WO1997001891A1 - Verfahren und vorrichtung zur informationsübermittlung mit mehrkanalsendern und tragbaren breitbandigen empfängern - Google Patents
Verfahren und vorrichtung zur informationsübermittlung mit mehrkanalsendern und tragbaren breitbandigen empfängern Download PDFInfo
- Publication number
- WO1997001891A1 WO1997001891A1 PCT/EP1996/002703 EP9602703W WO9701891A1 WO 1997001891 A1 WO1997001891 A1 WO 1997001891A1 EP 9602703 W EP9602703 W EP 9602703W WO 9701891 A1 WO9701891 A1 WO 9701891A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- carrier frequency
- information
- stage
- channels
- output
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims description 16
- 238000011144 upstream manufacturing Methods 0.000 claims abstract description 3
- 230000005540 biological transmission Effects 0.000 claims description 13
- 230000010355 oscillation Effects 0.000 claims description 6
- 239000000969 carrier Substances 0.000 claims description 5
- 230000008878 coupling Effects 0.000 claims description 5
- 238000010168 coupling process Methods 0.000 claims description 5
- 238000005859 coupling reaction Methods 0.000 claims description 5
- 230000003321 amplification Effects 0.000 claims description 3
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 3
- 230000005855 radiation Effects 0.000 claims description 3
- 238000000926 separation method Methods 0.000 claims description 3
- 230000001939 inductive effect Effects 0.000 claims description 2
- 238000010586 diagram Methods 0.000 description 7
- 238000011156 evaluation Methods 0.000 description 6
- 230000001419 dependent effect Effects 0.000 description 2
- 230000006698 induction Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000005236 sound signal Effects 0.000 description 2
- 210000000481 breast Anatomy 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 230000015654 memory Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B5/00—Near-field transmission systems, e.g. inductive or capacitive transmission systems
- H04B5/40—Near-field transmission systems, e.g. inductive or capacitive transmission systems characterised by components specially adapted for near-field transmission
- H04B5/48—Transceivers
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B17/00—Monitoring; Testing
- H04B17/30—Monitoring; Testing of propagation channels
- H04B17/309—Measuring or estimating channel quality parameters
- H04B17/318—Received signal strength
Definitions
- the invention relates to a method for wireless transmission of information with at least one multichannel transmitter, each multichannel transmitter emitting a carrier frequency in a carrier frequency channel assigned to it via an antenna, which contains the information as modulated information channels, and wherein each of the information channels another information output is assigned, as well as with a number of portable receivers which record and demodulate the radiated radio frequency of at least one carrier frequency channel, one of the information thus recovered being output in accordance with the selected information channel; it also relates to a device for carrying out the method, with multi-channel transmitters, each of which emits one of the carrier frequencies and is connected to one or more audio or data carrier playback units for the acceptance of the information to be modulated, and with a number of portable receivers Input stages which receive the transmitted signals in certain spatial areas and are provided with a demodulation stage, possibly with amplification, for outputting the information.
- Tape recorders are known for museums which are equipped with a tape cassette which contain information about the exhibits in a desired language; on the one hand, these devices are heavy, on the other hand they have to be switched off when lingering in front of an object, so that there is a risk that the "thread is lost”. It is also known to lay induction loops in the area of the exhibited objects which are connected to a multi-channel transmitter. These transmitters operate in the longest or long wave range and transmit in the frequency range from 35 to 140 kHz.
- At least two multi-channel transmitters are provided for the transmission of information, the number of which depends on the number of sights to be explained.
- the carrier frequencies of these multi-channel transmitters radiated via antennas have frequency differences which are greater than the bandwidth of the modulated information channels; This difference in frequency allows a selection of the carrier frequency which is decisive for the point of view, a carrier frequency channel being separated here so that the modulated information contents are retained.
- the portable receivers intended for receiving the information receive the radiated carrier frequencies assigned to the individual carrier frequency channels; they act as known recipients.
- the reception field strength of the carrier frequency channels is advantageously evaluated using a number of narrowband bandpass filters, the number of which corresponds to the number of carrier frequencies; this number of carrier frequencies in turn is at most equal to the number of sights.
- These narrow-band bandpass filters are each matched to the carrier frequency and their bandwidth is so dimensioned sen that the modulation-related sidebands are in the pass band.
