JP2012080448A - Radio communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication device capable of reducing interference caused by an interference wave generated periodically and preventing an inappropriate increase in transmission power in radio communication with another radio communication device.SOLUTION: A reception unit 30 of a radio communication device 2 includes an interference data measurement unit that measures cycle data of an interference wave from a reception signal with its frequency converted in a frequency converter 34 as interference data about the interference wave received in its own device. The cycle data of the interference wave that is measured in an interference data measurement unit 40 is inserted in a transmission packet in a transmission packet generation unit 12 as a part of transmission data. A control unit 20 writes the cycle data of the interference wave that is extracted from reception data from another radio communication device 2 to a storage unit 22 for every radio communication device. The control unit 20 adjusts one-time transmission time based on the cycle data of the interference wave corresponding to a transmission destination so as to reduce the interference by the interference wave to reception data in the radio communication device 2 as the transmission destination.

Description

  The present invention relates to a wireless communication apparatus.

  In wireless communication, in order to avoid mutual interference, a dedicated frequency band is generally assigned to each wireless communication system. However, radio waves from adjacent communication channels and radio waves from other systems are generated in this allocated communication band, and the generated radio waves may act as interference waves that interfere with wireless communication. In order to effectively use limited frequencies, the same frequency band may be used in a plurality of communication systems, and in this case, radio waves from other systems act as interference waves in the same frequency band. .

Moreover, in a wireless communication apparatus that performs vehicle-to-vehicle communication and road-to-vehicle communication, various noises generated on the vehicle side may act as interference waves.
With respect to such an interference wave, in Patent Document 1, a noise level around a wireless communication channel is measured, a noise level measured and transmitted by another wireless communication device, and a noise level measured by the device itself are calculated. Based on the above, it is attempted to improve communication quality between wireless communication devices by controlling communication parameters for performing wireless communication with other wireless communication devices.

JP 2010-16561 A

  As in Patent Document 1, in the technology for controlling the communication parameters for performing wireless communication based on the noise level measured by the own device and the other device, the transmission power or the like is always applied to the interference wave that is generated at all times. Communication parameters may be set appropriately. However, communication parameters are set for interference waves such as impulse noise that occurs periodically, including periods when no interference waves are generated, so communication parameters should be controlled appropriately based on the noise level. It is difficult.

  For example, when the communication parameter is controlled based on the level of the interference wave 300 periodically generated as shown in FIG. 12, if the transmission power is set as the communication parameter based on the maximum level 302 of the interference wave 300, the maximum level 302 Since transmission is performed with excessive power to the other parts, the transmission power is inappropriately increased.

On the other hand, if the transmission power is set based on the minimum level 304 of the interference wave 300, the interference due to the maximum level 302 cannot be reduced.
Even when the transmission power is set based on the average value 306 or the intermediate value 308 of the level of the interference wave 300, the interference due to the maximum level 302 cannot be reduced appropriately.

  The present invention has been made to solve the above problem, and in radio communication with other radio communication apparatuses, interference caused by periodically generated interference waves is reduced and transmission power is inappropriately increased. An object of the present invention is to provide a wireless communication apparatus that prevents this.

  According to the first to ninth aspects of the present invention, the receiving means receives transmission radio waves from other wireless communication devices and restores received data, and the interference wave measuring means is periodically generated and received by the receiving means. Period data representing the period of the interference wave is measured as the interference wave data related to the interference wave. Then, the transmission unit transmits the period data of the interference wave measured by the interference wave measurement unit to another wireless communication apparatus as a part of the transmission data.

Thereby, the wireless communication apparatus of the transmission source that measured the period data of the interference wave can inform the other radio communication apparatus of the period data of the interference wave measured by the own apparatus.
In another wireless communication device that has received interference wave cycle data from the transmission source wireless communication device, the interference wave cycle received from the transmission source wireless communication device when transmitting transmission data to the transmission source wireless communication device. Based on the data, it is possible to adjust transmission data to be transmitted to the transmission source wireless communication apparatus in consideration of a period in which no interference wave is generated. For example, transmission data can be transmitted to a wireless communication device that is a transmission source so that reception data and interference waves do not interfere as much as possible.

  Thereby, the interference by the interference wave with respect to the reception data in the transmission source wireless communication apparatus can be reduced. In addition, the transmission power is increased inappropriately compared to the system that always increases the transmission power to reduce the interference caused by the interference wave without considering the period when the interference wave is not generated. Can be prevented.

  According to the second and tenth aspects of the present invention, the receiving means extracts period data from the received data received from another wireless communication apparatus that has measured the period of the interference wave, and the transmitting means has transmitted the period data. 1 for transmitting transmission data to another wireless communication device that has transmitted periodic data based on the periodic data extracted by the receiving means in order to reduce interference caused by interference waves with respect to received data in another wireless communication device. Adjust the transmission time per time.

  In this way, when adjusting the transmission time per transmission when transmitting transmission data, if the transmission time becomes longer with respect to the periodically generated interference wave, the transmission data is likely to interfere with the interference wave, and the transmission time When becomes short, the transmission data hardly interferes with the interference wave.

  Therefore, based on the periodic data of the interference wave, by adjusting the transmission time per transmission when transmitting the transmission data to the other wireless communication apparatus that has transmitted the periodic data, Interference due to interference waves with respect to received data in the wireless communication device can be reduced as much as possible.

  According to the invention described in claim 3, the interference wave measuring means measures interference continuation data further including the duration of the interference wave generated every period as the interference wave data, and the transmission means is the interference wave measuring means. The measured interference continuation data is transmitted to another wireless communication apparatus as a part of transmission data.

  As a result, in addition to the period of the interference wave received by itself, the transmission source wireless communication apparatus notifies other wireless communication apparatuses of the interference continuation data including the duration of the interference wave generated every period. Can do.

