JPH09326716A - Fm multiplex radio receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a receiver to receive simultaneously broadcast waves of different frequencies as to FM multiplex data reception and voice signal reception by providing a plurality of sets of FM tuner sections and allowing them to receive broadcast programs independently and simultaneously. SOLUTION: A composite signal output from FM tuner sections 1A, 1B is given respectively to contacts a, b of changeover switches SW1, SW2 and a voice comparison section 10. The composite signal received via the contact (a) of the changeover switch SW1 is demodulated into a stereo sound signal by a stereo signal demodulator 2, amplified by a power amplifier 3 and outputted from a speaker 4. The composite signal received via the contact (b) of the changeover switch SW2 is demodulated into an FM multiplex display signal by an FM multiplex signal demodulation section 5, a digital signal is outputted on a display device 7 via a CPU 11 and a character or an image is displayed thereon. Thus, a sound signal of a broadcast station is heard on one hand, and multiplex data of other FM multiplex broadcast station are viewed in parallel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an FM multiplex radio receiver capable of displaying display information broadcast by an FM multiplex broadcast of another frequency at the same time while receiving broadcast radio waves.

[0002]

2. Description of the Related Art FIG. 3 is a configuration diagram showing a main configuration of a conventional FM multiplex radio receiver with an AM reception band. 1 is FM
In the tuner unit, generally, a single PL for selecting the reception frequency by tuning the FM reception circuit and the AM reception circuit by switching.
An L frequency synthesizer system is used (not shown), and is composed of an RF amplifier and a local oscillator, which includes an antenna input circuit by an electronic tuning circuit and a high frequency transistor, a frequency converter, a semiconductor integrated circuit including an intermediate frequency amplifier, an FM detector, and the like. The FM broadcast signal input from the antenna ANT is amplified by the RF amplifier, converted into an intermediate frequency signal by the frequency converter, increased in intermediate frequency and FM detected, and output to the FM stereo demodulation unit 2 as a composite signal. Is composed of.

Reference numeral 2 denotes an FM stereo signal demodulator section, which is AM /
It is composed of a semiconductor integrated circuit of an FM system FM stereo signal demodulation circuit and its peripheral circuits. Further, if necessary, the pulse noise elimination circuit (noise canceller N / C) is
It is provided before the M stereo signal demodulation circuit. Reference numeral 3 denotes a power amplification section, which is composed of a power amplification semiconductor integrated circuit and its peripheral circuits, etc., and is configured to power-amplify an input audio signal, output the amplified audio signal to a speaker 4, and output a sound from the speaker.

Reference numeral 5 designates an FM multiple signal demodulation section, which comprises a 76 kHz bandpass filter, a limiter and an MSK (Minimum Shift Keyin).
g) A demodulation circuit and a decoding circuit that demodulates the original data by error correction such as data loss for the demodulated MSK baseband signal, and outputs a data output and a clock signal. A data processing unit 6 is composed of a logic circuit or the like for processing the output of the decoding circuit, and performs processing such as data display signal output for displaying received data on the display 7.

Reference numeral 7 denotes a display, which uses an LCD or the like to display information such as characters and images for the purpose of FM multiplex broadcasting. Reference numeral 8 denotes an AM tuner section, which uses a PLL frequency synthesizer method (not shown) which is partially common (switched and used) with the FM receiving section, and an AM band RF amplifier, frequency converter,
It is composed of a semiconductor integrated circuit including an intermediate frequency amplifier and an AM detector and its peripheral circuits and the like, and an AM broadcast signal input from an antenna ANT is high frequency amplified by the RF amplifier and converted into an intermediate frequency signal by a frequency converter,
It is configured to be subjected to intermediate frequency amplification and AM detection and output to the power amplifier 3 as an audio signal.

Next, the operation will be described. Antenna AN
The FM broadcast wave output from T is input to the FM tuner 1, the broadcast frequency is selected or received manually or by a search, and the broadcast frequency is preset as necessary. Then, the composite signal which is the baseband of the FM broadcast signal processed by the FM tuner unit 1 is output to the FM stereo signal demodulation unit 2 and the FM multiple signal demodulation unit 5.

