JPH088914A - Radio transmitter-receiver - Google Patents

Abstract

PURPOSE:To prevent reduction in throughput of data by sending data in a short time even on data transmission collision. CONSTITUTION:The transmitter-receiver is provided with a radio transmission section 2 sending an input data signal DI via an antenna 1, a radio reception section 3 receiving a radio signal D via the antenna 1, and a collision countermeasures section 10 detecting a carrier of the received radio signal D and generating jamming signal J. Then the radio control section 4 stops tentatively transmission of the input data signal DI to allow the collision countermeasures section 10 to start detection of carrier and the transmission of the input data signal DI is restarted when no carrier is detected. Furthermore, when the carrier is detected, after the jamming signal J is sent, the transmission of the input data signal DI is restarted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio transmitter / receiver having a countermeasure function against a collision during radio packet communication.

[0002]

2. Description of the Related Art Conventionally, when a packet collision occurs in packet communication, the processing for the collision is performed by randomly performing a retransmission process after all the wireless transmission / reception devices judge the situation of the collision. I was going.

Further, as in the technique disclosed in Japanese Patent Laid-Open No. 62-135025, some communication devices are provided with a registration number, and when a collision occurs, data communication is performed according to the priority order of the registration numbers. It was That is, a central data processing device connected by a communication line is provided to a roadside device including a roadside transceiver and an antenna set on the roadside, and within a communication area of the roadside device, a mobile device and a roadside device existing in this area are provided. Communication between mobile devices is performed outside that area. Then, at this time, each time the mobile unit passes through the communication area of the roadside device, a different registration number is sequentially assigned to the mobile unit, and timing for avoiding communication data collision by simultaneous communication between a plurality of mobile units is provided. The change was made based on the priority order judgment based on the registration number.

[0004]

However, the above-mentioned conventional techniques have the following problems. In the technology that performs retransmission processing at random intervals at the time of collision,
After determining that the communication of all wireless transceivers have collided, the retransmission processing is performed at random timing,
Data transmission is generally delayed. Therefore, it takes a long time to transfer data such as a file transfer, and the throughput of data decreases.

Further, in the technique disclosed in Japanese Patent Laid-Open No. 62-135025, since priorities are set, the mobiles registered later have to wait until the order comes, and it takes a long time to establish communication. Will be required. Furthermore, there is a problem that a roadside device for giving a registration number to a moving body is indispensable, and the cost of the device becomes high accordingly.

The present invention has been made in view of the above problems, and provides a radio transmission / reception apparatus that can perform data transmission in a short time even in the event of a data transmission collision and prevent a decrease in data throughput. With the goal.

[0007]

In order to achieve the above object, the present invention provides a carrier of a received signal in a wireless transmitter / receiver including a wireless transmitter and a wireless receiver for transmitting and receiving a data signal via an antenna. Detection means and a jamming signal generation means, and the wireless transmission means temporarily stops the transmission of the data signal to start the carrier detection of the collision prevention means, and transmits the data signal when the carrier is not detected. And a radio control means for restarting the transmission of the data signal after the jamming signal is generated by the collision countermeasure means when the carrier is detected and the jamming signal is transmitted. There is.

A radio transmitting / receiving device according to claim 2 is
The radio control means is configured to stop the transmission of the data signal when the jamming signal is received and restart the transmission of the data signal after a predetermined time.

The radio transmitter / receiver according to claim 3 is
The collision countermeasure means includes a carrier detection unit that detects a carrier of a received signal and sends a carrier detection signal to the wireless control unit, and a jamming signal generation unit that generates a jamming signal and sends the jamming signal to the transmission unit. The control means operates the jamming signal generation section at the time of receiving the carrier detection signal, and restarts the transmission of the data signal after a predetermined time.

Further, a radio transmitting / receiving apparatus according to a fourth aspect of the present invention includes a first switch for switching between transmission of the data signal and transmission of a jamming signal, and a second switch for switching between a transmission state and a reception state. And a switch.

[0011]

According to the above radio transmission / reception apparatus, the transmission of the data signal by the radio transmission means is temporarily stopped, the carrier detection of the collision countermeasure means is started, and the transmission of the data signal is restarted when the carrier is not detected. When a carrier is detected, the jamming signal is transmitted by the collision countermeasure means, and then the transmission of the data signal is restarted.

Further, according to the wireless transmitting / receiving apparatus of the second aspect, when the jamming signal is received, the transmission of the data signal is stopped, and the transmission of the data signal is restarted after a predetermined time.

Further, according to the third aspect of the present invention, when the carrier of the received signal is detected, the carrier detection section sends the carrier detection signal C to the wireless control means and the jamming signal is sent by the wireless control means. The generator is activated. As a result, the jamming signal from the jamming signal generator is transmitted. Then, the transmission of the data signal is restarted after a predetermined time.

