WO1990013190A1 - Technique pour utiliser une frequence sousporteuse de station de radio pour transmettre, recevoir et diffuser un message en meme temps que la reproduction audio du programme radio - Google Patents

Technique pour utiliser une frequence sousporteuse de station de radio pour transmettre, recevoir et diffuser un message en meme temps que la reproduction audio du programme radio Download PDF

Info

Publication number
WO1990013190A1
WO1990013190A1 PCT/US1990/001921 US9001921W WO9013190A1 WO 1990013190 A1 WO1990013190 A1 WO 1990013190A1 US 9001921 W US9001921 W US 9001921W WO 9013190 A1 WO9013190 A1 WO 9013190A1
Authority
WO
WIPO (PCT)
Prior art keywords
signal
message
data
data signal
program
Prior art date
Application number
PCT/US1990/001921
Other languages
English (en)
Inventor
Jon P. Grosjean
Stuart E. Ross
Daniel J. Semple
Original Assignee
Spingarn, James, L.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Spingarn, James, L. filed Critical Spingarn, James, L.
Publication of WO1990013190A1 publication Critical patent/WO1990013190A1/fr

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
    • H04H20/33—Arrangements for simultaneous broadcast of plural pieces of information by plural channels
    • H04H20/34—Arrangements for simultaneous broadcast of plural pieces of information by plural channels using an out-of-band subcarrier signal
    • G—PHYSICS
    • G08—SIGNALLING
    • G08G—TRAFFIC CONTROL SYSTEMS
    • G08G1/00—Traffic control systems for road vehicles
    • G08G1/09—Arrangements for giving variable traffic instructions
    • G08G1/091—Traffic information broadcasting
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04H—BROADCAST COMMUNICATION
    • H04H2201/00—Aspects of broadcast communication
    • H04H2201/70—Aspects of broadcast communication characterised in that receivers can be addressed

