JP2010068402A - Communication equipment for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To exactly recognize a transmission channel of a starting signal on the portable machine side by a vehicle unit to transmit vehicle information to the portable machine in correct timing even when attenuation amounts of other channels except the one which performs intermittent reception are insufficient. <P>SOLUTION: In the communication equipment 1 for vehicle consisting of the portable machine 10 and the vehicle unit 20, the portable machine 10 continuously and wirelessly transmits a first transmission signal by first and second channels, and becomes a receivable state after transmission of the first transmission signal. The vehicle unit 20 intermittently perform a receiving operation for receiving the first transmission signal by the first channel and the second channel, receives a data signal as the same channel when the starting signal is received, and calculates transmission timing in which the portable machine 10 becomes a state that a second transmission signal can be received from a channel number to be recognized from channel information added to the starting signal and the starting point or the end point of the received data signal. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle communication device for performing multi-channel communication between a portable device and an in-vehicle device.

  Conventionally, locking / unlocking of vehicle doors and the like has been generally performed by inserting a mechanical key common to the ignition key into the key cylinder of the door. Recently, however, the mechanical key is attached to the door key. Keyless entry systems that can be operated remotely without being inserted into a key cylinder have become widespread. In addition to keyless entry systems, when a button on a portable device is pushed away from the vehicle, communication is performed between the portable device and the in-vehicle device, and information on the vehicle side is returned from the in-vehicle device to the portable device for carrying. A vehicle communication device that can be displayed on a machine has been proposed (see, for example, Patent Document 1).

  Further, in a system that performs wireless communication between a portable device and a vehicle-mounted device at a single frequency (one channel), there is a problem that reception cannot be performed correctly if there is noise in the used frequency band. Therefore, a system has been proposed in which wireless communication between a portable device and an in-vehicle device can be switched to a plurality of channels (see, for example, Patent Document 2). In the vehicle control system described in Patent Document 2, a signal is transmitted from a portable device through a plurality of channels, a channel with less noise is determined by a receiver on the vehicle side, and the information is transmitted to the portable device side again.

Note that although the FSK (Frequency Shift Keying) method is known as a noise-resistant modulation method, there is a problem that the FSK method-compatible transmission circuit and reception circuit have a complicated circuit configuration, leading to an increase in cost. Also, depending on the region, the maximum value of the radio wave output of the FSK radio signal is kept low due to legal restrictions. For example, in the United States, the maximum value of radio wave output is determined to be as low as 6 dB in the FSK method compared to the ASK (Amplitude Shift Keying) method. For this reason, there is a possibility that a sufficient communication distance cannot be secured by the FSK method.
JP-A-4-315683 JP 2008-101344 A

  However, the vehicle control system described in Patent Document 2 has a problem that it takes time because the receiver on the vehicle side must determine a channel with less noise and transmit the information to the portable device side again.

  The present inventors have developed a vehicular communication device that combines the ASK method and the multi-channel method, and can switch to a channel with less noise without transmitting channel information with less noise from the receiver to the portable device. FIG. 3A is a conceptual diagram of a wireless communication method applied to the vehicle communication device proposed by the present inventors. When the portable device is operated, an activation signal and data are first transmitted on channel CH1, and after the last data (DATA4) is transmitted on channel CH1, the activation signal and data are subsequently transmitted on channel CH2. After sending the last data (DATA4) on the channel CH2, it enters a standby state in which a signal returned from the vehicle unit waits for a predetermined period. Note that all data (DATA1 to DATA4) includes the same data part including a command code such as lock / unlock and the ID code of the portable device, and is reliably received by transmitting the same signal multiple times. I am doing so. Note that data number information indicating the number of times of data transmission is also added to each of DATA1 to DATA4, and only this portion is different.

  The vehicle unit intermittently receives the channel CH1 and the channel CH2, and attenuates the channel CH2 with a filter when receiving the channel CH1, and conversely attenuates the channel CH1 with the filter when receiving the channel CH2. As shown in FIG. 3A, the activation signal transmission section T1 is longer than the intermittent reception period T2 of the vehicle unit, so that the vehicle unit transmits the activation signal of the channel CH1. Can always receive the activation signal intermittently on the channel CH1. Similarly, while the portable device is transmitting the activation signal of channel CH2, the vehicle unit can always intermittently receive the activation signal on channel CH2. In addition, even if the vehicle unit intermittently receives the channel CH2 while the portable device is transmitting the activation signal on the channel CH1, the channel CH1 signal is attenuated by the filter and thus the channel CH1 activation signal is not received. .

