JP2020161881A - Vehicle communication device - Google Patents

Abstract

To prevent the interruption of communication as much as possible when noise radio waves arrive.SOLUTION: A vehicle communication device of an embodiment includes: a communication unit 4 for wirelessly communicating with a communication device outside a vehicle; a power measuring unit 5 for measuring power that can be interference noise that causes radio wave interference with wireless communication; a prediction unit 6 for predicting whether the interference noise arrives; and a switching unit for switching to another wireless communication band when the prediction unit 6 predicts that the interference noise arrives.SELECTED DRAWING: Figure 2

Description

The present invention relates to a vehicle communication device.

In wireless communication, different radio waves, that is, noise radio waves may arrive in the wireless communication band used for wireless communication, that is, the carrier frequency band, and the noise radio waves cause radio wave interference and interfere with communication. There is. In particular, when the carrier frequency band is the ISM band, the ISM band is widely used for applications other than communication waves, such as microwave ovens, so that noise radio waves often arrive.

The device described in Patent Document 1 is known as a configuration for preventing communication interruption due to the arrival of noise radio waves. In this device, in a device capable of communicating in a plurality of carrier frequency bands, the reception intensity of incoming noise radio waves is measured for each of the plurality of carrier frequency bands, and a carrier frequency band having a low reception intensity of noise radio waves is selected for communication. Is configured to do.

JP-A-2009-77224

In the case of a wireless device mounted on a vehicle, the radio wave environment is constantly changing depending on the movement of the vehicle and the position / presence / absence of occupants. Therefore, even if a carrier frequency band having a low reception intensity of noise radio waves is selected for communication, the arrival of noise radio waves may suddenly increase in the selected carrier frequency band, and communication may be disturbed. It was.
An object of the present invention is to provide a vehicle communication device capable of preventing communication interruption as much as possible when a noise radio wave arrives.

The invention of claim 1 is a communication unit 4 that wirelessly communicates with a communication device outside the vehicle, a power measurement unit 5 that measures power that can be interference noise that causes radio wave interference with wireless communication, and the interference noise. It is a vehicle communication device including a prediction unit 6 that predicts the presence or absence of the arrival of radio waves, and a switching unit that switches to another wireless communication band when the interference noise is predicted to arrive by the prediction unit 6.

Functional block diagram of the vehicle communication device showing the first embodiment Communication control flowchart Flow chart of control to calculate electric energy Diagram explaining the calculation of electric energy The figure which shows the 2nd Embodiment and shows the state which the interference noise has arrived in all the wireless communication bands. Functional block diagram of vehicle communication device

(First Embodiment)
Hereinafter, the first embodiment will be described with reference to FIGS. 1 to 4. As shown in FIG. 1, the vehicle radio device 1 of the present embodiment is composed of, for example, an ECU (Electronic Control Unit), and includes a control unit 2, a switching control unit 3, a communication unit 4, and a power measurement unit 5. And a prediction unit 6. The vehicle wireless device 1 includes a plurality of carrier frequency bands used for wireless communication, and is configured so that any one of the plurality of carrier frequency bands can be selected for wireless communication.

The control unit 2 has a function of controlling the entire vehicle wireless device 1, and is configured to be able to execute, for example, a communication application that executes and controls wireless communication. The switching control unit 3 receives an instruction signal from the control unit 2 and outputs a selection signal for selecting one from a plurality of carrier frequency bands to the communication unit 4.

The communication unit 4 has a function of receiving a selection signal from the switching control unit 3 and executing wireless communication in the selected carrier frequency band. The communication unit 4 includes a communication driver 7, a transmitting antenna 8, a receiving antenna 9, and a restorer 10. The communication driver 7 outputs radio waves in the selected carrier frequency band via the transmitting antenna 8. The restorer 10 receives and restores radio waves in the selected carrier frequency band transmitted from an external wireless device via the receiving antenna 9, and outputs the restored received signal to the prediction unit 6.

