WO2019111646A1

WO2019111646A1 - Communications system for vehicles, on-board communications device, and communications method for vehicles

Info

Publication number: WO2019111646A1
Application number: PCT/JP2018/041916
Authority: WO
Inventors: 松岡　健二
Original assignee: 株式会社オートネットワーク技術研究所; 住友電装株式会社; 住友電気工業株式会社
Priority date: 2017-12-04
Filing date: 2018-11-13
Publication date: 2019-06-13
Also published as: JP2019103003A

Abstract

Provided are a communications system for vehicles, an on-board communications device, and a communications method for vehicles, whereby the range for communications with a portable communications device is increased and the position of the portable communications device can be detected. This communications system for vehicles comprises: an on-board communications device that uses a plurality of transmission antennas for vehicles and sends wireless signals; and a portable communications device that receives the wireless signals and sends response signals. The on-board communications device: modulates transmission data by using ASK modulation, said transmission data including individual pieces of data stipulated for each transmission antenna; and simultaneously sends wireless signals for each transmission antenna, from each transmission antenna. The portable communications device: obtains individual pieces of data included in the reception data; and sends response signals being modulated transmission data including the individual pieces of data. The on-board communications device receives and demodulates the response signals sent from the portable communications device and, on the basis of the individual pieces of data included in the demodulated reception data, determines the position of the portable communications device relative to the vehicle.

Description

Communication system for vehicle, in-vehicle communication device, and communication method for vehicle

The present disclosure relates to a vehicular communication system, a vehicle-mounted communication device, and a vehicular communication method for performing communication with a vehicle and a portable communication device owned by a user.

A system for locking and unlocking a door of a vehicle without using a mechanical key has been put to practical use. For example, in the smart entry (registered trademark) system, the portable type of the user, for example, when the user carrying the portable communication device approaches the vehicle, or when the user performs an action such as gripping the door handle of the vehicle. Wireless communication is performed between the communication device and the on-vehicle communication device of the vehicle to unlock the door of the vehicle.

In addition, the in-vehicle communication device communicates with the user's portable communication device to detect that the user is approaching the vehicle, and the on-vehicle light and the on-vehicle light provided in the vehicle are automatically set in a predetermined pattern. Welcome lights to be lit have been put to practical use. As described above, by detecting the approach of the user to the vehicle by communication with the portable communication device, it is possible to provide various convenient functions to the user before the start of traveling of the vehicle. Become.

In patent document 1, the communication system for vehicles which can extend the reception range of the signal by a portable machine by transmitting a signal from a plurality of LF (Low Frequency) transmitting antennas arranged distantly to a vehicle to a portable machine at the same time Has been proposed.

International Publication Number WO 2017/078040

The vehicle communication system described in Patent Document 1 needs to simultaneously transmit radio signals from a plurality of antennas provided in the vehicle in order to expand the communication range with the portable device. Therefore, there is a problem that the position of the portable device can not be detected by using a plurality of antennas.

The present invention has been made in view of such circumstances, and the object of the present invention is to expand the communication range with the portable communication device carried by the user and to detect the position of the portable communication device. It is an object of the present invention to provide an on-vehicle communication system, an on-vehicle communication apparatus, and a on-vehicle communication method.

The vehicular communication system according to the present aspect includes an on-vehicle communication device for transmitting a wireless signal using a plurality of transmitting antennas disposed apart from the vehicle, and a wireless signal transmitted from the on-vehicle communication device. In a vehicular communication system including a portable communication device for transmitting a response signal, the on-vehicle communication device modulates transmission data including individual data defined for each of the transmission antennas by ASK (Amplitude Shift Keying) modulation. Modulation unit, and a transmission processing unit that simultaneously transmits the modulated radio signal for each of the transmission antennas from each of the transmission antennas, and the portable communication device is simultaneously transmitted from the plurality of transmission antennas. And a demodulation unit that receives and demodulates the radio signal that has been superimposed, an acquisition unit that acquires individual data included in the reception data that has been demodulated, and transmission that includes the acquired individual data And a response signal transmission unit for transmitting a response signal obtained by modulating the data, wherein the on-vehicle communication device receives and demodulates the response signal transmitted from the portable communication device; And a determination unit that determines the relative position of the portable communication device with respect to the vehicle based on the individual data included in.

The on-vehicle communication device according to the present aspect transmits a wireless signal using a plurality of transmitting antennas disposed apart from the vehicle, and receives a response signal from the portable communication device transmitted according to the wireless signal. In the on-vehicle communication device, a modulation unit that modulates transmission data including individual data determined for each of the transmission antennas according to the ASK modulation method, and a modulated wireless signal for each of the transmission antennas are simultaneously transmitted from each transmission antenna. A transmission processing unit to transmit, a demodulation unit to receive and demodulate the response signal from the portable communication device that acquires individual data included in the received wireless signal, returns it included in the response signal, and receives the demodulated signal And a determination unit that determines the relative position of the portable communication device with respect to the vehicle based on individual data included in the data.

A communication method for a vehicle according to this aspect comprises: an on-vehicle communication device for transmitting a wireless signal using a plurality of transmitting antennas arranged at a distance from the vehicle; and a wireless signal transmitted from the on-vehicle communication device In the vehicle communication method in which wireless communication is performed with a portable communication device that transmits a response signal, the in-vehicle communication device modulates transmission data including individual data defined for each of the transmission antennas by ASK modulation, The modulated radio signal for each transmission antenna is simultaneously transmitted from each transmission antenna, and the portable communication device receives and demodulates the radio signal transmitted simultaneously from the plurality of transmission antennas and superimposed. Acquiring the individual data included in the demodulated reception data, and transmitting a response signal obtained by modulating transmission data including the acquired individual data, and the on-vehicle communication device transmits the response signal to the portable communication device. And receiving and demodulating the response signal transmitted from, based on the individual data included in the received data demodulated to determine the relative position of the portable communication device relative to the vehicle.

The present application can not only be realized as a vehicular communication system provided with such a characteristic control unit, but can also be realized as a vehicular communication method in which such characteristic control is taken as a step, or such a step is It can be realized as a program for execution. In addition, the present invention can be realized as a semiconductor integrated circuit that realizes a part or all of the vehicular communication system, or as another system including the vehicular communication system.

According to the above, it is possible to provide a vehicular communication system and an on-vehicle communication device capable of detecting the position of the portable communication device while expanding the communication range with the portable communication device possessed by the user.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the outline | summary of the communication system for vehicles which concerns on this embodiment. It is a schematic diagram which shows an example of an ASK modulation system. It is a schematic diagram which shows the structural example of transmission data. It is a schematic diagram for demonstrating the superimposition of the radio signal corresponded to separate data. It is a block diagram showing composition of ECU concerning this embodiment. It is a block diagram which shows the structure of the portable remote control which concerns on this Embodiment. It is a flowchart which shows the procedure of the communication processing which ECU performs. It is a flowchart which shows the procedure of the communication processing which a portable remote control performs. It is a schematic diagram which shows the outline | summary of the communication system for vehicles which concerns on a modification.