Definitions

  • the present invention is directed to a technique for
  • Such a "live” message would preferably be of any desired length, but would have to be displayed by multiple number of segments, with the maximum segment length being determined by the size of the display.
  • Previous approaches have used a static display. For example, the December 1988 issue of Radio-Electronics includes on pages 65-68 and 76 an article on a European data system used in conjunction with FM programming. A subcarrier, typically at 57 kHz, is used to carry digital data for display on a radio. The displayed information describes the audio program as being
  • the radio programming such as music, can continue uninterrupted while, for example, the traffic conditions are being displayed rather than having to be audibly reproduced.
  • the radio station may find it easier to attract sponsors and, in addition, may succeed in keeping a broader range of listeners including those who are not interested in tuning to an audio program likely to be interrupted. There is also an economic incentive in
  • Another object of the present invention is to provide a technique for displaying a "live" message along with reproduction of a radio program.
  • Yet another object of the present invention is to provide a technique for displaying the "live" message under control of the broadcasting station while providing a flexible arrangement to produce the display in a variety of formats.
  • Yet another object of the present invention is directed to provide a technique for scanning a plurality of subcarrier frequencies at each broadcasting station to determine which one is transmitting a message.
  • One other object of the present invention is to transmit the message for display on the same subcarrier which is already transmitting other information, such as a continuous music program.
  • apparatus for transmitting and receiving a radio frequency signal comprising radio program input means for providing a program signal on a main carrier frequency of the main carrier frequency.
  • a data generating means provides a data signal on a subcarrier frequency transmitting means for combining the program signal and the data signal into a composite signal, and for radiating the composite signal.
  • a receiver means receives the radiated composite signal and separates it into a program signal component and a data signal component.
  • a speaker means audibly reproduces the program- signal component.
  • a display means dynamically displayes a message corresponding to the data signal component simultaneously with the audible reproduction of the program signal component.
  • a data generating means provides data signals to be transmitted during a plurality of time periods on a subcarrier frequency of the main carrier frequency. It includes: means for sequentially inputting portions of a message, represented by a plurality of input signal blocks, into a queue until the entire message is within the queue, and means for sequentially retrieving the plurality of input signal blocks individually from the queue and introducing all of the plurality of input signal blocks, individually and in turn, into the respective data signals transmitted during the plurality of time periods.
  • a transmitting means combines the program signal and the data signals into a composite signal, and radiates the composite signal.
  • a receiver means receives the radiated
  • a speaker means is coupled to the receiver means for audibly reproducing the program signal
  • a display means is coupled to the receiver means for displaying, simultaneously with the audible reproduction of the program signal component, all of the message portions, in turn, as data signals having the respective plurality of input signal blocks incorporated therein are received by the receiver means.
  • One other aspect of the present invention is directed to apparatus for transmitting and receiving a radio frequency signal, comprising radio program input means for providing a program signal on a main carrier frequency.
  • a data generating means provides data signals to be transmitted during a plurality of time periods on a subcarrier frequency of the main carrier frequency. It includes: means for storing portions of a message, represented by a plurality of input signal blocks, so that theentire message is stored, and means for retrieving the plurality of input signal blocks individually in an ordered sequence from the beginning of the message to its end and introducing all of the plurality of input signal blocks, individually and in turn, into the respective data signals transmitted during the plurality of time periods. Transmitting means, receiver means, speaker means, and display means are provided as already explained above.
  • Yet another aspect of the present invention is directed to apparatus for transmitting and receiving a radio frequency signal; comprising radio program input means for providing a program signal on a main carrier frequency.
  • a data generating means provides a data signal on a subcarrier frequency of the main carrier frequency. It includes: means for generating input signals having an average DC voltage level normally greater than zero, means for encoding the input signals to provide coded signals having an average DC voltage of substantially zero over a predetermined period of time, and means responsive to the coded signals for generating the data signal.
  • a transmitting means combines the program signal and the data signal into a composite signal, and radiates the composite signal.
  • a receiver means receives the radiated composite signal and separates it into a program signal component and a data signal component.
  • a means isprovided for decoding the data signal component.
  • a speaker means audibly reproduces the program signal component.
  • a display means displayes a message corresponding to the decoded data signal component simultaneously with the audible reproduction of the program signal component.
  • a further aspect of the present invention is directed to apparatus for transmitting and receiving a radio frequency signal, comprising radio program input means for providing a program signal on a main carrier frequency.
  • Information signal generating means provides an information signal normally
  • a data generating means provides a data signal to be transmitted on the subcarrier frequency and includes: first means for determining the given time intervals when the information signal is not transmitted on the subcarrier frequency, and means for
  • a transmitting means normally combines the program signal and the information signal into a first composite signal, and it combines the program signal and the data signal only during at least a portion of .the given time intervals to form a second composite signal.
  • a receiver means receives the first and second radiated composite signals and separates them into a program signal component, a first subcarrier frequency component, and a second subcarrier frequency component.
  • a second means determines the given time intervals when the information signal is not present on the subcarrier frequency component.
  • a speaker means audibly reproduces the program signal component and the first subcarrier frequency component.
  • a means is provided for inhibiting the speaker means during at least a portion of the given time intervals.
  • a display means displayes a message
  • Fig. 1 is a block diagram showing a transmitter arranged in accordance with the present invention.
  • Fig. 2 is a block diagram of a receiver arranged in
  • Fig. 3 is a flow chart describing repeated generation of a message by the transmitter.
  • Fig. 4 is a flow chart describing the operation of the receiver.
