JP6128544B2 - In-vehicle digital broadcast receiver - Google Patents

Description

  The present invention relates to an in-vehicle digital broadcast receiver mounted on a vehicle, and more particularly, to a channel search or scan technique for digital television broadcast.

  A full-segment and / or one-segment terrestrial digital broadcast can be received by the in-vehicle digital broadcast receiver. In digital terrestrial broadcasting, the channel frequency varies depending on the area. In general, in-vehicle digital broadcast receivers prepare channels that can be received according to the area and a channel list that includes those frequencies. The broadcast of the selected channel is received while referring to the list. The channel list is created or updated by executing a channel search or scan (hereinafter collectively referred to as channel search). For example, the channel search sweeps the frequency from the lower limit frequency to the upper limit frequency, and the channel has good reception sensitivity. Is detected.

  In order to efficiently perform channel search, a digital broadcast receiving apparatus that performs channel selection determination by excluding channels already stored in the channel list has been proposed in Patent Document 1. Further, in Patent Document 2, when searching for a channel number of a digital television broadcast wave that can be received by a digital tuner in a portable information terminal device, the channel number of an analog television broadcast wave that has already been extracted is subject to channel search. When searching for analog TV broadcast wave channel numbers that can be received by an analog tuner, channel numbers that have already been extracted are excluded from the channel search target. The search target is eliminated, and the time required for the channel search is shortened.

JP 2009-260812 A JP 2007-208563 A

  As multi-function mobile phones represented by smartphones become popular, the frequency of using smartphones in cars is increasing. The smartphone is equipped with a communication function such as a 3G line and wireless data communication, and it is possible to perform data communication via a voice call, the Internet, or the like using these. In addition to being used alone, a smartphone can be connected to an in-vehicle device to provide information from the smartphone to the in-vehicle device, remotely control the smartphone from the in-vehicle device, or change the smartphone screen to the in-vehicle device. It is possible to zoom in on the display.

  Against this background, smartphones and in-vehicle devices on mobile bodies will be required to improve their ability to communicate large amounts of data at high speed. Digital terrestrial broadcasting is one way to achieve this. The effective use of the empty frequency band is under consideration. In other words, the frequency band of terrestrial digital broadcasting is currently restricted for use for other purposes by law, etc., but there are unused channel frequency bands depending on the area. This is to make it available for wireless communication such as a wireless device / wireless base station other than broadcasting.

  Originally allocated for a certain purpose such as broadcasting, a frequency band that can be used for other purposes depending on geographical conditions and temporal conditions is called a white space. White space is being considered for secondary use by other systems for broadcasting and communication purposes when the frequency is not used or when the influence on the original system is sufficiently small. Currently, assuming secondary usage of frequencies in the terrestrial digital broadcasting band, wireless devices inquire about white space in the white space database installed on the Internet, set the operating frequency based on the results, and communicate Demonstration experiments of wireless communication networks that can be started are being conducted.

  FIG. 1A shows an example in which a frequency band of an unused channel of terrestrial digital broadcasting is used for wireless communication of an electronic device in a vehicle. A white space database (hereinafter referred to as a white space DB) 10 provides frequency information of unused channels corresponding to an area to the public via the Internet 12 or the like. A smart phone 20 as a wireless device is brought into the vehicle, and the smart phone 20 uses the 3G line and other lines 22 to inquire the white space DB 12 on the Internet 12 for the white space, and relates to the white space obtained therefrom. Based on the information, a frequency band of a channel that is not used in terrestrial digital broadcasting is used for the wireless communication 24. The wireless communication 24 enables connection with the Internet 12 and connection with the in-vehicle digital broadcast receiver 30.

  FIG. 1B shows an example in which a white space is used in a wide-area wireless communication network. The plurality of radio base stations 40A to 40D can perform network communication with each other, and one of these radio base stations 40A to 40D inquires the white space DB 10 on the Internet 12 for the white space, and based on the result, The frequency band of the channel used is used for radio communication of each radio base station. In this case, the frequency bands used by the radio base stations 40A to 40D are set differently. In the example of the figure, the wireless base station 40C establishes wireless communication with the plurality of smartphones 20, 20A to 20C, and the smartphone 20 brought into the vehicle 32 can wirelessly communicate with the nearest wireless base station 40C. .