[Description of the embodiment of the present disclosure]
First, embodiments of the present disclosure will be listed and described. In addition, at least part of the embodiments described below may be arbitrarily combined.

(1) The vehicular communication system according to the present aspect includes an on-vehicle communication device for transmitting a wireless signal using a plurality of transmitting antennas disposed apart from the vehicle, and a wireless signal transmitted from the on-vehicle communication device. In a vehicular communication system including a portable communication device for receiving and transmitting a response signal, the in-vehicle communication device performs ASK (Amplitude Shift Keying) modulation on transmission data including individual data defined for each of the transmission antennas. And a transmission processing unit for simultaneously transmitting, from each transmission antenna, the modulated radio signal for each of the transmission antennas, and the portable communication device is configured to transmit the plurality of transmission antennas from the plurality of transmission antennas. A demodulation unit that receives and demodulates a radio signal that is simultaneously transmitted and superimposed, an acquisition unit that acquires individual data included in the reception data that has been demodulated, and the acquired individual data And a response signal transmitting unit for transmitting a response signal obtained by modulating the reception data, wherein the on-vehicle communication device receives and demodulates the response signal transmitted from the portable communication device, and the received data obtained by demodulation And a determination unit that determines the relative position of the portable communication device with respect to the vehicle based on the individual data included in.

In this aspect, different individual data is defined for each of a plurality of transmitting antennas arranged at a distance from the vehicle. The on-vehicle communication device generates transmission data including individual data for each transmission antenna, modulates the transmission data according to the ASK modulation method, and simultaneously transmits signals modulated from the plurality of transmission antennas. By transmitting radio signals simultaneously from a plurality of transmitting antennas, the on-vehicle communication device can perform wireless communication with the portable communication device in a wide communication range. Further, when radio signals obtained by ASK-modulating different individual data are simultaneously transmitted, the combination of the values of the individual data results in a mixture of bits in which the signal amplitude is amplified and non-amplified bits. As a result, the individual data included in the wireless signal received by the portable communication device from the vehicle changes in accordance with the distance from the vehicle to the portable communication device, the position, and the like. By acquiring the individual data included in the wireless signal received by the portable communication device and including it in the response signal and transmitting it to the in-vehicle communication device, the in-vehicle communication device can accept the vehicle based on the individual data included in the response signal. The relative position of the portable communication device can be determined.

(2) Two individual data corresponding to two transmitting antennas having overlapping transmission ranges of radio signals are the logical product of the two individual data, the logical sum of the two individual data, and the two individual data Preferably, it is determined to be different from each value of.

In this aspect, different individual data is predetermined for each of the transmission antennas. Two individual data corresponding to two transmission antennas whose transmission ranges of radio signals overlap each other are determined such that the logical product, the logical sum, and the two individual data have different values. As a result, when two modulation signals obtained by ASK-modulating two different individual data are superimposed, the amplitude of the signal corresponding to a part of bits included in the individual data is amplified, and the receivable range is expanded. The position of the portable communication device can be determined based on the individual data included in the wireless signal received by the portable communication device.

(3) The transmission antennas are disposed at at least four locations on the right front, right rear, left front and left rear of the vehicle, and the transmission processing unit of the in-vehicle communication device includes the right front and right Preferably, simultaneous transmission of radio signals from the transmission antenna on the rear side and simultaneous transmission of radio signals from the transmission antennas on the left front and left rear sides are alternately performed.

In this aspect, transmitting antennas are disposed at at least four locations on the front right side, the rear right side, the front left side, and the rear left side of the vehicle. The on-vehicle communication device alternately performs simultaneous transmission of radio signals from the transmission antennas on the right front and right rear sides and simultaneous transmission of radio signals from the transmission antennas on the left front and left rear sides. As a result, communication and position determination with the portable communication device on the right side of the vehicle and communication and position determination with the portable communication device on the left side of the vehicle are alternately performed. By reducing the number of transmission antennas that transmit at the same time, it is possible to prevent the complication of the overlapping relationship of the wireless signals, and it is possible to easily determine the position of the portable communication device using different individual data.

(4) The on-vehicle communication device according to the present aspect transmits a wireless signal using a plurality of transmitting antennas disposed apart from the vehicle, and a response from the portable communication device to be transmitted according to the wireless signal. In an on-vehicle communication device for receiving a signal, a modulation unit that modulates transmission data including individual data defined for each of the transmission antennas according to an ASK modulation method, and a modulated radio signal for each of the transmission antennas is used for transmission. A transmission processing unit that transmits simultaneously from an antenna; and a demodulation unit that receives and demodulates the response signal from the portable communication device that acquires individual data included in the received wireless signal and returns it in a response signal. And a determination unit that determines the relative position of the portable communication device with respect to the vehicle based on individual data included in the demodulated reception data.

In this aspect, as in aspect (1), the in-vehicle communication device generates transmission data including individual data for each transmission antenna, and modulates the transmission data according to the ASK modulation method, and modulates each signal. Simultaneously from multiple transmit antennas. The portable communication device acquires individual data included in the received wireless signal, includes it in a response signal, and transmits it to the in-vehicle communication device. As a result, the in-vehicle communication device can perform wireless communication with the portable communication device in a wide communication range, and the in-vehicle communication device can compare the portable communication device to the vehicle based on the individual data included in the response signal. Position can be determined.

(5) The vehicle communication method according to this aspect comprises: an on-vehicle communication device for transmitting a wireless signal using a plurality of transmitting antennas disposed apart from the vehicle; and a wireless signal transmitted from the on-vehicle communication device In the vehicle communication method in which wireless communication is performed with a portable communication device that receives and transmits a response signal, the on-vehicle communication device performs ASK modulation on transmission data including individual data defined for each of the transmission antennas. The modulated and modulated radio signal for each of the transmitting antennas is simultaneously transmitted from each of the transmitting antennas, and the portable communication device receives the superimposed radio signals which are simultaneously transmitted from the plurality of transmitting antennas. And receiving the individual data included in the received data, and transmitting a response signal obtained by modulating transmission data including the acquired individual data, wherein the on-vehicle communication device transmits the response signal to the portable communication device. Receiving a response signal transmitted from the device and demodulating, on the basis of the individual data included in the received data demodulated to determine the relative position of the portable communication device relative to the vehicle.

