JP2000115004A - Fm broadcast automatic following-up method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a FM broadcast automatic following-up method which shortens the time needed to search for an alternative station after the reception state becomes worse and then switch the reception frequency. SOLUTION: A CD-ROM in a navigation device is stored previously with broadcasting station data indicating the positions of broadcasting stations together with map data. When an FM radio receiver receives group broadcasting station data sent by FM multiplexing, the navigation device calculates the distances between respective group broadcasting stations and the current position of the vehicle by using the broadcasting station data and rearranges the group broadcasting stations in the increasing order from the distances from the current position of the vehicle. The rearranged group broadcasting station information is stored in the FM radio receiver.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for automatically following an FM broadcast by an FM broadcast receiving system including an FM radio receiver and a vehicle-mounted navigation device.

[0002]

2. Description of the Related Art Recently, news,
Information such as weather forecasts and traffic information has been provided. One of the information multiplexed on the FM broadcast includes a frequency (AF: Alternative Fr.) of a broadcast station broadcasting the same program.
equencies) indicating affiliated broadcasting station information. In-vehicle radio receivers use this affiliated broadcasting station information to automatically change the receiving frequency when the reception status of the currently receiving broadcast deteriorates, and to continue the same program from other affiliated broadcasting stations. An automatic follow-up function for receiving has been put to practical use.

[0003] In an on-vehicle radio receiver provided with an auto-following function, a user can continuously receive the same program without operating the radio receiver even when the vehicle travels a long distance. it can. A similar system is the RDS (Radio Data System) proposed by the European Broadcasting Union (EBU) and currently in practical use all over Europe.

[0004] In this type of system, the series broadcast station information that is FM-multiplexed and transmitted is stored in a memory in the radio receiver, and when the reception state of the currently receiving broadcast is deteriorated, the computer in the radio receiver is activated. The reception frequency is changed with reference to the affiliated broadcasting station information in the memory, and an affiliated broadcasting station having a good reception state is searched. Then, when an affiliated broadcasting station with a good reception state is searched, the FM broadcasting is received from the affiliated broadcasting station (hereinafter, also referred to as “alternate station”).

[0005]

Normally, in an FM radio receiver provided with an automatic tracking function, when the reception condition deteriorates, the reception frequency is changed in accordance with the order of the series broadcast station information stored in the memory, and the reception condition is improved. Search for a affiliated broadcasting station. For this reason, the time required for switching to the substitute station is relatively short when the affiliated broadcasting station having a good reception condition at the current position of the vehicle is higher in the affiliated broadcasting station information, but is shorter when switching to the alternative station is lower. Becomes longer.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an FM broadcast automatic tracking method in which the time required to search for an alternative station and switch the reception frequency after the reception condition has deteriorated is short.

[0007]

An object of the present invention is to provide a method for automatically following an FM broadcast of an FM broadcast receiving system comprising a navigation device having a vehicle position detecting means and an FM radio receiver. The broadcast station data including the position data is stored in the navigation device, the FM radio receiver obtains the series broadcast station information multiplexed on the FM broadcast, and the series broadcast station information and the broadcast station data are obtained. Determines the priority order of each affiliated broadcasting station included in the affiliated broadcasting information, and the FM radio receiver, when the receiving state of the FM broadcast being received becomes worse, sequentially changes the receiving state from the broadcasting station with the higher priority order The problem is solved by an automatic multiplexing method for FM multiplex broadcasting, characterized in that a search is made to find a broadcasting station having a good reception condition.

An object of the present invention is to provide a method for automatically following an FM broadcast of an FM broadcast receiving system comprising a navigation device having a vehicle position detecting means and an FM radio receiver, wherein the broadcast includes position data of an FM broadcast station. Station data is stored in the navigation device, and the FM radio receiver obtains the series broadcast station information multiplexed on the FM broadcast, and obtains the series broadcast information by the series broadcast station information and the broadcast station data. Each of the included broadcast stations is classified into a priority station and a non-priority station, and the priority of each of the affiliated broadcast stations is determined. The FM radio receiver, when the reception state of the FM broadcast being received becomes poor, The problem is solved by an FM broadcast automatic tracking method characterized in that the reception state is checked in order from the broadcasting station having the highest priority of the priority stations, and a broadcasting station having a good reception state is searched.