  When wireless communication is performed using the band of terrestrial digital broadcasting, the frequency band to be used is determined with reference to the white space, so that it is considered that there is little influence on viewing the broadcast. However, since the in-vehicle digital broadcast receiver 30 performs a channel search to update the channel list as the vehicle moves, the wireless communication channel (frequency) used in the smartphone 20 becomes an obstacle. Thus, a frequency that does not need to be detected is detected by the channel search, and as a result, it takes time to determine whether or not there is a channel.

  FIG. 2 is a flow showing the operation of the channel search. The channel search is automatically performed at regular time intervals or is performed by a user operation. When the search is started, the frequency is first set (S100). For example, in terrestrial digital broadcasting, channels from “13” to “52” are assigned to the UHF frequency band. Therefore, a lower limit or upper limit frequency corresponding to channel “13” or “52” is set first. The

  Next, the presence / absence of a channel is determined based on the reception intensity of broadcast waves, the CN ratio, or the BER (error rate), and further, it is determined whether digital terrestrial broadcasting is based on the presence / absence of TMCC (Transmission and Multiplexing Configuration Control). The If a channel and TMCC are detected (S102), it is determined that the channel is a digital terrestrial broadcast channel (S108), and this channel is newly registered in the channel list or the previous channel is updated. If the upper or lower frequency has not been reached (S112), the next frequency is set (S100), and the channel search is continued. If neither channel nor TMCC is detected (S104), since no receivable signal exists, it is determined that there is no channel (S110), and the next search is performed. On the other hand, if a TMCC is not detected even though a channel is detected, detection of TMCC is repeated for a certain period, and if no TMCC is detected within the certain period, a time-out process is performed (S106). ), It is determined that there is no channel (S110). As described above, due to the interference of radio waves in the frequency bands used for the wireless communication of the smartphone 20 and the radio base station 40, the in-vehicle digital broadcast receiver 30 is in spite of the fact that those frequency bands are white space. A time-out time is required until a channel is detected as if there is a digital broadcast channel and it is finally determined that there is no channel. As a result, a time required for channel search becomes long.

  The present invention solves such a conventional problem, and when an unused frequency band used in broadcasting or the like is used in another wireless device or the like, it does not detect radio waves in the unused frequency band. An object of the present invention is to provide an in-vehicle digital broadcast receiver capable of performing channel search without delay.

  An in-vehicle electronic device according to the present invention has a function of receiving a digital TV broadcast. The in-vehicle electronic device includes a receiving unit that receives the digital TV broadcast, a search unit that searches for a channel of the digital TV broadcast, Acquisition means for acquiring frequency information of unused channels of digital television broadcasting in an existing area, and control of the search means so that channel search is executed by excluding frequencies of unused channels based on the frequency information. Control means.

  Preferably, the on-vehicle electronic device further includes a communication unit that wirelessly communicates with an external device, the communication unit performs wireless communication using a frequency of an unused channel based on the frequency information, and the search unit includes the search unit The frequency used by the communication means is excluded from the channel search. Preferably, the search means excludes a frequency used in a radio located in the same vehicle as the in-vehicle electronic device from the channel search. In a preferred example, when the frequency information includes position information of a radio or a radio base station that uses a frequency of an unused channel, the search means is within a certain distance from the position of the in-vehicle electronic device based on the position information. The frequency used in the radio or base station is excluded from the channel search. In a preferred example, when the frequency information includes power information of radio waves of a radio or a radio base station, the search means is used in a radio or radio base station whose power is a predetermined value or more based on the power information. Frequency to be excluded from channel search. In a preferred example, when the frequency information includes communication period information from communication start to communication end of a radio device or a radio base station, the search means is a radio device within the communication period based on the communication period information or The frequency used in the radio base station is excluded from the channel search.

  The wireless communication system of the present invention includes the on-vehicle electronic device having the above-described configuration and an information server that provides the frequency information, and the acquisition unit acquires the frequency information from the information server.

  According to the present invention, by acquiring frequency information of unused channels of digital television broadcasting, and searching for channels by excluding frequencies of unused channels based on the frequency information, Even if the frequency is used by another wireless device or the like, since the frequency is not detected, the time required for the channel search can be shortened.

