a sum signal (20).
6. Apparatus according to one or more of the preceding claims, characterized by comprising a block or filter (22) which receives the sum signal (20) and outputs a sum signal (20') with a frequency band tendentially equal to 15 kHz.
7. Apparatus according to one or more of the preceding claims, characterized in that the multiplexing signal (26) is manipulated by means of a filter unit (28) which outputs a further sum signal (30) or (A+B) signal, a single signal (A) and a single signal (B) of the two stereophonic channels, and a possible RDS signal (32).
8. Apparatus according to one or more of the preceding claims, characterized by comprising an encoding block (34) for the digital DRM signal.
9. Apparatus according to claim 8, characterized in that the encoding block (34) receives the signals outputted by the filter unit (28) and processes the digital DRM signal (36) with a band centre frequency tendentially equal to 38 IcHz.
10. Apparatus according to claim 8, characterized in that the encoding block (34) receives the left signal (14) and the right signal (16) of the analog stereophonic transmission.
11. Apparatus according to claim 8, characterized in that the encoding block (34) receives one or more pairs of additional analog radio signals.
12. Apparatus according to any of the preceding claims, characterized by comprising an additional adder block (38) adapted to receive as input the DRM signal (36) outputted by the encoding block (34), the analog sum signal outputted by a decision-making block (24), and any RDS signal outputted by an additional decision-making block (40), wherein said additional adder block outputs a multiplexing signal (46).
13. Apparatus according to any of the preceding claims, characterized by comprising a shift block adapted to change the band centre frequency of the DRM signal from 12 kHz to 38 kHz, or from the band centre frequency of the generated DRM signal to 38 kHz.
14. Apparatus according to any of the preceding claims, characterized by comprising a detector of remote control signals which are either sent to the same apparatus separately by means of another communication line or contained in that portion of the signal 26 which is normally reserved for the difference signal (A-B).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ITMI20071025 ITMI20071025A1 (en) | 2007-05-22 | 2007-05-22 | APPARATUS FOR THE CONTEMPORARY DIFFUSION OF AN ANALOGUE AND DIGITAL SIGNAL |
| PCT/IB2008/001254 WO2008142530A2 (en) | 2007-05-22 | 2008-05-20 | Apparatus for the simultaneous broadcast of an analog and digital signal |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| EP2158706A2 true EP2158706A2 (en) | 2010-03-03 |
Family
ID=40032229
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP08750987A Withdrawn EP2158706A2 (en) | 2007-05-22 | 2008-05-20 | Apparatus for the simultaneous broadcast of an analog and digital signal |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP2158706A2 (en) |
| IT (1) | ITMI20071025A1 (en) |
| WO (1) | WO2008142530A2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103457615A (en) * | 2013-08-16 | 2013-12-18 | 奥维通信股份有限公司 | Audio broadcasting frequency modulation transmitter based on digital-analog networking |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1772980A1 (en) * | 2005-10-06 | 2007-04-11 | Delphi Technologies, Inc. | Method and apparatus for for the transmission of broadcasts |
-
2007
- 2007-05-22 IT ITMI20071025 patent/ITMI20071025A1/en unknown
-
2008
- 2008-05-20 EP EP08750987A patent/EP2158706A2/en not_active Withdrawn
- 2008-05-20 WO PCT/IB2008/001254 patent/WO2008142530A2/en active Application Filing
Non-Patent Citations (1)
| Title |
|---|
| See references of WO2008142530A3 * |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2008142530A2 (en) | 2008-11-27 |
| WO2008142530A3 (en) | 2009-02-19 |
| ITMI20071025A1 (en) | 2008-11-23 |
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