FR2470491A1 - AUTOMATICALLY SWITCHED RADIO RECEIVER BETWEEN DIFFERENT PROGRAMMING TRANSMITTERS - Google Patents

Abstract

RADIO RECEIVER, IN PARTICULAR CAR RADIO WITH AUTOMATIC SWITCHING BETWEEN DIFFERENT TRANSMITTERS WITH CONCORDING PROGRAM. THIS RECEIVER IS GRANTED ON A REFERENCE TRANSMITTER SENDING THE DESIRED PROGRAM LOCATED IN A DETERMINED RECEPTION RANGE. THIS RECEPTION RANGE IS EXPLORED BY COMPARISON TRANSMITTERS SENDING A PROGRAM CORRESPONDING TO THE PROGRAM OF THE REFERENCE TRANSMITTER. THE CHORD DATA OF THE REFERENCE TRANSMITTER AND THAT OF THE COMPARISON TRANSMITTERS ARE STORED IN A MEMORY. AMONG THE TUNING DATA ARE SELECTED THOSE CORRESPONDING TO A TRANSMITTER WHOSE FIELD INTENSITY RECEIVED IS THE HIGHEST. WHEN THIS FIELD INTENSITY DECREASES BELOW A DETERMINED VALUE, OTHER CHORD DATA IS SELECTED AMONG THAT STORED IN THE MEMORY, AND CORRESPONDING TO THE TRANSMITTER, OF WHICH THE RECEIVED FIELD INTENSITY IS THEN HIGHEST. APPLICATION: CAR RADIO.

Description

"Automatically switched radio receiver between different

  The present invention relates to a receiver

  radio, in particular a car radio with automatic switching

  between different matching program transmitters.

  A car radio is known in which six program keys, each for ten different transmitters transmitting the same program, can be associated with the transmission frequencies when they are depressed. When a program key is pressed, the microprocessor-controlled receiver automatically searches for the strongest transmitter associated with that key and connects it to reception. If the field strength of the connected transmitter

  decreases, for example as a result of a change in the conditions

  The receiver automatically searches for the strongest transmitter again (VDI-Nachrichten, 12.10.1979, page 4, Funktechnik No. 10/1979, pages T 475).

at 476).

  Such a receiver certainly has advantages over simpler receivers without such an automatic system, but the transmitters associated with a certain program must first be determined by means of frequency tables and introduced by hand. If the six program keys are all occupied by different transmitters and if a change of location occurs to a region in which the transmitter on which the receiver is set is no longer received or only partially received while other non-memorized transmitters can be received, the setting on these transmitters must be done by hand without the possibility of automatic switching or the stored frequency groups must be completely or partially erased and replaced by

  new frequency groups. This erasure and this

  registrations are naturally particularly undesirable

  tables when the change of place is only temporary.

  The object of the invention is to provide a radio receiver of the aforementioned type which is also automatically adjusted to the most powerful transmitters of a program which can be received, the various frequencies of the program in question not however having to be introduced beforehand.

by hand.

  The method according to the invention is characterized in that the receiver can be tuned to a reference transmitter transmitting the desired program in a given reception range; this reception range can

  to be explored when searching for comparator transmitters

  his; the signal of each received comparison transmitter can be compared to the signal of the reference transmitter to detect the match of the program; the agreement data of the reference issuer and the agreement data of those among the comparison issuers whose program corresponds to that of the reference issuer,

  can be stored in a memory; when looking for

  the selection made may relate to that of the

  in agreement and memorized, which corresponds to the transmitter whose received field strength is the highest; and when decreasing the field strength the emitter

  selected below a certain value, the selection

  tion carried out may again relate to that of the data

  memorized agreement which corresponds to the issuer whose

  the received field strength is then the highest. More

  simplification of maneuvers, the process has the advantage

  age that the automatic system performs satisfactorily also when tuning to any new transmitter program

  and that it automatically finds issuers of comparisons

  its associated with this program, which is very advantageous especially when serving in places widely

  distant from each other or when changing frequency

  transmission facilities.

