JP2013236311A - On-vehicle digital broadcast receiver and reception channel changeover method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle digital broadcast receiver and a reception channel changeover method capable of selecting an optimum reception channel in accordance with an antenna installation position in a vehicle in addition to a vehicle present position.SOLUTION: An on-vehicle digital broadcast receiver includes: a broadcast area information storage unit 9 for storing reception mode information, which indicates a reception possibility of a one-segment broadcast/full-segment broadcast in accordance with channel information of a receivable broadcast station and an antenna arrangement position, as broadcast area information for each digital broadcast receivable area; and a channel changeover unit 10c for selectively changing over a reception channel corresponding to an antenna installation position on the basis of broadcast area information of a receivable area corresponding to a vehicle present position. A receivable channel is selected in accordance with a vehicle present position and an antenna installation position. Then, a full-segment broadcast is received when an antenna installation position is high and a full-segment broadcast is receivable.

Description

  The present invention relates to an in-vehicle digital broadcast receiving apparatus and a receiving channel switching method, and is particularly suitable for use in an in-vehicle digital broadcast receiving apparatus having a function of appropriately switching a receiving channel as a vehicle moves.

  In recent years, in-vehicle digital broadcast receivers have become widespread. In a vehicle-mounted digital broadcast receiver, if a vehicle moves out of a receivable area while viewing a digital broadcast of a certain channel, the digital broadcast of the channel that has been viewed cannot be received. In response to this problem, there is known a digital broadcast receiving apparatus that can continue receiving digital broadcasts even in a destination area (see, for example, Patent Documents 1 and 2).

  In the receiving apparatus described in Patent Literature 1, it is determined whether or not the current position of the moving body has changed from one region that has been previously divided to another region, and has been determined that the region has changed from one region to another region. In this case, the channel corresponding to the one region is switched to the channel corresponding to the other region.

  In the mobile communication terminal described in Patent Document 2, channel information of broadcast stations that can be received in the area where the mobile communication terminal is located is preset in the storage unit. And based on the channel information preset in this memory | storage part, reception of the broadcast which the user selected is started. Further, in Patent Document 2, the current position information is transmitted to a server including a database in which position information of a plurality of areas and channel information of broadcast stations that can be received in each area are stored in association with each other. It is also described that channel information of broadcast stations that can be received in the area where the mobile communication terminal is located is acquired from the server.

  By the way, Japanese terrestrial digital broadcasting has a structure in which the frequency bandwidth of one channel is divided into 13 segments, of which 12 segments are allocated to high-definition broadcasting and 4 segments are allocated to standard-definition broadcasting. . In addition, only one segment is allocated to broadcasting for mobile terminals such as mobile phones and in-vehicle devices having a small screen from the viewpoint of emphasizing mobility rather than image quality.

  Broadcasting for mobile terminals is referred to as “one-segment broadcasting” by omitting one segment. On the other hand, high-definition broadcasting that broadcasts one program using all 12 segments and standard-definition broadcasting that broadcasts up to three programs using 12 segments are called “full-segment broadcasting”. When receiving a digital broadcast of a channel corresponding to the current position of the vehicle, it is desired to be able to receive as much as possible a full segment broadcast with better image quality than the one-segment broadcast.

  On the other hand, in an in-vehicle digital broadcast receiving apparatus that receives a diversity of digital broadcasts by a plurality of receiving units, a channel list corresponding to the broadcast area is stored, and the channel list is used in the broadcast area of the vehicle. A technique has been proposed in which a reception channel and a reception hierarchy are set according to the current position.

JP 2007-311987 A JP 2007-318365 A

  However, the reception sensitivity of terrestrial digital broadcasting is greatly influenced by the environment around the receiving apparatus, the installation position of the antenna, and the like. In the above conventional technique, although a reception channel (including a reception hierarchy of full-segment broadcasting or one-segment broadcasting) can be set according to the current position of the vehicle, the installation position of the antenna is not considered. For this reason, there has been a problem that even if a channel list corresponding to a broadcast area is selected, it is not always possible to select an optimum reception channel for receiving full-segment broadcasting as much as possible.

  The present invention has been made to solve such a problem, and in addition to the current position of the vehicle, an optimal reception channel for receiving full-segment broadcasting as much as possible according to the installation position of the antenna in the vehicle. The purpose is to allow selection.