- An advantageously rectified control voltage the size of which is a measure of the reception field strength, is decoupled from each of the narrowband bandpass filters. With the help of this control voltage, the carrier frequency channel assigned to the largest of these control voltages is switched through to the demodulation stage, so that the information content of the carrier frequency channel which is incident with the greatest reception field strength can be output at this receiving location.
- a minimum level for the reception field strength is advantageously set, below which the output of the receiver is muted.
- the multichannel transmitters are set up in such a way that they transmit their carrier frequency via their antennas with such power and radiation characteristics that the field strengths of adjacent multichannel transmitters are of the same size at most at the borders of their adjacent near areas are. This ensures that a clean separation of the two reception channels is possible when changing from one reception area to the other. This is further improved if the portable receivers give priority to the received carrier frequency until the received field strength assigned to the next viewing location becomes greater than the field strength of the previously received carrier frequency.
- the multichannel transmitters output the information via several information channels in the form of different languages, the receiver reproducing them via the integrated loudspeaker or the connected earphones after the language has been selected.
- the multichannel transmitters output the information at least via one of the channels in the form of a character string, the receiver displaying this character string as readable characters on a display.
- a number of information channels outputting character strings can also be provided which, for example, output written information in different languages.
- the device with which this method can advantageously be carried out has multichannel transmitters in a number corresponding to the number of sights, and a number of receivers adapted to the number of visitors to be expected.
- Each of the multichannel transmitters has an oscillation and transmission output stage which is matched to one of the carrier frequencies corresponding to at most the number of multichannel transmitters in order to generate this carrier frequency, which is predetermined for this multichannel transmitter. They also have a modulation stage which is connected to the sound or data carrier playback unit for modulating at least two information channels.
- the distance between adjacent carrier frequency channels from one another corresponds at least to the sum of the bandwidths of the modulated information channels; this ensures that there is a frequency spacing necessary for the selection.
- the position of the information channels with respect to their sequence in the modulation of the individual carrier frequency channels themselves is always the same; If, for example, different languages are assigned to the individual information channels (German, English, French 7), they always have the same position with respect to the carrier frequency, so that they can always be recovered by demodulation, and in such a way that always the one selected of the information channels is output regardless of the carrier frequency.
- the information channel on the receiver side only has to be set by means of a selector switch when it is first switched on; when changing from the area of one of the multichannel transmitters assigned to one object under consideration to the next one of the multichannel transmitters associated with another object under consideration, no new setting is required.
- Each receiver has an input stage with a bandwidth that includes all carrier frequencies in the area of the carrier frequencies.
- This input stage - possibly with preamplification - is followed by a selection stage which divides the received radio frequency into carrier frequency channels.
- Such a selection stage can be formed, for example, by narrow-band bandpass filters, each with a passband that is assigned to the carrier frequency assigned to it. is switched off, which further have means with which a control voltage corresponding to the received field strength can be output for each of the carrier frequency channels.
- These receivers furthermore have a selection stage connected upstream of the demodulation stage, which can be switched by means of the control voltage in such a way that it switches through the carrier frequency corresponding to the largest of these control voltages to the demodulation stage, while suppressing weaker carrier frequencies.
- the number of carrier frequencies required for such a “high-frequency tour guide” corresponds in principle to the number of sights to be explained. In practice, however, it is sufficient - depending on the number of colors required for the color depiction of neighboring countries on maps - if at least 4 carrier frequencies, but at most 8 carrier frequencies are used. Since the reception field strengths decay rapidly outside the actual near field, a selection of the carrier frequency channel assigned to the reception location can also be ensured.
- the input of the portable receiver is designed to be broadband to receive all carrier frequencies; this ensures that all carrier frequency channels are picked up and possibly amplified via the input stage.
- Narrow-band filters are provided as selection elements for the carrier frequency channels, which filters, matched to the individual carrier frequencies, allow their separation. The pass characteristics of these narrowband bandpass filters are such that the modulation-related sidebands are passed through without significant attenuation.
- Each of the filters additionally has an inductive or capacitive coupling with a rectifier for coupling out a rectified control voltage, the size of which corresponds to the reception field strength of this carrier frequency channel.
- a rectifier for coupling out a rectified control voltage, the size of which corresponds to the reception field strength of this carrier frequency channel.