In the FM stereo signal demodulation unit 2, an audio signal such as stereo is demodulated from the input composite signal, output to the power amplification unit 3, power amplified by the power amplification unit, output to the speaker 4, and sound is output from the speaker. To be done. Also, the AM broadcast wave is input to the AM tuner unit 8 and F
As with the M wave, the broadcast frequency is selectively received by manual or search, and the broadcast frequency is preset as necessary.

Then, a band switch (not shown) for selecting the AM band or the FM band is operated, and the preset frequency is called if necessary, so that the AM band or the FM band is selectively received. It Here, the operation of receiving characters and images of FM multiplex broadcasting will be described. The composite signal output from the FM tuner unit 1 is branched and input to the FM multiple signal demodulation unit 5.

In the FM multiplex signal demodulation section 5, data is superimposed on the composite signal by an internal bandpass filter 7
The 6 kHz band subcarrier signal is filtered, and the data level subcarrier signal whose level is controlled by the amplitude is leveled by a limiter to have a constant amplitude. Then, this subcarrier signal is demodulated as digital data by an MSK demodulation circuit inside the FM multiplex signal demodulation unit 5, further input to a decoding circuit that decodes the original data by error correction, and is decoded by a decoder to decode characters and the like. It becomes a signal such as a data output and a clock output for synchronization, and is input to the data processing unit 6.

Then, the data processing unit 6 performs data arithmetic processing and the like, and the characters and images of the FM multiplex broadcast are displayed on the display 7.

[0011]

As described above,
A conventional FM multiplex radio receiver has a function of displaying FM multiplex data superimposed on the same broadcast wave being received on a display only while receiving the FM multiplex broadcast wave, and FM broadcasts other than the same broadcast wave are received. It does not have the function of displaying the FM multiplex data similar to the above while listening to AM broadcast or the like.

By the way, the broadcast program and the contents of the FM multiplex data are not always the same, and the taste of the viewer does not always match the contents of the FM multiplex broadcast program. For example, if you are receiving FM Osaka with FM multiplex data,
Of course, multiple data is displayed, but when receiving an FM broadcast station without FM multiple data, no data is displayed, and I want to know the multiple data of FM Osaka by listening to the voice of this broadcast station. We cannot meet the needs of users.

Therefore, in order to meet a wide variety of needs, it is an object to realize an FM multiplex radio receiver capable of simultaneously receiving broadcast waves of different frequencies for FM multiplex data reception and audio reception.

[0014]

According to the present invention, there are provided at least two receiving means for tuning and receiving a broadcasting station including an FM multiplex broadcasting station, and a sound of the broadcasting station received by the receiving means. Audio detection output means for detecting and outputting, multiplex data detecting means for detecting multiplex data of the FM multiplex broadcasting station received by the receiving means, and multiplex for displaying contents of the multiplex data detected by the multiplex data detecting means. With respect to the data display means and the broadcasting station received by one receiving means, the sound of the broadcasting station is output from the audio detection output means, and the other receiving means is searched for the FM multiplex broadcasting station and searched. And a control means for displaying the content of the multiplex data of the FM multiplex broadcasting station on the multiplex data display means via the multiplex data detection means.

Further, the control means causes the multiplex data display means to display a frequency list based on a frequency list information signal of a station having the same program identification code transmitted from the FM multiplex broadcasting station. Characterize. In addition, the control means causes the other receiving means to receive each broadcast station based on the frequency list detected by the multiplex data detecting means, and the current of the sound of each broadcast wave and the one receiving means. It is characterized by comprising a voice comparison means for comparing the voices of the broadcasting stations being received and determining the same station.

Further, the control means displays the multiplex data based on a multiplex signal of the same broadcasting station that is receiving audio or a multiplex signal of another broadcasting station that is different from receiving audio. It is characterized in that it is compatible with any of the following. Further, the control means includes:
For the multiplex data display means, display based on a multiplex signal of the same broadcast wave during reception of audio, or display of a plurality of the frequency information based on multiplex signals of different broadcast waves different from during reception of audio It is characterized in that it can be displayed on the display surface at the same time and is compatible with both.