  In order to solve the above-described problems, the present invention can receive one-segment broadcasting or receive full-segment broadcasting depending on the channel information of the receivable broadcasting station and the installation position of the antenna for each receivable area of digital broadcasting. A reception channel corresponding to the installation position of the antenna based on the broadcast area information storage unit storing the reception mode information indicating whether the reception is possible as broadcast area information and the broadcast area information of the receivable area corresponding to the current position of the vehicle And a channel switching unit for selecting and switching.

  According to the present invention configured as described above, among the receivable channels indicated by the broadcast area information of the broadcast area according to the current position of the vehicle, the receivable channel according to the installation position of the antenna in the vehicle Will be selected. Even at the same current position, whether or not full-segment broadcasting can be received depends on the ground height at which the antenna is installed. According to the present invention, when the installation position of the antenna is high and the full-segment broadcasting can be received, the full-segment broadcasting is received. Therefore, in addition to the current position of the vehicle, the optimum reception channel is selected according to the installation position of the antenna. And the reception rate of full-segment broadcasting can be increased.

It is a figure which shows the structural example of the vehicle-mounted digital broadcast receiver by this embodiment. It is a figure which shows an example of the broadcast area information by this embodiment. It is a figure which shows the receiving area according to vehicle height of full segment broadcasting / one segment broadcasting in this embodiment. It is a flowchart which shows the operation example of the vehicle-mounted digital broadcast receiver by this embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a configuration example of an in-vehicle digital broadcast receiving apparatus according to the present embodiment. In FIG. 1, an antenna 1 receives radio waves of digital broadcasting. The tuner 2 selectively extracts a broadcast wave signal having a reception frequency matching a desired channel from the digital broadcast radio wave received by the antenna 1 and outputs the broadcast wave signal.

  The OFDM demodulator 3 demodulates the broadcast wave signal received by the tuner 2 by OFDM (Orthogonal Frequency-Division Multiplexing) to obtain a transport stream (hereinafter referred to as TS). The error correction unit 4 corrects errors generated in the transmission path for the TS demodulated by the OFDM demodulation unit 3.

  The demultiplexer unit 5 obtains a video stream, an audio stream, and a data stream by separating the multiplexed TS. Then, the demultiplexer unit 5 outputs the audio stream to the audio decoder unit 6, outputs the video stream to the video decoder unit 7, and outputs the data stream to the data decoder unit 8. Here, the data stream includes information on the receiving channel such as the broadcasting station name, TSID, affiliated station ID, and physical channel, and information on the program such as the program name, broadcasting date and time, and description of the contents.

  The audio decoder unit 6 decodes the input audio stream and outputs it as an audio signal. The video decoder unit 7 decodes the input video stream and outputs it as a video signal. The data decoder unit 8 decodes the input data stream and outputs the decoded data stream to the control unit 10 as control data.

  The broadcast area information storage unit 9 receives, for each digital broadcast receivable area, a broadcast station capable of receiving digital broadcasts, channel information indicating the channels, and one-segment broadcasts according to the antenna installation position (ground height). Reception mode information indicating whether it is possible to receive full-segment broadcasting is stored as broadcast area information.

  FIG. 2 is a diagram illustrating an example of broadcast area information. As shown in FIG. 2, the broadcast area information stored in the broadcast area information storage unit 9 includes, as items, a broadcast station name, a TSID, an affiliated station ID, a reception mode, and a physical channel. Among these, the above-described channel information is constituted by the broadcasting station name, TSID, affiliated station ID, and physical channel.

  Here, the reception mode is information indicating whether the one-segment broadcasting can be received or the full-segment broadcasting can be received according to the ground height where the antenna is installed. In general, whether or not full-segment broadcasting can be received varies depending on the ground height at which the antenna is installed. This is because the reception sensitivity is improved when the antenna is installed at a high position, and the reception sensitivity is deteriorated when the installation position is low. On the other hand, the ground height where the antenna is installed varies depending on the vehicle type. That is, in the case of a vehicle type with a high vehicle height, the installation position of the antenna is high, and the area where full-segment broadcasting can be received increases. On the other hand, in the case of a vehicle type with a low vehicle height, the antenna installation position is low, and the area in which full-segment broadcasting can be received decreases. Therefore, in this embodiment, the reception possibility of one-segment broadcasting or full-segment broadcasting is shown as the reception mode according to the vehicle height.

  The physical channel is information indicating the channel (reception frequency) of the broadcasting station. The broadcast station name indicates the name of a broadcast station that can receive a digital broadcast. The TSID is an ID unique to the broadcasting station, and is assigned a unique ID nationwide. The affiliated station ID is an ID indicating which affiliated station the broadcast station belongs to. For example, when the affiliated station ID = 0, NHK general is assigned, when affiliated station ID = 1, NHK education is assigned, and when affiliated station ID = 2, affiliated ID is assigned.