The operation of the present invention will be described below.

In the present invention, broadcast station data including the position data of the FM broadcast station is stored in the navigation device, and each broadcast station indicated by the FM multiplexed broadcast station information is prioritized. . The priority order is determined, for example, in the order from the current position of the vehicle detected by the navigation device. If the receiving state of the currently receiving broadcasting station is deteriorated, the receiving state is checked in order from the affiliated broadcasting station having the highest priority to search for a broadcasting station having a good receiving state, and if a broadcasting station having a good receiving state can be searched, , F
Receive M broadcast.

Normally, the broadcast from the broadcast station closest to the current position of the vehicle has the best reception state. Therefore, as described above, the broadcast stations with good reception states are searched in order from the series broadcast stations having the highest priority. By doing so, there is no need to check the reception state of the second or subsequent affiliated broadcasting station, and the switching of the reception frequency is completed in a short time.

[0012] The priority may be determined by calculating the electric field strength (reception level) from each affiliated broadcasting station at the current position of the vehicle.

[0013] Further, each affiliated broadcasting station is classified into a priority station whose reception condition is presumed to be good according to the distance from the current position of the vehicle and the like, and a non-priority station other than the above. The receiving state may be checked preferentially. For example, check the reception state of each affiliated broadcasting station classified as a priority station, check the reception state of a non-priority station if the reception state is not good, and if it is still not possible to search for a reception station with a good reception state, It is preferable to search for a station having a good reception state from among the priority stations as much as possible by checking the reception state of each affiliated broadcasting station of the priority station again. Reception conditions may temporarily deteriorate even in the service area of a broadcasting station, such as when a vehicle is passing under a guardrail, but while checking the reception status of a non-priority station, This is because the vehicle may move to a place having a good reception state and receive a broadcast from the priority station.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a first embodiment of the present invention.
It is a block diagram showing the FM broadcast receiving system which realizes the FM broadcast automatic tracking method of an embodiment. This FM broadcast receiving system includes a navigation device 10 and an FM radio receiver 30.

The navigation device 10 is a CD-ROM
Alternatively, a DVD-ROM (hereinafter simply referred to as “CD-ROM”) 11, an operation unit 12, an interface 13,
A GPS receiver 14, a self-contained navigation sensor 15, a buffer memory 16, a control unit 17, a map drawing unit 18, an operation screen / mark generation unit 19, a guidance route storage unit 20, a guidance route rendering unit 21, , An image synthesizing unit 22 and a display device 23.

The CD-ROM 11 stores map data and broadcast station data. In the map data, roads and the like are represented as a set of vertices (nodes) whose longitude and latitude are known. The map data includes data indicating shapes of buildings, parks, rivers, and the like, and data for displaying names of buildings, parks, rivers, and the like.
Also, as shown in FIG. 2, the broadcast station data is composed of data indicating the station name of each broadcast station and data indicating the position of the broadcast station (position of the transmitting antenna).

The operation unit 12 includes a navigation device 10
There are provided operation buttons for operating the mouse, a joystick for moving the cursor, and the like. Interface 1
3 adjusts the timing of signal transmission and reception and the signal level in order to transmit and receive signals between the control unit 17 and the FM radio receiver 30.

The GPS (Global Positioning System) receiver 14 receives a GPS signal sent from a GPS satellite and outputs a signal indicating the latitude and longitude of the current position of the vehicle. The self-contained navigation sensor 15 is constituted by a sensor such as a gyro for detecting the rotation angle of the vehicle, and a traveling distance sensor for generating a pulse for each constant traveling distance.

The control unit 17 is constituted by a microcomputer, detects the current position of the vehicle from the outputs of the GPS receiver 14 and the self-contained navigation sensor 15, and controls the CD-R.
Predetermined map data is read from the OM 11 to the buffer memory 16 and a guide route from the departure point to the destination is searched for under the set search conditions using the map data read into the buffer memory 16.