Further, according to the radio transmitter / receiver of the present invention, the first switcher switches between transmission of the data signal and transmission of the jamming signal, and the second switcher switches between the transmission state and the reception state. Can be switched.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a wireless transmitting / receiving apparatus according to an embodiment of the present invention. As shown in FIG. 1, the wireless transmission / reception device of this embodiment includes a wireless transmission unit 2 as a wireless transmission unit that transmits a data signal via an antenna 1,
A wireless receiving unit 3 as a wireless receiving unit that receives a data signal via the antenna 1, and a wireless control unit 4 as a wireless control unit that controls the wireless transmitting unit 2 and the wireless receiving unit 3 and other circuits described later. Is equipped with.

The wireless transmission unit 2 receives the input data signal DI via the signal changeover switch 5 as the first changer, modulates the input data signal DI and outputs it to the antenna 1. The memory unit 6 is provided in front of the wireless transmission unit 2.
The input data signal DI is once stored in the memory unit 6 and then output to the wireless transmission unit 2 side via the signal changeover switch 5 switched by the control of the wireless control unit 4. It has become.

The radio receiving section 3 demodulates the radio signal D received by the antenna 1 and outputs it as an output data signal DO. Such a wireless transmitter 2 and a wireless receiver 3
Is connected to the antenna 1 via an RF changeover switch 7 as a second changer, and the RF changeover switch 7 is changed over by the control of the wireless control unit 4 so that transmission / reception is performed. .

Such a radio transmission / reception apparatus is further provided with a collision countermeasure unit 10 as a collision countermeasure unit controlled by the radio control unit 4. The collision countermeasure unit 10 includes a carrier detection unit 11, a jamming signal generation unit 12, and a timer 1.
3 and 3.

The carrier detection unit 11 is arranged between the reception terminal 71 of the RF changeover switch 7 and the radio control unit 4. The carrier detection unit 11 has a function of detecting a carrier (carrier wave) from the received wireless signal D and outputting a carrier detection signal C indicating the detection result to the wireless control unit 4.

The radio control unit 4 temporarily suspends the transmission operation of the radio transmission unit 2 and switches the RF changeover switch 7 to the reception terminal 71 side to perform reception control, and the carrier detection signal C from the carrier detection unit 11 is input. If not, it has a function of operating the wireless transmission unit 2 again. Also,
When the carrier detection signal C from the carrier detection unit 11 is input, the jamming signal generation unit 12 and the timer 13
And are designed to work.

The jamming signal generator 12 has its output end connected to the jamming signal terminal 51 of the signal changeover switch 5, generates a jamming signal J during operation, and transmits the jamming signal J via the signal changeover switch 5 by radio. It has a function of outputting to the transmitter 2.

The timer 13 operates when the carrier detection signal C from the carrier detection unit 11 is input to the radio control unit 4 as described above. The radio control unit 4 monitors the timer 13 and switches the signal changeover switch 5 to the transmission data terminal 52 after a predetermined time has elapsed so that the input data signal DI is retransmitted.

The radio controller 4 stops the transmission of the input data signal DI when the radio receiver 3 receives the jamming signal J. Then, after the jamming signal J is received, the transmission of the input data signal DI is restarted at a sufficient time interval.

Next, the operation of this embodiment will be described.
FIG. 2 is a schematic diagram showing a state in which packet communications of a plurality of wireless transmission / reception devices collide, and FIG. 3 is an operation sequence diagram of each wireless transmission / reception device.

As shown in FIG. 2, the wireless transmission / reception device 101
A case of transmitting data from the wireless communication device 100 to the wireless transmission / reception device 100 will be described. In the wireless transmission / reception device 101, the wireless control unit 4 switches the RF changeover switch 7 to the reception terminal 71 side to confirm that there is no carrier detection signal C from the carrier detection unit 11, and then sets the RF changeover switch 7 to the transmission terminal 72. Then, the wireless transmission unit 2 is operated to transmit data (S1 in FIG. 3).

That is, after the input data signal DI is once stored in the memory unit 6, it is input to the wireless transmission unit 2 via the signal changeover switch 5, and the wireless transmission unit 2 modulates the input data signal DI to the antenna 1. Output. Then, the wireless transmission unit 2 is temporarily stopped, the RF changeover switch 7 is switched to the reception terminal 71, and the reception state is established.
Start career sense by.

At this time, if there is no transmission from the wireless transmission / reception device 102 of FIG. 2 to the wireless transmission / reception device 100, there is no input of the carrier detection signal C to the wireless control unit 4, and the wireless control unit 4 is in a collision state. Judge that it has not occurred. Then, the RF changeover switch 7 is changed over to the transmission terminal 72 side, all the remaining input data signals DI are transmitted to the wireless transmission / reception device 100, and then the RF changeover switch 7 is changed over to the reception terminal 7.
It is switched to the 1 side to be in the receiving state (S2 in FIG. 3).