  For other wireless communication devices that have received the interference continuation data transmitted by the transmission source wireless communication device, the period during which the interference wave received by the wireless communication device that has transmitted the interference continuation data is continuously generated is accurately determined. Can know. In other words, it is possible to accurately know the period during which no interference wave is generated in the cycle.

  As a result, in another wireless communication device that has received the interference continuation data, for example, the reception data and the interference wave do not interfere with each other as much as possible, and the reception data can be received as much as possible during a period in which no interference wave is generated. Transmission data to be transmitted to the wireless communication device can be adjusted.

  According to the invention described in claims 4 and 11, the receiving means extracts from the received data the interference continuation data further including the duration of the interference wave generated every period, which is measured by the other radio communication apparatus as the interference wave data. The transmission unit transmits the interference continuation data based on the interference continuation data extracted by the reception unit in order to reduce interference due to the interference wave with respect to the reception data in the other wireless communication apparatus that has transmitted the interference continuation data. The transmission time per transmission when transmitting transmission data to another wireless communication apparatus is adjusted.

  Thus, in addition to the period of the interference wave, the wireless communication device that extracted the interference continuation data further including the interference wave duration from the reception data transmitted by another wireless communication device has transmitted the interference continuation data. In the wireless communication apparatus, it is possible to accurately know a period in which interference waves continuously occur for each period.

  Thereby, in order to reduce the interference due to the interference wave with respect to the received data in the other wireless communication device of the transmission source that has transmitted the interference continuation data, per transmission time when transmitting the transmission data to the wireless communication device of the transmission source The transmission time can be adjusted with high accuracy.

  According to the fifth and twelfth aspects of the present invention, the transmission means causes interference between the reception data and the interference wave in another wireless communication apparatus that has transmitted the interference wave data based on the interference wave data extracted by the reception means. The transmission time per transmission when transmitting the transmission data to another wireless communication apparatus that has transmitted the interference wave data is adjusted so that the probability of the transmission is less than a predetermined value.

  As a result, the probability that the received data and the interference wave interfere with each other in the other wireless communication apparatus that has transmitted the interference wave data, that is, the error rate that is the rate at which the wireless communication fails, can be set to a predetermined value or less.

  According to the sixth aspect of the present invention, the interference wave measuring means measures interference start data further including any start timing of the period as the interference wave data, and the transmitting means is the interference measured by the interference wave measuring means. The start data is transmitted to another wireless communication device as a part of the transmission data.

  As described above, if the period and the start timing of one of the periods are known for the periodically generated interference wave, the start timing at which the interference wave is generated in each period can be known. Therefore, in another wireless communication device that has received the interference start data transmitted from the transmission source wireless communication device, the interference wave received by the wireless communication device that has transmitted the interference start data is based on the received interference start data. , It is possible to know the timing that occurs in each cycle.

  As a result, in the transmission source wireless communication device, the transmission data is transmitted to the transmission source wireless communication device while avoiding the timing at which the interference wave is generated every period. Interference from waves can be reduced.

  In the inventions according to claims 7 and 13, the receiving means extracts interference start data further including any start timing of the period, measured by other wireless communication devices as interference wave data, from the received data, and transmitting means The other radio that has transmitted the interference start data based on the interference start data extracted by the receiving means in order to reduce interference due to the interference wave with respect to the received data in the other radio communication apparatus that has transmitted the interference start data. The transmission time per transmission and the transmission timing of transmission data when transmitting transmission data to the communication apparatus are adjusted.

  Thus, in addition to the period of the interference wave, the wireless communication apparatus that extracts the interference start data further including any start timing of the period from the reception data transmitted by the other wireless communication apparatus is Based on the start timing, it is possible to accurately know the start timing of each cycle in the wireless communication apparatus that has transmitted the interference start data.

  Therefore, by adjusting the transmission time and transmission timing per transmission when transmitting transmission data to the transmission source wireless communication device, the transmission source wireless communication device can interfere with reception data and interference at the start timing of each cycle. Interference with waves can be avoided as much as possible.

  In this case, if the transmission data transmitted by another wireless communication device includes the duration of the interference wave generated in each period in addition to the period and start timing of the interference wave, the interference wave is generated in each period. You can know the time zone when it does not occur. Thereby, the transmission time and transmission timing per transmission when transmitting the transmission data can be adjusted so that the transmission data does not interfere with the interference wave.

  According to the invention described in claim 8, the interference wave measuring means measures interference level data further including the signal level of the interference wave as interference wave data, and the transmitting means uses the interference level data measured by the interference wave measuring means. It transmits to other radio | wireless communication apparatuses as a part of transmission data.

  Accordingly, in another wireless communication device that has received the interference level data transmitted by the transmission source wireless communication device, the interference wave received by the wireless communication device that transmitted the interference level data is based on the received interference level data. In addition to the period and the start timing of any one of the periods, the signal level can be known.

  As a result, when transmission data is transmitted to the transmission source wireless communication apparatus, in the transmission source wireless communication apparatus, the interference transmitted by the transmission source wireless communication apparatus is reduced in order to reduce interference received by the reception data from the interference wave. The transmission data can be adjusted appropriately based on the level data.

  For example, as in the inventions of claims 9 and 14, when avoiding interference between received data and an interference wave in a wireless communication apparatus that has transmitted interference level data, a signal is obtained from the interference level data extracted from the received data. Based on the data excluding the level, the transmission time per transmission and the transmission timing of the transmission data are adjusted when transmitting the transmission data to the wireless communication apparatus that has transmitted the interference level data. In addition, in the case where the interference between the received data and the interference wave is unavoidable in the wireless communication apparatus that has transmitted the interference level data, the interference is determined based on the signal level among the interference level data extracted from the received data. The transmission power of the transmission data transmitted to the wireless communication apparatus that has transmitted the level data is adjusted only when the reception data interferes with the interference wave.