  • Fig. 5 is a flow chart describing how the receiver is controlled to display a message in various selected ways on a two line display, device.
  • Fig. 6 is a block diagram of another embodiment of the receiver capable of scanning a broadcast band for automatically finding the station which is broadcasting the message.
  • Fig. 7 is a flow chart describing how the receiver of Fig. 6 is controlled to scan the frequency band and to ensure the validity of the received message.
  • Fig. 8 is a block diagram of another embodiment of the transmitter capable of transmitting the message on a subcarrier freguency also being used for transmitting other information as well.
  • Fig. 9 is a block diagram of another embodiment of the receiver operable with the transmitter of Fig. 8.
  • transmitter 1 includes data generator 3 which is used to provide a selected message to be transmitted over a subcarrier freguency.
  • FM radio stations broadcast primary programming on a main carrier frequency (also called main channel), and other signals are broadcast using SCA (Sub-Carrier Authorization) carrier frequencies centered usually around 57, 67, 76 and 92
  • SCA Sub-Carrier Authorization
  • each SCA carrier uses approximately 5 to 10% of the transmitter power, radio stations usually use no more than two SCA carriers in order to retain sufficient power for the main channel.
  • Data generator 3 is used to not only input the desired message, but it also provides control signals that are required for both transmission and reception of the message. For example, at the transmission end, such control signals determine the repetition frequency at which the message is cyclically
  • control signals determine whether the displayed message is to be static, scrolling, flashing, etc. It is seen that these control signals set various attributes of the message.
  • control and “attribute” are used interchangeably hereinbelow. More details on the data generation aspect of the invention are provided below.
  • Data generator 3 provides at its output a signal, preferably digital, (called “data signal” hereinbelow) which is input to SCA generator 5 of a conventional design, such as product SCA-300 available from Circuit Research Laboratories.
  • SCA generator 5 provides a selected SCA carrier and modulates it by the output of data generator 3.
  • the modulated SCA carrier is combined in FM broadcast transmitter 7 (also conventional) with the program carried on the main channel as generated by audio program signal generator 9.
  • the resulting composite signal is radiated by antenna 11.
  • generator 3 can be in the form of ASCII characters. However, data generator 3 preferably converts the ASCII values to a binary output with an average voltage of 0. Doing so has the advantage of encrypting the message to block use of the system by unauthorized receivers. Also, it allows the signal to be
  • the signal radiated by antenna 11 is detected by receiver 15 depicted in Fig. 2.
  • Antenna 17 provides the detected signal to FM tuner 19.
  • the thus detected composite signal output by FM tuner 19 is then split.
  • the modulated main carrier is input to audio amplifier 21 for audible reproduction on speaker 23 in the conventional manner.
  • the composite signal is also input to SCA detector 25 which separates the SCA carrier from the composite signal.
  • SCA detector 25 is conventional in that it includes a bandpass or high pass filter to reject the main carrier, and an EXAR XR2211 phase lock loop circuit to demodulate the SCA carrier signal and produce a digital signal at the output of SCA detector 25.
  • the digitized output signal is input to SCA decoder and data signal processor 27 (called "decoder 27"
  • Decoder 27 is preferably a Zilog Z8
  • microcontroller which processes the thus separated signal to determine its message content as well as whatever control signals were radiated from transmitter 1. The message is then shown on display 29 with the attributes set by the decoded control
  • Display 29 can be an AND 501 or an OPTREX DMC-20215. It is a two-line device having a capacity of 20 characters per line.
  • Indicator 31 is useful to alert the listener to the fact that the station to which the radio is tuned is generating a data signal.
  • decoder 27 detects a characteristic of the data signal (discussed in detail below) and actuates indicator 31 so that the listener knows to immediately stop further scanning of the FM band.
  • Indicator 31 can take the form of an LED device.
  • An available option is to provide an alarm device 33 which is activated by decoder 27 when a certain type of message is
  • a volunteer fireman can be called to duty with a buzzer sounded by his radio.
  • Other outputs 35 of decoder 27 can be contemplated such as controlling any desired electrical load, such as a light.
  • decoder 27 While decoder 27 is generating its output signals and actuating devices such as 29, 33 and 35, the conventional audible reproduction of the radio program continues uninterrupted. In particular, this occurs even while a message and its associated control signals are detected, processed and displayed. Thus, a simultaneous display of the message along with audible
  • Data generator 3 is preferably embodied in the form of a personal computer ("PC" hereinafter).
  • the PC is provided with suitable software to generate a desired message. This can be in the nature of a wordprocessing program with typical function select features, alphanumeric character entry, text editing, and similar capabilities.
  • the messages can be prestored for
  • the PC is also utilized to generate the control signals, i.e.
  • the attributes can, for example, be stored in the PC and made available to the user for selection in a displayed table or by a menu-driven approach.
  • one message line is generated by the PC. Since display 29 can accommodate a maximum of 20 characters, a message line cannot exceed 20 characters in length. Data display 29 is of the two- line type. Thus, a maximum of two lines can be displayed
  • Each message line generated by the PC is provided with its own set of attributes which are selected by the user (i.e. the radio station operator). These attributes are selected by the user (i.e. the radio station operator).
  • TRANSMIT TIME- This is the time, in seconds, for which the current message line will be transmitted by the PC. Depending upon the selected display attributes, it is roughly equivalent to the length of time the message line would appear on the display 29.
  • DISPLAY LINE- This is the target line of the display where the text will appear. In a two-line display, the top or the bottom line may be selected.
  • the load mode may be set to either "NORMAL" or
  • This mode can be used to create a vertical scrolling effect similar to scanning up or down a page of text while exposing only two lines at a time. If the "NORMAL" mode is selected, the other display line is not affected by the load operation.
  • SPLIT-ON-LOAD- The just-transmitted text is loaded into the display 29 starting with the two center characters of the target line and proceeding outward to the two ends of the display line.
  • the characters are written into the display two at a time at the speed specified by SCROLL SPEED (see below). If the SCROLL UNLOAD attribute is additionally set, the message will scroll out of the center as two halves.
  • SCROLL DISPLAY- The text in the target display line
  • This speed attribute will also be used for other effects to be implemented in the future.
  • the data signal generated by the PC includes more than just the message signal and the control signal relevant to selection of the desired attributes.
  • the data signal is generated,
  • CRC Cyclic Redundancy Check
  • Block redundancy is used for error correction.
