JPH01228336A - Traffic information transmission/reception system - Google Patents

Abstract

PURPOSE:To selectively listen to traffic information by simultaneously transmit ting traffic information and a discrimination signal, which indicates that traffic information is transmitted at present, in a frequency band other than that of traffic information from a transmitter and converting traffic information to sound in a receiver at the time of detecting the discrimination signal. CONSTITUTION:In the case of a frequency modulated wave on which an RDS signal is superposed as the signal which the receiver should receive, the RDS signal modulates the amplitude of a subcarrier 45 whose frequency is three times as high as a pilot signal 42. RDS demodulating circuits 11a and 11b demodulate it to lead out an RDS digital signal. When a TP code of the RDS digital signal is '1', a tuned station way transmit traffic information, and when a TA code is '1', a traffic information program is transmitted in tuned broad cast. A control circuit 13 is set to the traffic information reproducing mode by the operation of a key input part 15 and is automatically tuned to the fre quency of broadcast of traffic information based on values of the TA code and the TP code in accordance with the RDS digital signal from RDS demodulating circuits, and traffic information is outputted as sounds from a speaker SP.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is suitably implemented in, for example, in-vehicle audio equipment, and is a traffic information transmitting/receiving device configured to selectively convert traffic information transmitted from a transmitting device into sound. Regarding the method.

2. Description of the Related Art A prior art similar to the present invention includes a configuration of a broadcasting station that broadcasts a program including traffic information and a receiving device that receives this broadcast.

In such prior art, the receiving device is equipped with, for example, a phase-locked loop (PLL) frequency synthesizer, and even if it is possible to select a desired broadcast station by so-called auto-tuning, the operator can tune all broadcasts. Performing such an operation, in which the user has to select stations one after another and search for a broadcasting station broadcasting traffic information, is unsafe and inconvenient, especially when using in-vehicle audio equipment.

Furthermore, in the Radio Data System (abbreviated as RDS) broadcasting service that has started in Europe, a code signal representing the program content is multiplexed with a normal audio signal and sent out. For example, mobile objects such as cars use such code signals to automatically switch between broadcasts of the same program on a different carrier frequency when the reception sensitivity of the broadcast they are receiving deteriorates as they move from region to region. switch and receive,
Receiving devices configured so that the same program can be listened to continuously have also been devised.

However, even in such a receiving device, it is not possible to selectively listen to only traffic information from a plurality of receivable broadcasts, and the convenience as an in-vehicle audio device is inferior.

Problems to be Solved by the Invention It is an object of the present invention to solve the above-mentioned problems and provide a traffic information transmission/reception system that can selectively listen to traffic information and improves convenience.

Means for Solving the Problems The present invention provides an audio signal representing traffic information from a transmitting device;
An identification signal indicating that traffic information is being transmitted in a frequency band different from that of the audio signal is simultaneously transmitted, and when the receiving device detects the identification signal, it converts the audio signal representing the traffic information into a sound. This is a traffic information transmission and reception method that is characterized by the following.

According to the present invention, the transmitter simultaneously transmits an audio signal representing traffic information and an identification signal representing that traffic information is being transmitted in a frequency band different from that of the audio signal. The receiving device detects the identification signal and converts the audio signal representing the traffic information into a sound when the identification signal is detected. Therefore, traffic information can be selectively listened to.

Embodiment FIG. 1 is a block diagram showing an in-vehicle audio device according to an embodiment of the present invention. Carrier waves from a plurality of broadcast stations are received by an antenna AT and demodulated using a superheterodyne method. Further, the audio device shown in the first diagram is equipped with a cassette tape recorder, and the signals on the magnetic tape TP are reproduced by the magnetic head HE. Above antenna AT
The signal from the magnetic head HE and the signal from the magnetic head HE are connected to the switching circuit 6.
The signal is switched and audible by the speaker SP.

In this embodiment, two systems are provided for receiving radio broadcasts, and corresponding parts are indicated by the same reference numerals with a and b attached.

The carrier wave from the radio broadcasting station is received by the antenna AT,
A high frequency amplification and mixing circuit 1a that performs high frequency amplification and mixing;
lb each. This high frequency amplification mixing circuit 1
a, lb are equipped with phase-controlled loop frequency synthesizers. That is, a control signal is applied from the control circuit 13 to the tuning circuits 10a and 10b via lines 11 and 12. According to this control signal, the tuning circuits 10a, 1
From 0b, the local oscillation frequency signal is applied to the high frequency amplification/mixing circuits 1a, lb via low-pass filters (hereinafter abbreviated as LPF) 9a, 9b, thereby changing the reception tuning frequency of the carrier wave in the high frequency amplification/mixing circuits 1a, lb. is set.