  This not only avoids interference between the reception data and the interference wave in the wireless communication apparatus that has transmitted the interference level data, but also avoids interference between the reception data and the interference wave in the wireless communication apparatus that has transmitted the interference level data. In this case, the transmission power of the transmission data transmitted to the wireless communication apparatus that has transmitted the interference level data is not always increased when transmitting the transmission data to the transmission source wireless communication apparatus. Since the adjustment is performed only when the interference wave interferes, it is possible to prevent the transmission power from being inappropriately increased.

  Also, instead of always avoiding interference between the received data and the interference wave in the wireless communication apparatus that has transmitted the interference level data, the interference between the reception data and the interference wave is accepted after adjusting the transmission power when necessary. Therefore, transmission data delay can be reduced.

  In addition, if the interference level data includes the duration of the interference wave generated every period, when transmitting the transmission data so that the transmission data does not interfere with the interference wave as much as possible avoiding the start time of each period, The transmission time and transmission timing per transmission when transmitting transmission data can be adjusted with higher accuracy. Furthermore, since the time zone in which the transmission data interferes with the interference wave can be detected with high accuracy, the transmission power can be appropriately set according to the presence or absence of interference with the interference wave.

1 is a block diagram illustrating a configuration of a wireless communication device according to a first embodiment. (A) is a block diagram which shows an example of the packet of 1st Embodiment, (B) is a table which shows the period of the interference wave in each radio | wireless communication apparatus. The characteristic view which shows the relationship between the reception power and error rate by ON / OFF of an air conditioner. The time chart which shows the relationship between the packet of 1st Embodiment, and an interference wave. (A) is a block diagram showing another example of the packet, (B) is another time chart showing the relationship between the packet and the interference wave. The flowchart which shows a communication process. (A) is a block diagram which shows an example of the packet of 2nd Embodiment, (B) is a time chart which shows the relationship between a packet and an interference wave. The flowchart which shows a communication process. The block diagram showing the structure of the radio | wireless communication apparatus of 3rd Embodiment. (A) is a block diagram which shows an example of the packet of 3rd Embodiment, (B) is a time chart which shows the relationship between a packet and an interference wave. The flowchart which shows a communication process. Explanatory drawing which shows the conventional transmission process based on the noise level with respect to an interference wave.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
The configuration of the wireless communication apparatus of the first embodiment is shown in the block diagram of FIG.

(Wireless communication device 2)
The wireless communication device 2 according to the first embodiment is installed in, for example, a vehicle or a roadside device around the road, and performs vehicle-to-vehicle communication between vehicles or road-to-vehicle communication between the vehicle and the roadside device. A transmission unit 10 and a reception unit 30 connected to the antenna 4 via the switching unit 6 are provided.

The transmission unit 10 includes a transmission packet generation unit 12, a modulation unit 14, a frequency converter 16, a high frequency amplifier 18, a control unit 20, a storage unit 22, and the like.
The transmission packet generation unit 12 generates a transmission packet in which transmission data is set, and the modulation unit 14 generates a predetermined transmission signal based on the transmission data set in the transmission packet. The frequency converter 16 frequency-converts the transmission signal generated by the transmission data in the modulation unit 14 into a preset frequency band of the wireless communication channel, and the high-frequency amplifier 18 transmits the transmission signal frequency-converted by the frequency converter 16. Amplify. By transmitting the transmission signal amplified by the high-frequency amplifier 18 to the antenna 4 via the transmission / reception switching unit 6 including a directional coupler or the like, the transmission signal is wirelessly transmitted from the antenna 4.

  The control unit 20 includes a microcomputer and adjusts the transmission data length generated by the transmission packet generation unit 12 based on the interference wave data transmitted from the other wireless communication device 2.

  In addition, the control unit 20 performs wireless communication on interference wave data related to the interference wave measured by the other wireless communication device 2, which is analyzed by the reception packet analysis unit 38 of the reception unit 30 described later and extracted from the reception data of the reception packet. Write to the storage unit 22 for each device. Note that the present embodiment is directed to those that generate periodically as interference waves.

The receiving unit 30 includes a high frequency amplifier 32, a frequency converter 34, a demodulating unit 36, a received packet analyzing unit 38, an interference wave data measuring unit 40, and the like.
The high frequency amplifier 32 amplifies the reception signal received by the antenna 4 and input via the transmission / reception switching unit 6, and the frequency converter 34 converts the reception signal amplified by the high frequency amplifier 32 to the intermediate frequency band or baseband. Frequency conversion to the received signal.

The demodulator 36 restores data (received data) transmitted from the other wireless communication device 2 from the reception signal frequency-converted by the frequency converter 34.
Further, the demodulator 36 determines whether or not the signal level of the received signal has reached a preset carrier sense (CS) level, so that the transmission radio wave from the other wireless communication device 2 currently arrives. It is determined whether there is a wireless communication channel.

  When the wireless communication channel is used in another wireless communication apparatus 2, the demodulator 36 outputs a carrier sense signal (CS signal) (not shown) indicating that fact. Then, when the CS signal is not output from the demodulation unit 36, that is, when the radio channel is empty, the modulation unit 14 generates a transmission signal based on the transmission data set in the transmission packet and starts transmission. .

  The reception packet analysis unit 38 receives the device ID of the wireless communication device 2 that has transmitted the corresponding reception data from the reception data restored by the demodulation unit 36, and the interference wave received and measured by the corresponding wireless communication device 2. The period data is extracted and output to the control unit 20.

  The interference wave data measurement unit 40 measures period data of the interference wave as interference wave data related to the interference wave received by the own apparatus from the reception signal frequency-converted by the frequency converter 34. The interference wave data measurement unit 40 may measure period data of the interference wave from the reception signal amplified by the high frequency amplifier 32. The interference wave data measuring unit 40 stores the period data of the measured interference wave and updates it every measurement.