The map drawing section 18 generates a map image using the map data read into the buffer memory 16 based on a command given from the control section 17. Operation screen
The mark generation unit 19 generates various menu screens (operation screens) according to the operation status, and generates various marks such as a vehicle position mark and a cursor, based on a command given from the control unit 17.

The guidance route storage unit 20 stores the guidance route data (node sequence) searched by the control unit 17.
The guidance route drawing unit 21 reads the data of the guidance route from the guidance route storage unit 20 and draws the guidance route in a color and a line width different from those of other roads.

The image synthesizing section 22 includes various marks and operation screens generated by the operation screen / mark generation section 19 and the guidance route drawing section 21 on the map image drawn by the map image drawing section 18.
Are superimposed and displayed on the display device 23.

The navigation device 10 configured as described above is similar to a conventional ordinary navigation device,
A map image around the vehicle is displayed on the display device 23, a guide route from the departure point to the destination is searched, and guidance information is appropriately displayed on the display device 23 so that the vehicle moves along the guide route. Has a function.

FIG. 3 is a block diagram showing the FM radio receiver 30. The FM radio receiver 30 includes an antenna 31,
Front end (F / E) 32, PLL (Phase Locked)
Loop) circuit 33, low-pass filter (LPF) 34, intermediate frequency amplification / FM detector (IF / DET) 35, noise canceller / stereo demodulation circuit (NC / MPX) 36,
A / D converters 37, 39, 41, high-pass filters (H
PF) 38, band pass filter 40, FM multiplex decoder 42, synchronization / error correction unit 43, control unit 44, RAM
(Random Access Memory) 45, an operation unit 46, and a display device 47.

The front end 32, together with the PLL circuit 33 and the low-pass filter 34, constitutes an electronic tuning unit.
The FM broadcast of the frequency set by the control unit 44 is received, converted into an intermediate frequency signal, and output. The intermediate frequency amplifier / FM detector 35 amplifies and detects the intermediate frequency signal output from the front end 34. The noise canceller / stereo demodulation circuit 36 removes ignition noise and the like included in the detected signal, and then demodulates and outputs the left channel audio signal (L) and the right channel audio signal (R).

The A / D converter 37 outputs a signal meter signal (hereinafter referred to as S) output from the intermediate frequency amplification / FM detector 35.
(Referred to as a meter signal) is converted from analog to digital and transmitted to the control unit 44. The S meter signal is a signal obtained by DC detection of the intermediate frequency signal, and indicates the electric field strength of the received radio wave. The high-pass filter 38 extracts a multipath component of 20 kHz or more superimposed on the S-meter signal and outputs it as a multipath signal. The A / D converter 38 converts the multi-pass signal output from the high-pass filter 38 from analog to digital and transmits the converted signal to the control unit 44. The band-pass filter 40 has a 100
A beat signal of kHz is extracted. The degree of adjacent interference can be known from the beat signal of 100 kHz. A
The / D converter 41 converts the 100 kHz beat signal output from the band-pass filter 40 from analog to digital, and transmits the signal to the control unit 44. The control unit 44 determines whether or not the reception state of the FM broadcast currently being received is good based on the S meter signal, the multipath signal, and the 100 kHz beat signal.

The FM multiplex decoder 42 and the synchronization / error correction unit 43 are circuits for demodulating FM multiplex data. That is, the FM multiplex decoder 42 extracts an L-MSK modulation signal component from the FM detection signal output from the intermediate frequency amplification / FM detector 35, demodulates the L-MSK modulation signal, and outputs bit string data. Synchronization / error correction unit 43
Recovers the FM multiplex data by dividing the bit string data output from the FM multiplex decoder 42 into predetermined blocks and frames and performing error detection and correction processing. The restored FM multiplex data is transmitted to the control unit 44.

The control unit 44 is constituted by a microcomputer, controls a reception frequency, displays FM multiplexed character information (news and weather forecast, etc.) on the display device 47, and stores the series broadcast station information in the RAM 45.
Or to save. Further, the control unit 44 transmits and receives various data to and from the navigation device 10.

The operation unit 46 is provided with operation buttons and the like for the user to select a channel or select a text program.