Outputs from the high frequency amplification/mixing circuits 1a, lb are given to intermediate frequency amplification/detection circuits 2a, 2b which perform intermediate frequency amplification and detection such as frequency discrimination. The signals from the intermediate frequency amplification and detection circuits 2a and 2b are transferred to the changeover switch 12.
are given to individual contacts Ta and Tb, respectively, and
The signals are respectively applied to RDS demodulation circuits 11a and llb, which will be described later.

At this time, the signal representing the detection state in the intermediate frequency amplification and detection circuits 2a and 2b is on the line l3. 14 to the control circuit 13. Common contact Tc of switch 12
The output is given to a demodulation circuit 4 via a noise canceller circuit 3, and is subjected to stereo IM modulation in the demodulation circuit 4. The output from demodulation circuit 4 is given to switching circuit 6.

The switching circuit 6 receives the signal from the demodulation circuit 4 and the signal reproduced from the magnetic tape TP by the magnetic head HE and amplified by the amplifier 5, and selects these two signals by the signal from the control circuit 13. and output to the adjustment circuit 7.

The volume and sound quality of this signal are adjusted by the adjustment circuit 7, and the signal is converted into sound by the speaker SP via the amplifier 8.

In this audio device, the operating state of the control circuit 13 can be operated by operating keys on the key input section 15, and the operating state of the control circuit 13 can be displayed on the display section 14.

For example, the signal received by the receiving device shown in FIG.
A case will be explained in which the DS signal is a frequency modulated wave (FM modulated wave) superimposed thereon. The frequency spectrum of such an FM modulated wave is shown in FIG. The frequency of the FM modulated wave is 15kHz to realize stereo broadcasting.
Below, the 0 frequency 19 includes the L+R signal 41, which is the sum of the left audio signal (L) and the right audio signal (R).
A kHz pilot signal 42 indicates the presence or absence of a stereo broadcast. When this pilot signal 42 is being transmitted, the left and right audio signals of the stereo broadcast are separated and stereo demodulated.

The suppressed carrier wave 44, which is a harmonic signal with a frequency of 38 kHz, which is twice the frequency of the pilot signal 42, causes the signals 43a and 43b (collectively referred to as L-R signal 43), which are the difference signals between the left and right voices, to be generated in the sideband. As frequency 23kHz~5
Included in the 3kHz range.

The aforementioned RDS signal amplitude modulates a subcarrier 45 of 57 kHz, which is three times the frequency of the pilot signal 42.

The RDS signal is therefore distributed as sideband signals 46a, 46b on both sides of the subcarrier 45.

The RDS demodulation circuits 11a and llb demodulate the sideband signals 46a and 46b with a configuration as described later, and derive the RDS digital signal shown in FIG. 3.

As shown in FIG. 3, this RDS digital signal is composed of a bit string of, for example, 104 bits as one group, and one group is composed of, for example, four blocks of 26 bits. One block is
For example, it consists of a 16-bit information word and a 10-bit check word, and the check word is placed for detecting/correcting errors in the information word.

The information in the first block of one group is called a PI code, and serves as an identification code for a broadcast program that includes this RDS digital signal. A code representing the type of this group is placed in the first 4-bit area 51 of the second block. Corresponding to the data in area 51, various other codes are placed in the third and fourth blocks.

The 6th bit of the second block is the identification code of the traffic information program called the TP code, and this TP code is "1".
When this happens, the tuned station is one that broadcasts traffic information. The 5 bits from the 7th bit to the 11th bit of the second block are called a PTY code, and are a code related to the program content. The 12th bit of the second block is a broadcast identification code for a traffic information program called a TA code, and when this TA code is "1", a traffic information program is being broadcast in the tuned broadcast. Many types of groups of such RDS digital signals are successively transmitted.

FIG. 4 is a block diagram showing the configuration of the RDS demodulation circuit 11a, and the RDS demodulation circuit 11b has a similar configuration, and only the RDS demodulation circuit 11a will be described below.

