JPH0724384B2 - FM multiplex broadcasting receiver - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a receiving apparatus for receiving an FM multiplex broadcast in which a voice and characters different from the main program are multiplexed and transmitted in the FM broadcast.

<Prior art> FM multiplex broadcasting is to multiplex current FM broadcasting to broadcast voice, characters, or program code different from the main program, and is intended to provide various new services. is there. Various systems have been developed and put to practical use in each country, and RDS (Radio Data System) in Europe and SCA in the US
(Subsidiary Communication Authorization)
In Japan, FM Tokyo has also started FM multiplex broadcasting with multiplexed audio since August 1988.

As a service that the receiver receives by such FM multiplex broadcasting, provision of a program different from the main program in audio broadcasting,
So-called "more channel" usage and data services for sending digital data such as characters / graphics and receiver control codes are conceivable. Examples of this data service include sending a program code to enable automatic recording and channel selection, or displaying information related to the main program during broadcasting to supplement the main program, FM broadcasting. Can be considered. Further, a text information service such as weather forecast, traffic information or news, which is completely independent of the main program, can be considered.

FIG. 4 shows the frequency spectrum of such FM multiplex broadcasting. The occupied bandwidth of FM broadcasting is defined as ± 100kHz, and the current FM broadcast stereo signal uses the band up to 53kHz, so the frequency band up to 100kHz is used for the FM multiplex signal. is doing.

The sub-carrier frequency, signal bandwidth, etc. are specified for this multiplexed signal so as not to interfere with the reception of current stereo broadcasting. The sub-carrier frequency is 76 kHz and the multiplexed signal level is 2.5% (maximum frequency deviation). ± 1.875kHz), frequency band is 6
04kHz to 91.6kHz, the subcarrier modulation method is specified as QPSK modulation.

In other words, FM multiplex broadcasting is a digital signal corresponding to ADPCM signal (adaptive differential CPM signal) or character information, which is obtained by digitizing an analog audio signal, and uses a 76 kHz subcarrier for QPS.
It is K-modulated and multiplexed with the current stereo signal for transmission, and the bit rate of the ADPCM signal is 32 kb / s.
The bit rate of the character signal is 1 kb / s, and the bit rate of the all digital signal (composite signal) including these is 48 kh / s.

<Problem to be Solved by the Invention> An object of the present invention is to provide an FM multiplex broadcast receiving apparatus capable of receiving such FM multiplex broadcast, particularly, FM multiplex broadcast in which voice and characters are multiplexed.

<Means for Solving the Problem> In order to achieve the above-mentioned object, the FM multiplex broadcast receiving apparatus of the present invention receives the FM multiplex broadcast, performs FM detection and stereo demodulation, and outputs audio corresponding to the main program. Output signal
FM tuner circuit, FM including a switching circuit for outputting either the audio signal from the FM tuner circuit or the audio signal different from the main program in response to the switching signal, and a speaker to which the audio signal from the switching circuit is applied The broadcast receiver and the FM signal output from the FM tuner circuit of the FM broadcast receiver are demodulated into the multiplexed character signal and the audio signal other than the main program, and are demodulated based on the display control signal. A multiple signal demodulation circuit unit that outputs a display signal corresponding to a character signal and outputs a demodulated audio signal different from the main program to the switching circuit of the FM broadcast receiver, and this multiple signal demodulation circuit unit The FM corresponding to the display section and the operation for displaying corresponding to the display signal from
A character display unit including an operation unit that outputs the switching signal to a broadcast receiver and outputs the display control signal to the multiplex signal demodulation circuit unit, the character display unit including the FM broadcast receiver and the A structure that is configured separately from the multiplex signal demodulation circuit unit and wirelessly performs at least part of transmission / reception of a signal between the character display unit and at least one of the FM broadcast receiver and the multiplex signal demodulation circuit unit. Is.

<Operation> According to the above configuration, the multiplexed voice signal and character signal are demodulated by the multiple signal demodulation circuit unit, and the display unit of the character display unit can perform display corresponding to the character signal. By operating the operation unit of the character display unit, the audio output of the FM broadcast receiver can be switched to either the main program audio or the multiplexed audio.

Moreover, the character display unit having the display unit and the operation unit is configured separately from the FM broadcast receiver and the multiple signal demodulation circuit unit, and at least the character display unit and the FM broadcast receiver and the multiple signal demodulation circuit unit are provided. Since at least a part of the transmission and reception of the signal to and from the one side is performed wirelessly, it is possible to reduce the number of cables and cords connected to the display character unit, and it is easy to carry.

<Example> Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an external perspective view of an FM multiplex broadcast receiving apparatus 1 according to an embodiment of the present invention, and FIG. 2 is a block diagram thereof.