  • the transmitter repeatedly sends the same block of the data signal within a certain interval of time to insure that the receiver is able to capture the block correctly.
  • the receiver is able to capture the block correctly.
  • transmission is done continuously so that the last bit of the block is immediately followed by the first bit of the block.
  • each block contains 32 bytes of information, with each byte having 8 bits.
  • the header portion is allocated a total of 7 bytes. It is used to help synchronize the receiver to the data signal and to alert the receiver to the existence of a data signal on its particular radio station and subcarrier.
  • the header portion includes 1 sync byte and six additional bytes representing six ASCII characters. The sync byte is used to flag the beginning of a block and to assist the receiver in locking-on to the data signal. Its value is assigned to be unique with respect to the rest of the data bytes in the block.
  • the receiver can use the unique sync byte to quickly determine the start of a data signal block.
  • the next six characters are selected to form a predesignated identification signal ("ID signal" hereinafter) indicative of the fact that a message is to follow. That is to say, the ID signal is not related to a particular message. Its function is to alert the receiver to the fact that a data signal, regardless of the message and control signals which are a part of it, exists on this particular SCA carrier of this particular radio station.
  • ID signal is the binary signal 11111111.
  • One arbitrary example of the ID signal is the set of ASCII characters for "ZEPHYR".
  • the portion of the protocol format immediately following the header portion is known as the system exclusive. It is allocated
  • the next portion of the protocol format allocates 20 bytes to the text of the message for one message line. Each byte
  • the final portion of the protocol format consists of 2 bytes allocated to the CRC.
  • the CRC value is derived from processing each byte of the entire block, "on the fly” through a standard
  • Fig. 3 depicts a flow chart describing how the PC generates a message which may require a multiplicity of display lines to be displayed in its entirety. In other words, the entire message may involve more than 20 characters. As indicated above, each line is transmitted repeatedly in order to provide block
  • the PC must not only transmit each message line repeatedly, but must also proceed from the transmission of each message line to the next until all of the message lines are transmitted. This operation involves first storing all of the message lines
  • Each message line is assigned a
  • Instruction 52 generates message line X which corresponds to a block of the data signal including a particular portion of the message along with its selected attributes.
  • Message line X is set by instruction 54 into its sequential position place within a queue. Once the entire message has been generated and stored, message line by message line, the PC provides a TRANSMIT signal indicative of such a state.
  • Decision box 56 then
  • the value of X is again set at 1 by instruction 62.
  • the task now at hand is to output the message, first repeatedly for each line and, then, to complete the output of all of the lines in the same manner. This is initiated by the user
  • instruction 64 outputs the first message line from data generator 3 (i.e. from the PC) to SCA generator 5.
  • the block which is representative of message line X is to continue to be output from the PC as long as the assigned TRANSMIT TIME is not exceeded.
  • box 66 compares the amount of time for which message line X has been transmitted against the assigned TRANSMIT TIME. If the TRANSMIT TIME has not been exceeded, the flow returns to instruction 64. When, however, the TRANSMIT TIME is eventually exceeded, then the flow proceeds to instruction 68 which
  • Vctiue of X increases the Vctiue of X by 1. That value is then compared in decision box 70 against the total number of message lines T stored in the queue, as explained above. If X does not exceed T, that indicates that more message lines remain in the queue.
  • receiver 15 detects it and a corresponding digital signal is produced by SCA detector 25 in the manner discussed above. Decoder 27 then processes that signal in accordance with the flow chart depicted in Fig. 4. Specifically, box 80 represents the receipt from SCA detector 25 of its output signal. Decoder 27 then determines, in ccordance with decision box 82, whether the ID signal has been received. In other words, after the sync pulse is detected, decoder 27 searches for the predesignated combination of six characters, namely "ZEPHYR". If that ID signal is not found, the operation returns to box 80 to await the receipt of the next block of data. However, if the ID signal is found at the input of decoder 27, the remainder of the block is detected and stored in memory per box 84. In addition, box 86 carries out a
  • Decision box 88 compares the calculated CRC value with the value of the received CRC bytes. If the two values are not equal, then it is determined that the data signal has been erroneously received, and the operation is returned to box 80. If, however, the two values are in agreement, the received block of data is taken as being error free. Then, decision box 90 determines whether the just-received block contains a message which has already been previously received. This involves a comparison between the message just stored and a message previously stored and used for display. The previously received message is stored in a buffer, and its bits are compared with those in the newly received message in a conventional way. If the two are the same, the message already in memory is retained for continuing display. However, if a new message is detected, a display buffer is updated with the new message line, in accordance with box 92.
  • instruction 94 causes the newly stored message line to be display on display 29.
  • the transmitter is provided with the capability of transmitting a plurality of message lines sequentially. These message lines can be components of a long message, or they can be a plurality of messages, as desired.
  • the receiver is highly flexible in terms of the messages which it can generate, store in a queue, and then transmit. Likewise, the receiver is capable of receiving each individual message line and retaining it for display as long as new message line, different from the existing one, is not
  • the new message line is utilized to update the display by replacing the existing message line, scrolling, flashing, etc.
  • Fig. 5 is an expanded version of the processing performed by boxes 90, 92 and 94 depicted in Fig. 4.
  • Fig. 5 shows the detailed steps involved in displaying message lines on both lines of display 29.
  • Instruction 100 is part of the timing cycle with which the various tasks of decoder 27 are
  • decision box 104 routes the operation to instruction 106 if no new message is detected.
  • Instruction 106 causes the message line to be input to display 29.
  • Decision box 108 determines whether any attributes regarding display effects are part of the block to which the current message text belongs. If an attribute is detected, it is utilized in box 110 to control the display, such as by flashing or scrolling, for example. If decision box 104 detects a new message, then box 112 inputs that, by virtue of instruction 106, to display 29. Then, operations 108 and 110 are carried out in the same manner as already
  • decision box 108 determines that no display effects were provided as attributes, then the flow proceeds to instruction 114 with regard to the second message line to beprocessed for that particular display cycle. The flow is also added to instruction 114 after instruction 110 is completed.