High frequency amplification and mixing circuit 1a and intermediate frequency amplification and detection circuit 2
Unnecessary frequency components of the RDS signal detected by a are removed by a band pass filter (abbreviated as BPF) 24, and only frequencies around 57 kHz are converted into t-waves. The RDS signal converted into V wave by BPF24 is 57
57kHz regenerated by two kHz subcarrier regeneration circuits
The two-phase P S K (P hase
(shift keying) is demodulated into a two-phase PSK signal in the signal demodulation circuit 25. This two-phase PSK signal is output to a clock recovery-0 circuit 30 and an analog/digital converter (hereinafter abbreviated as an A/D converter) 26. The clock regeneration circuit 30 regenerates a clock signal of, for example, 1187.5 Hz used in RDS broadcasting and outputs it to the A/D converter 26 and the correction circuit 27.

The digital signal from the A/D converter 26 is sent to a correction circuit 27.
synchronously with the clock signal from the clock generation circuit 30, the above-mentioned check word correction, etc. is performed, and the resultant signal is provided to the output circuit 28. In this way, the RDS digital signals collected for each block are derived from the output circuit 28 to the control circuit 13.

FIG. 5 is a block diagram showing the configuration of the control circuit 13. The RDS digital signals from the RDS demodulation circuit 11a and the RDS demodulation circuit 11b described above are sent to the input determination section 16a.
, 16b, it is determined whether the data is correct.

In other words, only the data that can be corrected by the correction circuit 27 is transferred from the input determination units 16a, 16b to the analysis units 17a, 17b.
The 0 analysis units 17a and 17b each output R
Various codes included in the DS digital signal are classified and analyzed.

In this embodiment, these analysis units 17a and 17b are RD
The TP code and TA code of the S digital signal are sent to the traffic information analysis section 21, and the memory 18a,
18b, respectively.

Further, the signal from the key input section 15 is input to the mode discrimination section 23, and various operation modes of the radio receiver are discriminated. The output of the mode determination section 23 is given to the traffic information analysis section 21. Also, lines l from the intermediate frequency amplification and detection circuits 2a and 2b.3. The signals via 14 are given to reception sensitivity determining sections 20a and 20b, respectively, which determine the reception sensitivities of the broadcasts tuned by the high frequency amplification and mixing circuits 1a and 1b, respectively. This reception sensitivity determination section 20
a.

The output of 20b is given to tuning control sections 19a and 19b. Further, a signal representing the frequency of a carrier wave including a TP code or a TA code is outputted from the traffic information analysis section 21 to the tuning control sections 19a and 19b. This tuning control section 1
9a and 19b lead out signals to the tuning circuits 10a and 10b, respectively, and thereby the high frequency amplification mixing circuits 1a and lb
The carrier frequencies to be tuned are set respectively.

FIG. 6 is a flowchart for explaining the operation of the radio receiver shown in the first diagram. When the traffic information setting signal is input to the mode determining section 23 by the operation of the key manual section 15, the control circuit 13 enters the traffic information reproduction mode and moves to step n1.

In step n1, the RDS digital signal from the RDS demodulation circuit 11a is checked, and the process moves to step n2 to check the RDS digital signal from the RDS demodulation circuit 11a.
It is determined whether the TA code of the DS digital signal is rl. If affirmative, high frequency amplification mixing circuit 1
Since traffic information is being broadcast on the carrier frequency tuned by a, the process moves to step n9, where the switch 12 is switched to a state where the individual contacts Ta and the common contact Tc are brought into conduction, and the high frequency amplification/mixing circuit 1a is tuned. The system converts the current broadcast into audio from the speaker SP and outputs traffic information.

In step n2, R from the RDS demodulation circuit 11a
If the TA code in the DS digital signal is "1", the process moves to step n3, and the R from the RDS demodulation circuit 11b is
Check DS digital signal.

After this, in step n4, R
A question is asked as to whether DS data is superimposed. That is, if the RDS digital signal is output from the RDS demodulation circuit 11b, the result is affirmative, and the process moves to step n5. If step n4 is negative, the process moves to step n13, which will be described later.

In step n5, the processing operation branches depending on whether the TP code of the RDS digital signal output from the RDS demodulation circuit 11b is "1". If affirmative, proceed to step n6; if negative, proceed to step n, which will be described later.
Move on to 13. In step n6, the RDS demodulation circuit 11
The processing operation branches depending on whether or not the TA code of the RDS digital signal from b is "1", and if it is "0", it is tuned in the high frequency amplification mixer circuit 1b.