FIG. 1A is an example when a frequency band of an unused channel of digital terrestrial television broadcasting is used for a wireless communication network. FIG. 1A is an example of an in-vehicle wireless communication network, and FIG. It is an example of a network. It is a flowchart explaining the channel search operation | movement of the conventional vehicle-mounted digital broadcast receiver. It is a block diagram which shows the structure of the terrestrial digital broadcast receiver which concerns on the Example of this invention. It is a block diagram which shows the functional structure of the channel search of the terrestrial digital broadcast receiver which concerns on the Example of this invention. It is a flow which shows the acquisition example of the information regarding a white space from white space DB. 4 is a flowchart illustrating an operation for channel search according to the first embodiment of the present invention. FIG. 7A shows an example of a channel search timing chart according to the first embodiment, and FIG. 7B shows an example of a channel search timing chart according to the second embodiment. It is a figure explaining an example of the information regarding the white space by the 3rd Example of the present invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. Here, as an in-vehicle electronic device, an in-vehicle digital broadcast receiver that receives digital terrestrial television broadcasting is illustrated, but the present invention is not limited to a digital broadcast receiver, and has such a digital broadcast reception function. Including electronic devices. Accordingly, the in-vehicle electronic device of the present invention may be equipped with a navigation function, an audio data reproduction function, a video data reproduction function, a function for communicating with other electronic devices, in addition to the digital terrestrial broadcast reception function. Good. In addition, although an example in which a smartphone is connected to an in-vehicle digital broadcast receiver as an in-vehicle wireless communication network is shown, a wireless device or a communication device constituting the network is an information terminal or personal computer having a wireless communication function in addition to the smartphone. It may be.

  FIG. 3 is a block diagram showing a schematic configuration of the in-vehicle digital broadcast receiver according to the embodiment of the present invention. The in-vehicle digital broadcast receiver 100 according to the present embodiment is processed by a receiver 120 that receives a digital broadcast signal from an antenna 110, a data processor 130 that processes a signal received by the receiver 120, and a data processor 130. An output unit 140 that outputs audio data and image data, a control unit 150 that controls each unit, a storage unit 160 that stores programs and data, an input unit 170 that receives operation information from a user, an external device, and the like by wire or wireless A data communication unit 180 that performs data communication is included.

  The receiving unit 120 includes a tuner that receives a broadcast signal having a frequency of a selected channel in response to a user instruction from the input unit 170. The data processing unit 130 is an A / D converter that converts the analog signal received from the receiving unit 120 into a digital signal, a demodulating unit that performs OFDM demodulation and TMCC demodulation of the received signal, frequency / time interleaving of the demodulated signal, error Decoding section that performs correction, etc., audio stream multiplexed on the decoded transport stream (TS) signal, demultiplexer that separates the image stream and data stream, audio stream, image stream, and data stream are each decoded It includes a decoding unit and the like. The output unit 140 includes a D / A converter that converts a digital audio signal into an analog audio signal, a speaker that outputs the analog audio signal, a drawing processing unit that draws an image signal on a display, a display, and the like.

  The control unit 150 includes processing units such as a microcontroller and a microprocessor, and controls each unit by executing a program. The program data is loaded from the memory in the control unit 150 or the storage unit 160. The control unit 150 mainly controls the operation of the tuner of the receiving unit 120, the operation of demodulation and decoding processing of the data processing unit 130, and the like. Furthermore, the control unit 150 executes a channel search before starting reception, or executes a channel search automatically or manually while the vehicle is moving, and creates a channel list. The channel list is referred to when the selected channel is received, and the control unit 150 causes the tuner to receive a broadcast signal having the frequency of the selected channel.

  The storage unit 160 can store various data and program data, and stores a channel list created by the control unit 150, for example. Furthermore, as will be described later, the storage unit 160 stores unused frequency information that is not assigned to a digital terrestrial broadcast channel in an area where the vehicle is located, that is, information related to white space. In a preferred embodiment, the information on the white space is acquired via the data communication unit 180 via an external device or from the white space DB on the Internet, and whenever the area where the vehicle is located is changed, the white space is related. Information is updated.

  The input unit 170 includes an interface for receiving an instruction from the user, for example, a mouse, a remote controller, a touch panel, and the like. The data communication unit 180 enables wired or wireless data communication such as wireless LAN, WiFi, WiMAX, USB communication, and Bluetooth (registered trademark).

  FIG. 4 is a block diagram illustrating a functional configuration of the channel search executed by the control unit 150 of the present embodiment. The channel search 200 holds information on a frequency of a channel that is not used in digital terrestrial broadcasting in an area where the vehicle is located, that is, a white space acquisition unit 210 that acquires information on a white space, and information on the acquired white space. A white space holding unit 220, a search execution unit 230 that executes a channel search by excluding frequencies of unused channels based on information about the held white space, and a channel list creation that creates a channel list based on the channel search result Part 240.