  • Operations 116, 118, 120, 122 and 124 which follow correspond to previously discussed operations 104, 112, 106, 108, and 110, respectively.
  • the only difference between the two sets of operations involves decision boxes 108 and 122. Whereas the former routes the operation to a processing of the second message line, the latter routes the operation back to instruction 100 to await the next display cycle.
  • Each of the two message lines is processed individually to determine its message content and to identify and implement whatever attributes were assigned to it.
  • the PC provides at its output ASCII characters corresponding to the selected message and attributes picked by the user.
  • the resulting digital 8-bit signals will have an average DC voltage of some magnitude, with that magnitude being dependent on the particular message and attributes selected.
  • a signal with an average DC voltage component transmitted from data generator 3 to SCA generator 5 has certain disadvantages. For example, it cannot be used on SCA generators which have an AC coupled input circuit or require zero volts DC average.
  • frequency shift keying is preferably used as a modulation technique on the SCA carrier.
  • frequency shift modulation (FSK) of the SCA carrier by the data signal requires that the receiver SCA
  • the SCA decoder has an FM detector with a voltage output proportional to frequency deviation in a comparator following the detector to detect frequency excursions greater than a preset threshold.
  • the comparator produces the logic signal output 1 when the frequency changes in one direction and 0 where it changes in the other direction. If the comparator is directly coupled to the FM detector, the frequency error in either the receiver or the transmitter will result in a different threshold for positive and negative freguency excursions. This will result in more errors in the data when noise is present.
  • the comparator can be AC coupled to the FM detector or has some means of setting the center voltage of its threshold to the center frequency of the SCA carrier, this problem can be avoided. This is possible only when the average frequency excursion of the SCA carrier is zero. This occurs when the data signal to the transmitter SCA generator has a zero or approximately zero average DC voltage.
  • the ASCII signals are converted by a specific code into other binary signals which, over a reasonable amount of time, will provide an average DC level of zero. This is accomplished by selecting a code which will convert the ASCII characters into a sequence of bytes with roughly the same number of ones and zeroes being input to the SCA generator 5.
  • a conversion table for this purpose is provided below. Converted values with an equal number of ones and zeroes have been assigned to those ASCII characters which are used most often. Other less often used ASCII characters are assigned converted values which have almost an equal number of ones and zeroes. Conversion values which do not have a good balance of ones and zeroes are not used.
  • the preferred SCA generator 5 has an automatic frequency control circuit with a relatively long time constant, and can therefore tolerate a reasonable amount of
  • offset in the driving signal. Over time, any offset errors due to the imperfection of the encoding/decoding scheme have a tendency to balance out to zero.
  • the following table is used by the PC of data generator 3 to encode the ASCII data into converted data.
  • the conversion table is stored in memory and accessed with control software the design of which is readily apparent to one with ordinary skill in the art. Accordingly, no further details of such software are provided.
  • the PC software first subtracts 32 from the ASCII value, and uses the modified value to index into the encoding look-up table to extract the converted character values. This is done because ASCII characters 0 to 31 are not useful in generating the types of message one would normally use in this environment. For the sake of convenience, hexadecimal rather than binary numbers are used in the encoding table. Each hexadecimal character is denoted by "%" which precedes it.
  • hexadecimal CA (binary 11001010) corresponds to a blank space in ASCII.
  • Hexadecimal 07 (binary 00000111) corresponds to an exclamation mark.
  • Hexadecimal 0B (binary 00001011) corresponds to a quotation mark.
  • Hexadecimal 0D (binary 00001101) corresponds to a number symbol.
  • the often used "blank" space has been assigned an equal umber of ones and zeroes, whereas the other three symbols which are much less frequently used have an almost equal number of zeroes and ones.
  • the following decoding table is used by decoder 27 of receiver 15 to decode incoming messages from the converted characters back into ASCII data.
  • the 8-bit value input by SCA detector 25 to decoder 27 is directly used to "index" this table.
  • the rows and columns of the decoding table have been labelled to show the hexadecimal values used to access the table.
  • the "high nibble” value refers to the first of the two hexadecimal characters, while the "low nibble” value refers to the remaining character.
  • the detected signal corresponds to hexadecimal % 36 (i.e. high nibble is 3 and low nibble is 6), that will be converted to the ASCII value for the character "K”.
  • transmitter 1 is provided with suitable data and software.
  • decoder 27 of receiver 15 the corresponding information and software are loaded into decoder 27 of receiver 15.
  • the processing steps of data generator 3 and decoder 27 are augmented from the version shown in Figs. 3 and 4, respectively, in order to encode and decode the data signal.
  • three bits were mentioned as being devoted to a message group user ID. It is contemplated that for certain types of messages, it will be desirable that only a particular group is to receive it for display. In the example already touched upon earlier, volunteer firemen would be called to duty with a suitable alert signal. Such a signal, obviously, is meant for only that group of radio listeners, namely volunteer firemen. It is, therefore, not desirable for all of the radio listeners to receive that alert signal. Other examples can readily come to mind. Consequently, the bits allocated for this purpose in the transmitter correspond with bits preset for a particular user group in their personal
  • decoder 27 is provided with the capability of processing the incoming message user group ID and comparing it to one previously stored therein. If a match is found, then the message is stored and displayed. Otherwise, the message is ignored by decoder 27.
  • Fig. 6 depicts another embodiment of receiver 15.
  • Search receiver 15' is capable of automatically scanning, the, FM
  • Tuner 19' is of the digital variety capable of having its tuning frequency controlled by an electrical signal. Such tuners are well known. An example would be the tuner included in the Nakamichi TM1 automobile radio.
  • antenna 17 provides a received signal to
  • Audio amplifier 21 receives the composite signal output by tuner 19', and inputs it to speaker 23.
  • detector 25 separates the received data signal from the main carrier and inputs it to decoder 27'.
  • Display 29, indicator 31, alarm 33, and the other outputs identified generally as 35 correspond to those discussed in detail above with respect to the embodiment depicted in Fig. 2.
  • tuner 19' When an automatic band scanning operation is desired, decoder 27' inputs a SCAN instruction to tuner 19'. Tuner 19' includes circuitry for detecting and responding to that signal to generate an automatic scanning operation which seeks out active stations radiating a detectable signal in that locality. When such an active station with a sufficiently strong main carrier signal is found, tuner 19' inputs a STOP signal to decoder 27'. Upon the receipt of a STOP signal., decoder 27' initiates the same