- a gate circuit is connected to each of the selection signal outputs in such a way that only the selection stage output is switched through from the gate circuit to the demodulator, the control voltage of which has the greatest value assumes while the other goal circuits are blocked.
- This gate circuit enables the automatic switching of the carrier frequency channel to be received.
- the demodulated signal contains the individual information channels side by side; these are selected with a selector switch and - after demodulation - are sent to the corresponding output in the form of an electro-acoustic or electro-optical converter.
- An alternative possibility for selecting the carrier frequency channel assigned to the receiving location is given in that the output of the input stage of the receiver is switched to a first mixer stage with a fixed frequency filter connected downstream.
- this first mixing stage the incoming high frequency is mixed with a mixing frequency to form an intermediate frequency.
- This mixed frequency is generated in an oscillation stage, the frequency of which is set by means of the control voltage emitted by the selection elements so that the mixed frequency with the carrier frequency assigned to the receiving location forms exactly the intermediate frequency passed by a downstream intermediate frequency filter.
- the bandwidth of the fixed frequency filter corresponds to the width of a carrier frequency channel.
- the signal selected in this way contains the information channels; these are selected with a selector switch and, after demodulation, are sent to the corresponding output in the form of an electro-acoustic or electro-optical converter.
- the demodulation stage for separating the information channels from the selected carrier frequency channel is advantageously preceded by a second mixing stage which forms a second intermediate frequency.
- the intermediate frequency formed here is formed with a mixed frequency, which can be adjusted with a selector switch with a rotary or slide switch is that the desired information channel is fed to the demodulation stage via a corresponding intermediate frequency filter tuned to a fixed frequency; the bandwidth of this intermediate frequency filter is dimensioned such that only the information channel in the pass band of the intermediate frequency filter lies, which was selected with the selector switch which switches the second mixer stage to the mixed frequency assigned to this carrier frequency channel. This information channel obtained in this way is then output after demodulation.
- the individual information channels of each of the multichannel transmitters are received and output with the same setting of the selector switch. This makes it possible for the user no longer to have to make a new setting of the desired information channel during the transition from the area of one of the multi-channel transmitters to a next area of another of the multi-channel transmitters.
- the receiver can be accommodated in a relatively small housing, so that it can be transported in a normal shirt pocket and put into operation by actuating a switch.
- This training represents a form with which the recipient can be accommodated in a simple manner and carried along on the tour of the tour.
- a loudspeaker and / or an earphone, via which the information can be heard, is advantageously provided for acoustically outputtable information in a manner known per se.
- the receiver has a display on which the information can be read.
- This display is advantageously an LCD display, the brightness and contrast of which can be adjusted in a manner known per se by means of actuators, wherein preferably backlighting is provided with brightness which can be adjusted in a manner known per se using an adjusting slide.
- the invention is explained in more detail on the basis of the exemplary embodiments illustrated in FIGS. 1 to 6; show
- Fig. 01 A block diagram of the multi-channel transmitter
- Fig. 02 A block diagram of a receiver with a secondary filter ter, gate switching and demodulation
- Fig. 04 A schematic representation of the transmission part
- Fig. 05 A schematic representation of the receiver part
- Fig. 06 A perspective view of the transmission device with an exchangeable sound carrier, here as a speech processor;
- Fig. 07 A perspective view of the receiving device.
- FIGS 1 to 3 show schematic circuits in the form of block diagrams.
- FIG. 1 shows a schematic block diagram of a multi-channel transmitter.
- the frequency-determining element is the quartz crystal Q1 which is matched to the carrier frequency and which interacts with the oscillation stage SSW. After amplification of the carrier frequency in the preamplifier stage, it is modulated with the signal content in the form of adjacent information channels.
- the information signals of the information sources IQ1, IQ2 and IQ3 are fed to the modulation stage MOD, the number of these information sources not being limited to the three sources shown here, and the information carriers of these information sources being interchangeable.
- IQ3 receive the information they provide to the modulation stage from information carriers, such as tapes, preferably endlessly running compact disks or permanent memories for digital signals (in particular for information which can be output optically via displays connected to the receiver) ) or the like .., in principle it is immaterial how the modulation takes place.