The FM radio receiver 3 configured as described above
At 0, when the user operates the operation unit 46 to set the reception frequency or the reception station, the control unit 44 controls the reception frequency of the electronic tuning circuit including the front end 32, the PLL circuit 33, and the low-pass filter 34, A predetermined FM broadcast is received. FM multiplex decoder 42 and synchronization
The error correction unit 43 restores the data multiplexed on the FM broadcast and outputs the data to the control unit 44.

FIG. 4 is a flowchart showing a method of automatically following an FM broadcast according to the first embodiment of the present invention, showing the operation from reception of affiliated broadcast station data to storage in the RAM 45.

First, in step S11, the control unit 44 of the FM radio receiver 30 extracts sequence broadcast station information multiplexed on the currently received FM broadcast. The affiliated broadcast station information includes, for example, the station name of the affiliated broadcast station and the broadcast frequency, as schematically shown in FIG. Next, in step S12, the control unit 44 stores the affiliated broadcast station information in the RA
It is stored in M45 and transmitted to the navigation device 10.

The control unit 17 of the navigation device 10
In step S21, when the system broadcast station information is received from the FM radio receiver 30, the process proceeds to step S22, and the current position of the vehicle and the system broadcast station information are referred to by referring to the broadcast station data stored in the CD-ROM 11. Calculate the distance between each affiliated broadcasting station included in.

Next, proceeding to step S23, the control section 17 of the navigation device 10 sorts the affiliated broadcasting station information by assigning priorities in order of decreasing distance between the current position of the vehicle and the affiliated broadcasting station. Then, the process shifts to step S24 to transmit the rearranged affiliated broadcasting station information to the FM radio receiver 30. FIG. 6 is a diagram schematically showing the affiliated broadcast station information after the rearrangement by the navigation device 10.

When the control unit 44 of the FM radio receiver 30 receives the affiliated broadcast station information from the navigation device 10 in step S13, the process proceeds to step S14,
Instead of the affiliated broadcasting station information stored in the RAM 45,
The affiliated broadcast station information sent from the navigation device 10 is stored in the RAM 45.

In this way, the RAM 45 stores the affiliated broadcasting station information in which the affiliated broadcasting stations are rearranged in the order from the position closest to the current position of the vehicle. Since the distance from the current position of the vehicle to each of the affiliated broadcasting stations changes with the movement of the vehicle, it is necessary to perform the above-described processing, for example, every time the vehicle moves a certain distance or every certain time.

FIG. 7 is a flowchart showing the operation when the reception frequency is changed.

In step S31, the control unit 44 of the FM multiplex receiver 30 checks the reception status of the currently receiving broadcast by the S meter signal, the multipath signal, or the adjacent interference signal, and in step S32, checks the reception status based on the check result. Is determined. When the reception state is good, the FM broadcast is continuously received from the currently receiving broadcast station, and the process returns to step S31 to continuously check the reception state.

If it is determined in step S32 that the reception state is poor, the process proceeds to step S33. Then, the control unit 44 refers to the affiliated broadcasting station information stored in the RAM 45, shifts to step S34, and changes the reception frequency to the affiliated broadcasting station of the first priority. Thereafter, the process proceeds to step S35 to check the reception state, and in step S36, the quality of the reception state is determined based on the check result. If it is determined that the reception state is good, the process is terminated and the FM broadcast is received from the affiliated broadcasting station.
On the other hand, if it is determined in step S36 that the reception state is bad, the flow shifts to step S37 to change the reception frequency to the next-priority affiliated broadcasting station, and returns to step S35 to check the reception state. Then, step S36
When the receiving state is determined to be good, the broadcast from the affiliated broadcasting station is received, and when the receiving state is determined to be bad, the process proceeds to step S37 to change to the next priority affiliated broadcasting station. Change the reception frequency.

As described above, in this embodiment, after acquiring the FM multiplexed series broadcast station information, the distance between the current position of the vehicle and each of the series broadcast stations is calculated, and from the current position of the vehicle, The affiliated broadcast station information is rearranged by assigning priorities in order from the closest. Then, when the reception state of the currently received FM broadcast becomes worse, the quality of the reception state is checked in order from the broadcasting station with the highest priority.