  For example, broadcast stations having the same TSID and different physical channels are in a relay station relationship. In addition, broadcasting stations having different TSIDs but having the same affiliated station ID are in a relationship of affiliated stations. In the example of FIG. 1 and 2 broadcasting stations, It is shown that the broadcasting stations 3 and 4 are affiliated with each other. No. 3 and 4 broadcasting stations, It is shown that the broadcasting station 5 has a relay station relationship with each other.

  In the present embodiment, for example, the nationwide broadcast area is divided into fine meshes, and the broadcast area information shown in FIG. 2 is stored in the broadcast area information storage unit 9 for each mesh (digital broadcast receivable area). Yes. Here, in a single mesh, when a digital broadcast can be received on a plurality of channels by combining a relay station and an affiliated station, a plurality of broadcast area information is stored. In addition, even when the same channel can receive both full-segment broadcasting and one-segment broadcasting, the broadcasting area information is stored in two.

  In the example of FIG. 2, five pieces of broadcast area information are shown. Of these, No. No. 1 broadcasting station and No. 1 broadcasting station. The two broadcasting stations are the same (TSID, affiliated station ID, and physical channel are all the same), but whether full seg broadcasting can be received or not depends on the vehicle height. Broadcast area information is stored in two. No. No. 3 broadcasting station and No. 3 broadcasting station. 4 broadcast stations can receive both full-segment broadcasts and one-segment broadcasts at all vehicle heights, but the broadcast station information is stored in the same broadcast station but divided into two segments: full-segment broadcasts and one-segment broadcasts. .

  The control unit 10 controls the overall operation of the in-vehicle digital broadcast receiving apparatus. That is, the control unit 10 controls operations of the tuner 2, the OFDM demodulation unit 3, the error correction unit 4, the demultiplexer unit 5, the audio decoder unit 6, the video decoder unit 7, and the data decoder unit 8. For example, based on the data stream supplied from the data decoder unit 8, the control unit 10 causes the display (not shown) to display information about the program such as the program name, broadcast date and time, and description of the content.

  Further, the control unit 10 controls switching of the reception channel in the tuner 2. For this switching control, the control unit 10 includes a current position information acquisition unit 10a, a vehicle height information acquisition unit 10b, and a channel switching unit 10c as functional configurations. The current position information acquisition unit 10a acquires current position information from the current position detection device 20 that detects the current position. The current position detection device 20 is provided in an in-vehicle navigation device (not shown).

  The vehicle height information acquisition unit 10b corresponds to the antenna position information acquisition unit of the present invention, and acquires vehicle height information from the system memory 30 as antenna position information regarding the antenna installation position. Since the antenna is generally installed at a high position on the rear glass of the vehicle or on the roof, the vehicle height information is used as the antenna position information in this embodiment. In the system memory 30, vehicle height information corresponding to the vehicle type is stored in advance. The system memory 30 is also provided in an in-vehicle navigation device (not shown).

  The channel switching unit 10c reads the broadcast area information of the receivable area (mesh) corresponding to the current position information acquired by the current position information acquisition unit 10a from the broadcast area information storage unit 9, and based on the read broadcast area information. Then, the reception channel corresponding to the vehicle height information acquired by the vehicle height information acquisition unit 10b is selected and switched.

  At this time, the channel switching unit 10c indicates that it can receive full-segment broadcasting from a broadcasting station that is indicated to be capable of receiving one-segment broadcasting based on the reception mode information included in the broadcast area information. The tuner 2 is controlled so as to select a channel indicated by the channel information with priority given to the broadcast station being broadcast. If the same broadcasting station can receive both one-segment broadcasting and full-segment broadcasting, the tuner 2 is controlled to receive the full-segment broadcasting.

  Also, the channel switching unit 10c selects a broadcast station that is indicated as a relay station rather than a broadcast station that is indicated as an affiliated station by the broadcast station information included in the broadcast area information. The tuner 2 is controlled so that the channel indicated by the channel information is preferentially selected.

  FIG. 3 is a diagram showing reception areas according to vehicle height of full-segment broadcasting / one-segment broadcasting. FIG. 3A shows a reception area related to a vehicle type with a low vehicle height, and FIG. 3B shows a reception area related to a vehicle type with a high vehicle height. In FIG. 3, one set of broadcast area information is stored for one mesh (rectangular region). As shown in FIG. 2, the broadcast area information includes reception mode information indicating whether full segment broadcasting or one segment broadcasting can be received according to the vehicle height. Depending on the vehicle height, the area in which full-segment broadcasting can be received varies depending on the vehicle height-specific reception mode information.