The power measuring unit 5 has a function of measuring power that can be interference noise that causes radio wave interference with wireless communication. The power measuring unit 5 is configured to measure the power that can cause interference noise in a wireless communication band other than the wireless communication band during communication, for example, a carrier frequency band adjacent to the carrier frequency band during communication. In this case, the power measuring unit 5 has a power receiving antenna 11 and a power checking unit 12. The power check unit 12 measures the power received by the power receiving antenna 11, that is, the power of the noise radio wave that can be interference noise in the wireless communication band during communication, that is, the wireless communication band adjacent to the carrier frequency band. The power check unit 12 also measures the power of noise radio waves that can be interference noise that causes radio wave interference with the wireless communication band during communication. Then, the power measurement result by the power measuring unit 5 is output to the prediction unit 6.

The prediction unit 6 has a function of inputting a measurement result from the power measurement unit 5 and a received signal from the communication unit 4 to predict the presence or absence of interference noise, that is, noise radio waves. The prediction unit 6 has an interference check unit 13 and a communication check unit 14. The communication check unit 14 calculates the rate of change of the BER (Bit Error Rate) based on the received signal from the communication unit 4, and outputs the calculated rate of change of the BER to the interference check unit 13. The interference check unit 13 calculates the rate of change of electric power based on the measurement result from the electric power measuring unit 5. Then, the interference check unit 13 predicts the presence or absence of interference noise, that is, the arrival of noise radio waves, based on the rate of change of BER and the rate of change of electric power, and outputs the prediction result to the control unit 2.

Based on the prediction result from the prediction unit 6, the control unit 2 switches and controls an instruction signal instructing to switch the wireless communication band during communication to another wireless communication band when it is predicted that interference noise will arrive. Output to unit 3. The switching control unit 3 receives an instruction signal from the control unit 2 and outputs a selection signal for selecting a carrier frequency band corresponding to the other wireless communication band from the plurality of carrier frequency bands to the communication unit 4. In the case of this configuration, the control unit 2 and the switching control unit 3 have a function as a switching unit.

Next, the operation of the vehicle radio device 1 having the above configuration will be described with reference to FIGS. 2, 3 and 4. The flowchart of FIG. 2 shows the contents of the wireless communication control of the vehicle wireless device 1, particularly the contents of the control when it is predicted that a noise radio wave will arrive. First, in step S10 of FIG. 2, the power of noise radio waves that can be interference noise is measured for the wireless communication band adjacent to the wireless communication band during communication.

Specifically, the process of step S10 is configured to execute the control of the subroutine shown in FIG. In step S110 of FIG. 3, for example, the electric energy of a plurality of wireless communication bands adjacent to the wireless communication band being communicated by the integration method, that is, the areas P1 and P2 of the electric energy shown in FIG. 4 are calculated. In step S110, it is preferable that the wireless communication band power amount during communication is also calculated.

Subsequently, the process proceeds to step S120, and the difference ΔP between the electric energy P1 calculated in the previous step S110 and the electric energy P2 calculated in this step S110, that is, ΔP = P2, for each of the plurality of adjacent wireless communication bands. -P1 is calculated. In step S120, it is preferable to calculate the difference ΔP of the wireless communication band during communication.

Then, the process proceeds to step S130, and it is determined whether or not the difference ΔP is larger than 0. Here, when the difference ΔP is larger than 0 (“YES” in step S130), the process proceeds to step S140. In this step S140, it is determined that the power has increased, and the determination result is stored in the internal memory. This ends the subroutine of FIG. Further, in step S130, when the difference ΔP is 0 or less, the process proceeds to “NO” and the subroutine of FIG. 3 is terminated.

After that, the process proceeds to step S20 of FIG. 2, and it is determined whether or not the electric power has increased. Here, when it is a determination result that the power has not increased (NO), the process proceeds to step S30, and it is determined whether or not the wireless communication is terminated. If the wireless communication is not completed in step S30 (NO), the process returns to step S10 and the above-described processing is repeated. Further, in step S30, when the wireless communication is terminated, the process proceeds to “YES” and the present control is terminated.