  • SCA detector 25 determines whether there is any signal modulated on the SCA carrier. If there is, then a determination is made of whether the ID signal is present. If such an ID signal is found, then the signal decoding and processing operations described above are carried out by decoder 27. If an SCA carrier is not detected at that station, or no ID signal is received, decoder 27' sends a SCAN signal again to tuner 19' so that further scanning of the FM band can take place to the next station. In this manner, the FM band is scanned until a station is found which transmits the ID signal being sought. At that point, decoder 27" no longer generates a SCAN signal, and tuner 19' therefore remains tuned to that station.
  • a further enhancement of the search receiver 15' involves the possibility that a station may be transmitting information on a plurality of SCA carriers. For example, it is not unlikely that two SCA carriers can be used by a station. These might be at 67 and 92 KHz. Therefore, search receiver 15' is provided with the capability of checking both SCA carriers at each
  • decoder 27' generates a SELECT signal for input.
  • SCA detector 25 by activating a switching device (not shown). This changes the detection frequency of SCA
  • detector 25 when the data signal is not detected in order to toggle from one of the SCA carriers to the others.
  • Fig. 7 shows a flow, chart depicting how decoder 27 controls the operation of search receiver 15'.
  • Box 130 represents the generation of the above-discussed SCAN signal to tuner 19'.
  • decoder 27 awaits receipt of a STOP signal, as per box 132.
  • decision box 134 represents a determination of whether a signal is detected on the SCA carrier. If not, then a further SCAN signal is generated to trigger tuner 19' into continuing its scanning operation. If, however, a signal is detected on the SCA carrier, instruction 136 sets decoder 27 to await receipt of the data signal in the form of a block, as discussed above.
  • decision box 138 determines whether the six bytes which succeed the sync byte correspond to the ASCII values of ZEPHYR. If not, the flow returns to box 130. If, however, the ZEPHYR ID signal is
  • Box 142 represents the detection of the transmitted CRC value which is then compared in decision box 144 with a calculated CRC value. If the two values do not agree, this indicates that an error has occurred, and the flow is returned to decision box 138. If, however, no error is
  • box 146 represents the processing of the system exclusive bytes. For example, this is where the above-discussed user group ID would be processed.
  • Decision box 148 provides an output indicative of whether the just-received message has previously been received. If it has, the operation is returned to decision box 138. If, however, the reception of a new message is indicated, the display buffer is updated by virtue of instruction 150 and displayed in accordance with instruction 152.
  • Flow is then returned to decision box 138 under a NEXT command for the processing of the next block of data signal .
  • FIG. 8 A further variation of the invention is depicted in Figs. 8 and 9. This variation is aimed at making it possible to share an
  • SCA carrier between certain programming being transmitted thereon and the data signal.
  • a particular SCA carrier might already be in use for transmitting continuous background music.
  • Fig. 8 depicts transmitter 1' having SCA audio input source 160 which provides, for example, the continuous music programming. Its output is provided to SCA generator 5. The same output is also provided to audio mute detector 162. This is a conventional circuit well known, for example, in the tape recording art where it is used to detect a blank space, or gap, on the tape.
  • audio mute detector 162 will sense any "dead time” beyond a certain duration when no signal from the audio program is detected, such as would occur between songs. Once such a "dead time” is detected, audio mute detector 162 generates an enable signal to data generator 3 which responds by immediately providing its data signal to SCA generator 5 in the manner described above with respect to the Fig. 1 embodiment. Thus, audio mute detector 162 ensures that the data signal from data generator 3 is input to SCA generator 5 only during the "dead time” in the music provided by SCA audio input source 160. SCA generator 5 provides its output to broadcast transmitter 7 which radiates the broadcast signal with antenna 11, as described above.
  • audio mute detector 162 In order to insure that, once a "dead time" is detected, the data signal from data generator 3 is not interfered with by the signal from SCA audio input source 160, audio mute detector 162 also generates a pause signal which it inputs to SCA audio input source 160 to initiate blocking or inhibiting of the output of programming signals therefrom.
  • the pause signal from audio mute detector 162 is designed to have a given duration before it resets itself to await the next "dead time”.
  • a suitable output signal is provided from data generator 3 to SCA audio input source 160 which will then keep SCA audio input source 160 in the inhibited mode for as long as the data signal is being sent, upon which time it will release the SCA audio input source and reset itself for the next "dead time". Since the PC is outputting the data signal at 1200 baud, approximately 1/2 sec. per line is required to transmit the blocks for two message lines.
  • Fig. 9 shows the modified receiver 15" for operating in conjunction with the modified transmitter 1' of Fig. 8.
  • antenna 17 provides the detected signal to tuner 19 for input to SCA detector 25 (for the sake of simplicity, audio amplifier 21 and speaker 23 are not shown).
  • the detected SCA signal at the output of SCA detector 25 is provided to SCA audio amplifier 170 for driving speaker 172.
  • SCA audio amplifier 170 and speaker 172 audio amplifier 21 and speaker 23, respectively, can be used.
  • the just-described arrangement enables the audio reproduction of whatever programming is being transmitted on the SCA carrier.
  • the detected SCA signal is also routed to audio mute
  • audio mute detector 174 has a shorter mute duration than that provided for audio mute detector 162 because, otherwise, some music would be missed if the
  • audio mute detector 174 senses a "dead time" in the SCA signal, it provides an inhibit control signal to SCA audio amplifier 170 to disable it from reproducing any sounds on speaker 172. This is necessary because, as explained above, the data signal is being transmitted during the mute period.
  • the detected SCA signal is also input to decoder 27".
  • Decoder 27 functions precisely in the same way as decoder 27, with one addition.
  • decoder 27" When a data signal is detected, decoder 27" generates a message inhibit signal which is input to the SCA audio amplifier 170 to keep it disabled during the entire
  • the received data signal is decoded and processed by decoder 27'' for input to data display 29.
  • the message mute signal is terminated to release the SCA audio amplifier 170 into its normal mode.
  • audio mute detector 162 can be eliminated. Instead, source 160 would put out a low freguency (25-50 Hz) tone during the "dead time”. Audio mute detector 174 would be replaced with a circuit to detect this tone.
  • the particular display device can be, for example, in the form of a one line, 16 character device or a two line, 24 character/line device both of which are readily available. The type of display used will determine the number of characters in the message portion of the blocks.

