JP2008312006A - Wireless communication system and wireless communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless communication system with which stable wireless communication with a mobile object is attained even when a used wireless frequency is restricted. <P>SOLUTION: The wireless communication system controls each of a base station 10 for high speed and a usual base station 20 to perform the wireless communication. The base station 10 for high speed includes an antenna 11 for high speed and a wireless communication unit 13 for high speed. The usual base station 20 includes an antenna 21 of a diversity system and a wireless communication unit 23 for usual. A server 30 acquires valid reception data received either from the base station 10 for high speed or the usual base station 20. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wireless communication system for collecting, for example, information related to a moving state of a moving object.

  In recent years, wireless communication has been used to provide real-time information on the moving state of moving objects such as automobiles, motorcycles, and trains (specifically, the position, posture, and moving speed of moving objects). A collection system has been developed. With such a system, for example, in motor sports, it is possible to monitor the traveling of automobiles and motorcycles that travel at high speed in a racetrack.

  By the way, compared with wired communication, wireless communication is more likely to cause a communication error depending on the environment. Specifically, communication is interrupted, and various data indicating position information and speed information transmitted from the mobile body cannot be received, and as a result, necessary data cannot be collected in real time. In particular, in wireless communication with a moving body that moves at high speed, continuous communication may become unstable.

An improvement method for stabilizing wireless communication with such a moving body has been proposed (see, for example, Patent Document 1). In the method according to this prior art document, when performing wireless communication with a moving object such as a train or a car, two wireless devices mounted on the moving object communicate with different base stations. In this case, when communication by one of the wireless devices cannot be performed, stable continuous communication is realized by starting communication with the next approaching base station.
JP 2007-6351 A

  In the method of the prior art document, it is necessary to assign two radio communication frequencies to one moving object. For this reason, the radio frequency that can be allocated in a place where a plurality of automobiles run is depleted, and if a moving object using the same frequency enters the same communication area, there is a problem that radio communication may interfere. is there.

  Therefore, an object of the present invention is to provide a wireless communication system capable of realizing stable wireless communication with a mobile body even when the wireless frequency to be used is limited.

  A wireless communication system according to an aspect of the present invention includes a first antenna for performing wireless communication with a mobile object, and a first antenna that processes reception of radio waves received by the first antenna and generates reception data. A second antenna for wireless communication between one wireless communication device and a moving body moving at a speed higher than a set speed, and processing radio waves received by the second antenna to generate reception data The same wireless communication channel is set for the second wireless communication device, the first wireless communication device, and the second wireless communication device, and the first wireless communication device or the second wireless communication is set. It is a structure provided with the control means which acquires the effective reception data received by radio | wireless communication with the said mobile body from one of the apparatuses.

  ADVANTAGE OF THE INVENTION According to this invention, even when the radio frequency to be used is limited, the radio | wireless communications system which can implement | achieve the stable radio | wireless communication with a mobile body can be provided. In particular, stable wireless communication with a moving body that moves at high speed can be realized.

  Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment]
FIG. 1 is a block diagram for explaining a configuration of a wireless communication system according to the present embodiment.

  As shown in FIG. 1, this system includes a high-speed antenna (second antenna) 11, a mixer 12, a high-speed wireless communication unit (second wireless communication apparatus) 13, and a data base 14. A station (referred to as a high-speed base station for convenience) 10, a normal radio base station (referred to as a normal base station for convenience) 20, and a server 30 are included.

  The normal base station 20 includes a diversity antenna (first antenna, referred to as a normal antenna for convenience) 21, a mixer 22, and a normal wireless communication unit (first wireless communication unit) composed of a plurality of antennas 21 A and 21 B. Communication device) 23 and a data processing unit 24.

  The high-speed antenna 11 is an antenna having directivity or gain characteristics different from those of the normal antenna 21. Specifically, for example, an adaptive array antenna adapted to wireless communication with a moving body moving at a speed higher than a set speed.

  The high-speed wireless communication unit 13 can assign a plurality of channels (wireless communication frequencies), and performs processing such as converting radio waves received by the high-speed antenna 11 into digital data. The normal wireless communication unit 23 can assign a plurality of channels (wireless communication frequencies), and performs processing such as converting radio waves received by the normal antenna 21 into digital data. In the present embodiment, description of the data transmission function of each of the high-speed wireless communication unit 13 and the normal wireless communication unit 23 is omitted.

  The data processing unit 14 performs processing such as decoding received data from data output from the high-speed wireless communication unit 13. Similarly, the data processing unit 24 executes processing such as decoding received data from data output from the normal wireless communication unit 23.