Since the affiliated broadcasting station of priority 1 is located closest to the current position of the vehicle, the broadcasting from the affiliated broadcasting station of priority 1 usually has the best reception state. Therefore, normally, it is not necessary to check the reception state of the affiliated broadcasting stations of priority 2 or later, and the switching of the reception frequency is completed in a short time. Further, even if the reception status of the broadcast from the broadcast station of the priority 1 is bad for some reason, the search is performed for the broadcast station having the good reception status in the descending order of the priority. be able to.

(Second Embodiment) Hereinafter, a second embodiment of the present invention will be described.
An automatic tracking method for FM multiplex broadcasting according to the embodiment will be described. Note that also in the embodiment, the configurations of the FM radio receiver and the navigation device are basically the same as those of the first embodiment, and thus the description will be made with reference to FIGS.

FIG. 8 is a view showing broadcast station data stored in the CD-ROM 11. In the present embodiment, the broadcast station data includes data of a broadcast station name, a transmission frequency, a transmission output (effective transmission radiation power), an antenna height, an altitude of a transmitting station, and a position (longitude and latitude). include.

The control unit 44 of the FM radio receiver 30
From the FM multiplex data restored by the M multiplex decoder 42 and the synchronization / error correction unit 43, the system broadcast station information (see FIG. 5) is acquired and transmitted to the navigation device 10.

The control unit 17 of the navigation device 10
When the affiliated broadcast station information is received, the electric field strength of the signal of each affiliated broadcast station at the current position of the vehicle is calculated with reference to the broadcast station data stored in the CD-ROM 11. The electric field intensity E ₀ (V / m) is obtained by the following equation (1).

[0047]

(Equation 1) However, h ₁ is the transmitting antenna height (m), h ₂ is the receive antenna height (m), d is the distance between the transmitting and receiving antennas (m), lambda is the wavelength of the transmission frequency (m ), W
Is the effective transmission radiation power (W), and λ = 300 / f (f
Is the reception frequency (MHz).

A series broadcast station having an electric field strength E ₀ calculated by the equation (1) of not less than a certain value (sufficient value as a reception level) is a priority station, and a series broadcast station having a value of not more than a certain value is a non-priority station. The priority stations and the non-priority stations are rearranged by assigning priorities in descending order of the electric field strength to obtain the series broadcast station information. Then, it transmits the affiliated broadcasting station information to the FM radio receiver 30. FIG. 9 is a diagram schematically illustrating the affiliated broadcast station information transmitted from the navigation device 10 to the FM radio receiver 30. As shown in FIG. 9, the navigation device 1
From 0, the series broadcast station information transmitted to the FM radio receiver 30 is such that each series broadcast station is classified as a priority station or a non-priority station, and a priority order is added.

The control unit 44 of the FM radio receiver 30 stores the affiliated broadcasting station information transmitted from the navigation device 10 in the RAM 45.

In this manner, the RAM 45 stores the affiliated broadcasting station information obtained by rearranging the affiliated broadcasting stations in the descending order of the electric field strength at the current position of the vehicle.

FIG. 10 is a flowchart showing the operation when the reception frequency is changed.

First, in step S41, the control unit 4
Reference numeral 4 designates the number of non-priority stations as B, and assigns 1 to a variable b. Next, in step S42, the number of priority stations is set to A, and 1 is substituted for a variable a.

Next, the reception status of the priority station is checked.
That is, in step S43, the control unit 44 receives the FM broadcast by adjusting the reception frequency to the sequence broadcast station having the priority 1 (a = 1), and determines whether the reception state is good or bad by the S meter, the multipath, and the degree of adjacent interference. Find out. In step S44, the reception state is determined to be good. If the reception state is determined to be good, the process is terminated and the FM broadcast is received from the affiliated broadcasting station.

On the other hand, if the reception state is not good, the process moves from step S44 to step S45, and the value of a is incremented. Then, in step S46, a
Is compared with the value of A, and when the value of a is smaller than A,
That is, when there is a priority station whose reception state has not been checked, the process returns to step S43 to check the reception state of the next priority station.

In this way, a search is made for a series broadcast station having a good reception state among the priority stations, and if a series broadcast station having a good reception state is found, FM broadcasts are received from the series broadcast station.

