JP3278970B2 - FM multiplex broadcast receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for receiving an FM multiplex broadcast signal, which is mounted on a mobile body such as an automobile and multiplexes traffic information from an FM broadcast station to a normal broadcast signal and transmitted. The present invention relates to an FM multiplex broadcast receiving device that guides traffic information to a passenger such as a driver in accordance with traffic information included in a multiplex broadcast signal.

[0002]

2. Description of the Related Art Conventionally, in order to guide various situations such as traffic jams, accidents, and construction on roads, FM multiplex broadcasting has been proposed in which FM broadcast stations multiplex traffic information with normal broadcast signals and transmit them. Has been put to practical use.

[0003]

However, such F
The service area of M multiplex broadcasting generally covers a wide area with a radius of 50 km or more, and the contents of traffic information are distributed over a wide area. For this reason, if such an FM multiplex broadcast signal is received and the traffic information contained in the signal is guided as it is, traffic information unnecessary for the user is guided, resulting in a problem that the usability is poor.

In order to solve such a problem, it is conceivable to allow a user to select only traffic information in a necessary area. In this case, however, the selection of traffic information is changed according to the movement of the vehicle. And such a choice is not sufficient because it is unsafe for the driver to make such a choice.

[0005] The present invention has been made in view of such a problem, and has been developed in consideration of traffic information included in an FM multiplex broadcast signal.
FM that can automatically select only the necessary traffic information corresponding to the position of the moving body and guide it to the occupants such as drivers.
It is intended to provide a multiplex broadcast receiving device.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides an FM multiplex broadcast which is obtained by multiplexing traffic information from a FM broadcast station to a normal broadcast signal as shown in FIG. A mobile FM multiplex broadcast receiving apparatus for receiving a signal, comprising: a receiving antenna capable of receiving an FM broadcast wave within an FM broadcast band; and measuring an electric field strength of all FM broadcast waves received by the receive antenna. Electric field strength measurement means, and for each area previously classified according to the broadcast station code,
The area is divided into a plurality of reception areas, and the divided area is further divided.
For each receiving area, the reception area data storage means for receiving area data obtained by setting the field strength of receivable FM broadcast waves is stored in advance in the receiving area, the receiver A
Broadcasting station code from FM broadcast wave received by antenna
And reads the area corresponding to the read broadcasting station code.
Receiving the electric field intensity of each FM broadcast wave measured for the received area data in the electric field strength measuring unit matches
A receiving area detecting means for detecting the signal area as a reception area where the device is located, the traffic information decoded for decoding the traffic information tunes the FM multiplex broadcast signals from the FM broadcasting radio waves the receiving antenna has received means and, from the traffic information decoded by the traffic information decoding means, and traffic information selection means for selecting traffic information that corresponds to the received area detected by the receiving area detecting means, the traffic information selection means And a traffic information conversion means for converting the traffic information selected in (1) into notification data such as a video signal and an audio signal and outputting the data.

[0007]

In the FM multiplex broadcast receiving apparatus of the present invention configured as described above, the electric field intensity measuring means measures the electric field intensity of all FM broadcast radio waves received by the receiving antenna,
FM received by the reception antenna by the reception area detection means
Read the broadcast station code from the broadcast wave and read it
To the reception area data of the area corresponding to the
On the other hand, a reception area where the electric field intensity of each FM broadcast radio wave measured by the electric field intensity measurement means matches is detected as a reception area where the device is located. In addition, the traffic information decoding means selects the FM broadcast signal from the FM broadcast wave received by the receiving antenna.
The multiplex broadcast signal is selected to decode the traffic information, and the traffic information selecting means selects traffic information corresponding to the reception area detected by the reception area detection means from the decoded traffic information. Then, the traffic information converting means converts the traffic information selected by the traffic information selecting means into notification data such as a video signal, an audio signal, and outputs the same.