  The interference wave data measurement unit 40 measures the period of the interference wave in a predetermined measurement period in which the wireless communication device 2 existing within the reception range is not transmitting transmission data. The predetermined measurement period during which the wireless communication device 2 does not transmit transmission data is set in advance in the communication system or is set by a wireless instruction from the roadside device. Periodic data of the device itself measured by the interference wave data measurement unit 40 is output to the transmission packet generation unit 12.

  As shown in FIG. 2A, the transmission packet generation unit 12 inserts into the transmission packet 100 the periodic data of the interference wave measured by the interference wave data measurement unit 40 of its own device as a part of the transmission data. Thus, a transmission packet 100 including a MAC header, a network header, periodic data, data, FCS (Frame Check Sequence), and the like is generated. The modulation unit 14 generates a transmission signal with the transmission packet 100.

  As described above, in the wireless communication system configured using the wireless communication device 2 of the present embodiment, interference measured by each wireless communication device 2 is not included in a transmission packet transmitted by another wireless communication device 2 as well as the own device. Wave period data will be included.

  As described above, the received packet analysis unit 38 outputs the periodic data extracted from the received data received from the other wireless communication device 2 to the control unit 20. As illustrated in FIG. 2B, the control unit 20 writes the identification information (ID) of the wireless communication apparatus 2, the interference wave period data as the interference wave data, and the update time of the period data in the storage unit 22.

  When the control unit 20 receives periodic data from the wireless communication device 2 having the same identification information as the identification information stored in the storage unit 22, the control unit 20 updates the original periodic data with the received periodic data, and sets the update time. rewrite. When periodic data is received from the wireless communication device 2 that is not stored in the storage unit 22, new identification information (ID), periodic data, and update time are written in the storage unit 22. In addition, when the periodic data is written in the storage unit 22 but has not been updated for a predetermined time, the control unit 20 deletes all data of the corresponding identification information.

(Interference wave)
Next, the interference wave generated periodically will be described. For example, in a motor with a brush that is a driving force of an air conditioner or the like mounted on a vehicle, when the brush and the commutator slide by the rotation of the motor, periodic impulse noise is generated as an interference wave.

  If this impulse noise interferes with reception data received from another wireless communication device 2, a reception error occurs. FIG. 3 shows the relationship between the received power of the received data and the PER (packet error rate), which is the probability that the received data has an error when the air conditioner is on / off.

  When the air conditioner is off, the received power that satisfies PER ≦ 0.01 (1%) as the communication quality required in the communication system is about −85 [dBm] or more. On the other hand, the received power that satisfies PER ≦ 0.01 when the air conditioner is on is approximately −65 [dBm] or more. That is, if the transmission power from the other wireless communication device 2 is the same, the communication range that satisfies PER ≦ 0.01 is narrowed.

  In FIG. 3, the characteristic indicated by the dotted line when the air conditioner is on is a characteristic when it is assumed that there is no interference due to thermal noise inside the wireless communication device, and converges to a specific value. In FIG. 3, 0.06 is the convergence value. This convergence value is an upper limit value of the probability that the impulse noise that is an interference wave interferes with the packet data, and that all of the packet data results in an error.

  If the transmission data is adjusted so that this upper limit satisfies PER ≦ 0.01, which is a required value of the quality of the communication system, the communication quality required in the range of all received power can be obtained regardless of the magnitude of the received power. Can be satisfied.

  Therefore, as shown in FIG. 4, the transmission cycle of the transmission packet 100 to be transmitted is Ts, the transmission time (packet length) required for one packet transmission is Tp, and the other radio communication apparatus 2 has transmitted as interference wave data. If the period of the impulse noise 200 is Tinp, the probability P1 that the transmission period Ts of the transmission packet 100 and the impulse noise 200 interfere with each other, and the probability P2 (PER) that the transmission time Tp of the transmission packet 100 and the impulse noise 200 interfere with each other. Is represented by the following equations (1) and (2).

P1 = Ts / Tinp (1)
P2 = P1 × Tp / Ts (2)
From the expressions (1) and (2), P2 (PER) = Tp / Tinp. That is, the probability that an error occurs due to interference between the transmission packet 100 and the impulse noise 200 is determined by one transmission time of the packet and the period of the impulse noise 200 regardless of the transmission period of the transmission packet 100.

Therefore, if one packet transmission time is set so as to satisfy PER ≦ 0.01, the communication quality required for the communication system can be satisfied. In order to satisfy PER ≦ 0.01, one of the following communication parameters may be appropriately set to adjust the packet transmission time.
(1) The data length of the data field set in the packet. If the data length is shortened, the packet transmission time is shortened.
(2) Modulation method. For example, if the number of waveform types when performing multilevel modulation with respect to amplitude, frequency, or phase increases, the packet transmission time becomes shorter for the same amount of data.
(3) Coding rate. If the coding rate is improved, the packet transmission time is shortened for the same amount of data.

(Other interference waves)
Here, when calculating PER, there are interference waves that are small enough to ignore the duration of interference waves generated continuously every period, such as impulse noise, and there are some that cannot be ignored. For example, when radio waves used in other communication systems act as interference waves that occur periodically in radio communication channels used in vehicle-to-vehicle communication and road-to-vehicle communication, the interference waves that continue every period It may be necessary to calculate the PER in consideration of the duration of.

  Therefore, as shown in FIG. 5A, each wireless communication device 2 uses the period of the interference wave 210 (see FIG. 5B) received by itself as the interference wave data set in the transmission packet 102. In addition, the duration of the interference wave 210 that continues for each period is measured and set in the transmission packet 102 as interference continuation data. Then, another wireless communication that has extracted the interference continuation data including the period of the interference wave and the duration for each period as the interference wave data from the received packet received from the other wireless communication apparatus 2 and has transmitted the interference continuation data. When transmitting to the apparatus 2 from the own apparatus, the transmission data is adjusted based on the extracted interference continuation data.

  When the interference continuation data composed of the period of the interference wave and the duration for each period is adopted as the interference wave data, the control unit 20 adds the information for each radio communication apparatus shown in FIG. Are added and stored in the storage unit 22.