The FM multiplex broadcast receiving apparatus 1 of this embodiment is an MF in which audio signals and character signals different from those of the main program are multiplexed as described above.
It is for receiving multiplex broadcasts, and includes an FM broadcast receiver 2, a multiplex signal demodulation circuit unit 3, and a laptop character display unit 4, and the FM broadcast receiver 2 and the multiplex signal demodulation circuit unit 3 are provided. Are connected via cords 6, 7, 12 and the multiple signal demodulation circuit unit 3 and the character display unit 4 are connected via a cable 13.

The FM broadcast receiver 2 receives an FM multiplex broadcast, performs FM detection and stereo demodulation, and outputs an audio signal corresponding to the main program, and an audio signal or a multiplex signal from this FM tuner circuit 5. A switching circuit 8 for outputting any one of the multiplexed audio signals different from the main program given from the demodulation circuit unit 3 via the code 6 according to the switching signal given via the code 7, and this switching circuit A sound volume adjusting circuit 9 for adjusting the level of the audio signal from 8 according to a remote control signal described later received by a remote control signal receiving unit (not shown), an amplifier 1, and a speaker 11.

The multiple signal demodulation circuit unit 3 demodulates the multiplexed character signal and audio signal different from the main program from the FM detection output of the FM tuner circuit 5 of the FM broadcast receiver 2 given via the code 12, Based on a display control signal given from the display unit 4 via the cable 13, a display signal corresponding to the demodulated character signal is output to the character display unit 4, and the demodulated audio signal is sent to the FM broadcast receiver 2
To the switching circuit 8.

This multiple signal demodulation circuit unit 3 is a 76 kHz bandpass filter 14 for extracting multiple signals from the FM detection output.
And this PLL circuit 15 locked at 76kHz and QP
QPSK decoder 16 for SK demodulation, digital signal from this QPSK decoder 16 is subjected to predetermined signal processing such as descrambling and error correction, and ADPCM signal which is 32 kb / s voice data and 1 kb / s character signal. , A digital signal processing unit 17 for outputting, an ADPCM decoder 18 for converting an ADPCM signal into an analog audio signal and outputting the analog audio signal to the FM broadcast receiver 2, and a display control signal for controlling display contents given from the character display unit 4. And a display control section 19 for converting the character signal into a corresponding display signal and outputting the converted signal.

The laptop-type character display unit 4 includes an LCD display unit 20 that performs a display corresponding to a display signal from the display control unit 19 of the multiplex signal demodulation circuit unit 3, and an operation unit 23 that includes a plurality of keys 21 and an encoder 22. And a remote control signal transmission unit 25 for converting an operation signal corresponding to the volume adjustment operation of the operation unit 23 into a remote control signal and transmitting it from the infrared light emitting diode 24 to the FM broadcast receiver 2.

In this embodiment, the character display unit 4 wirelessly transmits a volume adjustment signal to the FM broadcast receiver 2.

The keys 21 of the operation unit 23 are a program selection key for selecting a desired character information program, a scroll key for scrolling the display screen of the LCD display unit 20, the FM broadcast receiver 2
The FM / multiplex key for switching the audio output of the main program to either the main program sound or the multiplexed sound, the volume UP key and the volume DOWN key for volume adjustment, and the like are provided.

In response to these key operations, the display control signal is output from the encoder 22 of the operation unit 23 to the multiplex signal demodulation circuit unit 3 and the switching signal is output to the FM broadcast receiver 2. FIG. 3 is a block diagram showing details of the digital signal processing unit 17 and the display control unit 19 of the above-described multiple signal demodulation circuit unit 3.

In the QPSK demodulated digital data, the header signal (FC) of the data is detected by the FC detection circuit 26, and based on this,
The descrambling circuit 27 descrambles the signal, and the MC detection circuit 28 detects the MC signal, which is an identification signal, and the error correction circuit 29 corrects the error. The error is corrected and given to the CPU 33 for display control.

The CPU 33 extracts the CDPCM signal and the character signal according to the program of the ROM 31 and extracts the ADPCM signal from the ADPCM decoder 18
And the character signal is output to the character display unit 4
Based on the display control signal from the operation unit 23, the corresponding display signal is converted and output to the character display unit 4. Incidentally, 32 is a RAM.

The FM multiplex broadcast receiving apparatus 1 of the present invention having the above configuration
Then, the FM broadcast receiver 2 receives the FM multiplex broadcast, and the multiplex signal demodulation circuit unit 3 demodulates the multiplexed voice signal and character signal from the FM detection output of the FM broadcast receiver 2,
The demodulated audio signal is output to the FM broadcast receiver 2, while the character signal is used as a display signal corresponding to the display control signal from the character display unit 4 and is displayed on the character display unit 4.
It is displayed on the LCD display unit 20.