Abstract

Un message est transmis sur une sousporteuse de la fréquence porteuse principale d'une station radio (15). Le message est diffusé simultanément à la reproduction sonore du programme radio. Le message peut être diffusé d'une manière dynamique en ayant des parties distinctes qui se succèdent séquentiellement par le dispositif de diffusion (29) jusqu'à ce que la totalité du message soit passée et/ou en utilisant une variété de dispositifs de diffusion possibles, comme le déroulement et le clignotement. Un aspect comprend le balayage de la bande radio pour une station qui porte le message. Le balayage d'une pluralité de sousporteuses à chaque station est également effectué. Une version transmet le message durant les ''temps morts'' d'autres programmations normalement transmises sur la même sousporteuse. Les caractères alphanumériques du message sont convertis de préférence avant la transmission, en un signal de valeur moyenne égale à zéro. Les caractères convertis sont décodés au niveau du récepteur (15).
PCT/US1990/001921 1989-04-17 1990-04-06 Technique pour utiliser une frequence sousporteuse de station de radio pour transmettre, recevoir et diffuser un message en meme temps que la reproduction audio du programme radio WO1990013190A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US33931389A 1989-04-17 1989-04-17
US339,313 1989-04-17

Publications (1)

Publication Number Publication Date
WO1990013190A1 true WO1990013190A1 (fr) 1990-11-01

Family

ID=23328443

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1990/001921 WO1990013190A1 (fr) 1989-04-17 1990-04-06 Technique pour utiliser une frequence sousporteuse de station de radio pour transmettre, recevoir et diffuser un message en meme temps que la reproduction audio du programme radio

Country Status (2)

Country Link
AU (1) AU5544690A (fr)
WO (1) WO1990013190A1 (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0514624A2 (fr) * 1991-05-16 1992-11-25 Pioneer Electronic Corporation Récepteur radio avec RDS
GB2256346A (en) * 1991-04-19 1992-12-02 Ali Guryel Sub-carrier broadcast system
ES2048085A2 (es) * 1992-01-15 1994-03-01 Coca Rodriguez Sistema para visualizar se\ales codificadas enviadas por una emisora de radio.
WO1996004633A1 (fr) * 1994-07-29 1996-02-15 Seiko Communications Holding N.V. Publicite a double canal donnant l'emplacement d'un vehicule
GB2307152A (en) * 1995-11-10 1997-05-14 Motorola Ltd Radio communication system
EP0787412A1 (fr) * 1994-10-21 1997-08-06 Seiko Communications Holding N.V. Transmission de donnees numeriques a l'aide de sous-porteuses multiples
EP0928953A2 (fr) * 1998-01-07 1999-07-14 CLARION Co., Ltd. Appareil et méthode de commande d'un affichage pour une unité de navigation

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3632863A (en) * 1969-02-16 1972-01-04 Matsushita Electric Ind Co Ltd Information transmitting and receiving system employing an audio subcarrier modulated by binary signals
US3825892A (en) * 1972-06-06 1974-07-23 Int Standard Electric Corp Error detector for low disparity code signals
US3838444A (en) * 1972-10-30 1974-09-24 Hazeltine Research Inc System for transmitting auxiliary information in low energy density portion of color tv spectrum
US4281217A (en) * 1978-03-27 1981-07-28 Dolby Ray Milton Apparatus and method for the identification of specially encoded FM stereophonic broadcasts
US4369443A (en) * 1979-12-26 1983-01-18 Meta Systems, Inc. Message communication system with message storage
US4450589A (en) * 1981-05-27 1984-05-22 Blaupunkt-Werke Gmbh FM Receiver for reception of special announcements and general programs
US4646081A (en) * 1982-04-13 1987-02-24 Nec Corporation Radio paging receiver operable on a word scrolling basis

