JP2010161752A - On-vehicle radio device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an on-vehicle radio device preventing degradation of reception performance of on-road unit transmission data by transmission of radio data, and capable of transmitting radio data even in process of receiving on-road unit transmission data. <P>SOLUTION: When reception of VICS data is started by a VICS data reception section 12, a high-speed radio communication section 22 is caused to stop transmission of radio data to overlap reception timing of a specific reception object frame (solid lines in Fig.8) with respect to first VICS data; the high-speed radio communication part 22 is caused to stop transmission of radio data to overlap reception timing of a reception object frame (dotted lines in Fig.8) by using, as the reception object frame, a frame without being used as the reception object frame in the first VICS data with respect to subsequently-received second VICS data; and VICS data are identified from the respective first and second VICS data stored in a memory 12a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention performs transmission of radio data using a receiving unit that receives road unit transmission data wirelessly transmitted from a road unit and a radio signal in a frequency band that interferes with a transmission frequency of a radio signal transmitted from the road unit. And a wireless communication unit.

  As a next-generation high-speed wireless communication technology, there is a wireless communication standard such as WiMAX (registered trademark). Currently, notebook computers, mobile terminals, car navigation devices, and the like that are compatible with such wireless communication standards are being developed.

  As a communication apparatus including a communication unit corresponding to such a wireless communication standard, a communication unit corresponding to each communication method such as CDMA, WiMAX, WiFi (registered trademark) is provided, and information on the base station is stored in the base station database. Register and refer to the base station database to detect or predict a communicable base station. Based on the communication form of the base station, determine whether or not it is possible to establish a communication connection. There is a mobile communication device configured to communicate with a determined base station (see, for example, Patent Document 1).

JP 2007-318354 A

  By the way, the frequency band of the radio transmission signal used in the radio communication standard of the next-generation high-speed radio communication technology is 2545 to 2625 MHz. On the other hand, the radio beacon on-road unit transmits radio traffic information to a navigation device or the like. Since the frequency of the radio signal used in is 2499.7 MHz and the frequencies are close to each other, a radio communication apparatus equipped with a reception function for receiving VICS data and a radio communication function corresponding to the radio communication standard is provided. When trying to configure, when receiving a radio signal wirelessly transmitted from a radio beacon roadside device, there is a concern that the reception performance of VICS data is degraded due to radio wave interference. Note that in wireless communication devices that support the WiMAX standard, the maximum transmission power of wireless transmission signals is as high as about 200 mW, and it has been confirmed that the reception performance of VICS data is reduced due to radio wave interference.

  Therefore, as in the apparatus described in Patent Document 1, if communication is performed by switching to a communication method determined to require communication connection from a plurality of communication methods, the reception performance of VICS data is improved. It is possible to prevent the decrease. For example, when receiving VICS data transmitted from a radio beacon device while prohibiting transmission of wireless data corresponding to the WiMAX standard during reception of VICS data, it is possible to prevent a decrease in reception performance of VICS data. is there.

  However, in the WiMAX standard, uplink and downlink are assigned to wireless data transmission / reception frames, and if wireless data transmission is prohibited, communication error occurs and wireless data cannot be received, so VICS data (roadside equipment transmission data) In addition to receiving wireless data corresponding to WiMAX, it becomes impossible to receive the wireless data. In order to receive one VICS data, a period of about 0.9 seconds is required. For example, when the transmission of wireless data corresponding to WiMAX is prohibited during the reception of one VICS data, 0.9 is required. For example, when transmission of wireless data corresponding to WiMAX is prohibited during reception of two VICS data for about a second, wireless data corresponding to WiMAX cannot be transmitted / received for a relatively long period of time, such as about 1.8 seconds. For example, when wireless data corresponding to WiMAX is received and streaming video is played back, if the reception of wireless data is prohibited for such a period, the playback image of the streaming video will be disturbed, giving the user stress. There is a problem such as.

  The present invention has been made in view of the above problems, and prevents degradation of reception performance of roadside equipment transmission data due to transmission of wireless data, and enables transmission of wireless data even during reception of roadside equipment transmission data. For the purpose.