  In FIG. 3, reference numeral 31 is a relay station A full-seg broadcast receivable area (can also receive one-segment broadcasts), 32 is a relay station B full-seg broadcast receivable area (can also receive one-seg broadcasts), and 33 is a one-seg broadcast receivable area ( Full-segment broadcasting cannot be received). Of the one-segment broadcast receivable area 33, between the full-segment broadcast receivable area 31 of the relay station A and the full-segment broadcast receivable area 32 of the relay station B, the one-segment broadcast of the relay station A and the one-segment broadcast of the relay station B There are areas where broadcasts can be received.

  As is clear from a comparison between FIG. 3A and FIG. 3B, in the case of a vehicle type with a high vehicle height, the full-segment broadcast receivable area 31 of the relay station A and the full-segment broadcast receivable area 32 of the relay station B. However, it is wider than the low-car models. In the present embodiment, the channel switching unit 10c controls the tuner 2 so that the full-segment broadcasting is preferentially received in the area where the full-segment broadcasting can be received, so that the vehicle type with a high vehicle height is lower than the vehicle type with a low vehicle height. The reception rate of full-segment broadcasting can be increased.

  FIG. 4 is a flowchart showing an operation example (reception channel switching method) of the in-vehicle digital broadcast receiving apparatus according to the present embodiment. Note that the flowchart shown in FIG. 4 starts when the on-vehicle digital broadcast receiver is turned on.

  First, the current position information acquisition unit 10a acquires the current position information of the vehicle detected by the current position detection device 20 (step S1). And the channel switching part 10c reads the broadcast area information of the receivable area corresponding to the current position information acquired by the current position information acquisition part 10a from the broadcast area information storage part 9 (step S2). Further, the vehicle height information acquisition unit 10b acquires vehicle height information of the vehicle from the system memory 30 (step S3).

  Next, the channel switching unit 10c can receive full-segment broadcasting in the receivable area at the current position based on the broadcast area information read from the broadcast area information storage unit 9 in step S2 and the vehicle height information acquired in step S3. It is determined whether or not there is a broadcasting station (step S4). If there is no broadcast station capable of receiving full-segment broadcasting, the process proceeds to step S7.

  On the other hand, when there is a broadcasting station capable of receiving full-segment broadcasting, the channel switching unit 10c determines whether there is only one broadcasting station capable of receiving full-segment broadcasting (step S5). In the case of only one, the channel switching unit 10c controls the tuning of the tuner 2 so as to receive the full-segment broadcasting of the broadcasting station (step S6). Thereafter, the process proceeds to step S10.

  When there are a plurality of broadcast stations that can receive full-segment broadcasting in the receivable area at the current position, the channel switching unit 10c switches the reception channel from the currently receiving relay station to another relay station based on the broadcast area information. It is determined whether or not (step S7). Here, when the reception channel is switched from the relay station to another relay station, the channel switching unit 10c controls the tuning of the tuner 2 so as to receive the channel of the destination relay station (step S8).

  On the other hand, when the reception channel is switched from the relay station to the affiliated station (when No is determined in step S7), the channel switching unit 10c selects the tuner 2 so as to receive the channel of the source relay station. Is controlled (step S9). After the process of step S6, S8 or S9, the control unit 10 determines whether or not the power source of the in-vehicle digital broadcast receiving apparatus is turned off (step S10). If the power is not turned off, the process returns to step S1. On the other hand, when the power is turned off, the process of the flowchart shown in FIG. 4 ends.

  As described above in detail, according to the present embodiment, for each digital broadcast receivable area, whether one-segment broadcasting can be received or not according to channel information of receivable broadcasting stations and antenna installation position (vehicle height). Based on the broadcast area information storage unit 9 that stores the reception mode information indicating whether the broadcast can be received as broadcast area information, and the broadcast area information of the receivable area corresponding to the current position of the vehicle. A channel switching unit 10c that selects and switches a reception channel (including a reception layer of one-segment broadcasting or full-segment broadcasting).

  According to the present embodiment configured as described above, among the receivable channels indicated by the broadcast area information of the broadcast area corresponding to the current position of the vehicle, according to the installation position (vehicle height) of the antenna in the vehicle. A receivable channel is selected. According to the present embodiment, when the vehicle height is high and the full-segment broadcasting can be received, the full-segment broadcasting is received. Therefore, it is optimal to receive the full-segment broadcasting as much as possible according to the vehicle height in addition to the current position of the vehicle. It is possible to select a proper reception channel and to increase the reception rate of full-segment broadcasting.