It is assumed that the current broadcast does not provide traffic information, and the process moves to step n13, which will be described later.

In the high frequency amplification/mixing circuit 1b, if traffic information is being broadcast, that is, if the judgment in step n6 is affirmative, the process moves to step n7, and the individual contact Tb and the common contact Tc of the switch 12 are switched to a conductive state,
As a result, the traffic information broadcast tuned by the high frequency amplification/mixing circuit 1b is turned into sound from the speaker SP. At this time, in step n8, if traffic information starts in the broadcast tuned by the high-frequency amplification/mixing circuit 1a, that is, when the RDS demodulation circuit 11a
The TA code of the DS digital signal is rl.

If so, the process moves to step n9, where the switch 12 sets the individual contact Ta and the common contact Tc to a reverse conducting state, and the high frequency amplification/mixing circuit 1a gives priority to the broadcast traffic information tuned in and outputs it from the speaker sp. do.

After this, in step nlo, the traffic information of the tuned broadcast in the high frequency amplification/mixing circuit 1a is finished, that is, the RD
When the TA code of the RDS digital signal from the S demodulation circuit 11a becomes "0", step n13 described later is performed.
Move to.

In step n8, if the traffic information broadcast tuned by the high frequency amplification/mixing circuit 1a has ended, step n
Moving on to step 11, it is determined whether or not the broadcast in the high frequency amplification/mixing circuit 1b includes traffic information. If affirmative, the process moves to step n7, and the above-described operations are repeated. T! If so, the process moves to step n12, where the switch 12 brings the individual contact Ta and the common contact Tc into a conductive state, whereby the broadcast tuned by the high frequency amplification/mixing circuit 1a is output from the speaker SP.

In step n13, the tuning frequency in the high frequency amplification/mixing circuit 1b is changed and a so-called scanning operation is performed to tune to broadcasts received at a certain reception level or higher.

As explained above, in this embodiment, traffic information can be heard with a simple operation. Furthermore, no matter which broadcasting station broadcasts traffic information, the system is configured so that it automatically tunes to the frequency on which the traffic information is being broadcast and outputs it as sound from the speaker SP. There is no need to search for a broadcasting station, which improves convenience. In particular, if the present invention is applied to a vehicle-mounted audio device, traffic information can be heard with a simple operation, thereby improving safety.

In this embodiment, all broadcasts received at a reception sensitivity of a certain level or higher are scanned. If the carrier wave frequency of the station and its broadcasting station is stored in the memories 18a and 18b, and it is determined whether or not a TA code is included for such a broadcast, a faster scanning operation can be realized. This will further improve convenience.

Furthermore, although RDS broadcasting is not explained in this embodiment, it is not limited to RDS broadcasting, but can also be broadcasting in which an identification signal indicating that traffic information, such as a TA code, is being broadcast together with an audio signal indicating traffic information. If so, it is possible to implement the present invention, and such broadcasts may be broadcast using other modulation methods such as amplitude modulation.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, when the identification signal transmitted together with the traffic information from the transmitting device is detected by the receiving device, the traffic information is audible. Therefore, traffic information can be selectively listened to, and convenience can be improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an in-vehicle audio device according to an embodiment of the present invention, FIG. 2 is a diagram showing the frequency spectrum of the FM modulated wave on which the RDS signal is multiplexed, and FIG.
FIG. 4 is a block diagram showing the configuration of the demodulation circuit 11a, FIG. 5 is a block diagram showing the configuration of the control circuit 13, and FIG. 6 explains the operation of the audio device shown in FIG. 1. This is a flowchart for AT...Antenna, la, lb...High frequency amplification mixing circuit, 2a, 2b...Intermediate frequency amplification and detection circuit, 4.・
... Demodulation circuit, 7... Adjustment circuit, 10a, 10b...
・Tuning circuit, 11a, 1lb-RDS demodulation circuit,
13--control circuit, 14--display section, 15--key manual section, 45--subcarrier (RDS signal), 46--
...Sideband signal (RDS signal), SP...Speaker agent Patent attorney Number of strokes Keiichi

Claims (1)

[Scope of Claims] A transmitting device simultaneously transmits an audio signal representing traffic information and an identification signal representing that traffic information is being transmitted in a frequency band different from that of the audio signal, and the receiving device transmits the identification signal. 1. A traffic information transmitting/receiving system, characterized in that when the traffic information is detected, the audio signal representing the traffic information is converted into a sound.