Details of Embodiments of the Present Disclosure
A specific example of a vehicular communication system according to an embodiment of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, is shown by the claims, and is intended to include all modifications within the scope and meaning equivalent to the claims.

<System outline>
FIG. 1 is a schematic view showing an outline of a communication system 1 for a vehicle according to the present embodiment. The vehicular communication system 1 according to the present embodiment uses various four radio frequency (LF) transmitting antennas 4a to 4d and one radio frequency (RF) receiving antenna 5 provided in the vehicle 2 to transmit various radio signals. The electronic control unit (ECU) 3 that transmits and receives, and one or more portable remote controls (remote controllers) 7 that transmit and receive wireless signals to and from the ECU 3 are configured. The ECU 3 controls the operation of various electrical components mounted on the vehicle 2 based on the communication result of the wireless communication using the LF transmitting antennas 4a to 4d and the RF receiving antenna 5.

The four LF transmission antennas 4a to 4d are arranged in the tire house of each tire or in the vicinity thereof in association with the four tires of the vehicle 2, respectively. In FIG. 1, the vertical and horizontal directions of the drawing correspond to the longitudinal and lateral directions of the vehicle 2, the LF transmission antenna 4a is disposed on the right front side of the vehicle 2, and the LF transmission antenna 4b is disposed on the right rear side. The transmitting antenna 4c is disposed on the left rear side, and the LF transmitting antenna 4d is disposed on the left front side. The LF transmitting antennas 4a to 4d are connected to the ECU 3 disposed at an appropriate position of the vehicle 2 through signal lines. The LF transmission antennas 4a to 4d are antennas used when the ECU 3 transmits a radio signal of the LF band. The RF receiving antenna 5 is an antenna used when the ECU 3 receives a radio signal in the UHF (Ultra High Frequency) band.

The vehicular communication system 1 according to the present embodiment may have a function of monitoring the air pressure of the tire of the vehicle 2, that is, the so-called TPMS (Tire Pressure Monitoring System). In this case, each tire of the vehicle 2 is attached with a sensor unit having a function of air pressure detection of the tire and wireless communication. The ECU 3 transmits a radio signal to the sensor unit of each tire by the LF transmitting antennas 4a to 4d, and receives a response from the sensor unit by the RF receiving antenna 5. The ECU 3 acquires the detection result of the air pressure of the tire included in the response from each sensor unit, and displays the detection result of the air pressure of the tire on a display provided in the vicinity of the driver's seat of the vehicle 2, for example When the value of V falls below the threshold value, processing such as issuing a warning is performed.

The vehicular communication system 1 according to the present embodiment determines whether or not the portable remote controller 7 possessed by the user is present in the vicinity of the vehicle 2 and determines the relative position of the portable remote controller 7 with respect to the vehicle 2. Do. Thereby, the communication system 1 for vehicles can perform the process which unlocks the lock of the door of the vehicle 2 according to the approach of the portable remote control 7, or the process which lights the interior light and the exterior light of the vehicle 2, etc.

In the present embodiment, the ECU 3 performs processing alternately on the right and left sides of the vehicle 2. That is, the ECU 3 transmits radio signals by the

LF transmission antennas

4a and 4b on the right side of the vehicle 2 to determine the presence or absence of the portable remote controller 7, and then transmits radio signals by the

LF transmission antennas

4c and 4d on the left side It is determined whether the remote control 7 is present. The ECU 3 periodically and repeatedly performs the left and right alternate determination as in the determination on the right side, the determination on the left side, the determination on the right side, the determination on the left side, and so on. In the following description, details will be described focusing on the process related to the right side of the vehicle 2, but the process related to the left side is the same, so the detailed description will be omitted.

The ECU 3 periodically (for example, with a period of several hundreds of milliseconds to several seconds) transmits a radio signal of the LF band from the

LF transmitting antennas

4a and 4b in a situation where the portable remote controller 7 does not exist around the vehicle 2. The ECU 3 determines whether or not the portable remote controller 7 is within the communication range of the wireless communication by determining whether or not the response signal from the portable remote controller 7 to this signal transmission is received by the RF receiving antenna 5; It is determined whether or not the portable remote controller 7 exists around the vehicle 2. At this time, the ECU 3 simultaneously (simultaneously) transmits the same radio signal from the plurality of

LF transmission antennas

4a and 4b, the radio signals transmitted from the plurality of

LF transmission antennas

4a and 4b are superimposed, and the reach range thereof Spreads. Note that simultaneous transmission of radio signals by the plurality of

LF transmission antennas

4a and 4b may be performed by superimposing and amplifying the plurality of radio signals, as long as the reach range is expanded simultaneously, and some error may be tolerated.

The reach of the radio signal when the ECU 3 simultaneously transmits the same radio signal from the two

LF transmission antennas

4a and 4b, that is, the communicable range of the ECU 3 and the portable remote controller 7 is indicated as a dashed area A in FIG. Further, FIG. 1 shows a communicable range when the ECU 3 transmits a radio signal from only the LF transmission antenna 4a as a region B1 of a broken line, and a communicable range when the ECU 3 transmits a radio signal only from the LF transmission antenna 4b. Is shown as a dashed area B2. The position of the portable remote controller 7 shown in FIG. 1 can receive this radio signal when the ECU 3 simultaneously transmits radio signals from the two

LF transmission antennas

4a and 4b, but only one of the

LF transmission antennas

4a and 4b When the wireless signal is transmitted from the position, the wireless signal can not be received. When receiving the LF band radio signal from the ECU 3, the portable remote controller 7 returns a response signal in the UHF band.

The ECU 3 according to the present embodiment employs an ASK (Amplitude Shift Keying) modulation method (amplitude shift keying method) to transmit a wireless signal to the portable remote controller 7. FIG. 2 is a schematic view showing an example of the ASK modulation method. The ASK modulation method is one of the methods of converting digital data represented by binary values of "0" and "1" into a signal for wireless transmission using a carrier wave such as a sine wave. The ASK modulation method is a method of performing modulation by changing the amplitude corresponding to a bit string of transmission data while holding the frequency and phase of the carrier wave. In the ASK modulation method, for example, the amplitude of the carrier wave is reduced with respect to "0" of transmission data, and the amplitude of the carrier wave is increased with respect to "1" of transmission data. As shown in FIG. 2, the ECU 3 according to the present embodiment controls a switch or the like according to the value of transmission data, turns the carrier wave on and off, and outputs it to obtain a simple ASK modulation method to obtain a modulation wave ( This scheme modulates transmission data in what may be called an on-off modulation scheme.