Response data D from the wireless transmitter / receiver 100
Is input from the antenna 1 to the wireless reception unit 3 via the RF changeover switch 7, demodulated by the wireless transmission unit 2, and input as the output data signal DO (S3 in FIG. 3).

Next, the collision countermeasure operation will be described. The wireless transmission / reception device 101, after transmitting its own input data signal DI as described above, suspends the wireless transmission unit 2 to perform RF
The changeover switch 7 is switched to the receiving terminal 71 to bring it into the receiving state, and the carrier detection section 11 starts carrier sensing (S4 in FIG. 3).

At this time, if the wireless transmission / reception device 102 is also transmitting to the wireless transmission / reception device 100 (S5 in FIG. 3), the carrier detection unit 11 of the wireless transmission / reception device 101 detects the received wireless signal D of the wireless transmission / reception device 102. The carrier is detected from the inside, and the carrier detection signal C is output to the wireless control unit 4.

Then, the radio control unit 4 switches the signal changeover switch 5 to the jamming signal terminal 51 side and operates the jamming signal generation unit 12 and the timer 13.
As a result, the jamming signal generation unit 12 transmits the jamming signal J to cancel the carrier transmitted from the wireless transmission / reception device 102 (S6 in FIG. 3).

Then, the wireless control unit 4 switches the signal changeover switch 5 to the transmission data terminal 52 after a lapse of a predetermined time, and causes the wireless transmission unit 2 to retransmit the remaining input data signal DI (FIG. 3). S7).

After that, the wireless controller 4 switches the RF selector switch 7 to the receiving terminal 71 side to bring it into a receiving state, and receives the response data D from the wireless transmitter-receiver 100 (FIG. 3).
S8).

On the other hand, when the jamming signal J from the radio transmitter / receiver 101 is received on the radio transmitter / receiver 102 side (S9 in FIG. 3), the transmission is stopped, and after a sufficient time interval has elapsed, the carrier detector 11 and the radio are transmitted. The control unit 4 confirms whether there is a carrier from the wireless transmission / reception device 101 (or the wireless transmission / reception device 100), confirms that there is no carrier, and then transmits the data that could not be transmitted due to the collision ( S10 of FIG. 3).

As described above, according to the radio transmitter / receiver of the present embodiment, the radio transmitter / receiver that continuously transmits in the non-collision state and the earliest radio transmitter / receiver in the collision state causes the jamming signal J.
Therefore, data transfer such as file transfer can be performed in a shorter time than that of the conventional wireless transmission / reception device, and a decrease in data throughput can be prevented.

[0036]

As described above, according to the radio transmitter / receiver of the present invention, the carrier is detected at the time of collision, and after the jamming signal is transmitted by the collision countermeasure means, the transmission of the data signal is resumed continuously. Data transfer such as file transfer can be performed in a shorter time as compared with the conventional wireless transmission / reception device, and it is possible to prevent a decrease in data throughput. Further, unlike the technique described in Japanese Patent Application Laid-Open No. 62-135025, since no on-road device is required, the cost of the device can be reduced accordingly.

[Brief description of drawings]

FIG. 1 is a block diagram showing a wireless transmission / reception device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a state in which packet communications of a plurality of wireless transmission / reception devices are in collision.

FIG. 3 is an operation sequence diagram of each wireless transmission / reception device.

[Explanation of symbols]

 1 Antenna 2 Radio Transmission Section 3 Radio Reception Section 4 Radio Control Section 5 Signal Changeover Switch 7 RF Changeover Switch 10 Collision Countermeasure Section 11 Carrier Detection Section 12 Jamming Signal Generation Section 13 Timer

Claims (4)

[Claims] 1. A collision prevention means for detecting a carrier of a received signal and generating a jamming signal in a wireless transmission / reception device comprising a wireless transmission means and a wireless reception means for transmitting and receiving a data signal via an antenna, The transmission of the data signal by the wireless transmission means is temporarily stopped to start the carrier detection of the collision countermeasure means, the transmission of the data signal is restarted when the carrier is not detected, and the above is performed when the carrier is detected. A wireless transmission / reception device, comprising: wireless control means for causing the collision countermeasure means to perform a jamming signal generation operation and transmitting the jamming signal, and then restarting the transmission of the data signal. 2. The wireless transmission / reception apparatus according to claim 1, wherein the wireless control means stops the transmission of the data signal when the jamming signal is received and restarts the transmission of the data signal after a predetermined time. 3. The collision countermeasure means detects a carrier of a reception signal and sends a carrier detection signal to the radio control means, and a jamming signal generation section which generates a jamming signal and sends the jamming signal to the transmitting means. 3. The wireless transmission / reception apparatus according to claim 2, wherein the wireless control means operates the jamming signal generation unit at the time of receiving the carrier detection signal and restarts the transmission of the data signal after a predetermined time. 4. A first switcher for switching between transmission of the data signal and transmission of a jamming signal, and a second switcher for switching between a transmission state and a reception state. The wireless transmission / reception device according to claim 3.