  In order to achieve the above object, according to the first aspect of the present invention, when it is determined that the reception of the roadside transmission data is started by the reception unit, the first roadside transmission data received by the reception unit is detected. First, specify a frame number of a reception target frame to be intermittently received, and instruct the wireless communication unit to transmit wireless data by reducing the transmission strength of wireless data so as to overlap the reception timing of the specified frame number. 1 transmission control means, first storage means for storing first roadside machine transmission data received by the receiving part, and second roadside received by the receiving part following the first roadside machine transmission data For the machine transmission data, identify the frame number of the reception target frame that is intermittently received as the reception target frame, which is not the reception target frame in the first roadside transmission data, A second transmission control means for instructing the wireless communication unit to transmit the wireless data by reducing the transmission strength of the wireless data so as to overlap the reception timing of the identified frame number; and received by the receiving unit Second storage means for storing second road equipment transmission data, and road equipment transmission for specifying road equipment transmission data from the first and second road equipment transmission data stored in the first and second storage means And a data specifying means.

  According to such a configuration, when it is determined that reception of roadside device transmission data is started by the receiving unit, the frame of the reception target frame that is intermittently received with respect to the first roadside device transmission data received by the receiving unit The wireless communication unit is instructed to transmit the wireless data by reducing the transmission strength of the wireless data so as to overlap the reception timing of the specified frame number, and the first road unit transmission data is specified. Subsequently, for the second roadside equipment transmission data received by the receiving unit, the frame number of the reception target frame that is intermittently received as a reception target frame is specified as the reception target frame in the first roadside equipment transmission data. However, the wireless data transmission strength is reduced so that the wireless data is transmitted so as to overlap the reception timing of the specified frame number. Since the road unit transmission data is specified from the first and second road unit transmission data stored in the first and second storage means, the communication unit is instructed, so the reception performance of road unit transmission data by wireless data transmission Can be prevented, and wireless data can be transmitted even when roadside device transmission data is being received.

  Further, as in the invention described in claim 2, the first transmission control means divides the roadside equipment transmission data received by the receiving unit into continuous frame groups of 5 frames, and for each frame group, For each frame group, the first frame, the third frame, the fifth frame are the first group, the second frame, the fourth frame is the second group, and either the first group or the second group The frame number of the reception target frame is specified so that the second group is a reception target frame, and the second transmission control unit includes a group different from the group specified as the reception target frame by the first transmission control unit. Thus, the frame number of the reception target frame can be specified.

  Further, as in the invention described in claim 3, the wireless communication unit transmits wireless data for 18 frames during the reception period of each frame group of roadside equipment transmission data, and the first and second wireless data are transmitted. When the first group is specified as the reception target frame, the transmission control unit causes the wireless communication unit to transmit wireless data for four frames in the first frame, the third frame, and the fifth frame. When the wireless data of 3 frames is transmitted in the 4th frame and the second group is specified as the reception target frame, the wireless communication unit makes the 1st frame, 3rd frame, 5th frame. The wireless data for three frames can be transmitted in step 4, and the wireless data for four frames can be transmitted in the second frame and the fourth frame.

  According to a fourth aspect of the present invention, the roadside equipment transmission data specifying means performs the first transmission control from the first and second roadside equipment transmission data stored in the first and second storage means. Received at the timing when the transmission intensity of the radio data is reduced by the instruction of the second transmission control means received by the receiving unit at the timing when the transmission intensity of the radio data is reduced by the instruction of the means The road unit transmission data received by the unit can be extracted and combined so as to complement each other by the extracted road unit transmission data, and the road unit transmission data can be specified.

  The first and second transmission control means stop the transmission of the wireless data intermittently as in the invention described in claim 5, thereby more reliably transmitting the on-road equipment transmission data by transmitting the wireless data. Can be prevented from degrading.

  The invention according to claim 6 is characterized in that the road device is a radio beacon road device, and the road device transmission data wirelessly transmitted from the radio beacon road device is VICS data.

  In this way, by applying a radio beacon roadside machine having a relatively narrow area as a reception area to the roadside machine, the VICS data intermittently only during a relatively short period when the vehicle passes through the reception area of the radio beacon roadside machine. Reception can be performed.

  In the invention according to claim 7, the transmission frequency of the radio signal transmitted from the radio beacon roadside device is 2499.7 MHz, and the frequency band of the radio signal transmitted by the radio communication unit is 2545 to 2625 MHz. It is characterized by that.

It is a figure which shows the structure of the vehicle-mounted radio | wireless apparatus which concerns on one Embodiment of this invention. It is a figure for demonstrating the frame structure of VICS data. It is a figure for demonstrating the reception area of a radio beacon roadside machine. It is a figure for demonstrating the frame structure of the radio | wireless data of WiMAX specification. It is a flowchart of a control part. It is a timing chart which shows the relationship between the receiving frame of 1st VICS data, and WiMAX radio | wireless data. It is a timing chart which shows the relationship between the receiving frame of 2nd VICS data, and WiMAX radio | wireless data. It is a timing chart which shows the relationship between each receiving object frame of the 1st and 2nd VICS data.