Further, in the present embodiment, the transmission data transmitted from each of the LF transmission antennas 4a to 4d by the ECU 3 includes common data common to all the LF transmission antennas 4a to 4d and individual data different for each of the LF transmission antennas 4a to 4d. It is included. FIG. 3 is a schematic view showing a configuration example of transmission data. The transmission data that the ECU 3 transmits to the portable remote controller 7 includes, for example, a header, common data, individual data, and a footer. The header and footer include, for example, data defined by the communication protocol between the ECU 3 and the portable remote controller 7. The common data may include, for example, identification information of the vehicle 2 or authentication information for performing an authentication process.

The individual data included in the transmission data is 4-bit data in the present embodiment, and stores 4-bit IDs individually assigned to the LF transmission antennas 4a to 4d. In the present embodiment, individual IDs are previously assigned to the four LF transmission antennas 4a to 4d provided in the vehicle 2. In the present embodiment, ID = “0110” is assigned to the LF transmission antenna 4a on the right front side, and ID = “0011” is assigned to the LF transmission antenna 4b on the right rear side, and the LF transmission antenna on the left rear side It is assumed that ID = “1001” is assigned to 4c, and ID = “1100” is assigned to the LF transmission antenna 4d on the right front side.

The ID of each of the LF transmission antennas 4a to 4d can be determined, for example, based on the following conditions. The IDs of the LF transmitting antennas 4a to 4d include at least one bit "0" and at least one bit "1" ("0000" and "1111" are not used as IDs). The ID of each of the LF transmitting antennas 4a to 4d should be equal to or substantially the same as the Hamming weight (ie, the number of "1" s in the bit string). When comparing the IDs of two adjacent LF transmission antennas 4a to 4d (two LF transmission antennas 4a to 4d whose transmission ranges overlap) in the arrangement in the vehicle 2, the Hamming distance between both IDs (at each digit of the bit string) The number of items with different values must be 2 or more. When the IDs of two adjacent LF transmission antennas 4a to 4d are compared with each other, “1” exists at the same position in each digit of the bit string of both IDs.

In other words, if, for example, the IDs of two adjacent antennas are a and b, the logical sum of both IDs is c = a + b, and the logical product of both IDs d = a · b, a, b, c, a and b may be determined such that four of d have different values.

In the present embodiment, the

LF transmission antennas

4a and 4b are adjacent to each other, the

LF transmission antennas

4b and 4c are adjacent to each other, the

LF transmission antennas

4c and 4d are adjacent to each other, and the

LF transmission antennas

4d and 4a are adjacent to each other. Four IDs are defined as adjacent ones. However, in the present embodiment, since the processing is separately performed on the left side and the right side of vehicle 2, the above conditions are necessarily taken into consideration for the combination of

LF transmission antennas

4b and 4c and the combination of

LF transmission antennas

4d and 4a. You may define an ID without doing it.

Also, the four IDs employed in the present embodiment are an example, and the present invention is not limited to this. Furthermore, the above condition is also an example, and is not limited to this, and the ID may be determined according to different conditions. The ID of each of the LF transmission antennas 4a to 4d may be any value as long as the following processing can be realized.

The ECU 3 according to the present embodiment modulates transmission data having the same common data, the same header and footer, and different individual data according to the ASK modulation method, and the radio signal obtained by the modulation is included in this signal. It transmits simultaneously from

LF transmission antenna

4a, 4b corresponding to separate data. The radio signals simultaneously transmitted from the two

LF transmission antennas

4a and 4b are amplified in amplitude by superimposing portions corresponding to the common data, the header and the footer, and the reach range extends to the range A shown in FIG. However, the portions corresponding to the individual data of the radio signal have different data values, so that the amplitude is not necessarily amplified by superposition by transmission from the two

LF transmission antennas

4a and 4b.

FIG. 4 is a schematic view for explaining superimposition of radio signals corresponding to individual data. The top row of FIG. 4 shows the waveform of the carrier wave. Below the waveform of the carrier wave of FIG. 4, the individual data and its modulation wave included in the transmission data transmitted from the LF transmission antenna 4a, and the individual data and modulation thereof included in the transmission data transmitted from the LF transmission antenna 4b Shows the waves. The lowermost part of FIG. 4 shows a superimposed wave in the case where the modulated wave transmitted from the LF transmission antenna 4a and the modulated wave transmitted from the LF transmission antenna 4b are superimposed.

The modulated wave modulated by the ASK modulation method has a waveform in which a carrier wave is output corresponding to “1” included in the individual data. For this reason, when two modulated waves corresponding to two individual data having different values are superimposed, the amplitude of the superimposed wave is amplified only for the bits in which “1” s included in the two individual data overlap. The amplitude is not amplified for the other bits. In the case of the illustrated example, when two modulated waves corresponding to the two individual data of “0110” and “0011” are superimposed, the “1” of the third bit from the upper side overlaps, so the superimposed wave The amplitude corresponding to the third bit is amplified.

The radio signal reaches the range A shown in FIG. 1 for the bits whose amplitudes are amplified in the superimposed wave, but the radio signal reaches only the ranges B1 and B2 shown in FIG. 1 for the other bits. Therefore, for example, when the portable remote controller 7 is present at the position shown in FIG. 1, the individual data included in the wireless signal received by the portable remote controller 7 from the vehicle 2 is “0010”. In addition, in a place where the range B1 where the radio signal of the LF transmitting antenna 4a alone reaches and the range B2 where the radio signal of the LF transmitting antenna 4b alone reaches overlap, the portable remote controller 7 is included in the radio signal received from the vehicle 2. The individual data to be sent is "0111". At a place where the radio signal from the LF transmission antenna 4a arrives but the radio signal from the LF transmission antenna 4b does not reach, the individual data included in the radio signal received by the portable remote controller 7 from the vehicle 2 is "0110". Although the radio signal from the LF transmission antenna 4a does not arrive, at the place where the radio signal from the LF transmission antenna 4b arrives, the individual data included in the radio signal that the portable remote controller 7 receives from the vehicle 2 is "0011".

In other words, at the place where the radio signal is not received unless the amplitude is amplified by superposition, the logical product (AND) of the two individual data corresponding to the two

LF transmission antennas

4a and 4b that transmitted the radio signal It will be included as individual data in the received data of 7. Further, in a place where the range B1 in which the radio signal of the LF transmitting antenna 4a alone reaches and the range B2 in which the radio signal of the LF transmitting antenna 4b alone reaches overlap, the two

LF transmitting antennas

4a and 4b which transmit the radio signal The logical sum (OR) of the two individual data corresponding to is included in the reception data of the portable remote control 7 as the individual data. At the place where the portable radio signal from the LF transmission antenna 4a arrives, the reception data of the portable remote controller 7 includes the individual data of the LF transmission antenna 4a. At the place where the portable radio signal from the LF transmission antenna 4b arrives, the received data of the portable remote controller 7 includes the individual data of the LF transmission antenna 4b.