The multiplex data detecting means is a single multiplex signal demodulator for demodulating multiplex data, and the multiplex signal demodulator and the one receiving means or the other receiving means are selectively selected. It is characterized in that it comprises connection means for connection, and the control means switches the connection means to the receiving means side receiving the FM multiplex broadcasting station. Also,
Each of the plurality of receiving means includes a receiving antenna for individually receiving, and when the control means detects that the plurality of receiving means are receiving the same multiplex broadcasting station, the connecting means receives more noise. It is characterized in that the content of the multiplex data of the multiplex broadcasting station received by the receiving means is connected to the receiving means side having an antenna on the small side to display on the multiplex data display means.

[0018]

Next, an embodiment of the present invention will be described. FIG.
3 is a configuration diagram showing a main configuration of an embodiment of the present invention, and FIG.
The same block numbers as those of the above-described block numbers are denoted by the same reference numerals, and detailed description thereof will be omitted. SW1 and SW2 are changeover switches, which are composed of analog switch circuits in which switching elements such as transistors are combined.
It is driven by an H-level or L-level signal output from 11, and is configured to be connected to the next stage by switching a contact or b contact of the changeover switch.

Reference numeral 7 denotes a display, which is mainly composed of an LCD having a small power consumption and a short depth, and is arranged at an easily observable position on the front panel of the FM multiplex radio receiver. In the case of DARC level 1, information such as 15 characters × 2.5 lines) and images (in the case of DARC level 2, 15.5 characters × 8 lines in addition to pattern figure) are displayed.

Reference numeral 9 denotes a PLL synthesizer section, which is composed of a semiconductor integrated circuit and its peripheral circuits, such as a frequency divider and a phase detection charge pump, and is a local section corresponding to an integer value (N value) output from the signal processing section 11. A bias voltage for tuning is supplied to a voltage control oscillator (VCO) inside each tuner that controls the oscillation frequency and a tuning circuit of a high-frequency amplifier, and the difference between the frequency of the received signal tuning to the tuning circuit and the local oscillation frequency is constant. Is configured to be frequency and F
The M tuner unit 1A, the FM tuner unit 1B, and the AM tuner unit 8 are configured so that they can operate independently and simultaneously.

Reference numeral 10 is a voice comparison unit, which is composed of a semiconductor integrated circuit and its peripheral circuits, such as a comparator circuit, and is composed of two sets of F
The signal waveforms of the respective FM detection outputs outputted from the M tuner units 1A and 1B are compared and analyzed, and whether or not the signals of the detection outputs are the same, that is, whether the same broadcast contents are simultaneously received or not. It is configured as an interface to the signal processing unit 11 to be judged.

Reference numeral 11 denotes a signal processing section, which is composed of a microprocessor (CPU) and its peripheral circuits, and which is AM / FM /
Reception mode such as FM multiplexing, frequency search / preset /
The signal processing is performed by coded signals such as registration, storage, calculation, and reading of frequency calling. Reference numeral 12 denotes a multipath comparison unit, which is composed of a comparator circuit using a differential amplifier and the like and its peripheral circuits.
A signal processing unit for a multipath signal output from each AM modulation component detector for detecting multipath propagation distortion (AM modulation component) of FM broadcast wave provided in addition to an intermediate frequency amplification stage inside tuner units 1A and 1B 11 is configured as an interface.

Reference numeral 13 denotes a keyboard, which is constructed so that a plurality of analog switches are arranged on the operation panel of the receiver, and includes reception mode selection means (AM / FM / FM multiplex), channel selection means (search, manual), Input means to the signal processing unit 11 such as a preset means, a preset channel selection means, and a diversity mode selection means are configured. Next, a general operation will be described.