  The configuration of an in-vehicle wireless device according to an embodiment of the present invention is shown in FIG. The in-vehicle wireless device 1 transmits and receives a VICS data receiving device 10 for receiving VICS data wirelessly transmitted from the radio beacon roadside device 30 and a wireless signal corresponding to a WiMAX (Worldwide Interoperability) standard. A wireless communication device 20 is provided. The VICS data receiving device 10 and the high-speed wireless communication device 20 are connected to the navigation device 40 via a cable. In addition, the rear seat monitor 50 etc. are connected to the navigation apparatus 40 via the in-vehicle network.

  The VICS data receiving apparatus 10 performs processing such as amplification and demodulation on a VICS receiving antenna 11 for receiving a radio signal transmitted from the radio beacon roadside device 30 and a signal input from the VICS receiving antenna 11. The VICS data receiving unit 12 receives the VICS data and sends the received VICS data to the navigation device 40.

  The VICS data receiving unit 12 has a memory 12a for storing the received VICS data, and temporarily stores the last two received VICS data in the memory 12a. That is, when receiving the VICS data, the VICS data receiving unit 12 temporarily stores the received VICS data in the memory 12a, and when receiving the next VICS data following this VICS data, the VICS data is received first. When the next VICS data is received, the VICS data previously stored in the memory 12a is deleted, and the newly received VICS data is stored in place of the deleted VICS data. It is like that.

  The high-speed wireless communication apparatus 20 receives wireless data by performing a process such as amplification and demodulation on a transmission / reception antenna 21 that performs transmission / reception of a wireless signal corresponding to the WiMAX standard, and a signal input through the transmission / reception antenna 21. A high-speed wireless communication unit 22 that transmits received wireless data to the navigation device 40 and wirelessly transmits transmission data input from the navigation device 40 via the transmission / reception antenna 21 and a control unit 23 are provided.

  The control unit 23 is configured as a computer including a CPU, a memory, an I / O, and the like, and the CPU performs various controls on the high-speed wireless communication device 20 according to a program stored in the memory.

  Next, a radio signal transmitted from the radio beacon roadside machine 30 will be described. The frequency of the radio signal transmitted from the radio beacon roadside machine 30 is 2499.7 MHz. The VICS data transmitted from the radio beacon roadside machine 30 is divided into 128 kilobyte frames and transmitted. The contents provided using the VICS data include traffic jam information, link travel time, event regulation information, service area / parking area information, and the like.

  Next, the frame structure of VICS data will be described with reference to FIG. As shown in the figure, the VICS data includes a synchronization signal for establishing synchronization, a header, data, and a CRC code for error detection. The VICS data is divided into about 50 frames and transmitted. Since the amount of VICS data varies depending on the amount of information to be transmitted, the number of frames may be a value other than 50 frames.

  When the VICS data receiving unit 12 receives the VICS data, the VICS data receiving unit 12 notifies the control unit 23 of information for specifying the start timing of the VICS data from the synchronization signal included in the received frame of the VICS data. The control unit 23 uses the information for specifying the start timing of the VICS data so that the wireless data is transmitted by the high-speed wireless communication device 20 in synchronization with the VICS data received by the VICS data receiving unit 12. The wireless data transmission start timing is determined, and the high-speed wireless communication device 20 is instructed to transmit wireless data according to the transmission start timing.

  Further, the VICS data transmitted from the radio beacon roadside machine 30 is updated every certain period (for example, every few minutes), and the same VICS data is repeatedly transmitted until updated to new VICS data. Is done.

  The transmission period of the frame of VICS data is 18 milliseconds (ms) including an interval of 2 milliseconds (ms). Therefore, in order to complete the transmission of 50 frames of VICS data, 18 × 50 = 900 milliseconds = 0.9 seconds.

  As shown in FIG. 3, the radio beacon roadside machine 30 is installed mainly on the roadside of an expressway. Moreover, as shown in the figure, the reception area of the radio beacon roadside machine 30 is about 70 meters before and after the radio beacon roadside machine 30.

  For example, a vehicle traveling at 100 kilometers per hour (km) will pass through this 70 meter reception area in about 2.5 seconds. Therefore, the vehicle can receive about 2 to 3 VICS data within the reception area of the radio beacon roadside machine 30.