  Here, as shown in FIG. 5B, the period of the transmission packet 102 is Ts, the transmission time required for one packet transmission is Tp, and interference transmitted as interference continuation data from another wireless communication device 2 When the period of the wave 210 is Tinp and the duration of the interference wave 210 is Tu, the interference start timing at which the period of the interference wave 210 starts enters the transmission time Tp of the transmission packet 102, and the interference wave 210 and the transmission packet 102 interfere with each other. And the probability Pu that the interference wave 210 and the transmission packet 102 interfere with each other and the interference start timing are within the range of the duration Tu indicated by reference numeral 210a, and PER are the following equations (3), (4), ( 5).

Pi = Tp / Tinp (3)
Pu = Tu / Tinp (4)
PER = Pi + Pu = (Tp + Tu) / Tinp (5)
Therefore, as in the case of impulse noise in which the interference wave can ignore the duration of each period, the communication quality required for the communication system can be obtained by setting the single packet transmission time Tp so that the PER is equal to or less than a predetermined value. Can be met.

  In the case of broadcasting to a wireless communication device 2 including a plurality of wireless communication devices 2 that have transmitted either periodic data or interference continuation data as interference wave data, the corresponding wireless communication device 2 stored in the storage unit 22 Based on the interference wave data, the shortest transmission time is selected from the transmission times of the transmission packets set so that the PER expressed by the equation (2) or the equation (5) is equal to or less than a predetermined value.

  When transmitting to a specific wireless communication device 2 on a one-to-one basis, it is expressed by Equation (2) or Equation (5) based on the interference wave data of the corresponding wireless communication device 2 stored in the storage unit 22. The transmission time of the transmission packet that is set so that the PER to be performed is equal to or less than a predetermined value is selected.

(Communication processing)
Next, communication processing in the radio communication apparatus 2 that employs the period of the interference wave or the period of the interference wave and the duration of the interference wave for each period as the interference wave data will be described with reference to FIG.

  When the above-described predetermined measurement period for measuring the interference wave data is reached (S400: Yes), the interference wave data measurement unit 40 determines the period of the interference wave, or the period and duration of the interference wave from the output of the frequency converter 34. Is measured (S402). As a result of the measurement, when there is no interference wave of a predetermined signal level or higher (S404: No), the process proceeds to S400.

When there is an interference wave having a predetermined signal level or higher (S404: Yes), the interference wave data measurement unit 40 updates the interference wave data of the own device based on the measurement result (S406).
When it is not the predetermined measurement period of the interference wave data (S400: No), when the packet is received from the other wireless communication device 2 (S408: Yes), the demodulator 36 uses the frequency converter 34 to change the frequency. From the converted received signal, the received data transmitted by the other wireless communication device 2 is restored (S410). The packet reception determination is performed based on whether or not the demodulator 36 has detected a preamble included in the received signal.

  The reception packet analysis unit 38 extracts interference wave data from the restored reception data and outputs it to the control unit 20 (S412). The control unit 20 writes the interference wave data output from the received packet analysis unit 38, the identification information of the transmission source wireless communication device 2, and the update time in the storage unit 22.

  When a packet is not received from another wireless communication device 2 (S408: No) and there is a packet transmission request to the own device (S416: Yes), the transmission packet generation unit 12 is an interference wave data measurement unit. The interference wave data of its own device output from 40 is set in the transmission packet as a part of the transmission data (S418). For example, in the case of the wireless communication device 2 mounted on a vehicle, a transmission request is issued to the wireless communication device 2 from another in-vehicle device of the own vehicle.

  The control unit 20 reads out the interference wave data of the corresponding transmission destination wireless communication device 2 from the storage unit 22 depending on whether the transmission is one-to-one or broadcast transmission, and performs one transmission so that the PER is equal to or less than a predetermined value. Adjust the time. Then, the transmission packet generation unit 12 adjusts the transmission data length based on the one transmission time output from the control unit 20, and generates a transmission packet (S420). The control unit 20 may calculate the transmission data length based on one transmission time adjusted so that the PER becomes a predetermined value or less, and output the transmission data length to the transmission packet generation unit 12.

  When there is no destination interference wave data in the storage unit 22, the transmission packet generation unit 12 does not adjust the data length of the transmission packet. The transmission packet generated by the transmission packet generation unit 12 is transmitted from the antenna 4 through the transmission / reception switching unit 6 from the transmission unit 10.

As described above, the adjustment of the packet transmission time for one time is not limited to the adjustment of the transmission data length, and may be performed by adjusting the modulation method or the coding rate.
In this way, by measuring the period of the interference wave, or the period of the interference wave and the duration of the interference wave for each period as the interference wave data in each wireless communication device 2, and transmitting as a part of the transmission data, the interference wave The wireless communication device 2 that has received the data can adjust the transmission time per transmission packet so that the probability that the received data and the interference wave interfere with each other in the transmission source wireless communication device 2 is equal to or less than a predetermined value. .

Further, by setting the duration of the interference wave for each period in addition to the period of the interference wave as the interference wave data, the probability that the reception data and the interference wave interfere with each other can be controlled to a predetermined value or less with high accuracy.
In this way, by adjusting the transmission time per transmission packet, interference due to interference waves with respect to received data in the transmission source wireless communication device 2 can be reduced as much as possible without increasing transmission power. Therefore, it is possible to prevent the transmission power from being inappropriately increased in order to reduce interference due to the interference wave.

  In the first embodiment, the wireless communication device 2 corresponds to the wireless communication device of the present invention, and includes a transmission packet generation unit 12, a modulation unit 14, a frequency converter 16, a high frequency amplifier 18, a control unit 20, and a storage unit 22. The unit 10 corresponds to the transmission unit of the present invention, the high frequency amplifier 32, the frequency converter 34, the demodulation unit 36, and the received packet analysis unit 38 correspond to the reception unit of the present invention, and the interference wave data measurement unit 40 of the present invention. This corresponds to the interference wave measuring means. Packets 100 and 102 correspond to transmission data and reception data of the present invention, and impulse noise 200 and interference wave 210 correspond to the interference wave of the present invention.