  If the vehicle unit intermittently receives the channel CH1 while the portable device is transmitting the activation signal of the channel CH1, the vehicle unit is activated by the activation signal, waits on the channel CH1, and is sent following the activation signal. The DATA3 of the frequency is received. (FIG. 3 shows an example received by DATA3). The receipt of the DATA3 signal is recognized from the data number information given to the data. When the vehicle unit succeeds in receiving DATA3 of channel CH1, the vehicle unit waits for transmission of the last data (DATA4) of channel CH2 from the reception timing of DATA3, and then transmits vehicle-side information to the portable device.

  When there is noise in the channel CH1, there is a possibility that the activation signal cannot be received even if the vehicle unit intermittently receives the channel CH1 in the section in which the portable device transmits the activation signal of the channel CH1. In this case, it is determined that the channel CH1 has not been received, and the activation signal is received when the next channel CH2 is intermittently received. When the vehicle unit receives the activation signal on the channel CH2, the vehicle unit is activated by the activation signal, waits on the channel CH2, and receives, for example, DATA3 having a frequency of CH2 sent after the activation signal. When the vehicle unit succeeds in receiving DATA3 of channel CH2, the vehicle unit waits for transmission of the last data (DATA4) of the channel CH2 from the reception timing of DATA3, and then transmits vehicle-side information to the portable device.

  As described above, when the channel CH1 cannot be received with noise without transmitting channel information with less noise from the vehicle unit to the portable device as in Patent Document 1, it is received with the subsequent channel CH2. Can do.

  However, in the ASK system, when the frequency bands of the channel CH1 and the channel CH2 are close to each other, there is a possibility that a signal is received on another channel when the attenuation amount by the filter is insufficient. FIG. 3B shows an example in which a malfunction is caused due to insufficient attenuation by the filter. The channel CH2 is intermittently received by the vehicle unit in the transmission period T1 of the activation signal of the channel CH1, but the activation signal of the channel CH1 is received on the channel CH2 because the attenuation amount of the channel CH1 is insufficient at this time. . After starting up with channel CH2, in the reception state of channel CH2, actually, for example, DATA3 of the frequency of CH1 is received. The vehicle unit misrecognizes that DATA3 of channel CH2 has been received, and the vehicle side information is transmitted to the portable device with only the DATA4 section. At this time, since the portable device transmits the activation signal of channel CH2 and is not in a standby state in which a signal from the vehicle unit can be received, the vehicle-side information transmitted by the vehicle unit cannot be received. As a result, communication fails, and the operator is forced to perform another operation.

  The present invention has been made in view of such a point, and even if the attenuation amount of other channels other than intermittent reception is insufficient, the transmission channel of the activation signal on the portable device side is provided in the vehicle unit. It is an object of the present invention to provide a vehicle communication device that can accurately recognize and transmit vehicle information to a portable device at the correct timing.

  The vehicle communication device of the present invention is a vehicle communication device having a first device provided on one of the portable device or the vehicle unit and a second device provided on the other of the portable device or the vehicle unit. The first device transmits a first transmission signal to the second device, and the first transmission signal is composed of a continuous signal in the first channel and the second channel, and each channel signal includes a preamble signal. And the data signal, the data signal has channel information for identifying which channel, and can receive the second transmission signal returned from the second device after the transmission of the first transmission signal. The second device intermittently performs a reception operation for receiving the first transmission signal on the first channel and the second channel at a predetermined period, and at the time of intermittent reception on one of the channels. If a preamble signal is received, the data signal is received as it is on the same channel, and the first device comprises the channel number recognized from the channel information added to the data signal and the reference point of the received data signal. Calculates a transmission timing at which the second transmission signal can be received.

  According to this configuration, in the second device, the first device can receive the second transmission signal from the channel number recognized from the channel information included in the data signal and the reference point of the received data signal. Transmission timing, i.e., the timing at which the first device is not transmitting a signal, even if the attenuation of other channels other than intermittent reception is insufficient, the first device side The transmission channel of the first transmission signal can be accurately recognized by the second device, and the second transmission signal can be transmitted to the first device at the correct timing.