- the modulated high-frequency signal with its modulation-related bandwidth is now output via the transmitting power amplifier and emitted via an antenna shown here as a dipole, it being understood that other antenna shapes are also possible, the antenna shape being essential is dependent on the position of the carrier frequency in the radio frequency spectrum; L-antennas or T-antennas are also used for longer waves, with a grounded counterweight, while horns can be used in addition to dipole arrangements for very short waves.
- FIG. 2 shows a schematic block diagram of a receiver, the receiving antenna EDP of which, likewise shown here as a dipole, picks up the carrier frequency and outputs it to the input preamplifier EVV.
- the radio frequency output is passed to a number of carrier frequency filters TF1, TF2, TF3 ... TFn, each tuned to one of the carrier frequency channels and with a pass curve corresponding to the modulation-related bandwidth; the carrier frequency channels selected in these filters are switched to the demodulator stage DEM via carrier frequency gate switches TSI, TS2, TS3 .. TSn, which gate switch switches through the carrier frequency channel passed to it when it is received with maximum field strength.
- each of these filters can be addressed by this evaluation circuit BWS with an address via a reception field strength bus EBS; after responding via the assigned address, this information corresponding to the reception field strength is output via the reception field strength bus EBS to the evaluation circuit BWS, which sequentially polls all connected carrier frequency filters, compares the respective signals corresponding to the reception field strength and the address of that of the carrier frequency gate switch TSI, TS2, TS3, ... TSn determined for the carrier frequency channel incident with the maximum reception field strength and outputs it via the output bus ABS. This then addresses the carrier frequency gate switch TSI, TS2, TS3, ... TSn whose carrier frequency channel is assigned this maximum reception field strength.
- This carrier frequency gate switch is output via the output bus ABS, which then releases the passage for this carrier frequency channel and connects it to the demodulator DEM.
- a WSR selector switch allows the selection of the demodulated 1ated information channels, which corresponds to the desired speech or possibly also character output, the demodulation corresponding to the modulation used.
- the information channel selected with the selector switch WSR is then output via the loudspeaker LSP (or via a connected display DPL) and thus made audible (or visible).
- FIG. 3 Another type of information reception is shown in the schematic block diagram of FIG. 3:
- an overlay receiver is used to separate the carrier frequency channels.
- the input with the receiving antenna EDP is connected to an input preamplifier EVV, which amplifies the recorded frequency mixture and sends it to a first mixer MSI.
- a part is decoupled from the frequency mixture, from which the individual carrier frequency channels are separated using the narrow-band filters TF1, TF2, TF3,...
- the evaluation circuit here outputs a signal corresponding to this carrier frequency channel via the output line ALT, which goes to the oscillator 0S1 assigned to the first mixing stage and adjusts the mixing frequency generated there so that it exactly matches the carrier frequency of this carrier frequency channel in the first mixing stage MSI Intermediate frequency generated, which is passed by the downstream intermediate frequency amplifier ZF1 provided with appropriate filters.
- This intermediate frequency channel selected in this way is now demodulated, for which purpose a second mixer MS2 is used.
- the oscillator 0S2 assigned to this second mixing stage MS2 is connected to the selector switch WSR, with which the mixing frequency can be set so that the desired information band is filtered out on the intermediate frequency side and can thus be supplied to the demodulator DEM.
- the demodulated information signal can then be heard via the loudspeaker LSP (or output via a connected display DPL).
- FIG. 4 shows a schematic illustration of the transmitting part 1.
- the data or sound carrier 11 is connected to a transmitter 12.
- the data are advantageously repeated continuously.
- the data or sound carrier 11 can be formed by an endless magnetic tape. Additional data or sound carriers 11 'are provided in parallel. Alternatively, disks or electronic data and voice processors can also be used.
- Each data or sound carrier 11 emits its signal to a transmission stage 12 or 12 ', which in turn operate on antennas 13 and 13'.
- Each transmitter 12 works on a frequency channel; it goes without saying that the transmitter device 1 can also get by with a transmitter for the carrier frequency, and the frequency channels are formed by modulation methods.
- the transmission power is emitted via the antennas / antennas 13/13 ', the transmission power of the transmitters and / or the radiation characteristic being selected such that reception is only possible preferably in the supplied area.
- FIG. 5 shows a schematic representation of the receiver part 2.
- This part consists of a receiver 21.