  The white space acquisition unit 210 acquires information regarding the white space from the outside via the data communication unit 180. For example, in the case of a network for in-vehicle wireless communication as shown in FIG. 1A, the data communication unit 180 is wirelessly connected to the smartphone 20 and information regarding the white space provided by the white space DB 10 via the smartphone 20 is obtained. Can be acquired. Alternatively, the data communication unit 180 can directly access the white space DB 10 on the Internet 12 and acquire information on the white space therefrom.

  FIG. 5 shows an example of acquiring information related to white space. In the network environment shown in FIG. 1A, the smartphone 20 is assumed to have an application for acquiring information related to white space. When establishing wireless communication with another device or network, the smartphone 20 activates an application that acquires information regarding the white space. Next, the smartphone acquires the current position information from the GPS position information or the like (S200), and requests the white space DB 10 on the Internet 12 to distribute information regarding the white space. This request includes location information of the smartphone. In response to the request, the white space DB 10 transmits information regarding the white space in the area corresponding to the position of the smartphone 20 to the smartphone 20. The information regarding the white space includes, for example, information on the frequency of channels that are not used for terrestrial digital broadcasting in the area. Or, conversely, it may be information on the frequency of a channel used in terrestrial digital broadcasting in the area. Such frequency information is provided with position information including latitude and longitude for identifying the area, and when the smartphone 20 determines that it has deviated from the area based on the position information, Get information about white space again.

  When the smartphone 20 acquires information about the white space (S202), next, a frequency for wireless communication with the in-vehicle digital broadcast receiver 100 is set from a desired frequency band in the white space (S204). Next, the smartphone 20 establishes wireless communication with the in-vehicle digital broadcast receiver 100. When the wireless communication between the smartphone 20 and the in-vehicle digital broadcast receiver 100 is established, the white space acquisition unit 210 of the in-vehicle digital broadcast receiver 100 requests the smartphone 20 to transmit information related to the white space. In response, the smartphone 20 transmits information regarding the white space to the in-vehicle digital broadcast receiver 100. In this way, information on the white space is acquired, and the acquired information on the white space is held by the white space holding unit 220.

  In the above example, the information related to the white space is acquired via the smartphone 20, but the in-vehicle digital broadcast receiver 100 directly accesses the white space DB 10 on the Internet 12 by the data communication unit 180, and from there, the white space is related. Information may be acquired.

  Next, channel search in the in-vehicle digital broadcast receiver of this embodiment will be described with reference to the flowchart of FIG. First, the search execution unit 230 reads information on the white space held by the white space holding unit 220 (S300). Next, the frequency of the channel that is not used for terrestrial digital broadcasting in the area is extracted from the information regarding the white space (S302). Next, the search execution unit 230 sets the frequency by excluding the frequency of the unused channel from the search target frequency (S304). In digital terrestrial broadcasting, channels from “13” to “52” are assigned to the UHF frequency band, and the frequency is set from this frequency band by excluding the frequency band that can be secondarily used in white space.

  Next, the search execution unit 230 determines whether or not the reception sensitivity is good from the reception intensity, CN ratio, or error rate of the broadcast signal, and detects the presence or absence of a channel. Further, the presence or absence of TMCC is detected by TMCC demodulation or decoding. If the presence of a channel is detected and the TMCC is detected (S306), it is determined that a terrestrial digital broadcast channel is detected (S308). If the presence of a channel is not detected, TMCC is also not detected. In this case, it is determined that there is no channel for terrestrial digital broadcasting (S310). Next, the search execution unit 230 determines whether or not the search has ended. If the search has not ended, the frequency is set by increasing or decreasing the frequency value, and the next search is performed. This setting also excludes white space frequencies. Thus, in the frequency band from UHF channels “13” to “52”, the channel search is performed by excluding the white space frequency band, and based on the result, the channel list creation unit 240 detects the detected channel. And create or update a channel list that contains the frequency.

  FIG. 7A shows an example of channel search. Here, it is assumed that in the area A, the frequency bands of the channels “20” to “25” and “40 to 45” of the digital terrestrial broadcasting are unused in the area A based on the information regarding the white space. In this case, in the channel search, frequencies corresponding to the channels “13” to “20”, “26” to “39”, and “46” to “52” are searched, and the channel “ The frequencies “20” to “25” and “40 to 45” are excluded from the search.

  In the channel search of the present embodiment, the radio frequency set by the smartphone 20 is temporarily excluded from the channel search in the in-vehicle wireless communication network environment as shown in FIG. The radio frequency is not detected as a channel. As a result, as shown in FIG. 2, the time-out process until the presence / absence of TMCC detection for determining whether or not the channel is a terrestrial digital broadcast is not required, and the time required for the channel search can be shortened.