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3632863A (en) * 1969-02-16 1972-01-04 Matsushita Electric Ind Co Ltd Information transmitting and receiving system employing an audio subcarrier modulated by binary signals
US3825892A (en) * 1972-06-06 1974-07-23 Int Standard Electric Corp Error detector for low disparity code signals
US3838444A (en) * 1972-10-30 1974-09-24 Hazeltine Research Inc System for transmitting auxiliary information in low energy density portion of color tv spectrum
US4281217A (en) * 1978-03-27 1981-07-28 Dolby Ray Milton Apparatus and method for the identification of specially encoded FM stereophonic broadcasts
US4369443A (en) * 1979-12-26 1983-01-18 Meta Systems, Inc. Message communication system with message storage
US4450589A (en) * 1981-05-27 1984-05-22 Blaupunkt-Werke Gmbh FM Receiver for reception of special announcements and general programs
US4646081A (en) * 1982-04-13 1987-02-24 Nec Corporation Radio paging receiver operable on a word scrolling basis

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2256346A (en) * 1991-04-19 1992-12-02 Ali Guryel Sub-carrier broadcast system
GB2256346B (en) * 1991-04-19 1995-06-21 Ali Guryel Sub-carrier broadcast system
EP0514624A3 (en) * 1991-05-16 1993-03-10 Pioneer Electronic Corporation Radio receiver with rds
EP0514624A2 (fr) * 1991-05-16 1992-11-25 Pioneer Electronic Corporation Récepteur radio avec RDS
ES2048085A2 (es) * 1992-01-15 1994-03-01 Coca Rodriguez Sistema para visualizar se\ales codificadas enviadas por una emisora de radio.
WO1996004633A1 (fr) * 1994-07-29 1996-02-15 Seiko Communications Holding N.V. Publicite a double canal donnant l'emplacement d'un vehicule
EP0787412A4 (fr) * 1994-10-21 2002-09-18 Seiko Comm Holding N V Transmission de donnees numeriques a l'aide de sous-porteuses multiples
EP0787412A1 (fr) * 1994-10-21 1997-08-06 Seiko Communications Holding N.V. Transmission de donnees numeriques a l'aide de sous-porteuses multiples
GB2307152A (en) * 1995-11-10 1997-05-14 Motorola Ltd Radio communication system
GB2307152B (en) * 1995-11-10 1999-04-07 Motorola Ltd Method and apparatus for enhanced communication capability while maintaining standard channel modulation compatibility
EP0928953A2 (fr) * 1998-01-07 1999-07-14 CLARION Co., Ltd. Appareil et méthode de commande d'un affichage pour une unité de navigation
EP0928953A3 (fr) * 1998-01-07 2000-07-12 CLARION Co., Ltd. Appareil et méthode de commande d'un affichage pour une unité de navigation
US6268837B1 (en) 1998-01-07 2001-07-31 Clarion Co., Ltd Display control device and method

Also Published As

Publication number Publication date
AU5544690A (en) 1990-11-16

Similar Documents

Publication Publication Date Title
US5146612A (en) Technique for using a subcarrier frequency of a radio station to transmit, receive and display a message together with audio reproduction of the radio program
USRE40836E1 (en) Apparatus and methods for providing text information identifying audio program selections
US5161251A (en) Apparatus and methods for providing text information identifying audio program selections
US5581576A (en) Radio information broadcasting and receiving system
US7502604B2 (en) Wireless environment method and apparatus
US5548828A (en) RDS audio receiver having interrupt mode
US5497372A (en) FM multiplex broadcasting and receiving system
US5119503A (en) Apparatus and methods for broadcasting auxiliary data in an FM stereo broadcast system
US6212359B1 (en) Wireless Transceiver System For Digital Music
US5790958A (en) Radio reception system for general purpose computer
JPH11509393A (ja) オーディオ受信器と組み合わせた低電力データ受信器
EP0643500A1 (fr) Récepteur RDS qui émet des signaux de télécommande pour commander des appareils audio
WO1990013190A1 (fr) Technique pour utiliser une frequence sousporteuse de station de radio pour transmettre, recevoir et diffuser un message en meme temps que la reproduction audio du programme radio
US20010018343A1 (en) Paging service using broadcasting
US6847802B2 (en) Transmitter-receiver apparatus with signal coding unit according to RDS standard
JPH08279796A (ja) Ｆｍ多重放送受信装置およびｆｍ多重放送送信方法
JPH0974365A (ja) Ｆｍ多重受信機
CN102055541B (zh) 多路复用广播接收机
JP2885809B2 (ja) 受信機
JP2865017B2 (ja) ラジオ受信機
WO1997039540A1 (fr) Systeme de radiodiffusion
JP3354417B2 (ja) Ｒｄｓ受信機のオートプリセット方法
JPH0927790A (ja) 緊急情報送信方法、緊急情報受信装置及び受信方法、及び、緊急情報送受信システム
JP3272880B2 (ja) Ｒｄｓ受信機
JPH0927788A (ja) 緊急情報送信方法、緊急情報受信装置及び受信方法、緊急情報送受信システム、及び緊急情報送信フォーマット

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AU BR CA JP KR

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB IT LU NL SE

WWW Wipo information: withdrawn in national office

Ref document number: 1990908037

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 1990908037

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: CA