In this embodiment, a mobile FM multiplex radio receiver such as a vehicle is used as an example, and two sets of an FM tuner section 1A (tentatively called a main tuner) and an FM tuner section 1B (tentatively called a sub-tuner) are provided. Since the broadcasting can be received independently at the same time, it is possible for one tuner to receive the sound and the other tuner to receive the FM multiplex display of another broadcasting. Further, two sets of antenna ANT1 and antenna ANT2 can be received. Are connected to each of the FM tuners, so that when receiving the same broadcast, the signal-to-noise ratios (correlation with multipath distortion) of both output signals output from both FM tuners are compared. As a space diversity receiver that automatically selects the FM tuner with the larger signal-to-noise ratio, not only the voice diversity reception, It is configured to be diversity reception of M multiplexed display.

Here, the composite signal output of the FM tuner section 1A is the changeover switch SW1 and the changeover switch SW2.
Of the FM tuner 1B, while the composite signal output of the FM tuner 1B
1 and the b contact of the changeover switch SW2 and the voice comparison unit 10. The composite signal input through the a contact of the change-over switch SW1 is demodulated into an audio stereo signal by the stereo signal demodulator 2 and output to the power amplifier 3, and the audio signal amplified by the power amplifier 3 is output to the speaker 4. Sound is output from the speaker 4.

The stereo signal demodulator 2 has only one system, and the main tuner 1A is connected via the changeover switch SW1.
Alternatively, they are connected so as to be shared by the composite signal outputs of the sub tuner 1B. When both FM tuner units 1A and 1B are tuned to the same broadcast frequency, the multipath detection signals C1 and C output from both tuners are output.
2 is input to the CPU 11 via the multi-pass comparison unit 10, and the CPU 11 compares which of the FM tuner unit 1A and the FM tuner unit 1B has less noise and less frequency of noise generation. Based on C
A control signal for controlling the changeover switch SW1 is output via the X port of the PU 11, and the space diversity reception of the voice is performed by the changeover switch SW1 so as to selectively change the FM tuner on the less noise side.

Further, the composite signal input via the b contact of the changeover switch SW2 is an FM multiple signal demodulation section 5
Is demodulated to an FM multiplex display signal, and a digital signal is output to the display 7 via the CPU 11 to display characters and images. The FM multiplex signal adjuster 5 has only one system,
It is connected so as to be shared by the composite signal outputs of the main tuner 1A or the sub tuner 1B via the changeover switch SW2.

In the space diversity reception of the FM multiplex broadcasting, the changeover switch SW2 selects one of the two FM tuners based on the control signal from the Y port of the CPU 11 to operate the FM multiplex signal demodulating section 5. As described above, it is possible to configure the software program of the CPU 11 similar to the space diversity reception of the voice.

In the present invention, when the main tuner 1A and the sub tuner 2B are receiving the same multiplex broadcasting station, the CPU
11. The multipath comparison unit 12 switches the selector switches SW1 and SW2 to the tuner with less noise so that the multiplexed data easily affected by noise can be favorably received.
Improved the data acquisition efficiency. The switching conditions of these switches SW1 and SW2 may be appropriately selected by the user.

Now, still another operation will be described. When a plurality of different reception frequencies are simultaneously received by the main tuner 1A and the sub tuner 1B (operation description of the keyboard 13 is omitted), the audio comparison unit 10 can detect whether or not a plurality of audio broadcast contents are the same contents. The frequency at which the same content is detected is stored in the CPU 11, and the storage frequency with the least noise is automatically selected by scanning and receiving the storage frequency.

By repeating such an operation of automatically selecting a storage frequency (voice comparison network follow), stable reception with less noise is possible, and it is mounted on a vehicle that travels a long distance such that the service area of broadcasting changes. It is most suitable for FM receivers (including FM multiplexing).
In the present invention, when performing voice comparison network follow-up for reception of an FM multiplex broadcasting station, an AF list (affiliated station list) is acquired in advance from the multiplex data detected by the FM multiplex signal demodulation section 5, and only the affiliated stations are subjected to audio comparison. By making the same station determination, not only unnecessary search is omitted, but also news (local news) may be broadcast even in the same series of broadcasting stations, and it is possible to prevent different audio only by this AF list search. It is also possible to obtain the effect of being able to accurately follow the network.