  In the network environment for wide area wireless communication as shown in FIG. 1B, each frequency band used in each of the radio base stations 40A to 40D is included in the frequency band of white space. In the channel search of the in-vehicle digital broadcast receiver 100, the radio frequency band used in the radio base stations 40A to 40D is excluded from the search, so that the channel search is disturbed by the radio frequency of the radio base station, or the radio base station Therefore, the channel search time can be shortened.

  Next, a second embodiment of the present invention will be described. In the first embodiment, all unused frequency bands of the white space provided from the white space DB are excluded from the channel search. However, in actuality, only the frequency band that interferes with the in-vehicle digital broadcast receiver is the channel. It is sufficient to exclude from the search. On the other hand, when diversity reception is performed, there is a possibility that even a very weak broadcast wave within the white space can be received. Therefore, in the second embodiment, the frequency band excluded in the channel search is limited to the frequency band that is actually affected.

  In the second embodiment, in the in-vehicle wireless communication network environment as shown in FIG. 1A, the white space acquisition unit 210 acquires information on the radio frequency set by the smartphone 20 existing in the same vehicle. For example, the acquisition method requests transmission of information on the radio frequency set in the smartphone 20 via the data communication unit 180. Alternatively, when the smartphone 20 and the in-vehicle digital broadcast receiver 100 have established wireless communication, information on the radio frequency set or used by the data communication unit 180 is acquired.

  The search execution unit 230 excludes a frequency band that is a logical product of the frequency of the white space and the radio frequency set by the smartphone 20 from the channel search. When the smartphone 20 and the in-vehicle digital broadcast receiver 100 exist in the same vehicle, the radio wave of the frequency used by the smartphone 20 has an electric field strength that can be detected by channel search, but the frequency used by the smartphone is a channel. By excluding from the search, detection of the radio frequency of the smartphone is prevented.

  FIG. 7B shows an example of the channel search of the second embodiment. Here, in the area A, the terrestrial digital broadcast channels “20” to “25” and “40 to 45” are unused frequencies and the radio frequency set by the smartphone 20 is the channel “ 23 ". In this case, in the channel search, the channel “23” is excluded from the search, and the channels “20 to 22”, “24”, “25”, and “40 to 45” of other unused frequencies are searched. Become. In addition, when there is another smartphone or wireless device in the vehicle and it uses the frequency band of channel “43”, the frequencies of channels “23” and “43” are excluded from the search in the channel search. It will be.

  When the smartphone 20 uses the white space frequency, the wireless frequency of the smartphone is always included in the frequency band of the white space. Therefore, the in-vehicle digital broadcast receiver does not necessarily receive information on the white space from the white space DB 10. Don't need to get.

  Next, a third embodiment of the present invention will be described. In the first and second embodiments, the example of acquiring frequency information of unused channels in the area has been described. However, in the third embodiment, information on white space is not used as shown in FIG. It includes information such as the frequency of the channel used, the radio / radio base station communication period (start-end), the radio / radio base station power, and the radio / radio base station position (latitude / longitude).

  In the wide area wireless communication network as shown in FIG. 1B, the white space DB 10 sends information on the white space as shown in FIG. 8 via the Internet 12 to the wireless base station 40, the smartphone 20, or the in-vehicle digital broadcast receiver 100. Can be provided. The in-vehicle digital broadcast receiver 100 excludes the frequency used by the radio base station 40 </ b> C with which the smartphone 20 existing in the same vehicle is performing radio communication from the channel search. Radio waves of frequencies used in the other radio base stations 40A, 40B, and 40C do not always interfere with the channel search of the in-vehicle digital broadcast receiver 100 depending on the distance from the vehicle position to the radio base station and the power level. Absent.

  Therefore, the search execution unit 230 determines whether or not the positions of the other radio base stations 40A, 40B, and 40D are within a certain distance from the in-vehicle digital broadcast receiver 100, and is used by the radio base stations that are within the certain distance. It is determined that the frequency to be affected affects the channel search, and the frequency band is excluded from the search. In other words, it is determined that the frequencies used by the radio base stations that are separated by a certain distance do not affect the channel search, and those frequencies are included in the channel search target. Of course, when the own vehicle moves and starts radio communication with any of the other radio base stations 40A, 40B, and 40D, the frequency is excluded from the channel search.