  As will be described later, the server 30 performs control processing of the base stations 10 and 20 including channel (wireless communication frequency) allocation and the like, and the moving state of the moving body using wireless communication, that is, the position, posture, moving speed, etc. Processing to collect various information in real time is executed.

(System operation)
The operation of the system of this embodiment will be described below with reference to the flowchart of FIG.

  The system according to the present embodiment executes a process of collecting various types of information such as the position, posture, and moving speed of the moving body in real time in order to monitor the moving state of the moving body such as an automobile traveling on a racetrack.

  Here, the high-speed base station 10 and the normal base station 20 are each assumed to be a single unit for convenience, for example, and are arranged at predetermined positions on the racetrack. The server 30 assigns the same channel (same radio communication frequency) to the radio communication units 13 and 23 of the high-speed base station 10 and the normal base station 20 and activates both base stations 10 and 20 simultaneously.

  The mobile unit is equipped with a wireless communication device, and is transmitted data indicating a moving state such as a traveling position and speed (for convenience, it is referred to as ABCDEFGHI *, where “*” is a symbol indicating the end of the data. ) Are converted into radio waves and transmitted continuously (step S1). The high-speed base station 10 and the normal base station 20 receive radio waves from the moving body by the high-speed antenna 11 and the normal antenna 21, respectively (steps S2A and S2B).

  The normal base station 20 uses a diversity antenna as the normal antenna 21 as described above. The diversity method compensates the reception state of radio waves by switching the two antennas 21A and 21B even when the strength of radio waves transmitted from a mobile body is reduced due to fading. However, since the antenna switching determination process takes some time, the communication frequency is limited by the processing time. On the other hand, the high-speed base station 10 uses a high-speed antenna 11 adapted for wireless communication with a moving body moving at a speed higher than the set speed. Therefore, there is a high possibility that the high-speed base station 10 has normally received radio waves transmitted from a moving body that is traveling at high speed.

  In the high speed base station 10, the data processing unit 14 decodes the received data from the data output from the high speed wireless communication unit 13 and outputs the decoded data to the server 30 (step S3A). In this case, the reception data decoded by the high speed base station 10 is referred to as “ABCDEFGH”. On the other hand, in the normal base station 20, the data processing unit 24 decodes the received data from the data output from the normal wireless communication unit 23 and outputs it to the server 30 (step S3B). In this case, the reception data decoded by the normal base station 20 is “ABCDEF”.

  The server 30 acquires the reception data (ABCDEFGH) output from the data processing unit 14 of the high-speed base station 10 and the reception data (ABCDEF) output from the data processing unit 24 of the normal base station 20, and receives each reception data. Are compared (step S4). Here, neither the high-speed base station 10 nor the normal base station 20 was able to receive the data of the symbol (*) indicating the end of the transmission data in the transmission data (ABCDEFGHI *) transmitted by the mobile unit. Suppose.

  As a result of comparing the data capacities of the data, the server 30 has received data (ABCDEFGH) received at the high-speed base station 10 by a relative amount of data (GH). ), The received data (ABCDEFGH) received by the high speed base station 10 is employed (step S5). As a result, the server 30 stores various information such as the moving state of the moving body that is traveling at high speed, that is, the position, posture, and moving speed of the moving body, based on the received data received by the high-speed base station 10. Collect in real time.

  As described above, in the case of receiving and processing data transmitted from a mobile object moving at high speed, the normal base station 20 using the normal antenna 21 of the diversity scheme transmits the data from the mobile object. When the strength of the received radio wave decreases due to fading, the communication frequency is limited by the processing time for antenna switching determination, and there is a high possibility that the received data will be lost.

  Therefore, in the system according to the present embodiment, at the same time as the normal base station 20, the high-speed base station 10 to which the same channel (same radio communication frequency) is assigned acquires the received data from the mobile unit. In this case, the high-speed base station 10 can receive radio waves with higher accuracy than the normal base station 20 by the high-speed antenna 11 having relatively excellent directivity. Therefore, the server 30 can compensate for the loss of the reception data at the normal base station 20 by adopting the reception data decoded by the high speed base station 10 having a relatively large amount of reception data. In other words, in the system of the present embodiment, the server 30 employs, as formal received data, the data with less data loss among the received data received by the normal base station 20 or the high speed base station 10.

  Here, in wireless communication, when a part of transmission data is lost due to a wireless communication error, a retransmission request is generally sent to the transmission side when the lost data arrives. However, when the frequency of wireless communication is increased, if the retransmission request is made, the communication frequency is limited. Therefore, in the system according to the present embodiment, it is possible to omit the process of making a retransmission request to the mobile body on the transmission side by adopting received data with few data loss as formal data.