  According to the present invention, in the above vehicle communication device, the first device includes a data portion in which a preamble signal is constituted by a start signal having a predetermined pattern and a data signal repeats a signal including the same data unit a predetermined number of times. The first device transmits the first transmission signal, and the second device repeats the reception operation by the first channel and the second channel at a cycle shorter than the transmission interval of the activation signal, and receives the activation signal from the standby state. It is characterized by returning.

  With this configuration, the second device can be returned from the standby state by the first transmission signal transmitted from the first device, and the data portion of the first transmission signal has a portion that repeats the same data unit a predetermined number of times. Thus, redundancy of the data signal can be provided.

  In the above vehicle communication device, it is preferable that the first device transmits an ASK-modulated first transmission signal.

  Further, the vehicle communication device of the present invention is provided in one of the portable device or the vehicle unit, and in the vehicle communication device that performs wireless communication with a counterpart device provided in the other of the portable device or the vehicle unit. A reception signal for receiving a first transmission signal including a data signal having channel information in the first channel and the second channel is intermittently performed at a predetermined cycle, and a preamble signal is received at the intermittent reception in any channel. Is received on the same channel, the partner device can receive the data signal from the channel number recognized from the channel information added to the data signal and the reference point of the received data signal. It is characterized in that the transmission timing to be in a state is calculated.

  According to this configuration, since the transmission timing at which the counterpart device can receive is calculated from the channel number recognized from the channel information of the data signal and the reference point of the received data signal, intermittent reception is performed. Even if the amount of attenuation of other channels is insufficient, the transmission channel of the first transmission signal on the partner apparatus side can be accurately recognized, and the second transmission signal can be transmitted to the partner apparatus at the correct timing.

  According to the present invention, even if the attenuation of other channels other than intermittent reception is insufficient, the transmission channel of the activation signal on the portable device side is accurately recognized by the vehicle unit, and the correct timing is obtained. The vehicle information can be transmitted to the portable device.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an overall configuration diagram of a vehicle communication device according to an embodiment. The vehicle communication device 1 shown in FIG. 1 includes a portable device 10 that functions as a first device and is carried by an operator, and a vehicle unit 20 that functions as a second device and is mounted on a vehicle. And a plurality of channels consisting of channels CH2 are configured to wirelessly transmit substantially the same signals that differ only in frequency. For convenience of explanation, a signal transmitted from the portable device 10 to the vehicle unit 20 is referred to as a first transmission signal, and a signal transmitted from the vehicle unit 20 to the portable device 10 is referred to as a second transmission signal. . Further, the channel CH1 and the channel CH2 can use close frequency bands.

The portable device 10 includes a switch 11 that performs a predetermined operation such as locking or unlocking, a CPU 12 that generates first transmission data triggered by the operation of the switch 11, and an ASK that performs ASK modulation on the first transmission data. A modulation unit 13 and a transmitter 14 that transmits ASK-modulated first transmission data as a first transmission signal at a transmission frequency (channel CH1, channel CH2) set by the CPU 12 are provided. The transmitter 14 includes an oscillator, a PLL circuit, and the like, and a transmission frequency is determined according to frequency setting data set from the CPU 12 to the PLL circuit. The CPU 12 generates transmission data including an activation signal that becomes a preamble signal and a data portion that becomes a data signal.
The activation signal is also called a wake-up signal. When the signal is received on the receiver side, the receiver enters an activation state in which the signal can be determined from the sleep state. As one example, the activation signal is formed of, for example, a rectangular pulse of 50 pulses and is activated when 5 pulses are received. However, the waveform and the number are not limited thereto.
In this example, in order to increase the redundancy, the data portion of the first transmission data is composed of DATA1 to DATA4 consisting of repetitions of substantially the same data unit, but it is sufficient that at least DATA1 is included. Each of DATA1 to DATA4 includes the same command code such as lock / unlock, the ID code of the portable device, and channel information indicating the transmission frequency of the transmission signal. Data number information indicating whether there is data, specifically, information 1 is included in the case of DATA1, and information 2 is included in the case of DATA2.