  The transmission packet generation unit 12 and the control unit 20 constituting the transmission unit adjust the transmission time per transmission when transmitting the transmission data based on the interference wave data received from the other wireless communication device 2. It functions as a control means.

  6 corresponds to the function executed by the interference wave measuring means of the present invention, the processing of S408 to S412 corresponds to the function executed by the receiving means of the present invention, and the processes of S418 to S422. Corresponds to the function executed by the transmission means of the present invention, and the process of S420 corresponds to the function executed by the transmission packet generator 12 and the control unit 20 as control means among the functions executed by the transmission means of the present invention, The process of S414 corresponds to the function executed by the control unit 20 as the control means constituting the transmission means of the present invention.

[Second Embodiment]
A packet in which interference wave data used in the communication processing of the second embodiment is set is shown in FIG. In the second embodiment, as interference wave data, in addition to the period and duration of the interference wave, the start timing of any one of the interference wave periods is measured and set in the transmission packet 104 as interference start data. The configuration of the wireless communication apparatus of the second embodiment is substantially the same as that of the wireless communication apparatus 2 of the first embodiment shown in FIG.

  When the interference start data composed of the period of the interference wave, the duration for each period, and the start timing of any one of the periods of the interference wave is employed as the interference wave data, the control unit 20 (B) in FIG. In addition to the information for each wireless communication device shown in (2), the duration for each period of the interference wave and the start timing of one of the periods of the interference wave are added and stored in the storage unit 22.

  Each wireless communication device 2 measures the start timing of any one of the period, the duration, and the period of the interference wave shown in FIG. 7A from the interference wave received by itself as interference start data. Set. Then, the interference start data shown in (A) of FIG. 7 is extracted from the received packet 104 received from the other wireless communication device 2, and extracted when transmitting the interference start data to the other wireless communication device 2 that has transmitted the interference start data. The transmission data is adjusted based on the interference start data.

  The wireless communication device 2 that has received the interference start data shown in FIG. 7A transmits the interference start data from the start timing of one of the period, duration, and period of the interference wave received as the interference start data. When transmitting to the wireless communication device 2, it is possible to specify a time zone in which no interference wave is generated in the transmission source wireless communication device 2, that is, a time zone in which received data does not interfere with the interference wave.

  Therefore, as shown in FIG. 7B, the transmission time and transmission timing of the transmission packet 104 are set so that the reception data does not interfere with the interference wave 210 in the wireless communication device 2 that has received the transmission packet 104. Can be set appropriately.

(Communication processing)
A communication process when the interference start data shown in FIG. 7A is employed will be described with reference to FIG. In FIG. 8, steps that perform substantially the same processing as the flowchart shown in FIG. In FIG. 8, the process of S430 is added to the flowchart of FIG.

The interference wave data measurement unit 40 measures the interference start data including the start timing of any one of the period, duration, and period of the interference wave 210 as interference wave data (S402).
And even if there exists a transmission request with respect to an own apparatus (S416: Yes), the control part 20 is any of the period, duration, and period of the interference wave received as interference wave data from the wireless communication apparatus 2 of a transmission destination. If it is determined that the transmission packet 104 is at a timing at which it interferes with the interference wave of the transmission destination wireless communication apparatus 2 based on the start timing (S430: No), the transmission packet generator 12 waits for generation of the transmission packet 104. Let

  When the transmission packet 104 has a timing that does not interfere with the interference wave of the wireless communication apparatus 2 that is the transmission destination (S430: Yes), the process proceeds to S418. The interference wave data set in the transmission packet 104 in S418 is interference start data composed of the start timing of any one of the period, duration, and period of the interference wave, as shown in FIG.

  If the transmission packet 104 interferes with the interference wave 210 unless the length of the transmission time is adjusted, the transmission packet generator 12 transmits the transmission data length based on the destination interference wave data output from the storage unit 22 by the control unit 20. Is adjusted (S420).

  In the communication processing according to the second embodiment, the probability that the reception data and the interference wave interfere with each other is not lower than a predetermined value as in the first embodiment, and any one of the period, duration, and period of the interference wave is used. By adjusting the transmission timing and transmission time of the transmission packet 104 based on the start timing, reception data and interference waves can be prevented from interfering with each other. Thereby, the interference by the interference wave with respect to the received data can be reduced as much as possible without increasing the transmission power.

In the second embodiment, the packet 104 corresponds to transmission data and reception data of the present invention.
Further, the process of S430 in FIG. 8 corresponds to the function executed by the control unit 20 as the control means constituting the transmission means of the present invention.

[Third Embodiment]
FIG. 9 shows a wireless communication apparatus 8 according to the third embodiment. In the third embodiment, as shown in FIG. 10A, the interference wave data measurement unit 40 uses, as interference wave data, the start timing of any of the interference wave period, duration, and interference wave period, and The signal level of the interference wave is measured and set in the transmission packet 106 as interference level data. And the control part 20 sets the amplification factor of the high frequency amplifier 18 as needed based on the signal level of the interference wave received from the other radio | wireless communication apparatus 8, and adjusts the transmission power of transmission data.

  When the interference level data including the period of the interference wave, the duration of each period, the start timing of any one of the periods of the interference wave, and the signal level of the interference wave is used as the interference wave data, the control unit 20 In addition to the information for each wireless communication apparatus shown in FIG. 2B, the duration for each period of the interference wave, the start timing of one of the periods of the interference wave, and the signal level of the interference wave are additionally stored. Store in the unit 22.

(Communication processing)
Communication processing when the interference wave data shown in FIG. 10A is employed will be described with reference to FIG. In FIG. 11, steps that perform substantially the same processing as the flowchart shown in FIG. 6 are assigned the same step numbers. In FIG. 11, the processes of S430 and S440 are added to the flowchart of FIG.