On the other hand, if a broadcast station having a good reception state cannot be found among the priority stations, the flow shifts from step S46 to step S47 to check the reception state of the non-priority station. That is, in step S47, priority 1 (b =
Check the reception status of the non-priority station in 1), and check in step S4
At step 8, the reception status is determined. If it is determined in step S48 that the reception state is good, the process ends and the FM broadcast is received from the non-priority station. On the other hand, if the reception state of the non-priority station is poor, the flow shifts to step S49 to set b
Increments the value of. Then, in step S50, the value of b is compared with the value of B. If the value of b is smaller than the value of B, that is, if there is a non-priority station for which the reception state has not been checked, the process proceeds to step S43. return,
A search is again made for a station having a good reception state from the priority stations. This is because when checking the reception status of the priority station, the vehicle may temporarily pass through a place where radio waves are difficult to reach, such as a valley of a building or under a guard, and determine that the reception status is poor. is there.

If a broadcast station having a good reception state cannot be found even if the reception state of the priority station is checked again, step S
The process proceeds from step 46 to step S47 to check the reception state of the next non-priority station (priority level 2).

For example, as shown in FIG. 11, it is assumed that the vehicle is traveling on a road indicated by a thick line in the figure, and the current position of the vehicle is the position of point A. In addition, the frequency of the affiliated broadcasting stations a to f is indicated in the FM multiplexed affiliated broadcasting station information, and among these, the affiliated broadcasting stations a, b, c, and d are located at positions indicated by a to d in the figure. I do. Further, it is assumed that elliptical lines in the figure indicate service areas of affiliated broadcasting stations a to d, respectively.

In this case, in the present embodiment, the affiliated broadcasting stations a, b, and c at which sufficient electric field intensity is obtained at the position of point A are set as priority stations, and d, e, and f are set as non-priority stations. In addition, priority is given to the affiliated broadcasting stations a, b, and c in order from the point A, and the affiliated broadcasting station b is assigned the priority 1, the affiliated broadcasting station c is assigned the priority 2, and the affiliated broadcasting station a is assigned the priority. The priority is 3.
Priorities are also assigned to the affiliated broadcasting stations d, e, and f, which are non-priority stations. The affiliated broadcasting station d has a priority of 1, the affiliated broadcasting station e has a priority of 2, and the affiliated broadcasting station f has a priority of 3. And
When the reception state of the currently receiving FM broadcast deteriorates, a search is made for a broadcasting station having a good reception state in the order of b, c, a, d, b, c, a, e,.

As described above, in the FM broadcast automatic tracking method according to the present embodiment, each of the series broadcast stations included in the FM multiplexed series broadcast station information is assigned to the priority station based on the current position of the vehicle and the broadcast station data. And the non-priority stations, and rearranged in the order of the priority with the priorities. The rearranged affiliated broadcasting station information is stored in the RAM 45. Then, when the reception state of the currently receiving FM broadcast deteriorates, the reception state is checked in order from the priority station to search for a broadcasting station with a good reception state. Therefore, usually, the broadcast station having the highest electric field strength at the current position of the vehicle, that is, the broadcast station having the highest priority is selected as the substitute station, and the switching of the reception frequency is completed in a short time.

[0061]

As described above, according to the present invention,
The system acquires the broadcast station information multiplexed on the FM broadcast, sorts and stores the broadcast station information in the order of priority based on the current position of the vehicle detected by the navigation device, and stores the FM broadcast currently being received. If the receiving condition of the receiving device deteriorates, a search is made for a broadcasting station having a good receiving condition in the order of priority, so that a sequence broadcasting station having a good receiving condition can be searched in a short time, and the time required for switching the receiving frequency is short. .

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an FM broadcast receiving system that realizes an FM broadcast automatic tracking method according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing broadcast station data stored in a CD-ROM in the first embodiment.

FIG. 3 is a block diagram showing an FM radio receiver 30.

FIG. 4 is a flowchart showing an automatic FM broadcast tracking method according to the first embodiment, showing an operation from reception of affiliated broadcast station data to storage in a RAM.

FIG. 5 is a schematic diagram showing sequence broadcast station information transmitted by FM multiplexing.