  Embodiments of the invention will be described hereinafter, by way of example, with reference to the accompanying drawings in which: - FIG. 1 is the block diagram of an embodiment having two receiving sections; - fig. 2 is the block diagram of an embodiment having a receiving section;

  - fig. 3 is the organizational chart of the form of

  cution shown in FIG. 2, and

  - fig. 4 is a development of the organization

gram of fig. 3.

  The radio receiver shown in FIG. 1

  has two separate receiving sections 1 and 2

  which antenna signal is fed through the common antenna conductor 18. The useful signal outputs 11 or 12 of the two receiving sections are fed to the inputs of an inverter 7 and one of the two signals is each time transferred via an amplifier.

  8 to the loudspeaker 9. The two useful signals on the

  11 and 12 are, in addition, fed to the inputs of a comparator program circuit 6 whose output signal is transferred via a conductor 16 to

  a control unit 10. The reception section 2 comprises

  you still have a section of field intensity 14 that is con-

  connected to the control unit 10. While the reception section 1 can be tuned by a hand tuning device 3, the reception section 2 is implemented with the frequency tuning device 4 and the unit

  control 10 as a transmitter search receiver.

  Reference 5 designates a control key.

  The circuit arrangement of FIG. 1 operates in the following manner. The receiving section 1 is set to any transmitter via the manual tuning device 3. In this case, the wanted signal conductor 11 is connected via the inverter 7 to the amplifier 8. If the program of this transmitter is to be received, the control key 5 is

  actuated and the control unit 10 starts, with the

  4 and the receiving section 2, a transmitter search at the beginning of the selected range and the reception section 2 stops at the first transmitter whose field strength is sufficient. Program contents of useful signals present on drivers

  11 and 12-are compared to each other by the comparison circuit

  6. If both program contents

  are similar, this similarity is announced by

  driver 16 to the control unit which stores the frequency of the comparison transmitter received in the

  receiving section 2, in a memory 13, as belonging to

  part of the program of the reception section 1. The research

  by the receiving section 2 is then continued

  until a new transmitter is received. For this issue

  program comparison is also performed and, when the programs are in agreement, the frequency

  corresponding is stored. The search for

  comparison transmitters transmitting the same program as that of the received transmitter by means of the reception section 1, is continued until the end of the range

  chosen is reached. The frequencies of all transmissions

  transmit the same program as that received in the reception section 1, are now stored in

  the memory 13 of the control unit 10.

  The transmitters stored in the memory 13 of the control unit 10 are now extracted from each other.

  following the others for setting the de-re-section

  2 through the frequency tuning device 4 and their field strength on the conductor 14 is measured by an amplitude measuring device 15. After performing the field strength measurements of all the stored transmitters, the most powerful is selected each time and the reception section 2 is set

  on this transmitter via the access

  4. The useful signal of the conductor 12 is then transmitted via the inverter 7

  controlled by the control unit 10, to the amplifier 8.

  The transmitter thus selected and connected is also received

  long enough that its field strength is sufficient. Linen-

  For this purpose, the voltage is continuously monitored by the amplitude measuring device 15. If it falls

  below a fixed value, a new measure of inten-

  field of all stored transmitters as well as a setting of the receive section 2 on the transmitter on

  more powerful happen automatically. It is, however,

  it is also possible, after such a drop in field strength, to perform a new search for comparison transmitters followed by the connection of the transmitter on

more powerful.

  To check if the program content

  of the comparator issuer to which "and

  2 is the program content of the reference transmitter to which the receiver 1 is tuned, the comparison circuit 6 can be composed so that the audio signal from the comparison transmitter is compared therewith

  with the audio signal from the reference transmitter.

  In the case where the comparison transmitters and the reference transmitter are each of the kind transmitting in addition to the signal

  required audio, also a transmitter characterization signal.

  However, the comparison circuit 6 may be constructed such that at least a portion of the transmitter characterization signal transmitted by the comparison transmitter is compared with the corresponding portion of the transmitter characterization signal transmitted by the transmitter. reference. It should be noted that a transmitter with a transmitter characterization signal generator and a receiver with

  a device for recovering this signal of

  issuers have been amply described in the application

  French Patent No. 2,382,135. Furthermore, it should be noted that this transmitter characterization signal can

  be a digital signal but also an analogue signal

  than. This issuer characterization signal may indicate inter alia the name of the issuer to which it is granted but also or in addition, the agreement to an issuer issuing

  traffic communications.