Namely, in the FM multiplex broadcast receiving apparatus of the present invention, the FM broadcast radio waves receiving antenna receives
The device is located by reading the broadcast station code.
Region, and identify each FM station within that region.
Using the electric field strength of the FM broadcast wave transmitted from the
In which of the reception areas the device divided the area
Is detected, and the number of FMs that can be received within that area
Only traffic information corresponding to the detected reception area is selected from the traffic information included in the multiplex broadcast signal, and is converted into notification data. Therefore, it is possible to guide the user only to the traffic information corresponding to the position of the device.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 2 is a block diagram illustrating an overall configuration of an FM multiplex broadcast receiving apparatus according to an embodiment to which the present invention is applied. The FM multiplex broadcast receiving apparatus according to the present embodiment is realized alone or as a part of the function of a car radio. The FM multiplex broadcast receiving apparatus is mounted on a car and transmits traffic information included in the FM multiplex broadcast signal to a video signal. And outputs it to a display device such as a CRT or a liquid crystal display.

As shown in FIG. 2, the FM multiplex broadcast receiving apparatus according to the present embodiment has an FM diversity antenna (hereinafter simply referred to as a receiving antenna) 2 including a pair of FM antennas for receiving FM broadcast radio waves in the FM broadcast band. And F containing traffic information from the FM broadcast radio waves received by the receiving antenna 2.
Main tuner 4 for selecting and demodulating M multiplex broadcast signals
And a multiplex data decoder 6 for decoding traffic information included in the FM multiplex broadcast signal demodulated by the main tuner 4 and converting the traffic information into an RGB signal for display. A color encoder 8 for converting a signal or the like into a video signal capable of displaying a color image on a display device (not shown);
, A sub-tuner 10 for sequentially selecting all FM broadcast radio waves received and converting it into an intermediate frequency signal;
An electric field intensity detecting unit 12 for detecting the electric field intensity of all FM broadcast signals received by the receiving antenna 2 by sequentially measuring the voltage level of the intermediate frequency signal output from the (Conversion table)
And a microcomputer (hereinafter, simply referred to as a CPU) 20 including a CPU, a ROM, a RAM, and the like that control the operations of the above-described units.

Here, the conversion table stored in the conversion table storage unit 14 is based on the electric field strength of each FM broadcast radio wave detected by the electric field strength detection unit 12 based on the FM broadcast radio wave reception area, that is, the vehicle position. As shown in FIG. 3, a secondary mesh code representing a reception area dividing the whole of Japan at intervals of 5 minutes in the north-south direction and 0.125 degrees in the east-west direction, Each F in the area
And measurement results obtained by measuring the electric field strength of the M broadcast radio wave. This conversion table is created for each prefecture, such as Tokyo, Aichi, Osaka, and so on. This conversion table corresponds to the reception area data of the present invention, and the conversion table storage unit 14 storing this conversion table corresponds to the reception area data storage means of the present invention.

Next, the CPU 20 drives the sub-tuner 10 to cause the electric field intensity detecting unit 12 to detect the electric field intensity of the FM broadcast radio wave.
4 for determining the vehicle position based on the conversion table stored in the multiplex data decoder 4 and decoding only the traffic information corresponding to the vehicle position by the multiplexed data decoder 6. The control process is performed as shown in FIG. Execute.

That is, when the power is turned on, the CPU 20 first drives the sub-tuner 10 to sequentially select receivable FM broadcast radio waves in the FM broadcast band in step 110, and then detects the electric field strength. Detecting the electric field strength of the FM broadcast radio wave receivable at the current position by reading the electric field strength output from the section 12 and storing it in the RAM in association with the frequency of the FM broadcast radio wave; Executes processing as measurement means.

Since the electric field intensity output from the electric field intensity detector 12 may fluctuate by about 30 dB due to the effects of fading or the like, in step 110, the instantaneous electric field intensity output from the electric field intensity detector 12 is calculated. Instead of using the data as it is, the median value of the electric field intensity fluctuation distribution within a predetermined time is selected, and the value is stored in the RAM as the electric field intensity of the FM broadcast radio wave.

Next, at step 120, the frequencies of the FM broadcast radio waves are read from the electric field intensity data stored in the RAM at step 110 in the order of the electric field intensity, and the main tuner 4 reads the frequency of the FM broadcast wave. A broadcast station performing FM multiplex broadcasting is searched for in such a procedure that FM broadcast radio waves are selected and the main tuner 4 determines whether or not the selected FM broadcast radio waves are FM multiplex broadcast signals.