  As yet another aspect, the search execution unit 230 determines whether or not the output power of the radio base station radio wave is smaller than a predetermined value. It is determined that the channel search is affected, and the frequency is excluded from the channel search. In this case, it is good also as a weighting requirement in case the distance to a wireless base station is below a fixed distance.

  As yet another aspect, the search execution unit 230 may exclude the frequency used in the radio base station from the channel search according to the communication period of the radio base station. That is, if it is within the communication period, it may be determined that the radio wave of the frequency of the radio base station has an influence on the channel search, and that frequency may be excluded from the channel search.

  Although the preferred embodiments of the present invention have been described in detail, the present invention is not limited to specific embodiments, and various modifications and changes can be made within the scope of the gist of the invention described in the claims. Is possible.

10: White space DB 20: Smartphone 30: In-vehicle digital broadcast receiver 40: Wireless base station 100: In-vehicle digital broadcast receiver 200: Channel search 210: White space acquisition unit 220: White space holding unit 230: Search execution unit 240: Channel list creation section

Claims (6)

An in-vehicle electronic device having a function of receiving a digital television broadcast,
A connection means for connecting an external device having a wireless communication function;
Receiving means for receiving digital television broadcasts;
Search means for searching for digital TV broadcast channels;
An acquisition means for acquiring frequency information of unused channels of digital television broadcasting in an area where an in-vehicle electronic device exists;
Communication means for performing wireless communication using the frequency of the unused channel via the external device;
And control means for controlling the search means as a channel search by excluding the frequency band to be a logical product of the frequencies utilized by the frequency and the external device of said unused channel is performed,
In-vehicle electronic device having An in-vehicle electronic device having a function of receiving a digital television broadcast,
A connection means for connecting an external device having a wireless communication function;
Receiving means for receiving digital television broadcasts;
Search means for searching for digital TV broadcast channels;
An acquisition means for acquiring frequency information of unused channels of digital television broadcasting in an area where an in-vehicle electronic device exists;
Communication means for performing wireless communication using the frequency of the unused channel via the external device;
The search means is controlled so that the channel search is executed by excluding from the channel search the frequency used by the radio or radio base station with which the external device located in the same vehicle as the in-vehicle electronic device performs radio communication. Control means to
In-vehicle electronic device having An in-vehicle electronic device having a function of receiving a digital television broadcast,
  A connection means for connecting an external device having a wireless communication function;
  Receiving means for receiving digital television broadcasts;
  Search means for searching for digital TV broadcast channels;
  An acquisition means for acquiring frequency information of unused channels of digital television broadcasting in an area where an in-vehicle electronic device exists;
Communication means for performing wireless communication using the frequency of the unused channel via the external device;
When the frequency information includes position information of a radio or a radio base station that uses a frequency of an unused channel, it is used by a radio or radio base station within a certain distance from the position of the on-vehicle electronic device based on the position information. Control means for controlling the search means so that the channel search is executed by excluding the frequency to be performed from the channel search;
  In-vehicle electronic device having An in-vehicle electronic device having a function of receiving a digital television broadcast,
  A connection means for connecting an external device having a wireless communication function;
  Receiving means for receiving digital television broadcasts;
  Search means for searching for digital TV broadcast channels;
  An acquisition means for acquiring frequency information of unused channels of digital television broadcasting in an area where an in-vehicle electronic device exists;
Communication means for performing wireless communication using the frequency of the unused channel via the external device;
When the frequency information includes power information of radio waves of a radio or a radio base station, a channel search is performed by excluding from the channel search the frequency used in the radio base station whose power is a predetermined value or more based on the power information. Control means for controlling the search means so that
  In-vehicle electronic device having An in-vehicle electronic device having a function of receiving a digital television broadcast,
  A connection means for connecting an external device having a wireless communication function;
  Receiving means for receiving digital television broadcasts;
  Search means for searching for digital TV broadcast channels;
  An acquisition means for acquiring frequency information of unused channels of digital television broadcasting in an area where an in-vehicle electronic device exists;
Communication means for performing wireless communication using the frequency of the unused channel via the external device;
  When the frequency information includes communication period information from communication start to communication end of the radio or radio base station, the frequency used in the radio or radio base station within the communication period based on the communication period information. Control means for controlling the search means so that the channel search is executed excluding the channel search;
  In-vehicle electronic device having On-vehicle electronic device according to any one of claims 1 to 5 ,
An information server for providing the frequency information,
The acquisition unit is a wireless communication system that acquires the frequency information from the information server.

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