- the data and sound signals already received are transmitted through a loudspeaker 22 provided in the housing or through an earphone connected to the AF output 22 ' made audible.
- a switch 25 is provided, which follows the antenna and acts on the RF input. It goes without saying that the voltage supply is also switched on or interrupted to protect the batteries.
- the frequency channels are set by one or more switching elements 23-23 '. As a result, the information in different frequencies, if it is sent in different languages, is set to receive the desired language.
- a slide switch or a rotary switch switches the frequency channels and at the same time indicates the selected position 24-24 '.
- FIG. 6 shows a perspective view of the transmission device 1 with an exchangeable data and sound carrier, shown here as a speech processor 11.
- a speech processor 11 In the housing 10 there is a transmitter 12, the signals of which are optionally fed to an antenna 13 which emits the signal in accordance with its antenna characteristic.
- the data or sound carriers, components 11-11 'shown here as speech processor 11, can be removed, exchanged or changed.
- the transmitting device is advantageously provided with an electrical mains connection with a connecting cable 14.
- FIG. 7 shows a perspective view of the receiving device 2.
- This part consists of a housing 20, in which openings for a loudspeaker 22 and setting button 24 and a switch 25 are arranged.
- the receiver 2 is advantageously designed with a data, audio signal output socket 22 'for connection to a further hearing instrument, such as an earphone.
- the receiver 2 can advantageously be attached to a e.g. Keychain to be attached.
- a clip provided on the back of the receiver also allows the receiver 2 to be worn on the shirt pocket or a breast pocket of a jacket or jacket. This type of transport is made possible by the small mass, since the information is transmitted wirelessly.
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- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Quality & Reliability (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Circuits Of Receivers In General (AREA)
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU63594/96A AU6359496A (en) | 1995-06-27 | 1996-06-21 | Data-transfer method and device with multi-channel transmitters and wide-band portable receivers |
EP96922877A EP0872031A1 (de) | 1995-06-27 | 1996-06-21 | Verfahren und vorrichtung zur informationsübermittlung mit mehrkanalsendern und tragbaren breitbandigen empfängern |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19523305 | 1995-06-27 | ||
DE19523305.0 | 1995-06-27 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1997001891A1 true WO1997001891A1 (de) | 1997-01-16 |
Family
ID=7765356
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP1996/002703 WO1997001891A1 (de) | 1995-06-27 | 1996-06-21 | Verfahren und vorrichtung zur informationsübermittlung mit mehrkanalsendern und tragbaren breitbandigen empfängern |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0872031A1 (de) |
AU (1) | AU6359496A (de) |
WO (1) | WO1997001891A1 (de) |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3934202A (en) * | 1974-03-25 | 1976-01-20 | Telesonic Systems, Inc. | Tour guide system including means for noise and crosstalk suppression |
US4457019A (en) * | 1982-08-12 | 1984-06-26 | By-Word Corporation | System for separately receiving multiple station audio-tour signals |
WO1991006158A1 (en) * | 1989-10-18 | 1991-05-02 | Neil Poch | Recorded message delivery system |
DE4235453A1 (de) * | 1992-10-21 | 1994-05-05 | Grundig Emv | Verfahren zur Signalklassifizierung bei FDM-Funkübertragungssystemen |
-
1996
- 1996-06-21 EP EP96922877A patent/EP0872031A1/de not_active Withdrawn
- 1996-06-21 WO PCT/EP1996/002703 patent/WO1997001891A1/de not_active Application Discontinuation
- 1996-06-21 AU AU63594/96A patent/AU6359496A/en not_active Abandoned
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3934202A (en) * | 1974-03-25 | 1976-01-20 | Telesonic Systems, Inc. | Tour guide system including means for noise and crosstalk suppression |
US4457019A (en) * | 1982-08-12 | 1984-06-26 | By-Word Corporation | System for separately receiving multiple station audio-tour signals |
WO1991006158A1 (en) * | 1989-10-18 | 1991-05-02 | Neil Poch | Recorded message delivery system |
DE4235453A1 (de) * | 1992-10-21 | 1994-05-05 | Grundig Emv | Verfahren zur Signalklassifizierung bei FDM-Funkübertragungssystemen |
Also Published As
Publication number | Publication date |
---|---|
AU6359496A (en) | 1997-01-30 |
EP0872031A1 (de) | 1998-10-21 |
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