  Next, with reference to FIG. 4, a frame structure of WiMAX standard wireless data will be described. The frame length of one frame of WiMAX is 5 milliseconds (ms), and a downlink (DL) composed of a synchronization signal, a header and data, and an uplink (UL) composed of a header and data are allocated therein. It has been.

  If reception of VICS data by the radio beacon roadside device 30 and transmission of radio data by the uplink are performed at the same time, reception performance of VICS data is degraded due to radio wave interference.

  Therefore, the control unit 23 according to the present embodiment intermittently transmits wireless data for a certain period including the reception period of a specific reception target frame with respect to the first VICS data received by the VICS data receiving unit 12. Then, with respect to the second VICS data transmitted subsequent to the first VICS data, the reception target frame is defined as a reception target frame that is not a reception target frame when the first VICS data is received. The transmission of wireless data is intermittently stopped for a certain period including the reception period of the VICS, and the VICS data receiving unit 12 combines the first and second VICS data stored in the memory 12a so as to complement each other. Perform processing to identify data.

  Next, this process will be described with reference to FIG. When the ignition switch of the vehicle is turned on, the in-vehicle wireless device 1 and the navigation device 40 are in an operating state, and the control unit 23 periodically performs the process shown in FIG.

  First, it is determined whether reception of VICS data is started (S100). When receiving the VICS data transmitted from the radio beacon roadside device 30, the VICS data receiving unit 12 in the present embodiment notifies the control unit 23 of information indicating that the VICS data has been received. The control unit 23 determines whether reception of the VICS data is started based on whether information indicating that the VICS data has been received has been notified.

  When the vehicle is located outside the reception area of the radio beacon roadside machine 30 and the information indicating that the VICS data has been received from the VICS data receiving unit 12 is not notified, the determination in S100 is NO, and WiMAX transmission / reception is performed. The high-speed wireless communication unit 22 is instructed to perform in the normal mode (S102). The high-speed wireless communication unit 22 in the present embodiment has a normal mode for transmitting wireless data at a predetermined transmission strength and a transmission stop mode for stopping transmission of wireless data. Here, an instruction is given to set the mode of the high-speed wireless communication unit 22 to the normal mode. As a result, the high-speed wireless communication unit 22 starts transmission / reception of wireless data in the normal mode.

  When the vehicle enters the reception area of the radio beacon roadside machine 30 and is notified of information indicating that the VICS data has been received from the VICS data receiving unit 12, the determination in S100 is YES, and then the first time The frame number of the VICS data (corresponding to the first VICS data) to be received is determined (S104). That is, the frame number of the reception target frame that is intermittently received for the VICS data received for the first time is determined.

  FIG. 6 is a timing chart showing the transmission / reception timing of WiMAX wireless data by the first to fifth frames of the VICS data received for the first time and the high-speed wireless communication unit 22. In FIG. 6 and FIG. 7 to be described later, the interval between the downlink and the uplink and the interval between the frames as shown in FIG. 4 are omitted. In the present embodiment, the first frame (No in the figure) is assigned to each of the first to fifth frames, the sixth to the tenth frames, the first to the fifteenth frames of the first VICS data. .3), the third frame (No. 3), the fifth frame (No. 5) as the first group, the second frame (denoted as No. 2 in the figure) and the fourth frame ( With No. 4) as the second group, the frame number of the reception target frame is determined so that the first group becomes the reception target frame.

  In the present embodiment, the VICS data is divided into frame groups of every 5 frames such as the 1st to 5th frames, the 6th to 10th frames, the 11th to 15th frames, and so on. As shown in FIG. 6, the reception period of 5 frames of VICS data and the transmission period of 18 frames of wireless data are each equal to 90 milliseconds (ms), and the wireless data is synchronized with each frame group. This is because transmission can be performed repeatedly.

  Next, it is determined whether or not the frame received by the VICS data receiving unit 12 is a reception target frame (S106). Specifically, the frame number is specified from the header included in the frame received by the VICS data receiving unit 12, and it is determined whether or not the frame received by the VICS data receiving unit 12 is a reception target frame.

  Here, when the first frame, which is the reception target frame, is received by the VICS data receiving unit 12, the determination in S106 is YES, and the transmission of the WiMAX wireless data is stopped (S108). In the present embodiment, the high-speed wireless communication unit 22 is instructed to stop the transmission of WiMAX wireless data for four frames so as to overlap the reception timing of the reception target frame. That is, it instructs to set the mode of the high-speed wireless communication unit 22 to the transmission stop mode.

  Next, it is determined whether reception of the frame being received is completed (S110). When the reception of each frame is completed, the VICS data receiving unit 12 in the present embodiment notifies the control unit 23 of information indicating that the reception of each frame is completed. The control unit 23 determines whether reception of the frame being received is completed based on whether this information is notified.

  Until the reception of the frame being received is completed, the determination in S110 is NO, and the process returns to S108. When reception of the frame being received is completed, the determination in S110 is YES, and it is then determined whether or not reception of the first VICS data (first VICS data) has been completed (S112). When the reception of VICS data transmitted from the radio beacon roadside machine 30 is completed, the VICS data receiving unit 12 in the present embodiment notifies the control unit 23 of information indicating that the reception of VICS data is completed. Yes. The control unit 23 determines whether reception of the VICS data is completed based on whether this information is notified.

  If the reception of the first VICS data is not completed, the determination in S112 is NO and the process returns to S106.

  Next, when the second frame that is not the reception target frame is received by the VICS data receiving unit 12, the determination in S106 is NO, and the high-speed wireless communication unit 22 is instructed to perform WiMAX transmission / reception in the normal mode. (S114). In the present embodiment, the high-speed wireless communication unit 22 is instructed to perform transmission and reception of WiMAX wireless data for three frames in the normal mode. That is, it instructs to set the mode of the high-speed wireless communication unit 22 to the normal mode.

  When the VICS data receiving unit 12 receives the third frame, which is the reception target frame, the determination in S106 is YES, and the high-speed wireless communication unit 22 is instructed to stop transmission of WiMAX wireless data for four frames. (S108).

  When the fourth frame that is not the reception target frame is received by the VICS data receiving unit 12, the determination in S106 is NO, and the high-speed wireless communication unit 22 performs transmission and reception of WiMAX wireless data for three frames in the normal mode. (S114).

  When the fifth frame, which is the reception target frame, is received by the VICS data receiving unit 12, the determination in S106 is YES, and the high-speed wireless communication unit 22 is instructed to stop transmission of WiMAX wireless data for four frames. (S108).

  In this way, as shown in FIG. 6, during the reception of the first, third, and fifth frames of VICS data, transmission / reception of WiMAX wireless data is stopped, and the second and fourth frames of VICS data are stopped. During reception, transmission / reception of WiMAX wireless data is performed.

  In addition, 5 frames of VICS data and 18 frames of WiMAX wireless data are each 90 milliseconds (ms), and the 6th to 10th frames, 11th to 15th frames of the first VICS data, The same processing is repeated for each frame group.

  When the reception of the first VICS data is completed, the determination in S112 is YES, and then the VICS data (second VICS data) received by the radio beacon roadside machine 30 following the first VICS data. A frame number is determined (S116). That is, the frame number of the reception target frame received by the second VICS data is determined.

  FIG. 7 shows a timing chart of the first to fifth frames of the second VICS data and WiMAX wireless data. In the present embodiment, the second frame (No. in the figure) is assigned to each of the first to fifth frames, the sixth to tenth frames, the first to the fifteenth frames of the second VICS data. .2) and the frame number of the reception target frame is determined so that the second group constituted by the fourth frame (No. 4) is the reception target frame.

  Next, it is determined whether or not the frame received by the VICS data receiving unit 12 is a reception target frame (S118). That is, it is determined whether the frame of the reception target frame has been received by the VICS data receiving unit 12.

  Here, when the first frame that is not the reception target frame is received by the VICS data receiving unit 12, the determination in S106 is NO, and the high-speed wireless communication unit 22 is instructed to perform WiMAX transmission / reception in the normal mode (S126). ).

  Next, it is determined whether or not reception of the second VICS data (second VICS data) is completed (S124).

  Until the reception of the second VICS data is completed, the determination in S124 is NO and the process returns to S118.

  Next, when the second frame, which is the reception target frame, is received by the VICS data receiving unit 12, the determination in S118 is YES, and the high-speed wireless communication unit is configured to stop transmission of WiMAX wireless data for four frames. 22 is instructed (S120).

  When the third frame that is not the reception target frame is received by the VICS data receiving unit 12, the determination in S118 is NO, and the high-speed wireless communication unit 22 performs transmission / reception of WiMAX wireless data for three frames in the normal mode. (S126).

  When the VICS data receiving unit 12 receives the fourth frame, which is the reception target frame, the determination in S118 is YES, and the high-speed wireless communication unit 22 is instructed to stop transmission of WiMAX wireless data for four frames. (S120).

  When the fifth frame that is not the reception target frame is received by the VICS data receiving unit 12, the determination in S118 is NO, and the high-speed wireless communication unit 22 performs transmission and reception of WiMAX wireless data for three frames in the normal mode. (S126).

  When the sixth frame, which is the reception target frame, is received by the VICS data receiving unit 12, the determination in S118 is NO and the high-speed wireless communication unit 22 is instructed to stop transmission of WiMAX wireless data for four frames. (S120).

  In this way, as shown in FIG. 7, during the reception of the second, fourth, and sixth frames of VICS data, transmission / reception of WiMAX wireless data is stopped, and the first, third, and second of VICS data are stopped. During the reception of 5 frames, WiMAX wireless data is transmitted and received.

  FIG. 8 shows a timing chart of each reception target frame of the first VICS data and the second VICS data. In the figure, a frame indicated by a solid line is a reception target frame, and a frame indicated by a dotted line indicates that the frame is not a reception target frame.

  As shown in the figure, the first VICS data is overlapped with the reception timing of a specific reception target frame (first, third, fifth, sixth, eighth, tenth,...) The transmission of the wireless data is intermittently stopped, and the second VICS data transmitted subsequent to the first VICS data is not received as a frame to be received when the first VICS data is received (second and second frames). The fourth, sixth, seventh, ninth, eleventh,...) Are received frames, and the transmission of wireless data is stopped so as to overlap the reception timing of the received frame.

  In the first VICS data, the first, third and fifth frames (first group) for the first to fifth frames, the sixth to tenth frames, the first to fifteenth frames,... The frame number of the reception target frame is determined so that becomes the reception target frame. However, in the second VICS data, the second to sixth frames, the seventh to eleventh frames, the twelfth to eleventh frames are shifted by one frame. For each frame group of the sixteenth frame,..., The first, third and fifth frames are the reception target frames, so that the first to fifth frames, the sixth to tenth frames, and the first to eleventh frames For each frame group of the fifteenth frame,..., The second and fourth frames (second group) are set as reception target frames.

  When the reception of the second VICS data is completed, the determination in S124 is YES, and then the VICS data transmitted by the radio beacon roadside device 30 is identified by combining the first and second received data ( S128). In the present embodiment, from the first and second VICS data stored in the memory 12a, the VICS data received by the VICS data receiving unit 12 at the timing when the transmission of WiMAX wireless data is stopped according to the instruction in S108; The VICS data received by the VICS data receiving unit 12 is extracted at the timing when the transmission of WiMAX wireless data is stopped according to the instruction in S120, and the extracted VICS data is combined so as to complement each other. The VICS data transmitted by the machine 30 is specified. Note that, for the frame determined as the reception target frame in both the first and second VICS data, as in the sixth frame shown in FIG. 8, either of the first or second VICS data is used. It may be used.

  Further, as shown in FIG. 6, in the frame group of the first to fifth frames, the first, third, and fifth frames are set as reception target frames, and transmission of wireless data is intermittently stopped in the reception target frames. In this case, the high-speed wireless communication unit 22 can perform transmission / reception of 6 frames out of 18 frames to be transmitted / received in this frame group. In addition, in the frame group of the first to fifth frames, when the second and fourth frames are set as reception target frames and the transmission of wireless data is intermittently stopped in the reception target frame, the high-speed wireless communication unit 22 9 frames out of 18 frames to be transmitted / received in the frame group can be transmitted / received.

  According to the configuration described above, when it is determined that the reception of the VICS data is started by the VICS data receiving unit 12, the reception target frame to be intermittently received with respect to the first VICS data received by the VICS data receiving unit 12 The frame number is specified, the high-speed wireless communication unit 22 is instructed to stop the transmission of wireless data and transmit the wireless data so as to overlap the reception timing of the specified frame number, and the first VICS data Subsequently, for the second VICS data received by the VICS data receiving unit 12, the frame number of the reception target frame that is intermittently received as a reception target frame is specified as a reception target frame in the first VICS data. Wireless data transmission so that it overlaps the reception timing of the specified frame number The high-speed wireless communication unit 22 is instructed to stop and transmit wireless data, and the VICS data is specified from the first and second VICS data stored in the memory 12a. It is possible to prevent deterioration in data reception performance and to transmit wireless data even during reception of roadside device transmission data.

  Further, by applying the radio beacon roadside machine 30 having a relatively narrow area as the reception area to the roadside machine, the VICS data intermittently only during a relatively short period when the vehicle passes through the reception area of the radio beacon roadside machine 30. Reception can be performed.

  In addition, this invention is not limited to the said embodiment, Based on the meaning of this invention, it can implement with a various form.

  For example, in the above embodiment, the VICS data received by the receiving unit at the timing when the transmission of the wireless data is stopped in S108 from the first and second VICS data stored in the memory 12a, and the wireless data in S120. Although the VICS data received by the VICS data receiving unit 12 is extracted at the timing when the transmission of the VICS is stopped, the extracted VICS data is combined so as to complement each other, and the VICS data is specified. For example, it is detected from the CRC code of the first VICS data stored in the memory 12a whether there is an error in each frame of the first VICS data. If no error is detected, the first VICS data Is identified as VICS data transmitted from the radio beacon roadside machine 30, and an error is detected In this case, the frame in which the error in the first VICS data is detected is complemented by the second VICS data stored in the memory 12a so as to be specified as the VICS data transmitted from the radio beacon roadside machine 30. It may be.

  In the above-described embodiment, the configuration in which the transmission of the wireless data is stopped for a certain period (for 4 frames of wireless data) including the reception period of the reception target frame to be intermittently received has been described. However, the configuration is limited to such a configuration. Instead, for example, the transmission of wireless data is stopped so that it overlaps at least the reception timing of the reception target frame to be intermittently received, such as stopping the transmission of wireless data so as to coincide with the reception timing of the reception target frame to be intermittently received. What is necessary is just to comprise.

  In the above embodiment, the transmission of wireless data is stopped in S108 and S120. However, it is not always necessary to stop the transmission of wireless data, and the transmission strength of wireless data may be reduced.

  In the above embodiment, the VICS data receiving unit 12 determines that the reception of VICS data is started, and then determines the frame number of the reception target frame to be intermittently received. The frame number of the target frame is determined and stored in the memory, and when reception of the VICS data is started by the VICS data receiving unit 12, the frame number of the reception target frame that is intermittently received by reading the information stored in the memory May be specified.

  In the above-described embodiment, the configuration including the high-speed wireless communication unit 22 corresponding to the WiMAX standard as the wireless communication unit has been shown. However, the next-generation PHS, regional WiMAX, LTE (Long Term Evolution), and the like are transmitted from road devices It is good also as a structure provided with the high-speed radio | wireless communication part corresponding to each specification which transmits or transmits / receives radio data using the radio signal of the frequency band which interferes with the transmission frequency of the radio signal to be performed. When the radio beacon road machine 30 is a road machine, the transmission frequency of the radio signal transmitted from the radio beacon road machine 30 is 2499.7 MHz, and the transmission frequency of the radio signal used in the high-speed radio communication unit 22 is The frequency may be 2545 to 2625 MHz defined in the wireless communication standard of the next-generation high-speed wireless communication technology. The transmission frequency of the radio signal transmitted from the road unit and the transmission frequency of the radio signal used in the high-speed radio communication unit 22 are the transmission frequency of the radio signal transmitted from the radio beacon road unit 30 shown here and the high-speed radio. It is not limited to the transmission frequency of the radio signal used in the communication unit 22.

  Further, in the current WiMAX standard, uplink and downlink are assigned to wireless data transmission / reception frames, and communication with a counterpart device is performed using the uplink and downlink. A system that can communicate with the counterpart device by switching between the normal mode using the uplink and the downlink and the downlink mode using only the downlink is configured, and reception of the VICS data is started by the VICS data receiving unit 12. If the other side apparatus is instructed to switch to the downlink mode, communicates with the other side apparatus in the downlink mode, and it is determined that the reception of the VICS data by the VICS data receiving unit 12 is completed. Or instructing the other device to switch to normal mode. There.

  In the above-described embodiment, the configuration for determining whether the reception of the VICS data is started based on whether the VICS data is received from the VICS data receiving unit 12 has been described. To determine whether or not the reception strength of the radio signal transmitted from the radio beacon roadside machine 30 is equal to or higher than the threshold, and determine that the reception intensity of the radio signal transmitted from the radio beacon roadside machine 30 is equal to or higher than the threshold. In addition, when the VICS data is received from the VICS data receiving unit 12, it may be determined whether or not the reception of the VICS data is started. Further, the position information of the radio beacon road machine 30 and the current position information of the own vehicle are acquired from the navigation device 40, and the reception of the VICS data is performed based on whether or not the own car has entered the reception area of the radio beacon road machine 30. It may be determined whether or not is started.

  The correspondence relationship between the configuration in the above embodiment and the configuration of the claims will be described. The VICS data receiving unit 12 corresponds to a receiving unit, the high-speed wireless communication unit 22 corresponds to a wireless communication unit, and S104 and S106. , S108, S110, S112, and S114 correspond to the first transmission control means, the memory 12a corresponds to the first and second storage means, and S116, S118, S120, S122, S124, and S126 correspond to the second transmission. This corresponds to the control means, and S128 corresponds to the roadside machine transmission data specifying means.

DESCRIPTION OF SYMBOLS 1 In-vehicle wireless device 10 VICS data receiving device 11 VICS receiving antenna 12 VICS data receiving unit 12a Memory 20 High-speed wireless communication device 21 Transmission / reception antenna 22 High-speed wireless communication unit 23 Control unit 30 Radio beacon on-road device 40 Navigation device 50 Rear seat monitor

Claims (7)

Wireless data with a predetermined transmission intensity using a receiving unit that receives road unit transmission data wirelessly transmitted from a road unit, and a radio signal in a frequency band that interferes with a transmission frequency of a radio signal transmitted from the road unit An in-vehicle wireless device including a wireless communication unit that transmits
The roadside machine transmission data is divided into a plurality of frames and transmitted.
When it is determined that reception of the roadside device transmission data is started by the receiving unit, the frame number of the reception target frame to be intermittently received with respect to the first roadside device transmission data received by the receiving unit is specified, First transmission control means for instructing the wireless communication unit to transmit the wireless data by reducing the transmission strength of the wireless data so as to overlap the reception timing of the identified frame number;
First storage means for storing the first roadside machine transmission data received by the receiving unit;
For the second roadside machine transmission data received by the receiving unit following the first roadside machine transmission data, a frame that is not a reception target frame in the first roadside machine transmission data is used as a reception target frame. The wireless communication unit is configured to identify a frame number of a reception target frame to be intermittently received, and to transmit the wireless data with a reduced transmission strength of the wireless data so as to overlap with a reception timing of the identified frame number. Second transmission control means for instructing;
Second storage means for storing the second roadside machine transmission data received by the receiving unit;
On-vehicle equipment comprising roadside device transmission data specifying means for specifying roadside device transmission data from the first and second roadside device transmission data stored in the first and second storage units Wireless device. The first transmission control means divides the roadside equipment transmission data received by the receiving unit into frame groups for every five consecutive frames, and for each frame group, a first frame, a third frame, The fifth frame is the first group, the second frame, the fourth frame is the second group, and the reception target frame is set such that one of the first and second groups becomes the reception target frame. Identify the frame number of
The second transmission control means specifies a frame number of the reception target frame so that a group different from the group specified as the reception target frame by the first transmission control means becomes the reception target frame. The in-vehicle wireless device according to claim 1, wherein The wireless communication unit is configured to transmit the wireless data for 18 frames during the reception period of each frame group of the roadside machine transmission data,
When the first and second transmission control means specify the first group as a reception target frame, the first and second frames are transmitted to the wireless communication unit in the first frame, the third frame, and the fifth frame. When the wireless data for 4 frames is transmitted, the wireless data for 3 frames is transmitted in the second frame and the fourth frame, and the second group is specified as a reception target frame, The wireless communication unit transmits the wireless data for three frames in the first frame, the third frame, and the fifth frame, and the four frames in the second frame and the fourth frame. The in-vehicle wireless device according to claim 1, wherein wireless data is transmitted.   The roadside equipment transmission data specifying means transmits the wireless data from the first and second roadside equipment transmission data stored in the first and second storage means according to an instruction of the first transmission control means. Received by the receiving unit at a timing when the transmission strength of the roadside transmission data received by the receiving unit at a timing when the strength is reduced and a transmission strength of the wireless data is reduced by an instruction from the second transmission control means 4. The roadside device transmission data is extracted and combined with each of the extracted roadside device transmission data so as to complement each other to identify the roadside device transmission data. The in-vehicle wireless device according to one.   5. The in-vehicle wireless device according to claim 1, wherein the first and second transmission control units intermittently stop transmission of the wireless data. The road machine is a radio beacon road machine,
The in-vehicle wireless device according to any one of claims 1 to 5, wherein roadside device transmission data wirelessly transmitted from the radio beacon roadside device is VICS data. The transmission frequency of the radio signal transmitted from the radio beacon roadside machine is 2499.7 MHz,
The in-vehicle wireless device according to claim 6, wherein a frequency band of the wireless signal transmitted by the wireless communication unit is 2545 to 2625 MHz.

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