The portable remote controller 7 that has received the wireless signal transmitted by the ECU 3 of the vehicle 2 acquires individual data included in the received data. The portable remote controller 7 generates a response signal including the acquired individual data and information such as identification information and authentication information, and transmits the response signal as a UHF band radio signal. The ECU 3 receives the response signal transmitted from the portable remote controller 7 as a wireless signal in the UHF band to the RF receiving antenna 5. The ECU 3 determines, based on the information included in the response signal from the portable remote controller 7, whether or not the portable remote controller 7 of the transmission source is the correct one associated with the vehicle 2. Note that the vehicle communication system 1 may be configured to transmit and receive radio signals several times in order to perform authentication processing between the ECU 3 and the portable remote controller 7. When the portable remote control 7 is correct, the ECU 3 determines the relative position of the portable remote control 7 with respect to the vehicle 2 based on the individual data included in the response signal. The position of the portable remote controller 7 determined by the ECU 3 is in which of the four ranges shown in FIG. 1 the portable remote controller 7 is present.

<Device configuration>
FIG. 5 is a block diagram showing the configuration of the ECU 3 according to the present embodiment. The ECU 3 according to the present embodiment includes a processing unit (processor) 30, a storage unit (storage) 31, an LF transmission unit 32, an RF reception unit 33, an input unit 34, an in-vehicle communication unit 35, and the like. The processing unit 30 is configured using an arithmetic processing unit such as a central processing unit (CPU) or a micro-processing unit (MPU), and reads and executes the program 31 a stored in the storage unit 31 to perform various operations. Processing and control processing can be performed. In the present embodiment, the processing unit 30 performs, for example, communication processing with the portable remote controller 7, position determination processing of the portable remote controller 7, and the like. The processing unit 30 may also perform lock control processing of the door of the vehicle 2 according to the communication with the portable remote controller 7, and lighting control processing of the interior light and the exterior light. Furthermore, the processing unit 30 can also perform processing related to TPMS, for example, communication processing with the sensor unit of each tire, determination processing of the tire pressure of the tire, notification processing of the determination result, and the like.

The storage unit 31 is configured using, for example, a non-volatile memory element such as a flash memory or an EEPROM (Electrically Erasable Programmable Read Only Memory). The storage unit 31 stores various programs 31 a executed by the processing unit 30 and various data necessary for the processing of the processing unit 30. In the present embodiment, the storage unit 31 stores the ID attached to the four LF transmission antennas 4a to 4d as the ID information 31b. Further, the processing unit 30 may store various data generated in the processing process in the storage unit 31.

The LF transmitter 32 is connected to four LF transmitter antennas 4a to 4d via signal lines. The LF transmission unit 32 modulates the digital transmission data supplied from the processing unit 30 based on the ASK modulation scheme, and outputs the modulated signal to the LF transmission antennas 4a to 4d to thereby transmit an LF band radio signal. Send The processing unit 30 can provide different transmission data to the LF transmission unit 32 for each of the LF transmission antennas 4a to 4d, and the LF transmission unit 32 modulates different transmission data for each of the LF transmission antennas 4a to 4d. It can transmit simultaneously from the LF transmission antennas 4a to 4d. In the present embodiment, processing unit 30 generates transmission data having different IDs as individual data for each of LF transmission antennas 4a to 4d and supplies them to LF transmission unit 32, and LF transmission unit 32 transmits radio signals having different individual data. It simultaneously transmits from a plurality of LF transmission antennas 4a to 4d. The RF reception unit 33 receives a radio signal in the UHF band at the RF reception antenna 5 and applies digital reception data obtained by demodulating the received radio signal to the processing unit 30.

The input unit 34 receives input of signals from various electrical components provided in the vehicle 2 and gives the received input signal to the processing unit 30 as digital input data. In the present embodiment, a signal from an IG (ignition) switch 61 of the vehicle 2 and a signal from a door switch 62 provided on each door of the vehicle 2 are input to the input unit 34. The IG switch 61 inputs an IG signal indicating the operating state of the engine of the vehicle 2 to the ECU 3. The door switch 62 detects an opening operation of the user with respect to the door of the vehicle 2 and inputs a signal to notify the presence or absence of the opening operation to the ECU 3.

The in-vehicle communication unit 35 is connected to a communication line disposed in the vehicle 2 and can communicate with other in-vehicle devices via the communication line. The in-vehicle communication unit 35 can be configured to perform communication in accordance with, for example, a CAN (Controller Area Network) communication protocol. The in-vehicle communication unit 35 transmits the message by converting the transmission message supplied from the processing unit 30 into an electric signal and outputting the electric signal to the communication line. Further, the in-vehicle communication unit 35 receives a message by sampling and acquiring the potential of the communication line, and gives the received message to the processing unit 30. In the present embodiment, the lighting ECU 63, the door ECU 64, and the like are connected to the ECU 3 via a communication line.

The lighting ECU 63 is connected to a plurality of interior lights and exterior lights mounted on the vehicle 2 and controls lighting and extinguishing of these. The control target of the lighting ECU 63 may be, for example, an existing light emitting unit such as a headlamp of the vehicle 2, a tail lamp, a direction indicator, a hazard lamp, and a room lamp. In the present embodiment, the control target of the lighting ECU 63, as the light emitting portion for the welcome light, illuminates the front, the rear, the side, the right diagonal front, the left diagonal front, the right diagonal rear and the left diagonal rear of the vehicle 2 exceptionally. Let it be a light emitting part. The ECU 3 can control lighting and extinguishing of the light emitting units by giving an instruction of lighting or extinguishing each light emitting unit to the lighting ECU 63 through communication by the in-vehicle communication unit 35.

The door ECU 64 drives a lock mechanism that locks and unlocks the door of the vehicle 2. The ECU 3 can control locking / unlocking of the door of the vehicle 2 by giving an instruction to the door ECU 64 by communication by the in-vehicle communication unit 35. For example, when the door switch 62 provided at the door of the vehicle 2 is operated, the ECU 3 performs wireless communication with the portable remote controller 7, succeeds in the authentication of the portable remote controller 7, and the portable remote controller 7 exists around the vehicle 2. If it is determined that the door ECU 64 determines that the door ECU 64 is locked or unlocked. Further, for example, the ECU 3 determines the position of the portable remote controller 7 when the door of the vehicle 2 is opened and closed with the IG switch 61 turned off, and a locking instruction is issued to the door ECU 64 when the portable remote controller 7 is separated from the vehicle 2 It may be sent to. When the door ECU 64 receives a locking or unlocking command from the ECU 3, the door ECU 64 drives the locking mechanism to lock or unlock the door of the vehicle 2. Further, the door ECU 64 locks or unlocks the door of the vehicle 2 by driving the lock mechanism according to the operation of the locking / unlocking switch provided in the vehicle, and the information indicating the locking / unlocking state of the door of the vehicle 2 is It transmits to ECU3 by communication. The ECU 3 can recognize the locking / unlocking state of the door of the vehicle 2 by receiving the information transmitted from the door ECU 64 by the in-vehicle communication unit 35.

Further, in the ECU 3 according to the present embodiment, the processing unit 30 reads out and executes the program 31a stored in the storage unit 31 so that the communication processing unit 41, the position determination unit 42, etc. It is realized as a block. The communication processing unit 41 performs wireless communication with the portable remote controller 7 by exchanging commands and information with the LF transmission unit 32 and the RF reception unit 33. For example, the communication processing unit 41 causes the LF transmission unit 32 to periodically transmit a wireless signal, and determines whether the RF reception unit 33 has received a response signal to the wireless signal. A process is performed to determine whether the remote control 7 is present. When the communication processing unit 41 receives a response signal from the portable remote controller 7, the communication processing unit 41 performs processing to determine whether the portable remote controller 7 is legitimate or not based on the information included in the response signal. The communication processing unit 41 controls which one of the four LF transmission antennas 4a to 4d is to be used when transmitting a radio signal by the LF transmission unit 32, and transmission from each of the LF transmission antennas 4a to 4d Perform processing such as data generation.

The position determination unit 42 receives the response signal transmitted from the portable remote controller 7 by the RF reception unit 33, and performs processing of determining the position of the portable remote controller 7 based on the individual data included in the received response signal. The ECU 3 stores, for example, in the storage unit 31, the correspondence between the individual data that can be received by the portable remote controller 7 and the position around the vehicle 2 with respect to the individual data. The position determination unit 42 can determine the position of the portable remote controller 7 by comparing the correspondence relationship between the stored individual data and the position with the individual data included in the response signal from the portable remote controller 7.

According to the position of the portable remote controller 7 determined by the position determination unit 42, for example, the processing unit 30 gives a command to turn on / off the light emitting unit to the lighting ECU 63 to emit light according to the position of the portable remote controller 7 Lights up or blinks to realize a welcome light.

FIG. 6 is a block diagram showing the configuration of the portable remote controller 7 according to the present embodiment. The portable remote controller 7 according to the present embodiment is configured to include a control unit 70, a storage unit 71, an LF reception unit 72, an RF transmission unit 73, and the like. The control unit 70 realizes wireless communication between the ECU 3 of the vehicle 2 and the portable remote controller 7 by controlling the operation of each part of the portable remote controller 7. The storage unit 71 is configured using, for example, a non-volatile memory element such as an EEPROM or a mask ROM (Read Only Memory). The storage unit 71 stores various data necessary for the process performed by the control unit 70. For example, the storage unit 71 stores authentication information 71 a necessary for an authentication process with the ECU 3 of the vehicle 2. The authentication information 71a can be, for example, information such as identification information of the portable remote controller 7, a password, and an encryption key.

The LF reception unit 72 is connected to the LF reception unit 72. The LF reception unit 72 supplies digital reception data obtained by demodulating the radio signal of the LF band received by the LF reception antenna 7 a to the control unit 70. The RF transmission unit 73 is connected to the RF transmission antenna 7 b. The RF transmission unit 73 transmits a radio signal in the RF band by outputting a signal obtained by modulating the data for transmission given from the control unit 70 to the RF transmission antenna 7 b.

The control unit 70 of the portable remote controller 7 according to the present embodiment acquires the individual data included in the reception data when the LF reception unit 72 receives the radio signal of the LF band transmitted by the ECU 3 of the vehicle 2. The control unit 70 generates transmission data for response including the acquired individual data and the authentication information 71 a stored in the storage unit 71, and supplies the transmission data to the RF transmission unit 73. At this time, the portable remote controller 7 performs an authentication process to determine whether the received radio signal in the LF band is from the legitimate vehicle 2 and for response only when it is determined to be the legitimate one. Transmission data may be generated. However, in the present embodiment, the description of the authentication process by the portable remote controller 7 is omitted. The RF transmission unit 73 to which transmission data for response is given from the control unit 70 modulates this and outputs it to the RF transmission antenna 7 b to transmit a response signal in the UHF band to the vehicle 2.

<Processing procedure>
FIG. 7 is a flowchart showing the procedure of communication processing performed by the ECU 3. However, since this flowchart shows the procedure of the communication processing regarding the right side of the vehicle 2 and the communication processing regarding the left side is the same, the detailed procedure is omitted. The communication processing unit 41 of the processing unit 30 of the ECU 3 according to the present embodiment acquires an ID corresponding to the

LF transmission antennas

4a and 4b to be used from the ID information 31b stored in the storage unit 31 (step S1). The communication processing unit 41 sets the acquired ID as individual data, and generates two transmission data to be transmitted by the two

LF transmission antennas

4a and 4b (step S2). The communication processing unit 41 gives the generated transmission data to the LF transmission unit 32, and gives a transmission command to the LF transmission unit 32, thereby simultaneously transmitting radio signals from the two

LF transmission antennas

4a and 4b on the right front side and the right rear side. Is sent (step S3). The communication processing unit 41 determines whether the RF receiving unit 33 receives a response signal from the portable remote controller 7 (step S4).

When the response signal from the portable remote controller 7 is not received (S4: NO), the communication processing unit 41 stands by for a predetermined time by counting using the timer function in the processing unit 30 (step S7). The predetermined time defines a cycle in which the ECU 3 checks the presence or absence of the portable remote controller 7. For example, a time of several hundred milliseconds to several seconds is set in advance. After the predetermined time has elapsed, the ECU 3 performs communication processing on the left side of the vehicle 2 (step S8), and returns the process to step S1.

When the response signal from the portable remote control 7 is received (S4: YES), the communication processing unit 41 determines whether or not the portable remote control 7 is legitimate based on the authentication information included in the response signal. A process is performed (step S5), and it is determined whether the authentication is successful (step S6). If the authentication fails (S6: NO), that is, if the portable remote control 7 is not legitimate, the communication processing unit 41 stands by for a predetermined time (step S7) and performs communication processing on the left side of the vehicle 2 (step S7) S8), the process returns to step S1.

If the authentication is successful (S6: YES), that is, if the portable remote control 7 is legitimate, the position determination unit 42 of the processing unit 30 acquires individual data included in the response signal from the portable remote control 7 (step S9). The position determination unit 42 determines the position of the portable remote controller 7 based on the acquired individual data and the correspondence between the individual data stored in the storage unit 31 and the position (step S10). The processing unit 30 performs control to turn on the light emitting unit of the vehicle 2 mounted at the corresponding position based on the position of the portable remote controller 7 determined in step S10 (step S11), and ends the process.

FIG. 8 is a flowchart showing the procedure of communication processing performed by the portable remote controller 7. The control unit 70 of the portable remote controller 7 determines whether or not the radio frequency signal transmitted by the ECU 3 of the vehicle 2 has been received by the LF reception unit 72 (step S21). When the wireless signal is not received (S21: NO), the control unit 70 stands by until the wireless signal is received. If a wireless signal is received (S21: YES), the control unit 70 acquires individual data included in the received data (step S22). The control unit 70 transmits a response signal including the acquired individual data from the RF transmission unit 73 to the ECU 3 (step S23), and ends the process.

<Summary>
The vehicular communication system 1 according to the present embodiment having the above configuration has a plurality of LF transmission antennas 4a to 4d spaced apart from each other on the vehicle 2, and separate individual data (for each LF transmission antenna 4a to 4d ( Determine the ID). The ECU 3 generates transmission data including individual data for each of the LF transmission antennas 4a to 4d, modulates the generated transmission data with the LF transmission unit 32 according to the ASK modulation method, and respectively modulates the modulated signals. Send at the same time from 4d. By simultaneously transmitting radio signals from the plurality of LF transmission antennas 4a to 4d, the ECU 3 can perform radio communication with the portable remote controller 7 in a wide communication range A.

Further, when radio signals obtained by ASK-modulating different individual data are simultaneously transmitted, the combination of the values of the individual data results in a mixture of bits in which the signal amplitude is amplified and non-amplified bits. Thereby, the individual data included in the wireless signal received by the portable remote controller 7 from the ECU 3 of the vehicle 2 changes in accordance with the distance from the vehicle 2 to the portable remote controller 7, the position, and the like. By acquiring individual data included in the wireless signal received by the portable remote controller 7 and including it in the response signal and transmitting it to the ECU 3, the ECU 3 compares the portable remote controller 7 with respect to the vehicle 2 based on the individual data included in the response signal. Position can be determined.

For the four LF transmission antennas 4a to 4d provided in the vehicle 2, different individual data are predetermined. The two individual data corresponding to the two LF transmission antennas 4a to 4d having overlapping radio signal transmission ranges are determined such that the logical product, the logical sum, and the two individual data have different values. Thus, when two modulation signals obtained by ASK-modulating two different individual data are superimposed, the amplitude of the signal corresponding to a part of the bits included in the individual data is amplified and the receivable range is determined. spread. Therefore, by determining the individual data included in the wireless signal received by the portable remote controller 7, the position of the portable remote controller 7 can be determined.

In the vehicle 2, an LF transmission antenna 4a is disposed on the right front side, an LF transmission antenna 4b is disposed on the right rear side, an LF transmission antenna 4c is disposed on the left rear side, and an LF transmission antenna 4d is disposed on the left front side. It is done. The ECU 3 alternately performs transmission of radio signals using the right front and right rear

LF transmission antennas

4a and 4b and transmission of radio signals using the left rear and left front

LF transmission antennas

4c and 4d. . Thus, the ECU 3 alternately performs communication with the portable remote controller 7 on the right side of the vehicle 2 and position determination, and communication with the portable remote controller 7 on the left side of the vehicle 2 and position determination. By using two LF transmitting antennas 4a to 4d for simultaneously transmitting radio signals, it is possible to prevent the complication of the overlapping relationship of radio signals and to facilitate position determination of portable remote controller 7 using different individual data. .

With the above configuration, the vehicular communication system 1 according to the present embodiment can expand the communicable range between the ECU 3 and the portable remote controller 7 possessed by the user, and the ECU 3 detects the position of the portable remote controller 7. Can.

In the present embodiment, although the LF transmitting antennas 4a to 4d and the RF receiving antenna 5 for performing wireless communication with the portable remote controller 7 are shared by the ECU 3 with wireless communication with the TPMS sensor unit, It is not limited to this. Apart from the antenna for the TPMS, the LF transmitting antennas 4a to 4d and the RF receiving antenna 5 may be provided for the ECU 3 to perform wireless communication with the portable remote controller 7. Further, TPMS may not be mounted on the vehicle 2.

In the vehicle communication system 1 according to the present embodiment, the four LF transmission antennas 4a to 4d provided in the vehicle 2 are divided into two

LF transmission antennas

4a and 4b on the left side and two LF transmission antennas 4c on the right side, Although divided into 4 d and configured to perform processing such as wireless communication with the portable remote controller 7 and position determination alternately on the right and left sides of the vehicle 2, the present invention is not limited to this. For example, the processing may be performed by dividing the four LF transmission antennas 4a to 4d into the front side and the rear side of the vehicle 2. For example, as shown in the following modified example, the four LF transmission antennas 4a to 4d may be left and right You may process without dividing.

(Modification)
FIG. 9 is a schematic view showing an outline of a communication system 1 for a vehicle according to a modification. The vehicular communication system 1 according to the modification is configured to simultaneously transmit radio signals from four LF transmission antennas 4a to 4d provided in the vehicle 2. The left front side LF transmission antenna 4a of the vehicle 2 is assigned ID = "0110", the right rear side LF transmission antenna 4b is assigned ID = "0011", and the left rear side LF transmission antenna 4c. The ID = “1001” is assigned, and the LF transmission antenna 4 d on the front right is assigned an ID = “1100”. The ECU 3 according to the modification generates four transmission messages storing respective IDs of individual data, ASK-modulates each transmission message, and simultaneously transmits radio signals from the corresponding LF transmission antennas 4a to 4d.

The radio signals transmitted from the four LF transmission antennas 4a to 4d differ in reach of the radio signal for each of the LF transmission antennas 4a to 4d. The reach of the radio signals from the four LF transmitting antennas 4a to 4d partially overlap, and the radio signal is superimposed on this overlap to amplify the amplitude, and the reach of the radio signal is expanded. . At this time, for radio signals corresponding to individual data having different values to be transmitted for each of the LF transmission antennas 4a to 4d, the amplitude is amplified only for the bits in which “1” s included in the individual data overlap. The bits are not amplified in amplitude. Thereby, according to the position where the portable remote control 7 exists, the separate data contained in the radio signal which the portable remote control 7 receives becomes a different value.

In FIG. 9, when four LF transmission antennas 4 a to 4 d installed at four places on the right front side, right rear side, left rear side and left front side of the vehicle 2, radio signals with different individual data are simultaneously transmitted The values of the individual data in the received data according to the position of the portable remote controller 7 that receives the wireless signal are shown in FIG. However, in the illustrated example, two adjacent LF transmission antennas 4a to 4d such as right front and right rear, right rear and left rear, left rear and left front, and left front and right front The values of the individual data when two radio signals of are superimposed are shown.

In this example, the transmission range of each of the LF transmission antennas 4a to 4d is appropriately set so that three or more radio signals transmitted from the three or more LF transmission antennas 4a to 4d are not superimposed. It shall be. Alternatively, the process of simultaneously transmitting radio signals from the two LF transmission antennas 4a to 4d may be sequentially performed while changing the combination of the LF transmission antennas 4a to 4d. For example, processing for transmitting radio signals from the two LF transmission antennas 4a to 4d in the order of right front and right rear, right rear and left rear, left rear and left front, left front and right front, It may be repeated periodically.

When receiving the radio signal from the vehicle 2, the portable remote controller 7 acquires individual data included in the radio signal, and transmits the acquired individual data to the vehicle 2 by including the acquired individual data in the response signal. The ECU 3 of the vehicle 2 having received the response signal from the portable remote controller 7 acquires the individual data included in the response signal, and determines the position of the portable remote controller 7 based on the acquired individual data. The ECU 3 stores in advance the correspondence between the individual data received as a response signal and the relative position to the vehicle 2 as shown in FIG. 9, and determines the position of the portable remote controller 7 based on the stored correspondence. Do. The ECU 3 performs control to turn on / off, for example, light emitting units provided in various places of the vehicle 2 according to the determined position of the portable remote controller 7, and implements the function of the welcome light.

For example, when the individual data included in the response signal from the portable remote control 7 is "0100", the ECU 3 determines that the portable remote control 7 exists in front of the vehicle 2, and the light emission provided on the left and right of the front side of the vehicle 2 Control can be performed to turn on the unit. Further, for example, when the individual data included in the response signal is “1001”, the ECU 3 determines that the portable remote control 7 exists in the left rear of the vehicle 2 and turns on the light emitting unit provided on the left rear side of the vehicle 2 Control can be performed.

The correspondence between the reception range of the wireless signal and the individual data shown in FIG. 9 is an example, and the present invention is not limited to this. Also, a system may be adopted in which radio signals from three or more LF transmission antennas 4a to 4d are allowed to be superimposed. In this case, it is preferable to set the number of bits of the ID attached to each of the LF transmission antennas 4a to 4d to 5 bits or more, and to appropriately determine each ID so that superposition of three or more individual data can be distinguished.

1 communication system for vehicle 2 vehicle 3 ECU (vehicle-mounted communication device)
4a to 4d LF transmission antenna (transmission antenna)
5 RF Reception Antenna 7 Mobile remote control (portable communication device)
7a LF reception antenna 7b RF transmission antenna 30 processing unit 31 storage unit 31a program 32 LF transmission unit (modulation unit)
33 RF Receiver (Demodulator)
34 input unit 35 in-vehicle communication unit 41 communication processing unit (transmission processing unit)
42 Position determination unit (determination unit)
61 IG switch 62 door switch 63 lighting ECU
64 door ECU
70 control unit (acquisition unit)
71 storage unit 71a authentication information 72 LF reception unit (demodulation unit)
73 RF transmitter (response signal transmitter)

Claims

An on-vehicle communication device for transmitting a wireless signal using a plurality of transmitting antennas arranged at a distance from a vehicle, a portable communication device for receiving a wireless signal transmitted from the on-vehicle communication device and transmitting a response signal In a vehicle communication system comprising
The in-vehicle communication device is
A modulation unit that modulates transmission data including individual data determined for each of the transmission antennas according to ASK (Amplitude Shift Keying) modulation;
A transmission processing unit that simultaneously transmits the modulated radio signal for each of the transmission antennas from each of the transmission antennas;
The portable communication device is
A demodulation unit that receives and demodulates radio signals that are simultaneously transmitted and superimposed from the plurality of transmission antennas;
An acquisition unit for acquiring individual data included in the demodulated reception data;
A response signal transmission unit that transmits a response signal obtained by modulating transmission data including the acquired individual data;
The in-vehicle communication device is
A demodulation unit that receives and demodulates a response signal transmitted from the portable communication device;
A determination unit that determines the relative position of the portable communication device with respect to the vehicle based on individual data included in the demodulated reception data.
The two individual data corresponding to the two transmitting antennas overlapping in the transmission range of the radio signal are the logical product of the two individual data, the logical sum of the two individual data, and the two individual data, respectively. The communication system for a vehicle according to claim 1, wherein the value is determined to be different from the value.
The transmitting antennas are disposed at at least four locations on the front right side, the rear right side, the front left side, and the rear left side of the vehicle,
The transmission processing unit of the in-vehicle communication device simultaneously transmits radio signals from the transmission antennas on the right front side and the right rear side, and simultaneously transmits radio signals from the transmission antennas on the left front side and the left rear side. The communication system for vehicles according to claim 1 or 2 which performs alternately.
In an on-vehicle communication device, which transmits a wireless signal using a plurality of transmitting antennas arranged at a distance from a vehicle and receives a response signal from a portable communication device transmitted according to the wireless signal,
A modulation unit that modulates transmission data including individual data defined for each of the transmission antennas according to an ASK modulation method;
A transmission processing unit that simultaneously transmits the modulated radio signal for each of the transmission antennas from each of the transmission antennas;
A demodulation unit that receives and demodulates the response signal from the portable communication device, which acquires individual data included in the received wireless signal, includes it in a response signal, and returns it;
A determination unit that determines the relative position of the portable communication device with respect to the vehicle based on individual data included in the demodulated reception data.
An on-vehicle communication device for transmitting a wireless signal using a plurality of transmitting antennas arranged at a distance from a vehicle, a portable communication device for receiving a wireless signal transmitted from the on-vehicle communication device and transmitting a response signal In the vehicle communication method in which the wireless communication is performed,
The in-vehicle communication device is
The transmission data including individual data defined for each of the transmission antennas is modulated by ASK modulation,
Simultaneously transmitting the modulated radio signal for each of the transmitting antennas from each of the transmitting antennas;
The portable communication device is
Receive and demodulate radio signals simultaneously transmitted and superimposed from the plurality of transmission antennas;
Acquire individual data included in the demodulated received data,
Transmitting a response signal obtained by modulating transmission data including the acquired individual data;
The in-vehicle communication device is
Receiving and demodulating a response signal transmitted from the portable communication device;
A communication method for a vehicle, comprising: determining a relative position of the portable communication device with respect to the vehicle based on individual data included in the demodulated reception data.