  As described above, in the transmission section of the channel CH1, the channel information for identifying the channel CH1 is added to the data signal, and in the transmission section of the channel CH2, the channel information for identifying the channel CH2 is added to the data signal. Append. The channel information is added only to the data signal of one channel, and the channel information is not added to the data signal of the other channel so as to have channel information for identifying which channel the data signal is. Also good. Since the CPU 12 further transmits the first transmission signal through the channels CH1 and CH2, the transmission frequency of the transmitter 14 is set to the channel CH1 from the start of transmission, and the predetermined interval from the end of the transmission period of the channel CH1 is set. Set to channel CH2.

  The portable device 10 includes a receiver 15 that receives the second transmission signal at the reception frequency (channel CH1, channel CH2) set by the CPU 12, and a vehicle in which the CPU 12 decodes the second transmission signal received by the receiver 15. A device 16 for displaying information and a clock unit 17 for supplying an operation clock to the CPU 12 are provided. The receiver 15 includes an oscillator, a PLL circuit, a detection circuit, and the like, and a reception frequency is determined according to frequency setting data set from the CPU 12 to the PLL circuit. As will be described later, the CPU 12 sets the channel CH1 as a reception frequency in the receiver 15 after a predetermined time after the transmission section of the channel CH2 elapses, waits for a predetermined period t1 channel CH1, and then sets the channel CH2. And wait for t2 channel CH2 for a certain period.

  The vehicle unit 20 receives the first transmission signal transmitted from the portable device 10, sets the reception frequency (channel CH 1, channel CH 2) in the receiver 21, and then starts the second after being activated by the activation signal. The CPU 22 that generates the transmission data of and the device 25 that detects the door lock state and the like. The receiver 21 includes an oscillator, a PLL circuit, a detection circuit, and the like, and a reception frequency is determined according to frequency setting data set from the CPU 12 to the PLL circuit. The vehicle unit 20 operates so as to intermittently receive the first transmission signal in order to save power in the standby state. In the intermittent reception operation, the channel CH1 is first received and the channel CH2 is subsequently received. The CPU 22 is activated by receiving the activation signal by intermittent reception, and determines the channel number (CH1, CH2) from the channel information added to the data signal successfully received. Furthermore, from the data number included in the data signal, the time when the data transmission of the channel CH2 ends in the portable device 10 is calculated, and the transmission end timing in the portable device 10 is determined as the transmission timing on the vehicle unit side. A second transmission signal is transmitted at the determined transmission timing.

  In addition, the vehicle unit 20 includes an ASK modulation unit 23 that performs ASK modulation on second transmission data including vehicle information generated by the CPU 22, and a transmission frequency (channel CH 1, channel CH 2) set by the CPU 22 and subjected to ASK modulation. A transmitter 24 that wirelessly transmits two transmission data (second transmission signal), a main clock unit 26 that generates a main operation clock of the CPU 22, and a sub clock unit 27 that generates a sub clock that is an operation clock during standby. Is provided. The CPU 22 operates with a sub-clock with low power consumption while the vehicle unit 20 repeats the intermittent reception operation in the standby state, and operates with a higher-speed main clock after being activated by the activation signal.

Next, the operation of the present embodiment configured as described above will be described.
With reference to FIG. 2, it demonstrates concretely how the transmission timing of a 2nd transmission signal is determined in the vehicle unit 20. FIG.

  In the portable device 10, the CPU 12 generates first transmission data composed of an activation signal and a data portion with the operation of the switch 11 as a trigger. In the transmission section of channel CH1, channel information indicating channel CH1 is added to the data signal, and in the transmission section of channel CH2, channel information indicating channel CH2 is added to the data signal. Further, DATA1 to DATA4 constituting the data part are numbered consecutively and given data numbers. The first transmission data to which the channel information or the like is added is ASK modulated by the ASK modulation unit 13, converted into a first transmission signal from the transmitter 14, and transmitted by radio. At this time, as shown in FIG. 2, in the transmission section of the channel CH1, since the CPU 12 sets frequency setting data of the channel CH1 in the PLL circuit of the transmitter 14, the first transmission signal is transmitted on the channel CH1, and the channel CH2 In the transmission section, since the frequency setting data of the channel CH2 is set, the first transmission signal is transmitted on the channel CH2. The portable device 10 transmits the first transmission signal on the channel CH2 and then receives the second transmission signal returned from the vehicle unit 20, so that the receiver 15 is set to the channel CH1 in the standby section t1, and the standby section At t2, it is set to channel CH2.