The above operation can be performed by adding or modifying the software program of the CPU 11. Next, regarding operation, a microprocessor (CPU)
The FM multiplex broadcast display operation based on the software 11 will be described with reference to the flowchart shown in FIG. The receiver state of this embodiment immediately before step S1 is an example when the FM broadcast is being received in the diversity reception mode or the last reception mode is the diversity reception mode.

First, in step S1, the keyboard 13
When the user manually turns on the FM multiplex button (FM multiplex selection switch) for selecting the above reception mode, the FM multiplex mode is set and the microprocessor 1
The operation 1 is started. Then, in step S2, C
Based on the control signals from the X and Y ports of the PU 13, the changeover switch SW1 is connected to the a contact (the output side of the FM tuner section 1A), and the changeover switch SW2 is the b contact (the output side of the FM tuner section 1B). Connected to.

Therefore, the sound of the broadcasting station received by the FM tuner section 1A is output from the speaker 4 via the FM stereo signal demodulating section 2 and the power amplifying section 3. Next, in step S3, the FM tuner section 1B searches for FM broadcasting stations including an FM multiplex station having an electric field strength that can be received. In step S4, it is detected by the search whether or not the channel is selected. If the channel can be selected (YES), the process proceeds to step S5. If the channel cannot be selected (NO), the process returns to step S3 to continue the search. .

In step S5, it is detected whether or not the selected broadcasting station is an FM multiplex station, and if it is an FM multiplex station (YES), the process proceeds to step S6, and if it is not an FM multiplex station (NO). Returning to step S3, the search is continued. Then, in step S6, the frequency, station name, etc. of the selected FM multiplex station are registered in the FM multiplex station list on the basis of the multiplex data demodulated by the FM multiplex signal demodulation unit 5, and temporarily stored.

In step S7, it is detected whether or not the search is completed so that the entire FM broadcast wave band is searched from one end to the other end, and the search is completed (YES). In the case, the process proceeds to step S8, and when the search is not completed (NO), the process returns to step S3 and the search is continued. Then, in step S8, the result of storing all the detected FM multiplex stations on the display 7 is displayed as F
Display as M multi-station list.

At this time, for example, when listening to a general FM station without FM multiplexing by voice, the frequency and station name of the broadcasting station with FM multiplexing are displayed on the display 7. Next, in step S9, the user observes the FM multiplex station list to determine which FM multiplex station is to be selectively received, and the number in the FM multiplex station list (each time the multiplex station is registered Is automatically assigned a number, and a push button (on the keyboard 13) having a number corresponding to that (which is programmed in the CPU 13 to be displayed) is manually operated to perform a tuning operation (instruction input).

Then, in step S10, step S
The reception frequency of the FM tuner unit 1B is set on the basis of the instruction input from 9. Then, in step S11, FM
The multiplex broadcast is received, and the FM multiplex data that is the broadcast content is F
The signal is demodulated by the M-multiplex signal demodulation unit 5 and input to the CPU 11. Then, in step S12, the contents of the FM multiplex broadcast (song name, artist name, weather forecast, traffic information, etc.) are displayed on the display device 7, and the intended purpose can be reached.

Next, in step S13, the user manually operates the FM multiple button to turn it off, if necessary. In this way, in step S14, the state returns to the reception state immediately before the start of step S1 (the reception frequency of the FM tuner section 1B changes to the FM tuner section 1B).
It is changed to the same frequency as A, and it becomes diversity reception mode).

Then, in step S15, the FM multiplex broadcast display operation ends. In this embodiment, step S1
The sound of the FM tuner 1A before was always output, but not limited to this, if the frequency of the multiplex broadcasting station is set in step S10, the frequency of the FM tuner 1A is set to the frequency of this multiplex broadcasting. The switch S1 may be switched to the b side so that the sound of this multiplex broadcasting station can be output.