The search operation in step 120 is performed until a search for a broadcasting station performing FM multiplex broadcasting can be performed or the search operation is completed for all FM broadcast radio waves storing the field intensity data in step 110. When the search operation is repeatedly performed and the search operation is completed, the process proceeds to step 130, where it is determined whether a broadcast station performing FM multiplex broadcasting has been searched. Then, in step 130, the FM
If it is determined that the broadcast station performing the multiplex broadcast cannot be searched, the process is temporarily terminated, and step 1 is performed again.
Move to 10.

On the other hand, if it is determined in step 130 that a broadcast station that is performing FM multiplex broadcasting has been searched, the process proceeds to step 140 and the frequency selected by the main tuner 4 is changed to the currently selected FM station. After fixing to the frequency of the multiplex broadcast signal, the broadcast station code included in the traffic information decoded by the multiplex data decoder 6 is read, and in step 150, based on the broadcast station code, stored in the conversion table storage unit 14. From among the conversion tables for each prefecture, the conversion table for the prefecture including the broadcasting station corresponding to the broadcasting station code is selected and set as the conversion table for detecting the reception area. For example, the frequency 8 shown in FIG.
When the FM broadcasting station with the broadcasting station name "NHK Tokyo" of 2.5 MHz is searched as an FM multiplex broadcasting station, a conversion table of Tokyo including this broadcasting station is set.

As described above, when the conversion table for detecting the reception area is set in step 150, step 16
0, and using this set conversion table,
A process as a receiving area detecting means for searching a secondary mesh code corresponding to the electric field strength data in the RAM obtained in step 110 is executed. For example, when the conversion table of Tokyo shown in FIG. 3 is set as the conversion table for detecting the reception area, the conversion table of Tokyo corresponds to the secondary mesh corresponding to the electric field intensity data in the RAM. Ask for the code.

Then, in step 170, the secondary mesh code 9 consisting of a reception area indicated by hatching in FIG. 5 corresponding to the secondary mesh code retrieved in step 160 and a surrounding reception area shown in FIG. The reception area corresponding to the traffic information is set as an area to which the traffic information is to be guided, and a process as a traffic information selection means for outputting a selection command for converting only the traffic information in this area to an RGB signal to the multiplex data decoder 6 is executed. Then, the process is temporarily terminated, and the process returns to step 110 again.

The multiplex data decoder 6 operates not only as the traffic information decoding means of the present invention together with the main tuner 4 but also as the traffic information converting means of the present invention,
Upon receiving the selection command from U20, based on the position code included in the decoded traffic information, only the traffic information in the designated area is converted into RGB signals,
Output to

Here, the reception area corresponding to the secondary mesh code as described above is not set as an area for guiding traffic information as it is, but the reception area for nine secondary mesh codes including the reception area around the reception area is not set. Is set as an area for guiding traffic information because the reception area corresponding to the secondary mesh code is about 10 km square, the movement range of the vehicle is slightly narrower, and the electric field strength detector 1
This is because the electric field intensity detected in step 2 is affected by fading or the like, and the secondary mesh code searched from the electric field intensity data may be shifted from the current position of the vehicle.

Further, since the conversion table is created from the measurement results of the electric field strength of each FM broadcast wave in each reception area corresponding to the secondary mesh code, as shown in FIG. In some cases, two or more secondary mesh codes are set for the same electric field intensity pattern. Therefore, a step of searching the conversion table for a secondary mesh code corresponding to the electric field intensity data in the RAM. At 160, two or more secondary mesh codes may be set at the same time, but in this embodiment,
When two or more secondary mesh codes are set at the same time as described above, an area to which traffic information is to be guided is set for each secondary mesh code, thereby simultaneously notifying the traffic information in each area. It has been like that.

Further, as described above, since the electric field strength detected by the electric field strength detection unit 12 is affected by fading or the like, in step 160, a corresponding secondary mesh code is obtained from the electric field strength data in the RAM. Although the search may not be performed, in this embodiment, in such a case, the process of step 170 is not performed. As a result, the multiplexed data decoder 6 outputs the traffic information of the previously set area as it is.

As described above, in the FM multiplex broadcast receiving apparatus of the present embodiment, the F
Detects the electric field strength of all FM broadcast radio waves in the M broadcast band,
Based on the detected electric field strength data, a vehicle position is detected using a conversion table, and only traffic information in an area corresponding to the vehicle position is converted into a video signal.