  In addition, although the said embodiment demonstrated the example which uses vehicle height information as antenna position information regarding the installation position of an antenna, this invention is not limited to this. For example, vehicle type information may be used instead of vehicle height information. In this case, the reception mode information included in the broadcast area information may be configured to indicate the reception possibility of the one-segment broadcasting / full-segment broadcasting for each vehicle type, but there is a demerit that the amount of information increases. Therefore, the broadcast area information remains the same as that shown in FIG. 2, and table information stored in association with vehicle type information and vehicle height information is prepared separately, and the vehicle type information acquired from the system memory 30 is converted into vehicle height information. It may be.

  Moreover, in the said embodiment, the reception mode information according to vehicle height is memorize | stored in the broadcast area information storage part 9, and it refers to reception mode information according to the vehicle height information which the vehicle height information acquisition part 10b acquires. Although an example of selecting a receivable channel according to the vehicle height information has been described, the present invention is not limited to this. For example, the broadcast area information storage unit 9 included in the in-vehicle digital broadcast receiving device of a certain vehicle type may store broadcast area information indicating only channels that can be received according to the vehicle height of the vehicle type. In this way, the reception mode information indicates only the reception possibility of the one-segment broadcasting / full-segment broadcasting, and the vehicle height information acquisition unit 10b is unnecessary.

  Moreover, although the said embodiment demonstrated the structure with which the broadcast area information storage part 9 was provided in a vehicle-mounted digital broadcast receiver, this invention is not limited to this. For example, the broadcast area information storage unit 9 may be provided in a server that can be connected to a vehicle-mounted digital broadcast receiver via a communication network such as the Internet, and the broadcast area information may be downloaded from the server to the vehicle-mounted digital broadcast receiver. Good.

  In addition, each of the above-described embodiments is merely an example of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed in a limited manner. That is, the present invention can be implemented in various forms without departing from the gist or the main features thereof.

9 Broadcast area information storage unit 10a Current position information acquisition unit 10b Vehicle height information acquisition unit 10c Channel switching unit

Claims (4)

A vehicle-mounted digital broadcast receiver used in a vehicle equipped with a current position detection device for detecting a current position,
For each digital broadcast receivable area, broadcast area channel information of the receivable broadcasting station and reception mode information indicating whether one-seg broadcasting can be received or full-seg broadcasting can be received according to the antenna installation position. A broadcast area information storage unit stored as:
A current position information acquisition unit for acquiring current position information detected by the current position detection device;
A vehicle-mounted digital system comprising: a channel switching unit that selects and switches a reception channel based on the broadcast area information of a receivable area corresponding to the current position information acquired by the current position information acquisition unit Broadcast receiving device. An antenna position information acquisition unit for acquiring antenna position information related to the antenna installation position;
The channel switching unit responds to the antenna position information acquired by the antenna position information acquisition unit based on the broadcast area information of the receivable area corresponding to the current position information acquired by the current position information acquisition unit. The in-vehicle digital broadcast receiving apparatus according to claim 1, wherein a receiving channel is selected and switched. The channel switching unit selects a broadcast station that is indicated to be able to receive full-segment broadcasting by the reception mode information rather than a broadcast station that is indicated to be capable of receiving one-segment broadcasting by the reception mode information. 2. The in-vehicle digital broadcast receiving apparatus according to claim 1, wherein a channel indicated by the channel information is preferentially selected. A method of switching a reception channel by a vehicle-mounted digital broadcast receiver used in a vehicle equipped with a current position detection device for detecting a current position,
A first step in which a current position information acquisition unit of the in-vehicle digital broadcast receiving apparatus acquires current position information detected by the current position detection apparatus;
A second step in which an antenna position information acquisition unit of the in-vehicle digital broadcast receiving apparatus acquires antenna position information related to an installation position of the antenna in the vehicle;
The channel switching unit of the above-mentioned in-vehicle digital broadcast receiver can receive one-segment broadcasts or receive full-segment broadcasts depending on the channel information of the receivable broadcasting stations and the antenna installation position for each digital broadcast receivable area. A third step of reading out broadcast area information of a receivable area corresponding to the current position information acquired in the first step from a broadcast area information storage unit storing reception mode information indicating whether it is possible as broadcast area information. When,
The channel switching unit includes a fourth step of selecting and switching the reception channel corresponding to the antenna position information acquired in the second step based on the broadcast area information read out in the third step. A receiving channel switching method characterized by the above.

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