  The interference wave data measurement unit 40 measures the interference level data including the period, duration, and start timing of the interference wave 210 and the reception level of the interference wave 210 as interference wave data (S402).

  Even if there is a transmission request to the own device (S416: Yes), the control unit 20 is any of the interference wave cycle, duration, and cycle among the interference wave data received from the destination wireless communication device 8. Based on the start timing, when the transmission packet 106 interferes with the interference wave of the destination wireless communication apparatus 8 and transmission can be delayed (S430: No), the transmission packet generator 12 The generation of the transmission packet 106 is waited and the transmission timing is adjusted.

  When the transmission packet 106 does not interfere with the interference wave 210 of the transmission destination wireless communication apparatus 8 or when the transmission packet 106 interferes with the interference wave 210 of the transmission destination wireless communication apparatus 8 but transmission cannot be delayed (S430: Yes), the process proceeds to S418.

  As shown in FIG. 10A, the interference wave data set in the transmission packet 106 in S418 is based on the period of the interference wave 210, the duration, the start timing of one of the periods, and the reception level of the interference wave 210. Interference level data.

  The transmission timing of the transmission packet 106 is a timing at which the transmission packet 106 does not interfere with the interference wave 210. However, if the transmission packet 106 interferes with the interference wave 210 unless the length of the transmission time is adjusted, the transmission packet generator 12 The transmission data length is adjusted based on the transmission destination interference wave data output from the storage unit 22 (S420).

  As illustrated in FIG. 10B, the control unit 20 has a timing at which the transmission packet 106 a interferes with the interference wave 210 of the transmission destination wireless communication apparatus 8, but cannot transmit the interference wave 210. The transmission power of the corresponding transmission packet 106a is set according to the signal level. Since the upper limit of the transmission power is determined by the characteristics of the high-frequency amplifier 18, the control unit 20 performs interference between the basic transmission power and the maximum transmission power set when the transmission packet 106 does not interfere with the interference wave 210. The transmission power of the corresponding transmission packet 106a is set according to the signal level of the wave 210.

  In addition, when transmitting the interference wave data including the signal level of the interference wave, it is desirable to transmit it by adding the position information of the wireless communication device 8 as the transmission source. Thereby, the wireless communication device 8 that has received the interference wave data can calculate the distance between the devices from the position of the wireless communication device 8 that is the transmission source and the position of the device itself. Therefore, the wireless communication device 8 that has received the interference wave data can adjust the transmission power of the transmission data based on the signal level of the received interference wave and the distance between the devices.

  In the third embodiment described above, as the interference wave data, wireless communication that has transmitted interference level data including the interference wave period, duration, start timing of any one of the interference wave periods, and the signal level of the interference wave When the transmission data is transmitted to the device 8 and the reception data and the interference wave interfere with each other on the reception side that receives the transmission data, by adjusting the transmission power according to the signal level of the interference wave on the reception side, It is possible to transmit without delaying the transmission timing.

The transmission data whose transmission power is to be adjusted is not limited to data whose transmission timing is not desired to be delayed, but may be all transmission data that interfere with interference waves.
In this way, the transmission power is not always increased when transmitting the transmission data, but the transmission power of the transmission data transmitted to the wireless communication device 8 that has transmitted the interference level data interferes with the reception data and the interference wave. Since it increases only when the transmission power increases, it is possible to prevent the transmission power from increasing inappropriately.

In the third embodiment, the wireless communication device 8 corresponds to the wireless communication device of the present invention, and the packet 106 corresponds to transmission data and reception data of the present invention.
Moreover, the process of S440 of FIG. 11 is corresponded to the function which the control part 20 as a control means which comprises the transmission means of this invention performs.

[Other Embodiments]
In the above embodiment, the interference wave data related to the interference wave measured by the own device is transmitted as a part of the transmission data, and the interference wave data measured by the other wireless communication device from the reception data transmitted by the other wireless communication device. Based on the extracted interference wave data, transmission data to be transmitted to the wireless communication apparatus that transmitted the interference wave data was adjusted.

  On the other hand, the interference wave data related to the interference wave measured by the own device is transmitted as a part of the transmission data, or the interference wave data is extracted based on the interference wave data extracted from the reception data transmitted by another wireless communication device. Only one of the functions of adjusting transmission data to be transmitted to a wireless communication apparatus that has transmitted data may be realized by the wireless communication apparatus.

  In addition to the combination of the interference data of the above embodiment, as interference wave data, interference start data composed of start timings of either the interference wave period or the interference wave period, or the interference wave period and the interference wave period Interference level data consisting of either of the start timing and the signal level of the interference wave may be adopted.

2, 8: wireless communication device, 4: antenna, 6: transmission / reception switching unit, 10: transmission unit, 12: transmission packet generation unit (transmission unit, control unit), 14: modulation unit (transmission unit), 16: frequency conversion (Transmission means), 18: high frequency amplifier (transmission means), 20: control section (transmission means, control means), 22: storage section (transmission means), 30: reception section, 32: high frequency amplifier (reception means), 34: Frequency converter (reception unit), 36: Demodulation unit (reception unit), 38: Received packet analysis unit (reception unit), 40: Interference wave data measurement unit (interference wave measurement unit)

Claims (14)