  In the vehicle unit 20, the CPU 22 intermittently receives the channel CH1 and the channel CH2 by the sub clock. By making the intermittent reception cycle in the vehicle unit 20 shorter than the transmission interval T1 of the activation signal, the activation signal can be reliably received by the intermittent reception to be in the activated state.

  FIG. 2 shows a state in which the vehicle unit 20 performs intermittent reception of the channel CH2 in a section in which the portable device 10 transmits an activation signal on the channel CH1. At this time, since the signal of the channel CH1 was not sufficiently attenuated by the filter (not shown) of the receiver 21, the activation signal of the channel CH1 was received during the intermittent reception of the channel CH2 and the received data was taken into the CPU 21. .

The conventional method recognizes that the received data received during the intermittent reception operation of the channel CH2 is the data of the same channel CH2, but in the present invention, the channel number is determined from the channel information added to the received data signal. To do. Therefore, as shown in FIG. 2, even when the activation signal of the channel CH1 is received during the intermittent reception of the channel CH2, the channel information added to the data signal continuously received after the activation signal indicates the channel CH1. If so, the transmission timing is calculated as a data signal transmitted at the frequency of the channel CH1. After the vehicle unit 20 is activated by the activation signal, the data unit is received with the setting of the channel CH2 that has received the activation signal. For example, it is assumed that DATA3 is successfully received on channel CH2. The CPU 22 uses the predetermined reference point such as the start point, the end point, or the intermediate point of the DATA3 of the channel CH1 as a base point to complete the transmission of the DATA4 of the channel CH2 in the portable device 10 and the time TA until the standby state of the channel CH1 is set. calculate. In the example shown in FIG. 2, the end point of DATA3 is used as a base point, and the following calculation formula is used.
TA = (DATA4 transmission section of channel CH1) + (transmission section of channel CH2)
The CPU 22 starts a timer (not shown) and waits for transmission until the time TA elapses.
On the other hand, vehicle information is acquired from the device 25 to generate second transmission data. The type of vehicle information is not limited, but can include, for example, information on lock / unlock of vehicle doors or air conditioner information.
Although the details are omitted in the above description for the well-known matters, if the ID included in the data code of the first transmission signal is a predetermined ID in the CPU 22, it is included in the data code. A control signal is output so as to perform locking or unlocking according to the lock or unlock command signal. And after performing this process, vehicle information is acquired from the apparatus 25 and 2nd transmission data are produced | generated. The acquisition of the vehicle information does not actually detect the lock / unlock of the door, but the CPU 22 uses the predetermined ID as the ID included in the data code of the first transmission signal to lock or unlock the signal. Data may be acquired from the CPU 22 when it is determined.

  When the CPU 22 detects that the time TA has elapsed from the end point of DATA3, the CPU 22 sets the transmission frequency of the transmitter 24 to the channel CH1 and supplies the second data including the vehicle information to the ASK modulation unit 23. The second transmission signal subjected to ASK modulation is wirelessly transmitted from the transmitter 24 through the channel CH1.

  As shown in FIG. 2, by delaying the transmission timing of the second transmission signal by the time TA in the vehicle unit 20, the portable device 10 is in a state of waiting for the second transmission signal on the channel CH1. Therefore, in the portable device 10, the second transmission signal can be received by the receiver 15 whose reception frequency is set to the channel CH1. The reception data output from the receiver 15 that has received the second transmission signal is captured by the CPU 12, decoded into vehicle information, and displayed on the device 16. As a result, the vehicle information is displayed on the device 16 of the portable device 10 that has been switched.

  In FIG. 2, the same data is transmitted twice from the vehicle unit 20 at two frequencies of the channel CH1 and the channel CH2. After the standby of channel CH1 in portable device 10, standby time t2 of channel CH2 is set. As a result, the second transmission signal transmitted from the vehicle unit 20 can be correctly received even if any channel has noise.

  In the above case, the CPU 22 of the vehicle unit 20 may transmit the second transmission signal using only CH1. That is, the second transmission signal may be transmitted only with the frequency of the identified channel information.

In the example shown in FIG. 2, the channel CH1 has no noise, and the vehicle unit 20 can receive the signal of the channel CH1 (however, it is received at the reception frequency of CH2). There may be a case where a signal cannot be received due to noise. In such a case, the same processing as described above is performed in the transmission section of channel CH2. Since the channel information is also added to the activation signal transmitted on the channel CH2, the correct channel number can be determined by the CPU 22 of the vehicle unit 20 even when it is received at the reception frequency of CH1. It is possible to calculate an appropriate transmission timing in accordance with the reception frequency timing of the intermittent reception of the portable device.
In this embodiment, the example in which the reception timing at which the second transmission signal can be received is set in accordance with the reception frequency timing of the intermittent reception of the portable device has been described. However, the second transmission signal can be received. As a method of setting the reception timing, it is not always necessary to match the timing of the reception frequency of the intermittent reception of the portable device. In other words, the second transmission signal may be transmitted from the vehicle to the portable device after the transmission time of the portable device is removed. Specifically, the time for the portable device to finish signal transmission of the first transmission signal is calculated, and after that, the second transmission signal is repeatedly transmitted, and the portable device receives any of those signals. It ’s fine.

  In the above description, the mobile device 10 transmits the first transmission signal in the order of channel CH1 and channel CH2, and the vehicle unit 20 receives intermittently in the order of channel CH1 and channel CH2. The order is not limited. For example, the mobile device 10 may transmit the first transmission signal in the order of channel CH2 and channel CH1, and the vehicle unit 20 may perform intermittent reception in the order of channel CH1 and channel CH2.

  Moreover, in the above description, although the 1st transmission signal is transmitted with respect to the vehicle unit 20 from the portable device 10, the vehicle unit 20 replies to the portable device 10 by making vehicle information into the 2nd transmission signal with respect to this. The vehicle communication device can also be configured with the vehicle unit as the first device and the portable device as the second device. For example, the present invention can also be applied to a device that receives a signal from a portable device when a button on the vehicle side is pressed and returns a signal from the portable device to the vehicle to lock / unlock, such as a PASSIVE keyless entry system.

1 is an overall configuration diagram of a vehicle communication system according to an embodiment. The figure which shows the signal sequence between the portable machine and vehicle unit in the said one Embodiment. (A) The figure which shows the signal sequence between a portable machine and a vehicle unit, (b) The figure which shows the signal sequence between a portable machine and a vehicle unit at the time of channel misjudgment by a vehicle unit

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle communication system 10 Portable machine 11 Switch 12, 22 CPU
13, 23 ASK modulation unit 14, 24 Transmitter 15, 21 Receiver 16, 25 Device 17 Clock unit 26 Main clock unit 27 Sub clock unit

Claims (4)

In a vehicle communication device having a first device provided on one of a portable device or a vehicle unit and a second device provided on the other of the portable device or the vehicle unit,
The first device transmits a first transmission signal to the second device, and the first transmission signal is composed of a continuous signal in the first channel and the second channel, and each channel signal includes a preamble signal. And the data signal, the data signal has channel information for identifying which channel, and can receive the second transmission signal returned from the second device after the transmission of the first transmission signal. Become
The second device intermittently performs a reception operation of receiving the first transmission signal on the first channel and the second channel at a predetermined period, and a preamble signal is received at the time of intermittent reception on any channel. If this is the case, the first apparatus receives the data signal while maintaining the same channel, and the first device receives the second transmission signal from the channel number recognized from the channel information added to the data signal and the reference point of the received data signal. A vehicle communication device that calculates a transmission timing at which reception is possible. The first device transmits a first transmission signal composed of a data portion in which a preamble signal is composed of a start signal of a predetermined pattern and a data signal repeats a signal including the same data unit a predetermined number of times,
The second apparatus is characterized in that the receiving operation by the first channel and the second channel is repeated at a cycle shorter than the transmission period of the activation signal, and the apparatus returns from the standby state by receiving the activation signal. The vehicle communication device according to claim 1.   The vehicle communication device according to claim 1, wherein the first device transmits an ASK-modulated first transmission signal. In the vehicle communication device that is provided on one of the portable device or the vehicle unit and wirelessly communicates with a counterpart device provided on the other of the portable device or the vehicle unit.
The reception operation for receiving the first transmission signal including the preamble signal and the data signal having the channel information is intermittently performed at a predetermined period in the first channel and the second channel, and intermittent reception is performed on any channel. If a preamble signal is sometimes received, the data signal is received as it is on the same channel, and from the channel number recognized from the channel information added to the data signal and the reference point of the received data signal, the counterpart device A vehicle communication device that calculates a transmission timing at which reception is possible.

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