Further, in step S20, when it is a determination result that the power has increased (YES), the process proceeds to step S40, and whether or not the BER has increased, that is, whether or not the rate of change of the BER has become larger than the set value. To judge. In step S40, when BER is not rising (NO), the process proceeds to step S30 to determine the end of wireless communication.

Further, in step S40, when BER rises (YES), the process proceeds to step S50. In this case, when the power rises and the BER rises, it is determined that interference noise, that is, noise radio waves are predicted to arrive in the wireless communication band during communication, and based on this prediction, the following Executes the processing of. That is, in step S50, a plurality of wireless communication bands having a low electric energy, that is, carrier frequency bands are selected. Subsequently, the process proceeds to step S60, and the wireless communication band having the smallest power change amount, that is, the wireless communication band having the least arrival of noise radio waves is selected from the plurality of selected wireless communication bands. Then, the process proceeds to step S70, and the process of switching the wireless communication band during communication to the selected wireless communication band, that is, the wireless communication band having the smallest power change amount is executed. After that, the process proceeds to step S30 to determine the end of wireless communication.

In the present embodiment having such a configuration, when the power that can be the interference noise that causes radio wave interference for wireless communication is measured, the presence or absence of the interference noise is predicted, and the interference noise is predicted to arrive, It was configured to switch to another wireless communication band. According to this configuration, when interference noise is predicted to arrive, the band is switched to another wireless communication band. Therefore, even if interference noise arrives, interference does not occur and wireless communication is prevented from being interrupted as much as possible. It is possible to maintain a communicable state.

Further, in the present embodiment, since the power that can cause interference noise is measured for the wireless communication band other than the wireless communication band during communication, it is possible to satisfactorily select the candidate wireless communication band to be switched.

In the present embodiment, BER, that is, when the bit error rate rises, it is determined that the interference noise has arrived, so that the arrival of the interference noise can be accurately determined. Further, in the present embodiment, since it is configured to determine that the interference noise has arrived based on the change in the power measured by the power measurement unit 5, the arrival of the interference noise can be accurately determined.

In the present embodiment, since the wireless communication band having a low electric energy measured by the power measuring unit 5 is selected as the switching candidate wireless communication band, the wireless communication band is switched to a wireless communication band in which the possibility of interference noise is low. be able to.

In the present embodiment, the wireless communication band of the selected switching candidates is switched to the wireless communication band in which the amount of change in the power measured by the power measuring unit 5 is small, so that interference noise may occur. Can be switched to a lower wireless communication band.

In the present embodiment, the power of the wireless communication band adjacent to the wireless communication band during communication is checked, the rate of change of the power is calculated, and the arrival of interference noise is predicted based on the calculated rate of change of the power. Has been done. Then, in this embodiment, it is configured to discriminate a communication wave or an electromagnetic wave from the rate of change of electric power and the rate of change of BER of the wireless communication. Further, in the present embodiment, by monitoring the rate of change of power in a plurality of wireless communication bands and the rate of change of BER, it is possible to discriminate a communication wave or an electromagnetic wave, for example, due to the influence of a microwave oven or the like for several tens of seconds. It is possible to predict that the interference will continue for several minutes, that is, the arrival of noise radio waves. It is also possible to predict the affected wireless communication band.

(Second Embodiment)
5 and 6 show a second embodiment. The same components as those in the first embodiment are designated by the same reference numerals. FIG. 5 shows a state in which interference noise is generated in all the wireless communication bands capable of wireless communication by the vehicle communication device 1. In such a state, it is predicted that communication will be interrupted soon. Therefore, in the second embodiment, when the state shown in FIG. 5 is predicted to arrive, a signal indicating that the communication is interrupted is transmitted to the other party of the communication.

Specifically, as shown in FIG. 6, a signal can be directly output from the interference check unit 13 of the prediction unit 6 to the communication driver 7 of the communication unit 4. Then, the interference check unit 13 interrupts the wireless communication to the other party of the wireless communication when it is predicted that interference noise, that is, noise radio waves will arrive in all the wireless communication bands in which the vehicle communication device 1 can wirelessly communicate. An instruction signal for transmitting a signal to that effect is output to the communication driver 7 of the communication unit 4. When the instruction signal from the interference check unit 13 is input, the communication driver 7 is configured to transmit a signal indicating that the wireless communication is interrupted to the other party of the wireless communication, that is, a radio wave via the transmission antenna 8. There is. In the case of this configuration, the interference check unit 13 and the communication driver 7 constitute a signal transmission unit.

The configuration of the second embodiment other than the above is the same as the configuration of the first embodiment. Therefore, even in the second embodiment, substantially the same action and effect as in the first embodiment can be obtained. In particular, in the second embodiment, when it is predicted that interference noise will arrive in all the wireless communication bands capable of wireless communication by the vehicle communication device 1, a signal indicating that the wireless communication is interrupted is sent to the other party of the wireless communication. Since it is configured to transmit, the other party of the wireless communication can recognize in advance that the wireless communication will be interrupted, and can take measures for that purpose.

The controls and methods thereof described in the present disclosure are realized by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. May be done. Alternatively, the controls and methods thereof described in the present disclosure may be implemented by a dedicated computer provided by configuring the processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and method thereof described in the present disclosure may be a combination of a processor and memory programmed to perform one or more functions and a processor composed of one or more hardware logic circuits. It may be realized by one or more dedicated computers configured. Further, the computer program may be stored in a computer-readable non-transitional tangible recording medium as an instruction executed by the computer.

Although the present disclosure has been described in accordance with the examples, it is understood that the present disclosure is not limited to the examples or structures. The present disclosure also includes various modifications and modifications within an equal range. In addition, various combinations and forms, as well as other combinations and forms that include only one element, more, or less, are also within the scope of the present disclosure.

In the drawing, 1 is a vehicle radio device, 2 is a control unit, 3 is a switching unit, 4 is a communication unit, 5 is a power measurement unit, 6 is a prediction unit, 7 is a communication driver, 8 is a transmission antenna, and 9 is a reception antenna. 10 is a restorer, 11 is a power receiving antenna, 12 is a power check unit, 13 is an interference check unit, and 14 is a communication check unit.

Claims (7)

A communication unit (4) that performs wireless communication with a communication device outside the vehicle,
A power measuring unit (5) that measures the power that can be an interference noise that causes radio wave interference in wireless communication, and
The prediction unit (6) that predicts the presence or absence of the interference noise, and
A switching unit that switches to another wireless communication band when the prediction unit predicts that the interference noise will arrive,
Vehicle communication device equipped with. The vehicle communication device according to claim 1, wherein the power measurement unit is configured to measure power that can cause interference noise even in a wireless communication band other than the wireless communication band during communication. The vehicle communication device according to claim 1 or 2, wherein the prediction unit is configured to determine that the interference noise has arrived when the bit error rate increases. The vehicle communication device according to any one of claims 1 to 3, wherein the prediction unit is configured to determine that the interference noise has arrived based on a change in electric power measured by the power measurement unit. .. The vehicle communication device according to claim 2, wherein the switching unit is configured to select a wireless communication band having a low electric energy measured by the power measuring unit as a switching candidate wireless communication band. The vehicle communication device according to claim 5, wherein the switching unit is configured to switch from the selected switching candidate wireless communication bands to a wireless communication band in which the amount of change in power measured by the power measuring unit is small. .. The prediction unit is configured to include a signal transmission unit that transmits a signal indicating that communication is interrupted to the other party of communication when the interference noise is predicted to reach all communicable wireless communication bands. The vehicle communication device according to any one of claims 1 to 6.

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