FIG. 6 is a schematic diagram showing affiliated broadcasting station information after rearrangement by the navigation device.

FIG. 7 is a flowchart showing a method of automatically following an FM broadcast according to the first embodiment, showing an operation when a reception frequency is changed.

FIG. 8 is a schematic diagram showing broadcast station data stored on a CD-ROM in the second embodiment.

FIG. 9 is a schematic diagram showing affiliate broadcast station information sent from a navigation device to an FM radio receiver in the second embodiment.

FIG. 10 is a flowchart showing an FM broadcast automatic tracking method according to the second embodiment, showing an operation when a reception frequency is changed.

FIG. 11 is a diagram illustrating a method for automatically following an FM broadcast according to a second embodiment.

[Explanation of symbols]

 Reference Signs List 10 navigation device, 11 CD-ROM, 14 GPS receiver, 15 self-contained navigation sensor, 17 control unit, 30 FM radio receiver, 32 front end, 35 intermediate frequency amplifier / detector, 36 noise canceller / stereo demodulation circuit, 42 FM Multiplex decoder, 43 synchronization / error correction unit, 44 control unit, 45 RAM.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tadashi Suzuki 1-1-8 Nishigotanda, Shinagawa-ku, Tokyo Alpine Inc. (72) Inventor Koji Watanabe 1-1-18 Nishigotanda, Shinagawa-ku, Tokyo Alpine, Inc. F term (reference) 2F029 AA02 AB01 AB07 AB09 AB13 AC02 AC09 AC14 AC19 AD01 5J103 AA13 CA04 CB04 GA07 GA11 GB04 5K061 AA03 AA09 BB04 CC20 FF13 JJ07

Claims (5)

[Claims] 1. An FM broadcast automatic tracking method for an FM broadcast receiving system comprising a navigation device provided with a vehicle position detecting means and an FM radio receiver, comprising: transmitting broadcast station data including position data of the FM broadcast station; It is stored in the navigation device, and acquires the series broadcast station information multiplexed to the FM broadcast by the FM radio receiver. Each of the series broadcast station information and the broadcast station data included in the series broadcast information by the broadcast station data The FM radio receiver determines the priority order of the affiliated broadcast stations, and when the reception state of the FM broadcast being received deteriorates, the FM radio receiver checks the reception state in order from the broadcast station with the highest priority, and the broadcast station with the good reception state A method for automatically following FM multiplex broadcasts, comprising: 2. The system according to claim 1, wherein the priority is determined by calculating a distance between a current position of the vehicle detected by the navigation device and each of the affiliated broadcasting stations, and determining the priority in order from the current position of the vehicle. FM automatic tracking method as described in the above. 3. The broadcasting station data includes transmission output data of each broadcasting station, and the priority is calculated by calculating an electric field intensity of each affiliated broadcasting station at a current position of the vehicle detected by the navigation device. 2. The FM broadcast automatic tracking method according to claim 1, wherein the determination is made in the descending order. 4. An FM broadcast automatic tracking method for an FM broadcast receiving system comprising a navigation device provided with a vehicle position detecting means and an FM radio receiver, wherein the broadcast station data including the position data of the FM broadcast station is transmitted. It is stored in the navigation device, and acquires the series broadcast station information multiplexed to the FM broadcast by the FM radio receiver. Each of the series broadcast station information and the broadcast station data included in the series broadcast information by the broadcast station data The affiliated broadcasting stations are classified into a priority station and a non-priority station, and the priority order of each affiliated broadcasting station is determined. When the receiving state of the FM broadcast being received becomes poor, the FM radio receiver determines the priority station. A method for automatically following an FM broadcast, comprising: checking a receiving state in order from a broadcasting station having a higher priority; and searching for a broadcasting station having a good receiving state. 5. When a broadcast station having a good reception condition cannot be searched from among the priority stations, a broadcast station having a good reception condition is searched for from the non-priority stations, and a reception station among the non-priority stations is received. 5. The FM broadcast automatic tracking method according to claim 4, wherein, when a broadcast station having a good condition cannot be searched, a broadcast station having a good reception condition is further searched from among the priority stations.