Receiving means for receiving transmission radio waves from other wireless communication devices and restoring received data;
Interference wave measuring means for measuring period data representing the period of the interference wave as interference wave data relating to the interference wave that is periodically generated and received by the receiving means;
Transmitting means for transmitting the periodic data measured by the interference wave measuring means to another wireless communication device as a part of transmission data;
A wireless communication apparatus comprising: The receiving means extracts the periodic data from the received data;
The transmitting means is configured to convert the periodic data based on the periodic data extracted by the receiving means in order to reduce interference due to the interference wave with respect to the received data in another wireless communication apparatus that has transmitted the periodic data. Adjusting the transmission time per transmission when transmitting transmission data to another wireless communication device that has transmitted,
The wireless communication apparatus according to claim 1. The interference wave measuring means measures interference continuation data further including a duration time of the interference wave generated every cycle as the interference wave data,
The transmission means transmits the interference continuation data measured by the interference wave measurement means to another wireless communication apparatus as a part of transmission data.
The wireless communication apparatus according to claim 1, wherein the wireless communication apparatus is a wireless communication apparatus. The receiving means extracts the interference continuation data from the received data;
The transmission unit is configured to reduce the interference based on the interference continuation data extracted by the reception unit in order to reduce interference due to the interference wave with respect to the reception data in another wireless communication apparatus that has transmitted the interference continuation data. Adjusting the transmission time per transmission when transmitting transmission data to another wireless communication device that has transmitted continuation data;
The wireless communication apparatus according to claim 3.   The transmission means extracts the interference wave extracted by the reception means so that the probability that the reception data and the interference wave interfere with each other in another wireless communication apparatus that has transmitted the interference wave data is equal to or less than a predetermined value. 5. The radio according to claim 2, wherein a transmission time per transmission when transmitting transmission data to another wireless communication apparatus that has transmitted the interference wave data is adjusted based on the data. Communication device. The interference wave measuring means measures interference start data further including a start timing of any one of the periods as the interference wave data,
The transmission means transmits the interference start data measured by the interference wave measurement means to another wireless communication apparatus as a part of transmission data.
The wireless communication device according to claim 1, wherein the wireless communication device is a wireless communication device. The receiving means extracts the interference start data from the received data;
The transmission unit is configured to reduce the interference based on the interference start data extracted by the reception unit in order to reduce interference due to the interference wave with respect to the reception data in another wireless communication apparatus that has transmitted the interference start data. Adjusting the transmission time per transmission and the transmission timing of the transmission data when transmitting the transmission data to another wireless communication device that has transmitted the start data;
The wireless communication apparatus according to claim 6. The interference wave measuring means measures interference level data further including a signal level of the interference wave as the interference wave data;
The transmission means transmits the interference level data measured by the interference wave measurement means to another wireless communication apparatus as a part of transmission data.
The wireless communication apparatus according to claim 6 or 7, wherein The receiving means extracts the interference level data from the received data;
When the transmission unit avoids interference between the reception data and the interference wave in another wireless communication apparatus that has transmitted the interference level data, the transmission unit calculates the signal level from the interference level data extracted by the reception unit. Based on the excluded data, the transmission time per transmission and the transmission timing of transmission data when transmitting the transmission data to another wireless communication apparatus that has transmitted the interference level data are adjusted, and the interference level data is transmitted. In the case where the received data and the interference wave interfere with each other in the other wireless communication apparatus, the interference is unavoidable, based on the signal level of the interference level data extracted by the receiving means, The transmission power of transmission data to be transmitted to another wireless communication apparatus that has transmitted interference level data is set as the reception data and the interference wave. Only be adjusted when the interference,
The wireless communication apparatus according to claim 8. Interference with periodically generated interference waves received from other radio communication devices to restore received data and received by other radio communication devices, measured and transmitted as part of the transmission data Receiving means for extracting period data representing the period of the interference wave as wave data from the received data;
In order to reduce interference caused by the interference wave with respect to the received data in the other wireless communication apparatus that has transmitted the periodic data, other periodicities that have transmitted the periodic data based on the periodic data extracted by the receiving unit A transmission means for adjusting a transmission time per transmission when transmitting transmission data to the wireless communication device;
A wireless communication apparatus comprising: The reception means extracts interference continuation data further including a duration of the interference wave generated for each period, measured by another wireless communication device as the interference wave data, from the reception data,
The transmission unit is configured to reduce the interference based on the interference continuation data extracted by the reception unit in order to reduce interference due to the interference wave with respect to the reception data in another wireless communication apparatus that has transmitted the interference continuation data. Adjusting the transmission time per transmission when transmitting transmission data to another wireless communication device that has transmitted continuation data;
The wireless communication apparatus according to claim 10.   The transmission means, based on the interference wave data extracted by the reception means, has a probability that the reception data and the interference wave interfere with each other in another wireless communication apparatus that has transmitted the interference wave data below a predetermined value. 12. The radio according to claim 10, wherein a transmission time per transmission when transmitting transmission data to another wireless communication apparatus that has transmitted the interference wave data is adjusted so as to become Communication device. The reception means extracts interference start data further including a start timing of any one of the periods measured by another wireless communication device as the interference wave data from the reception data,
The transmission unit is configured to reduce the interference based on the interference start data extracted by the reception unit in order to reduce interference due to the interference wave with respect to the reception data in another wireless communication apparatus that has transmitted the interference start data. Adjusting the transmission time per transmission and the transmission timing of the transmission data when transmitting the transmission data to another wireless communication device that has transmitted the start data;
The wireless communication apparatus according to claim 10 or 11, wherein the wireless communication apparatus is a wireless communication apparatus. The reception means extracts interference level data further including a signal level of the interference wave measured by another wireless communication device as the interference wave data from the reception data,
When the transmission unit avoids interference between the reception data and the interference wave in another wireless communication apparatus that has transmitted the interference level data, the transmission unit calculates the signal level from the interference level data extracted by the reception unit. Based on the excluded data, the transmission time per transmission and the transmission timing of transmission data when transmitting the transmission data to another wireless communication apparatus that has transmitted the interference level data are adjusted, and the interference level data is transmitted. In the case where the reception data and the interference wave interfere with each other in the other wireless communication device, the interference is unavoidable, based on the signal level of the interference level data extracted by the reception means, The transmission power of transmission data to be transmitted to another wireless communication apparatus that has transmitted interference level data is set as the reception data and the interference wave. Only be adjusted when the interference,
The wireless communication apparatus according to claim 13.

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