Therefore, according to the FM multiplex broadcast receiving apparatus of the present embodiment, only the traffic information near the vehicle position can be automatically selected and guided to the vehicle driver by the video.
Therefore, the driver can know necessary traffic information without performing an operation for selecting traffic information, and can improve the safety of the vehicle driving operation.

In this embodiment, an apparatus has been described in which the multiplex data decoder 6 converts traffic information into RGB signals, and further converts the RGB signals into video signals for display with the color encoder 8. A display device capable of displaying traffic information by digital data obtained by decoding traffic information is provided on the multiplex broadcast receiving device itself or a car radio or the like having a built-in FM multiplex broadcast receiving device.
The digital information of traffic information may be directly output to this display device, or a voice synthesizing device for converting the digital data obtained by decoding the traffic information into a voice signal may be provided, and the traffic information may be guided from a speaker by voice. It may be.

[0027]

As described above in detail, in the FM multiplex broadcast receiving apparatus of the present invention, FM reception antenna receives
By reading the broadcast station code from the broadcast wave,
Identify the area where the device is located and
Electric field strength of FM broadcast radio wave transmitted from FM broadcast station
Using the device to divide the area into multiple
Detects where it is located in the rear and receives within that area
From the traffic information included in possible FM multiplex broadcast signals,
Only the traffic information corresponding to the detected reception area is selected and converted into notification data.

Therefore, according to the FM multiplex broadcast receiving apparatus of the present invention, it is necessary to check whether the traffic information in the area where the apparatus is located.
Therefore, only the traffic information corresponding to the reception area where the device is actually located can be automatically selected and guided to the vehicle driver. Therefore, the vehicle driver can know necessary traffic information without performing an operation for selecting traffic information, and can improve the safety of the vehicle driving operation.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating the configuration of the present invention.

FIG. 2 is a block diagram illustrating an overall configuration of an FM multiplex broadcast receiving apparatus according to an embodiment.

FIG. 3 is an explanatory diagram illustrating a configuration of a table (conversion table) for electric field strength-reception area conversion.

FIG. 4 is a flowchart illustrating a control process for displaying traffic information.

FIG. 5 is an explanatory diagram illustrating a relationship between a secondary mesh code and a traffic information guidance area.

[Explanation of symbols]

2 ... Reception antenna 4 ... Main tuner 6 ... Multiple data decoder 8 ... Color encoder 10 ... Sub tuner 12
... Electric field strength detection unit 14 ... Conversion table storage unit 20 ... Microcomputer (CPU)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-336816 (JP, A) JP-A-4-167825 (JP, A) JP-A-1-223828 (JP, A) JP-A-4- 326627 (JP, A) JP-A-4-167824 (JP, A) JP-A-1-276300 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04B 1/16 H03J 7 / 18

Claims (1)

(57) [Claims] 1. An FM multiplex broadcast receiving apparatus for a mobile unit, which receives an FM multiplex broadcast signal transmitted by multiplexing traffic information from an FM broadcast station to a normal broadcast signal, comprising: A receiving antenna capable of receiving broadcast radio waves, electric field strength measuring means for measuring the electric field strengths of all FM broadcast radio waves received by the receive antenna, and a local area classified in advance corresponding to a broadcast station code.
Area is divided into a plurality of reception areas, and each of the divided reception areas is further divided.
For each signal area, a reception area data storage means for receiving area data obtained by setting the field strength of receivable FM broadcast waves is stored in advance in the receiving area, the FM broadcast wave received by the receiving antenna Release from inside
Read the transmission station code, and add the
The electric field intensity of each FM broadcast wave measured by the electric field intensity measuring means with respect to the reception area data of the corresponding area is
The reception area matching the reception area where the device is located
A receiving area detecting means for detecting in a traffic information decoding means for decoding the traffic information tunes the FM multiplex broadcast signals from the FM broadcasting radio waves the receiving antenna has received, in The traffic information decoding means From the decrypted traffic information,
Traffic information selecting means for selecting traffic information corresponding to the receiving area detected by the receiving area detecting means; and transmitting the traffic information selected by the traffic information selecting means to notification data such as video signals and audio signals. An FM multiplex broadcast receiving apparatus, comprising: