JP2010166468A - In-vehicle communication device - Google Patents

Abstract

[PROBLEMS] To reduce the possibility of in-vehicle communication colliding with communication in another automobile when an oncoming vehicle or an adjacent vehicle approaches.
The communication condition of the in-vehicle wireless communication unit (12) is changed in a direction to reduce interference with the outside of the vehicle based on information obtained from the outside by the external wireless communication unit (13, 14, 15). The in-vehicle wireless communication external control unit (11) that performs the control to be performed is employed in the in-vehicle communication device (1). For example, when multiple cars using UWB approach in the car, if there are free channels, separate channels are used to avoid communication collisions, and if there are no free channels, the transmission power is reduced. If there is no vacant channel and no reduction in transmission power is expected, avoid communication collision by adjusting the transmission timing from the data center outside the vehicle to the wireless communication external control unit. The information is notified, and the wireless communication external control unit changes the communication condition in a direction to reduce the interference with the outside of the vehicle accordingly.
[Selection] Figure 1

Description

  The present invention relates to an in-vehicle communication device that performs wireless communication with a mobile terminal in a vehicle, and relates to, for example, a technique that is effective when applied to a UWB communication system in an automobile.

  In recent years, products that transmit HD (High Definition) moving images wirelessly using a wireless system such as UWB (Ultra Wide Band) or wireless LAN (802.11n draft) have appeared in the home, and conventional wired video transmission has been performed. Replacement is expected. On the other hand, in Europe, ECC / TG3 has been actively discussed so that UWB can be used in automobiles, and it is expected that outdoor use will be possible following the United States. The transmission power of UWB is as low as 1/1000 compared to the wireless LAN, and the transmission distance is within the line of sight, and the UWB is as short as about 10 m compared to 100 m of the wireless LAN. On the other hand, UWB has a single channel bandwidth of 528 MHz, which is wider than 20 MHz (or 40 MHz) of wireless LAN, and realizes a maximum transmission speed of 480 Mbps / 1 channel. Suitable for

  The same frequency band (2.4 GHz band) is used for communication between in-vehicle communication devices (car navigation systems, etc.) and mobile terminals (mobile phones, etc.) in a car environment using narrowband wireless communication such as Bluetooth (registered trademark). A communication error occurs when the wireless LAN (802.11b / g) is used. Patent Document 1 discloses interference by preventing the frequency channel used in communication between the wireless LAN base station and the in-vehicle communication device from overlapping with the frequency channel used in communication between the in-vehicle communication device and the mobile terminal. Techniques to avoid this are shown.

JP 2007-243765 A

  The present inventor has studied how to avoid that wireless communication used in a vehicle is used in another vehicle and interfere with the wireless communication. According to this, when an oncoming vehicle or an adjacent vehicle uses the same UWB channel, there is a high possibility that a communication collision will occur. On the other hand, it is not always possible to make communication channels different from each other. This is because there may be no free channel. Furthermore, when searching for an empty channel, it is necessary to grasp the state of the other party. Patent Document 1 does not consider these points at all.

  The objective of this invention is providing the vehicle-mounted communication apparatus which can reduce possibility that the communication in a vehicle will collide with the communication in another motor vehicle when an oncoming vehicle or an adjacent vehicle approaches.

  Another object of the present invention is to connect the communication connection in the vehicle without imposing a burden on the user even if the communication in the vehicle collides with the communication in another vehicle when an oncoming vehicle or an adjacent vehicle approaches. An object of the present invention is to provide an in-vehicle communication device that can automatically restore required information without blocking.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  The following is a brief description of an outline of typical inventions disclosed in the present application.

  That is, an in-vehicle wireless communication external control unit that performs control to change the communication condition of the in-vehicle wireless communication unit in a direction to reduce interference with the outside of the vehicle based on information obtained externally by the outside wireless communication unit is mounted on the vehicle. Adopted in communication equipment. For example, when multiple cars using UWB approach in the car, if there are free channels, separate channels are used to avoid communication collisions, and if there are no free channels, the transmission power is reduced. If there is no vacant channel and no reduction in transmission power is expected, avoid communication collision by adjusting the transmission timing from the data center outside the vehicle to the wireless communication external control unit. The information is notified, and the wireless communication external control unit changes the communication condition of the in-vehicle wireless communication unit in a direction to reduce the interference with the outside of the vehicle. As a result, the possibility of a communication collision is greatly reduced by obtaining information on the transmission channel, transmission power, and transmission timing that are in use by a car that may approach.

  In the unlikely event that a communication collision occurs, the UWB communication is not interrupted and the superframe period, beacon transmission period, data transmission period, etc. are held internally, and after the reception environment has been improved, A retransmission request is made to the data transmission side based on the signal error rate BER (Bit Error Rate) measured every time.

  The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.

  That is, it is possible to reduce the possibility that communication in the vehicle collides with communication in another vehicle when an oncoming vehicle or an adjacent vehicle approaches.

  Even if an in-vehicle communication collides with another in-vehicle communication when an oncoming vehicle or an adjacent vehicle approaches, the required information can be obtained without imposing a burden on the user and without interrupting the in-vehicle communication connection. Can be restored automatically.

1. First, an outline of a typical embodiment of the invention disclosed in the present application will be described. Reference numerals in the drawings referred to in parentheses in the outline description of the representative embodiments merely exemplify what are included in the concept of the components to which the reference numerals are attached.

  [1] An in-vehicle communication device (1, 7) according to the present invention includes an in-vehicle wireless communication unit (12) capable of wireless communication with an in-vehicle portable terminal (3), and an outside vehicle that performs wireless communication with devices outside the vehicle. Based on the information obtained by the wireless communication unit (13, 14, 15) and the outside wireless communication unit, control is performed to change the communication condition of the in-vehicle wireless communication unit in a direction to reduce interference with the outside of the vehicle. An in-vehicle wireless communication external control unit (11). Since the wireless communication external control unit controls communication conditions according to information supplied from the outside, it is possible to dynamically change communication conditions according to the relationship with the outside of the vehicle, and reduce the possibility of communication collision with others. Can do.

  [2] In the in-vehicle communication device according to item 1, the in-vehicle wireless communication unit is a UWB communication unit that performs UWB communication with a mobile terminal. The outside wireless communication unit is a communication unit (13, 14) that performs wireless communication with a data center outside the vehicle, receives information about the UWB channel, UWB transmission power, and UWB transmission timing from the data center, and receives the received information. Based on the above, the UWB communication unit is controlled.

  [3] In the in-vehicle communication device according to Item 2, the outside wireless communication unit includes a mobile phone communication unit (32) that performs communication via a mobile phone network or a wireless LAN communication unit (32) that performs communication via a wireless LAN network. 33).

  [4] In the in-vehicle communication device according to item 1, the in-vehicle wireless communication unit is a UWB communication unit (12) that performs UWB communication with a mobile terminal. The outside wireless communication unit is a communication unit (15) that performs wireless communication with other automobiles. The in-vehicle wireless communication external control unit (11) transmits information related to its own UWB channel, UWB transmission power, UWB transmission timing to another vehicle via the outside-vehicle wireless communication unit, and from the other vehicle to the UWB. Control is performed to receive information on the channel, UWB transmission power, and UWB transmission timing, and the UWB communication unit is controlled based on the received information. It is expected to converge to a state where there is no risk of communication collision by sequentially repeating the operation of changing the communication condition setting so as to avoid communication collision with each other by directly communicating with other vehicles. . This makes it possible to avoid UWB communication collision without using a mobile phone network or the like when passing each other.

  [5] In the in-vehicle communication device according to item 4, the wireless communication unit for outside the vehicle is a WAVE communication unit that performs Wave communication having a longer communication distance than UWB communication.

  [6] In the in-vehicle communication device according to [1], the in-house communication unit divides input information for each frame and assigns a frame number to the data division unit (120), and based on the information divided for each frame. A signal error rate measurement information generation unit (125) for generating information for measuring the signal error rate, and a modulation unit for transmitting the information divided for each frame and the signal error rate measurement information in the same frame (127), a signal error rate checking unit (122) for measuring a signal error rate based on information divided for each received frame and information for signal error rate measurement, and a frame number and a signal before and after transmission Based on the frame number of the frame whose error rate exceeds the threshold, the wireless communication is cut off from the frame number management unit (121) for retransmitting from the frame whose signal error rate exceeds the threshold. Comprising frame period within the beacon transmission period, and a timing internal counter for counting the data transmission period (124), the.

  [7] An in-vehicle communication device according to another aspect of the present invention includes an in-vehicle UWB communication unit (12) capable of UWB communication in the vehicle. The UWB communication unit divides input information for each UWB superframe, and assigns a frame number to a data division unit, and information for measuring a signal error rate based on the information divided for each UWB superframe. A signal error rate measurement information generation unit to be generated, a modulation unit that transmits information divided for each UWB superframe and signal error rate measurement information in the same UWB superframe, and a received UWB superframe that is divided A signal error rate tester for measuring a signal error rate based on the received information and signal error rate measurement information, a frame number before and after transmission, and a frame number of a UWB superframe in which the signal error rate exceeds a threshold The frame number management unit that retransmits from the superframe whose signal error rate exceeds the threshold, and wireless communication is blocked. Comprising UWB superframe period, the beacon transmission period, and the timing internal counter for counting the data transmission period, the even if internal.

  [8] In the in-vehicle communication device according to item 7, an in-vehicle wireless communication unit (13, 14) that performs wireless communication with an external data center, and a UWB channel, UWB transmission power, and UWB transmission obtained by the out-of-vehicle wireless communication unit. A UWB communication external control unit (11) for controlling the UWB communication unit based on information on timing;

2. Details of Embodiments Embodiments will be further described in detail.

  FIG. 1 illustrates an automobile to which an in-vehicle communication device according to an embodiment of the present invention is applied and a part of an external network that can be connected thereto. In the figure, a single automobile 6 is representatively illustrated. The automobile 1 is equipped with an in-vehicle communication device 2, and the in-vehicle communication device 2 can be controlled by a mobile terminal 3 through wireless communication. The in-vehicle communication device 2 is incorporated in a car navigation system (not shown), for example, and has a function of controlling communication with the mobile terminal 3 and a network outside the vehicle. As a network outside the vehicle, for example, a mobile phone base station 4, a wireless LAN (WLAN) base station 5, and a data center 2 are shown. The mobile phone base station 4 represents a base station in each mobile communication cell included in the mobile phone network. The wireless LAN base station 5 is a general term for communication nodes included in a public wireless LAN network. The data center 2 is arranged with the in-vehicle communication device 1 as a target, and distributes control information and content information necessary for the operation of the in-vehicle communication device 1 installed in various automobiles via a mobile phone network and a public wireless LAN network. It is provided to control the etc.

  UWB (Ultra Wide Band) is used for wireless communication between the mobile terminal 3 and the in-vehicle communication device 1. UWB is a well-known communication method capable of low power consumption and high-speed communication in which information is transmitted by an ultrashort pulse wave using a frequency of several gigahertz band without using a carrier wave. Since UWB transmits information using ultra-short pulse waves, it has a high time resolution and is therefore inherently strong against interference waves from other terminals and multipath interference waves. The present invention intends to further enhance the resistance against interference from other terminals, and the contents thereof will be described in detail below.

  The in-vehicle communication device 1 includes a UWB communication external control unit 11, a UWB communication unit 12 for performing wireless communication with other devices, a mobile phone communication unit 13, a WLAN communication unit 14, a WAVE communication unit 15, and a data processing unit 16. Prepare. The UWB communication external control unit 11 that controls the UWB communication unit 12 based on information supplied from the outside of the in-vehicle communication device 1 includes a UWB channel control unit 111, a UWB transmission power control unit 112, and a UWB timing control unit 113. Has been. The WAVE communication unit 15 is a circuit that performs Wave communication having a communication distance longer than that of UWB communication.

  Based on the information obtained from the outside by the mobile phone communication unit 13, the WLAN communication unit 14, or the WAVE communication unit 15, the UWB channel control unit 111 causes the UWB communication unit 12 to select a transmission channel, and the UWB transmission power control unit 112 The transmission power value by the UWB communication unit 12 is determined, and the UWB timing control unit 113 performs respective control for determining the transmission timing by the UWB communication unit 12.

  The information obtained from the outside is information generated in the data center 2 from the viewpoint of preventing the automobile 6 from interfering with UWB communication equipment mounted on another vehicle, and may interfere with the communication environment such as the distance to the other party. Transmission channel designation information for using different transmission channels, transmission power designation information for reducing interference when there is no available transmission channel, and mutual transmission power when the transmission power cannot be reduced. This is transmission timing designation information for designating transmission timing necessary for performing information transmission at different timings.

  The data center 2 includes a mobile phone communication unit 21, a WLAN communication unit 22, and a UWB system management unit 23 for wireless communication with other devices. The UWB system management unit 23 includes a UWB user management unit 231, a UWB channel management unit 232, a UWB transmission power management unit 233, and a UWB timing management unit 234.

  The UWB system management unit 23 obtains information on UWB communication from the in-vehicle terminal device 1 of the automobile 6 or other automobile via the cellular phone base station 4 or the WLAN base station 5 by the mobile phone communication section 21 or the WLAN communication section 22. To do. Based on this, the UWB user management unit 231 manages information on users who use UWB within a certain area, the UWB channel management unit 232 manages channels used by the user, and the UWB transmission power management unit 233 The UWB timing management unit 234 manages the timing for avoiding a communication collision between users who use the same channel. Based on the management information, the UWB system management unit 2 transmits the transmission channel designation information, transmission power reduction designation information, and transmission timing designation information to a user who uses UWB within a certain area.

  In the mobile terminal 3, the UWB communication unit 31 performs high-speed wireless data communication such as high-quality video with the in-vehicle communication device 1. In addition, the mobile terminal 3 includes a mobile phone communication unit 32 and a WLAN communication unit 33 for wireless communication with other devices.

  The mobile phone base station 4 and the WLAN base station 5 mediate communication between the moving automobile 6 and the data center 2, and a user on the automobile 6 selects either one of the base stations and selects the data center. Communicate.

  FIG. 2 shows an embodiment of the present invention in an area where there are relatively many users using UWB such as urban areas. The cars A to D are approaching the intersection, and the channels to be used are different. Information about the user's usage channel, transmission power, and timing is notified from each automobile to the mobile phone base station 4 and sent to the data center 2 in a lump. When vehicles using UWB are close, if there are more channels available than the number of vehicles, communication collision can be avoided by specifying the use of different channels in the transmission channel specification information. There may be a shortage of channels under heavy traffic conditions. Therefore, the UWB signal leaked outside the vehicle is reduced by notifying the in-vehicle communication device 1 that performs UWB communication with the transmission power defined in the vehicle from the data center 2 so as to reduce the transmission power with the transmission power designation information. be able to. Therefore, when vehicles located in front and behind in a traffic jam situation use the same channel, communication is possible even if the distance between the two vehicles is reduced.

  Furthermore, when UWB usage in the vehicle expands, channel shortage and radio wave interference from nearby vehicles become issues. Currently, UWB is operated in one system for one channel (three channels are occupied when frequency hopping), and a communication collision occurs when another UWB system using the same channel comes close. . Therefore, a communication collision using a period in which transmission / reception is not performed by notifying transmission timing designation information such as a super frame, a beacon transmission period, a data transmission period, etc. of a UWB system used in an adjacent vehicle from the data center 2 is performed. It can be avoided.

  As described above, in the above embodiment, when a plurality of vehicles using UWB approach in the vehicle, if there is an empty channel, a separate channel is used to avoid a communication collision and there is no empty channel. If the data center 2 avoids a communication collision by reducing the transmission power, and if there is no vacant channel and the effect of reducing the transmission power is not expected, the data center 2 can avoid the communication collision by adjusting the transmission timing. A system that notifies the user of channel, transmission power, and timing information via telephone or WLAN base stations 4 and 5 is adopted. Thereby, the interference tolerance of UWB communication can be strengthened according to the use condition.

  FIG. 3 illustrates a case where communication is performed between vehicles to which the in-vehicle communication device of FIG. 1 is applied. Individually, wireless communication is performed using the WAVE communication unit 15 between the vehicle 6 equipped with the in-vehicle communication device 1 and the portable terminal 3 in FIG. 1 and the vehicle 9 similarly equipped with the in-vehicle communication device 7 and the portable terminal 8. Since the in-vehicle communication device 1 and the in-vehicle communication device 7, and the mobile terminal 3 and the mobile terminal 8 are the same, detailed description thereof is omitted. It goes without saying that the user ID for specifying the user is different between the in-vehicle communication device 1 or the portable terminal 3 and the in-vehicle communication device 7 or the portable terminal 8.

  FIG. 4 shows a case where communication is performed in the form of FIG. 3 in a situation where two vehicles 6 and 9 facing each other pass each other. Wireless communication is directly performed between the two vehicles 6 and 9 without using a mobile phone or a WLAN base station. Since the WAVE communication distance is about 100 m, the UWB communication external control unit 11 uses the WAVE communication network to sequentially exchange information on the UWB usage channel, transmission power, and timing. Use separate channels to avoid communication collisions, reduce transmission power if there are no free channels, avoid communication collisions, adjust transmission timing if there are no free channels and no reduction in transmission power is expected This operation is sequentially repeated until there is no risk of collision. By repeating this operation sequentially, it is expected to converge to a state where there is no risk of communication collision. This makes it possible to avoid UWB communication collision without using a mobile phone network or the like when passing each other.

  As described above, in the form of FIGS. 3 and 4, when two automobiles 6 and 9 using UWB approach in the vehicle, if there is an empty channel, communication is performed using different channels. Avoid collision, reduce transmission power if there is no empty channel, avoid communication collision, and avoid communication collision by adjusting transmission timing if there is no empty channel and the effect of reducing transmission power is not expected As described above, since a mechanism that directly notifies the two vehicles 6 and 9 of channel, transmission power, and timing information without using a base station is adopted, even in a driving environment where a mobile phone or a public LAN network cannot be used. Or, it is possible to reinforce the interference resistance of UWB communication according to the use situation without requiring the running cost of using those networks. Kill.

  FIG. 5 shows still another example of the UWB communication unit 12. Here, a configuration for automatically recovering communication without burdening the user when a communication collision occurs even when the UWB communication is performed in the vehicle with the means shown in FIGS. 1 to 4 described above. Only. Assuming a case in which high-quality video is distributed from the in-vehicle communication device 1 and viewed on the mobile terminal 3 in a car, the data processing unit 16 includes an uncompressed video signal generation unit 160 that generates an uncompressed video signal, A video signal compression unit 161 that compresses the signal to match the wireless transmission band is provided. The uncompressed video signal generated by the uncompressed video signal generation unit 160 becomes a compressed video signal by the video signal compression unit 161 and is input to the UWB communication unit 12. The UWB communication unit 12 includes a data division unit 120, a frame number management unit 121, a bit error (BER) inspection unit 122, a data synthesis unit 123, a timing internal counter 124, a BER measurement bit generation unit 125, a demodulation unit 126, and a modulation unit 127. And a high frequency unit 129.

  At the time of data transmission of the in-vehicle communication device 1 that distributes the video (for example, at the time of data transmission toward the mobile terminal 3), the compressed video signal is divided by the data dividing unit 120 to be transmitted within one superframe. Then, numbering is performed, and the frame number is notified to the frame number management unit 121. The frame number management unit 121 manages the compressed video signals that have been divided before and after transmission using the frame numbers. The BER measurement bit generation unit 125 generates a BER measurement bit based on the divided compressed video signal. The modulation unit 127 includes the compressed video signal divided by the beacon signal and the BER measurement bit in the super frame, and causes the high frequency unit 129 to transmit the beacon signal as a UWB signal.

  On the other hand, when data is received by the mobile terminal that views the video, the demodulator 126 extracts the compressed video signal divided from the beacon signal and the BER measurement bit from the UWB signal, and sends it to the BER checker 122. The BER checking unit 122 calculates the BER based on the BER measurement bits and the divided compressed video signal. At this time, when the BER exceeds a certain threshold, the frame number management unit 121 is notified of the frame number as having a signal error. The data synthesis unit 123 performs processing for returning the divided compressed video signal to the compressed video signal again based on the frame number. At this time, if a frame number having a signal error is notified from the frame number management unit 121, the processing is interrupted.

  The frame number management unit 121 manages the frame number with a signal error received from the BER checking unit 122 and distributes the video signal in addition to the management of the divided compressed video signal before and after transmission. A retransmission request from a frame number with a signal error to 1 and a retransmission instruction from the frame number requested for retransmission are performed. By sending a frame number having a signal error to the in-vehicle communication device 1 at the time of data transmission of the mobile terminal 3 that views the video signal, the frame number management unit 121 of the in-vehicle communication device 1 performs video based on the sent frame number. Resend the signal.

  The timing internal counter 124 keeps track of the superframe period, the beacon transmission period, the data transmission period, etc., and can transmit and receive signals until it recovers without interrupting UWB communication even if a communication collision occurs. It is possible to try.

  FIG. 6 is a diagram showing the relationship between the UWB super frame (65.536 ms), the beacon transmission period, and the data transmission period. The specified portion of the video signal bit is copied and used as a BER measurement bit. The BER checking unit 122 compares the specified portion of the video signal bit with the BER measurement bit, and sets the bit error to 0 if they are the same.

  As long as wireless communication is used, there is a possibility that communication may be interrupted due to unexpected radio wave interference. According to the configuration of FIG. 5, once a communication collision occurs, it is automatically performed without imposing a burden on the user. Communication can be restored.

  FIG. 7 illustrates an operation sequence by the UWB communication unit 13, the UWB communication external control unit 11, the outside communication unit, and the outside communication device. Various wireless communication units (mobile phone communication unit 13, WLAN communication unit 14, WAVE communication unit 15) in the vehicle are used as external communication units, and various wireless devices (base stations 4 and 5, data center 2, etc.) outside the vehicle are used. Car)) as an external communication device.

  The UWB communication external control unit 11 instructs the UWB communication unit to notify the channel number (data transmission channel number) in order to notify the out-of-vehicle communication device of the usage status of the UWB communication unit 12. Channel Number corresponds to the hopping pattern and the frequency band to be used.

  The UWB communication external control unit 11 transmits Channel Number 1 acquired from the UWB communication unit 12 to the external communication device via the external communication unit.

  The out-of-vehicle communication device reads the used frequency band and hopping pattern from the received Channel Number 1 and compares it with the surrounding usage situation. When it overlaps with the surrounding usage situation, the outside-vehicle communication apparatus instructs the UWB external control unit 11 to change to Channel Number2. The UWB communication external control unit 11 that has received an instruction to change to Channel Number 2 via the outside communication unit instructs the UWB communication unit 12 to change to Channel Number 2.

  After a while, the UWB communication external control unit 11 instructs the UWB communication unit 12 to notify the Channel Number and TxPowerControlLevel (transmission power level). The UWB OFDM scheme is obliged by the WiMedia standard to control transmission power according to the usage situation, and TxPowerControlLevel controlled by PHY-BB corresponds to the transmission level.

  The UWB communication external control unit 11 transmits Channel Number 2 and TxPowerControl Level 1 acquired from the UWB communication unit 12 to the external communication device via the external communication unit.

  The out-of-vehicle communication device reads the used frequency band and hopping pattern from the received Channel Number 2 and compares it with the surrounding usage situation. Also, the transmission level is read from the received TxPowerControlLevel1 and compared with the surrounding usage status. Even if the channel number cannot be changed, if the collision can be avoided by lowering the transmission level, the in-vehicle communication apparatus instructs the UWB external control unit 11 to change to TxPowerControlLevel2. The UWB communication external control unit 11 that has received an instruction to change to TxPowerControlLevel2 via the outside communication unit instructs the UWB communication unit 12 to change to TxPowerControlLevel2.

  After a while, the UWB communication external control unit 11 instructs the UWB communication unit 12 to notify the TxPowerControlLevel, the Beacon timing, and the Data timing. The Beacon timing and the Data timing are controlled in a super frame (SuperFrame) of a MAC address (Media Access Control address).

  The UWB communication external control unit 11 transmits the TxPowerControlLevel2, the Beacon timing 1 and the Data timing 1 acquired from the UWB communication unit 12 to the external communication device via the external communication unit.

  The external communication device reads the transmission level from the received TxPowerControlLevel2 and compares it with the surrounding usage status. Also, the timing is read from the received Beacon timing 1 and Data timing 1 and compared with the surrounding usage situation. Even if the Channel Number cannot be changed and the TxPowerControlLevel cannot be changed, if the collision can be avoided by changing the timing, the in-vehicle communication device changes the Beacon timing 2 and Data timing 2 to the UWB communication external control unit 11 To instruct. The UWB communication external control unit 11 that has received an instruction to change to the Beacon timing 2 and the Data timing 2 via the outside communication unit instructs the UWB communication unit to change to the Beacon timing 2 and the Data timing 2. .

  After a while, the UWB communication external control unit 11 instructs the UWB communication unit 12 to notify the Beacon timing and the Data timing.

  The UWB communication external control unit 11 transmits the Beacon timing 2 and the Data timing 2 acquired from the UWB communication unit 12 to the external communication device via the external communication unit.

  Although the invention made by the present inventor has been specifically described based on the embodiments, it is needless to say that the present invention is not limited thereto and can be variously modified without departing from the gist thereof.

  For example, the in-vehicle communication device can be applied not only to car navigation but also to other in-vehicle devices. The vehicle communication unit connected to the outside of the vehicle is not limited to a mobile phone, WLAN, and WAVE, and can be changed as appropriate. The vehicle is not limited to an automobile, and may be a train or the like.

FIG. 1 is a block diagram illustrating a part of an automobile to which an in-vehicle communication device according to an embodiment of the present invention is applied and an external network connectable thereto. FIG. 2 is an explanatory diagram illustrating the operation mode of the present invention in an area where there are relatively many users using UWB such as urban areas. FIG. 3 is a block diagram illustrating a case where communication is performed between automobiles to which the in-vehicle communication device of FIG. 1 is applied. FIG. 4 is an explanatory diagram showing a case where communication is performed in the form of FIG. 3 in a situation where two opposing vehicles pass each other. FIG. 5 is a block diagram showing still another example of the UWB communication unit. FIG. 6 is an explanatory diagram showing the relationship between the UWB superframe, the beacon transmission period, and the data transmission period. FIG. 7 is a flowchart illustrating an operation sequence performed by the UWB communication unit, the UWB communication external control unit, the external communication unit, and the external communication device.

DESCRIPTION OF SYMBOLS 1,7 In-vehicle communication apparatus 2 Data center 3,8 Mobile terminal 4 Mobile phone base station 5 WLAN base station 6,9 Automobile 11 UWB communication external control part 12 UWB communication part 13 Mobile phone communication part 14 WLAN communication part 15 WAVE communication part 16 Data processing unit 23 UWB system management unit 231 UWB user management unit 232 UWB channel management unit 233 UWB transmission power management unit 234 UWB timing management unit 111 UWB channel control unit 112 UWB transmission power control unit 113 UWB timing control unit 160 Uncompressed video Signal generation unit 161 Video signal compression unit 120 Data division unit 121 Frame number management unit 122 BER inspection unit 123 Data synthesis unit 124 Timing internal counter 125 BER measurement bit generation unit 126 Demodulation unit 127 Modulation unit

Claims (8)

An in-vehicle wireless communication unit capable of wireless communication with a mobile terminal in the vehicle;
A wireless communication unit for outside the vehicle that performs wireless communication with devices outside the vehicle,
An in-vehicle wireless communication external control unit that performs control to change communication conditions of the in-vehicle wireless communication unit in a direction to reduce interference with the outside of the vehicle based on information obtained by the out-of-vehicle wireless communication unit Communication device. The in-vehicle wireless communication unit is a UWB communication unit that performs UWB communication with a mobile terminal,
The outside wireless communication unit is a communication unit that performs wireless communication with a data center outside the vehicle, receives information about the UWB channel, UWB transmission power, and UWB transmission timing from the data center, and based on the received information, The in-vehicle communication device according to claim 1, which controls a UWB communication unit.   The in-vehicle communication device according to claim 2, wherein the external wireless communication unit is a mobile phone communication unit that performs communication via a mobile phone network or a wireless LAN communication unit that performs communication via a wireless LAN network. The in-vehicle wireless communication unit is a UWB communication unit that performs UWB communication with a mobile terminal,
The outside wireless communication unit is a communication unit that performs wireless communication with other automobiles,
The in-vehicle wireless communication external control unit transmits information related to its own UWB channel, UWB transmission power, and UWB transmission timing to another vehicle via the outside-vehicle wireless communication unit, and from the other vehicle to the UWB channel, UWB. The in-vehicle communication device according to claim 1, wherein control for receiving information related to transmission power and UWB transmission timing is performed, and the UWB communication unit is controlled based on the received information.   The in-vehicle communication device according to claim 4, wherein the external wireless communication unit is a WAVE communication unit that performs Wave communication having a communication distance longer than that of UWB communication. The in-house communication unit divides input information for each frame, and assigns a frame number to a data dividing unit,
A signal error rate measurement information generating unit for generating information for measuring a signal error rate based on information divided for each frame;
Information divided for each frame, a modulation unit for transmitting signal error rate measurement information in the same frame, and
Information divided for each received frame, a signal error rate tester that measures a signal error rate based on signal error rate measurement information, and
A frame number management unit that retransmits from a frame whose signal error rate exceeds the threshold, based on the frame number before transmission and the frame number that has been transmitted, and the frame number of the frame whose signal error rate exceeds the threshold;
The wireless communication apparatus according to claim 1, further comprising: a timing internal counter that counts a frame period, a beacon transmission period, and a data transmission period even when wireless communication is interrupted. A wireless communication device including a UWB communication unit for in-vehicle UWB communication, wherein the UWB communication unit is
A data dividing unit that divides input information for each UWB superframe and assigns a frame number;
A signal error rate measurement information generating unit that generates information for measuring a signal error rate based on information divided for each UWB superframe;
Information divided for each UWB superframe, a modulation unit for transmitting signal error rate measurement information in the same UWB superframe, and
A signal error rate inspection unit for measuring a signal error rate based on the information divided for each received UWB superframe and the signal error rate measurement information;
A frame number management unit for retransmitting from a super frame whose signal error rate exceeds the threshold, based on the frame number of the UWB super frame before and after transmission and the signal error rate exceeding the threshold;
A wireless communication apparatus comprising: a timing internal counter that counts a UWB superframe period, a beacon transmission period, and a data transmission period even when wireless communication is interrupted. A wireless communication unit for external communication that performs wireless communication with a data center outside the vehicle;
The in-vehicle communication device according to claim 7, further comprising: a UWB communication external control unit that controls the UWB communication unit based on information on the UWB channel, UWB transmission power, and UWB transmission timing obtained by the external wireless communication unit. .

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