  The embodiment illustrated in FIG. 2 will be

described below.

  Unlike the embodiment shown in FIG. 1, that shown in FIG. 2 does not have,

  for reasons of economy, only one delivery section

  The useful signal on the conductor 42 arrives via the amplifier 8 to the loudspeaker 9. The receiver 20 is tuned through the frequency tuner 21 from the unit.

  by means of a search for automatic transmitters

  or by pressing one of the program keys 39. While in the arrangement shown in FIG. 1 for the comparison of the program, the useful signals of the two receiving sections 1 and 2 were compared between

  they, in the assembly shown in FIG. 2, the comparison

  This is done by switching the reception frequencies of the receiver 20. In this system, only short-term samples of the wanted signal can be sampled naturally, but these samples, with corresponding intermediate storage, can be processed according to

  the known rules of the technique of multiplexing with

  in time. For this reason, the output signals of the useful signal inverter 24 each pass through a low-pass filter 25 or 26 to the inputs of the program comparator circuit 27. The field strength signal the control unit via the conductor 43 and a

amplitude measurement 22.

  The control unit 30 is equipped with a micro-

  processor and contains, in addition to the usual components, the following special sets which can however be separated from the usual components of the microprocessor by a corresponding addressing. A frequency working memory 31 is provided in which are stored the frequencies of transmitters which have been found during the search of comparison transmitters transmitting the same program, as well as an associated address counter 33 which, for each comparison transmitter found transmitting the same program, is switched to progress from one position. In addition, a program key frequency memory 32 is provided, in which the frequencies

  associated with the program keys 39 are stored.

  To this program key frequency memory 32 is further associated an address counter 34 by which the individual storage locations of this memory are activated. Finally, there is further provided a cycle counter which counts the number of tuning operations on the most powerful emitter of the transmitters stored after a drop in field strength and which will be further described later. The control unit is furthermore controlled by a search key 37, a transmitter change key 38 and a key

  program occupancy 40 and sends a corresponding signal

  to a program key occupation light

  41 when all program keys are busy.

  The operation of the circuit circuit of the

  Fig. 2 will now be described in more detail with reference

  this is an organization chart (Fig. 3). After switching on the receiver, it is first checked whether the received transmitter field strength at this time is sufficient. If so, the frequency of this transmitter is stored in the storage location "O" of the frequency working memory 31 (FIG 2). Then, a silent chord is made via the driver 19

  amplifier 8 and a feedback from the search loop.

  receiver 20 at the beginning of the chosen range. The account

  The address server 33 is then moved to the memory address

re "1".

  The search is then continued, that is to say for the first time starting naturally from the beginning of the range. We then check if the end of the range is already reached. If this is not the case, the search receiver stops on the next received transmitter. The frequency of this transmitter is stored in the memory 31 and, in particular, in the storage location "1" previously set by the address counter 33. Then, via the control unit 30, the receiver

  is subject to a switch back and forth through

  intermediary of the frequency tuning device 21 between

  the two transmission frequencies stored in the slots

  storage items "0" and "1". The inverter 24 is inverted in synchronism with this switching and distributes the useful signals present on the conductor 42 and associated

  at the selected frequencies, on the inputs of the pass filters

  25, 26. The outputs of the low-pass filters then appear, according to the time division multiplexing rules, continuous signals which are compared to one another.

  the other in the program comparator circuit 27.

  If the programs are different, the search operation continues (new start at the last described program cycle) and the next transmitter found is stored

  at the same storage address "1" which means that the transmission

  previous provider is deleted. If the compared programs are similar, the address counter 33 is increased by one

  position (thus at storage location 2) and the operation

  research is continued as in the previous case.

  tooth. The next transmitter is then stored in the

  storage medium "2". A comparison of programs

  now between the transmitters contained in the

  storage "0" and "2" etc. This operation is

  repetition and the frequencies found from the transmitters

  Reason are stored in the corresponding storage locations determined by the advancement of the address counter 53, until the end of the range is reached. When the end of the range is reached, the cycle counter 35 is set to zero and an inversion of the receiver 20 via the frequency tuner 21 is made between the transmitters stored in the storage locations. 0 "to" n ". The field intensity signals belonging to the various frequencies are emitted on the conductor 43 by the amplitude measuring device 22 and are compared in the control unit 30. The most powerful transmitter is assigned to the location of "0" storage while all other transmitters, including the received transmitter in the first place, are

  distributed over the remaining storage locations "1" to "n".

  The receiver 20 is then tuned to the frequency of

  the storage location "0" and the silent

  driver 19) is cut. In addition, the cycle counter is advanced by one position. If the cycle counter has not yet reached the "m" position, it must be checked whether the field strength of the transmitter received at this time is sufficient. If so, it must be verified whether the transmitter change key 38 is actuated. If it is not, check whether one of the program keys 39 is actuated. When no program key is pressed, check whether the key

  37 is operated. If it is not action-

  Once again, the field strength of the

  the set transmitter and re-interrogate the various

  ches. If, however, the field strength of the received transmitter has fallen to a value which no longer allows satisfactory reception, the program branches out

  and there is again switching between frequencies

  these transmitters that are stored in the storage locations "0" to "n", an assignment to the most powerful transmitter of the storage location "0", a receiver agreement on the frequency of the content transmitter in

  the storage location "0" and a deletion of the

  silent cord (in itself not necessary) and a progress of the counting state of the cycle counter 35.

  If this last mentioned cycle is

  ran more than "m" times, this obviously means that the

  reception conditions have changed considerably.

  The program branches out, that is to say we do not check

  if the field strength of the transmitter is still sufficient

  successively, but that a series of searches for comparison transmitters

  to the transmitter contained in storage location "0".

  This series of research is followed by a return of

  zero cycles as well as the selection of the transmitter

  most powerful among the founders.

  The value "m" of the counter of cylces is chosen such that a new series of searches of comparison transmitters is started in good time before the conditions of reception have been modified to the point that one no longer has a transmitter of powerful comparison stored during the previous search. For example, the value "m" may be equal to 3, which means that it is only

  the fourth round of the cycle that a new research

  of comparator transmitters and a selection of the

  the most powerful stored device are made.

  A new search for issuers of comparisons

  sound can also be engaged by hand, by actuation

  of the transmitter change key 38.

  If, after switching on the receiver (program start), the field strength of the received transmitter is not sufficient, the program is already branching into this program.

  moment and there is a return from the search for

  at the beginning of the range. Issuer search begins

  then the receiver stops on the next transmitter.

  If the field strength of the transmitter thus found is sufficient, the frequency of this transmitter is stored in

  storage location "0" and there is a search for

  A number of comparison transmitters emitting the same program as well as a selection of the most powerful transmitter, etc. If the transmitter on which the receiver is tuned

  when it is switched on or the one found during the search

  If the transmitter does not transmit the desired program, the search key 37 can be operated and the search continues from the previous location and stops on the next transmitter. After verifying the field strength of this transmitter and storing the frequency in the storage location "0", a search of the transmitters

  comparison occurs as described above.

  Each of the program keys 39 is provided

  to be occupied by the frequency of a transmitter of a program

  determined me. When pressing a key of

  determined gram, the address counter 34 is set to

  a given address and the frequency stored in the

  The associated storing memory of the program key frequency memory 32 grants the receiver 20 via the frequency tuning device 21 on the desired frequency. The intensity of the emitter field is then checked and the frequency in the storage location "O" of the frequency working memory 31 is stored. As already described, the search for comparison transmitters transmitting the same program and the subsequent switching of the most powerful transmitter,

are then performed.

  If the conditions of reception remain unchanged,

  the last selected transmitter continues to be returned without modification. In the microprocessor, the program cycle in which the intensity of the transmitter's field is checked and the individual keys

  37, 38 and 39 are interrogated, are traversed without

  rash. Fig. 4 now illustrates a development

  of the flow diagram of fig. 3 according to which, in particular

  bind, the program cycle is divided between the points and 51 of FIG. 3 at location 52 and is connected to the points and 51 of FIG. 4. This derived program, represented in FIG. 4, is provided when transmission frequencies

  corresponding to a different program must be

  automatically and must be assigned to individual program keys. This is done

as follows.

  As long as the program occupancy key 40 is not pressed, the program returns

  by point 51 in the normal cycle of fig. 3. However,

  As soon as the program occupancy key is pressed, there is a silent chord of the amplifier 8 and a return of the search operation to the beginning of the range. In addition, the address counter 34 is switched to the address associated with the first program key. Then, the search continues (started for the first time naturally at the beginning of the range). If the end of the range is not reached yet, the search receiver stops

  on the next transmitter and the frequency found is

  fired at the first program key 39, i.e. the corresponding frequency is stored in the address "1" of the program key frequency memory 32. The frequency tuning device 21 then undergoes a switching back and forth between the transmitter found

  and the transmitters of the previous program keys.

  If the transmitter program found differs from the programs

  With all the previous program keys, the address counter 34 moves to the next position. If the found transmitter is the first transmitter, ie the transmitter to be assigned to the first touch

  program, a comparison with the programs of the

  previous programs, of course can not be made, but in this case the decision is that of a

different programs.

  As soon as the address counter 34 is reached

  At the following address, it is checked whether, in general, another program key is still available. if

  this is the case, the research continues and the judgment on

  next transmitter takes place when the end of the search range has not yet been reached. The previous cycle is then traversed in the same way until all the program keys are occupied.

by different transmitters.

  However, if, while the end of the gam-

  I have not reached yet, no program key

  is no longer available, a busy indicator 41 lights up.

  The program then takes place after deletion of the agreement

  silent until point 51 of the program according to FIG. 3.

  It is the same when the end of the range is at-

  hue. If, during a comparison of programs, it turns out that the program of the transmitter found is not

  different from the programs of all program keys

  my previous ones, the address counter 34 is progressing

  not, but the search operation is continued and the

  storage placement of this program key is

  busy by the then newly found transmitter.

  With the method illustrated in FIG. 4, he is

  therefore possible to use the program comparator

  my 27 not only to find comparators

  its emitting the same program, but also to ensure each time a new automatic occupation of the program keys 39 by different programs, without these transmitters must be listened to each separately. Yes

  one of the program keys 39 thus occupied is now

  When the receiver is pressed, the receiver is tuned to the corresponding frequency and an automatic search for comparison transmitters transmitting the same program proceeds and is followed by an agreement on the most powerful of the transmitters found. Program comparator circuits 6 (Fig.1) and 27 (Fig. 2) may be constructed in any suitable manner. As far as the circuit as shown in FIG. 2, the useful signal on the

  conductor 42 is connected via the inverting

  24 in synchronism with 1-a frequency switching performed by the frequency tuner 21, and through the two low-pass filters 25 and

  26 to the inputs of the program comparator circuit 27.

  Low-pass filters ensure that the signal samples are again transformed into continuous signal successions, the inverting frequency of the invert-

  24 having to be given naturally on the frequency

247049 1

  The highest to operate, that is, according to time-division multiplex rules, the

  inversion frequency must be twice that.

  However, when performing a program comparison, the highest program frequencies to be transmitted should not be used, but

  fractions at lower frequencies. The comparative circuit

  The program controller 27 may operate in cooperation with the control unit 30 in such a manner that the continuous output signals of the low-pass filters 25 and 26 analyzed at specified times are stored in the control unit 30 and are then compared and after a certain number of checks, the degree of concordance

  or discrepancy be used as a criterion for the existence

  this or the non-existence of a program concordance.

  It is also possible to give up the memory

  13 (Fig. 1), or 31 (Fig. 2), and after the

  initial setting of a reference transmitter transmitting the program

  wished me to explore the reception range chosen to detect only comparison transmitters that have a higher field strength than the transmitter of

  reference. For this purpose, the susceptibility threshold of the

  searcher is automatically set to

  corresponding to the intensity of the field of the

  reference. Each transmitter found whose intensity

  field is higher is then checked with regard to

  does the concordance of the programs and the first transmitter of this kind emitting the same program is then connected

  upon receipt in lieu of the reference issuer.

  It serves simultaneously as a new reference transmitter.

  If the field strength of this connected transmitter were to fall below a predetermined value, the above-mentioned more powerful transmitter search operation and the

  connection of newly found transmitters are repeated.

* The unit of inten-ted-damp to partrdeele a new operation of re-

  dheerhe is locked, must be high enough for a

  Satisfactory program compilation is still possible.

24704i1 1 5

Claims (6)

  A radio receiver, in particular a car radio with automatic switching between different transmitters with matching program, characterized in that it can be tuned to a reference transmitter transmitting the desired program in a given reception range; this reception range can be explored when searching for comparison transmitters; the signal of each transmitter   received comparison can be compared to the signal of the   reference to detect the concordance of the program   me; the agreement data of the reference issuer as well as the agreement data of those among the issuers of   comparison of which the program corresponds to that of the   reference, can be stored in a memory; when searching, the selection made can carry   on that of the memorized data thus memorized which corresponds to   to the transmitter whose received field strength is highest; and when decreasing the field strength of the selected transmitter below a determined value, the selection made may again relate to that of the memorized tuning data which corresponds to the transmitter whose intensity of received field is then the highest.   2. Radio receiver according to claim 1, characterized in that after the appearance of a determined frequency of the decrease of the intensity of the field and a new consecutive selection of that of the stored tuning data of the If the transmitter then has the highest received field strength, a new search for the matching program comparison transmitters can be performed; the chord data found during this new search can be stored again; and among the newly stored chord data, the one that corresponds to the transmitter having the field strength   highest received can be selected.   Radio receiver according to Claim 1, characterized in that, for the reception of the receiver on the reference transmitter, a first reception section   is intended to produce a reference receiver signal.   this and for the tuning of the receiving area during the search of comparison transmitters, a second receiving section is provided to produce a signal comparison issuer.   Radio receiver according to Claim 1, characterized in that for the reception of the receiver on the reference transmitter and for the analysis of the   reception during a search of comparator transmitters   its, a reception section is provided and is granted   periodically and alternately on the reference transmitter   this and on a comparison transmitter, the output signal   of this reception section being analyzed in synchronism   with the tuning circuit and that the analyzes thus obtained   nude being brought alternately to a first and to a second signal output.   Radio receiver according to Claim 4, characterized in that a low-pass filter is connected each time to the first and second signal outputs to produce the signal of the reference transmitter or the transmitter.   signal from the comparison transmitter.   Radio reducer according to Claim 3 or 5, characterized in that the signal of the reference transmitter and the signal of the comparison transmitter are   brought to a program comparator circuit.   Function of the blocks of fig. 3 = Switching on 61 = Transmitter field strength sufficient, yes or no 62 = Frequency storage at memory address "0" 63 = Silent tuning, return of the search loop at the beginning of the range, Address from memory to "1" 64 = Continuation of the search loop = End of range reached, yes or no 66 = Stop on the next transmitter, storage of the frequency in the memory 67 = Switching back and forth between l Reference Transmitter and Comparison Transmitter 68 = Equal / Unequal Program Contents 69 = Memory Address Advancement of "1" = Resetting Cycle Counter 71 = Switching Between Frequencies of Storage Locations " O "and" n "storage of the strongest transmitter at the memory address" 0 "72 = Tuning of the receiver at the frequency of the memory location" O "Suppression of the silent tuning 73 = Progress of the cycle counter 74 = Count state (of the cycle counter)> "m" = Field strength of sufficient transmitter 76 = Transmitter change key (pressed) 77 = Program key (pressed) 78 = Search key (pressed) 79 = Transmitter search and stop on the next transmitter = Return of search transmitter at the beginning of the range 81 = Tuning of the transmitter at the frequency of the program key (pressed) Function of the blocks of fig. 4 -   82 = Program occupancy timer (enabled), yes or no 83 = Suppression of silent tuning 84 = Silent tuning, return of the search to the beginning of range, address counter 34 on the first program key = Pursuit 86 = End of range reached 87 = Stopping on the next transmitter, assigning the frequency found to the program key 88 = Switching back and forth between the transmitter found   transmitters of the previous program key   89 = All different programs? 90 = Progress of the address counter 34 to the next program key 91 = Program key occupation flag 92 = Last program key