The above is the embodiment of the FM multiplex receiver in combination with the space diversity receiving system using two antennas, but it is possible to realize the gist of the present invention by using a single antenna. As described above, according to the present embodiment, two systems of FM tuners are used, but since only one system is provided for each of the FM stereo signal demodulation section and the FM multiplex signal demodulation section, it is possible to save space on the printed circuit board to be constructed. Cost reduction is possible.

[0042]

As described in detail above, according to the present invention, it is possible to simultaneously receive a broadcasting station having a different frequency for FM multiplex data reception and audio reception. It is possible to realize an FM multiplex radio receiver capable of displaying multiplex data relating to other FM multiplex broadcasting stations in parallel while being displayed.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of one embodiment of the present invention.

FIG. 2 is a flowchart showing a multiple broadcast display operation according to the embodiment of the present invention.

FIG. 3 is a configuration diagram showing a configuration of a conventional example.

[Explanation of symbols]

 1 ... FM tuner section 2 ... FM stereo signal demodulation section 3 ... Power amplification section 4 ... Speaker 5 ... FM multiple signal demodulation section 6 ...・ ・ ・ Data processing unit 7 ・ ・ ・ Display device 8 ・ ・ ・ AM tuner unit 9 ・ ・ ・ PLL frequency synthesizer unit 10 ・ ・ ・ Voice comparison unit 11 ・ ・ ・ Signal processing unit ( CPU) 12 ... Multipath comparison unit 13 ... Keyboard

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H04L 27/14 H04L 27/14 B

Claims (7)

[Claims] 1. At least two receiving means for tuning and receiving a broadcasting station including an FM multiplex broadcasting station, and an audio detection output means for detecting and outputting the audio of the broadcasting station received by the receiving means. A multiplex data detecting means for detecting the multiplex data of the FM multiplex broadcasting station received by the receiving means, a multiplex data displaying means for displaying the contents of the multiplex data detected by the multiplex data detecting means, and the reception of one of them. For the broadcasting station received by the means, the sound of the broadcasting station is output from the audio detection output means, and the other receiving means is searched for the FM multiplex broadcasting station, and the searched multiplex data of the FM multiplex broadcasting station is searched. And a control means for displaying the contents of the above on the multiplex data display means via the multiplex data detection means.
M multiplex radio receiver. 2. The control means causes the multiplexed data display means to display a frequency list based on a frequency list information signal of a station having the same program identification code transmitted from the FM multiplex broadcasting station. An FM multiplex radio receiver as claimed in claim 1, characterized in that 3. The control means causes the other receiving means to receive each broadcast station based on the frequency list detected by the multiplex data detection means, and to receive the sound of each broadcast wave and the one reception. 3. A voice comparison means for comparing the voice of a broadcasting station currently being received by the means to determine the same station.
The described FM multiplex radio receiver. 4. The control means displays the multiplex data based on a multiplex signal of the same broadcasting station receiving the audio or displaying a multiplex signal of another broadcasting station different from the one receiving the audio. 2. The FM multiplex radio receiver according to claim 1, wherein the FM multiplex radio receiver is compatible with any of the above. 5. The control means displays to the multiplex data display means based on a multiplex signal of the same broadcast wave as when audio is being received or a multiplex signal of a plurality of different broadcast waves different from when audio is being received. 2. The FM multiplex radio receiver according to claim 1, wherein a plurality of displays of the frequency information are simultaneously displayed on the same display surface, and both of them correspond to each other. 6. The multiplex data detection means is a single multiplex signal demodulator for demodulating multiplex data, and selectively outputs the multiplex signal demodulator and the one receiving means or the other receiving means. 2. The FM multiplex radio receiver according to claim 1, further comprising connecting means for connecting, wherein said control means switches said connecting means to a receiving means side receiving an FM multiplex broadcasting station. 7. The plurality of receiving means each include a receiving antenna for individually receiving, and when the control means detects that the plurality of receiving means are receiving the same multiplex broadcasting station, the connecting means is connected to the connecting means. On the other hand, it is characterized in that the content of the multiplex data of the multiplex broadcasting station received by the receiving means is connected to the receiving means side having an antenna with less noise and is displayed on the multiplex data display means. The FM multiplex radio receiver according to claim 1.