The output of the speaker 11 of the FM broadcast receiver 2 is selected by the switching signal from the character display unit 4 as either the main program sound or the multiplexed sound from the multiple signal demodulation circuit unit 3, and The volume is controlled by a remote control signal from the character display unit 4.

In this way, the FM multiplex broadcast receiving apparatus 1 of the present invention can receive an FM multiplex broadcast in which voice and characters are multiplexed.

Further, the character display unit 4 of the present invention includes an LCD display unit 2
Since 0 and the operation unit 23 for controlling each unit are integrated, the operation can be performed while observing the display content of the LCD display unit 20, which is very convenient.

Further, in this embodiment, the character display unit 4 is a laptop type, so that it is convenient to carry and easy to use.

In addition, each of the following configurations can be cited as another embodiment of the present invention.

The FM broadcast receiver 2 and the multiple signal demodulation circuit unit 3 are integrated.

One-way or two-way wireless cable 13 using infrared remote control signal.

Wireless cable 13 and codes 6, 7, 12 using infrared remote control signal, FM transmitter, etc.

As shown in FIG. 5, by adding an R-DAT recorder 40, the demodulated ADPCM signal or character signal is recorded on the DAT tape so that the receiver can reproduce it whenever he / she likes. System

<Effects of the Invention> As described above, the FM multiplex broadcast receiver of the present invention includes the FM broadcast receiver, the multiplex signal demodulation circuit unit, and the character display unit. It is demodulated by the multiplex signal demodulation circuit unit, and a display corresponding to the character signal can be displayed on the display unit of the character display unit. It is possible to switch to either the main program audio or the multiplexed audio. That is, according to the FM multiplex broadcast receiving apparatus of the present invention, it is possible to receive an FM multiplex broadcast in which voice and characters are multiplexed.

Furthermore, since the character display unit is integrated with the display unit and the operation unit for controlling each unit, the character display unit can be operated while observing the display content of the display unit, which is very convenient. Moreover, the character display unit having the display unit and the operation unit is configured separately from the FM broadcast receiver and the multiple signal demodulation circuit unit, and at least the character display unit and the FM broadcast receiver and the multiple signal demodulation circuit unit are provided. Since at least a part of the transmission and reception of the signal with the one side is performed wirelessly, it is possible to reduce the number of cables and cords connected to the character display unit,
The character display unit can be easily carried and the operability is improved.

[Brief description of drawings]

FIG. 1 is an external perspective view of an embodiment of the present invention, and FIG.
FIG. 3 is a block diagram, FIG. 3 is a block diagram showing details of the digital signal processing unit and display control unit in FIG. 2, and FIG.
Frequency spectrum of multiple broadcast, FIG. 5 is an external perspective view of another embodiment of the present invention. 1 ... FM multiplex broadcast receiver, 2 ... FM broadcast receiver, 3 ...
… Multiple signal demodulation circuit unit, 4 …… Character display unit.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical indication location H04N 7/081 (72) Inventor Satoru Yamada 1-10-11 Kinuta, Setagaya-ku, Tokyo Japan Broadcasting Corporation Broadcasting Technology In-lab (72) Inventor Toru Kuroda 1-10-11 Kinuta, Setagaya-ku, Tokyo In-house Broadcasting Technology Research Laboratories, Japan Broadcasting Association (56) Reference (JP, A)

Claims (1)

[Claims] Claim: What is claimed is: 1. An FM multiplex broadcast receiving apparatus for receiving an FM multiplex broadcast that multiplexes and transmits an audio signal, a character signal, etc., different from the main program, to the FM broadcast. FM tuner circuit that performs FM detection and stereo demodulation to output an audio signal corresponding to the main program, either the audio signal from this FM tuner circuit or the audio signal different from the main program, depending on the switching signal. An FM broadcast receiver equipped with a switching circuit for outputting as an output and a speaker to which a sound signal from the switching circuit is given, and a character signal and a main program multiplexed from the FM detection output of the FM tuner circuit of the FM broadcasting receiver. Demodulates the other audio signal, outputs a display signal corresponding to the demodulated character signal based on the display control signal, and outputs a demodulated audio signal different from the main program to the FM broadcast receiver. Before A multiplex signal demodulator circuit unit to be output to the switching circuit, the FM corresponding to the display portion and the operation for performing display corresponding to the display signal from the multiplex signal demodulation circuit unit
A character display unit including an operation unit that outputs the switching signal to a broadcast receiver and outputs the display control signal to the multiplex signal demodulation circuit unit, the character display unit including the FM broadcast receiver and the It is configured separately from the multiplex signal demodulation circuit unit, and at least part of transmission and reception of signals between the character display unit and at least one of the FM broadcast receiver and the multiplex signal demodulation circuit unit is performed wirelessly. FM multiplex broadcasting receiver characterized by.