  Thereby, if it is the system of this embodiment, the stable radio | wireless communication with the mobile body which drive | works especially more than a setting speed is implement | achieved, and the required reception data for monitoring the movement state of a mobile body is acquired. Is possible. In this case, since the same channel (same radio communication frequency) is assigned to the high-speed base station 10 and the normal base station 20, a situation in which the assigned radio communication frequency is exhausted can be prevented.

  In addition, although the case where each of the high-speed base station 10 and the normal base station 20 is single has been described, the present invention is not limited to this, and each of the high-speed base station 10 and the normal base station 20 or only the high-speed base station 10 is used. A configuration in which a plurality of units are used may be used.

  In addition, although the movement monitoring of the motor sports car was described as an application field of the system of the present embodiment, the present invention can be applied to, for example, a patrol car and a white bike traveling monitoring.

  Further, in the present embodiment, the wireless communication with the moving body moving at a high speed has been described. However, in the wireless communication with the relatively low speed moving body, the received data received by the base station 20 is more data amount. If there are many, naturally, the reception data normally received by the base station 20 is adopted. Furthermore, when the received data received by each of the high speed base station 10 and the normal base station 20 has the same data amount, either one of the received data or a combination of the received data may be employed.

[Second Embodiment]
FIG. 3 is a flowchart for explaining the operation of the wireless communication system according to the second embodiment. The configuration of the system is the same as that of the system according to the first embodiment shown in FIG.

  In the system of the present embodiment, the server 30 first acquires the reception data received by the reception operation of the normal wireless communication unit 23 of the normal base station 20 (step S11). The received data includes data indicating the moving state of the moving body, that is, the position and the traveling speed (moving speed). The server 30 measures the traveling speed (moving speed) of the moving body using the received data (step S12).

  When the traveling speed of the moving body is equal to or lower than the set speed and is relatively low, the server 30 continues the reception operation of the normal wireless communication unit 23 as it is (steps S13 and S14). On the other hand, when the traveling speed of the moving body is equal to or higher than the set speed and is relatively high, the server 30 activates the high-speed wireless communication unit 13 of the high-speed base station 10 (step S15). At this time, the server 30 assigns the same channel as the channel (wireless communication frequency) set in the normal wireless communication unit 23 to the high-speed wireless communication unit 13 (step S16).

  As a result, the server 30 causes the normal wireless communication unit 23 and the high-speed wireless communication unit 13 to perform reception operations simultaneously, and receives data based on the radio wave received by the high-speed antenna 11 and the radio wave received by the normal antenna 21. Each of the received data based on can be acquired (step S17).

  As described above, according to the system of the present embodiment, when the mobile object that is the object of wireless communication is traveling at a relatively low speed, the server 30 is obtained by the reception operation of the normal wireless communication unit 23 of the normal base station 20. The received data can be acquired and information such as the moving state of the moving body, that is, the position and speed can be collected. In this case, since the moving body is low speed, there is a high possibility that received data with little data loss will be acquired even if the antenna switching process with the normal antenna 21 of the diversity method is executed. Therefore, since the operation of the high-speed wireless communication unit 13 can be stopped, it is possible to save power consumption.

  On the other hand, when the mobile body is traveling at a relatively high speed, the server 30 causes the normal wireless communication unit 23 of the normal base station 20 and the high-speed wireless communication unit 13 of the high-speed base station 10 to simultaneously execute the reception operations. As a result, it is possible to compensate for data loss and to obtain normal received data. Therefore, the same effects as those of the first embodiment described above can be obtained.

  The server 30 may preferentially use the reception data obtained by the reception operation of the high-speed wireless communication unit 13 and use the reception data obtained by the reception operation of the normal wireless communication unit 23 as compensation data.

[Third Embodiment]
4 and 5 are diagrams for explaining the configuration and operation of the wireless communication system according to the third embodiment. Note that the basic configuration of the system is the same as that of the system according to the first embodiment shown in FIG.

  FIG. 4 shows the relationship between the moving body 40 traveling at high speed on the road 41 and the high-speed base station 10 having the high-speed antenna 11 of the wireless communication system or the normal base station 20 having the normal antenna 21. It is a figure which shows the state which is performing radio | wireless communication. In this case, the communication area 210 using the normal antenna 21 is different from the communication area 110 using the high-speed antenna 11.

  In such a state, when the reception operations of the high-speed wireless communication unit 13 using the high-speed antenna 11 and the normal wireless communication unit 23 using the normal antenna 21 are simultaneously performed, the high-speed wireless communication unit The received data received at 13 may always have more data loss. In such a case, it is effective to adjust the direction of the high-speed antenna 11 within a predetermined setting range.

  Therefore, the system of the present embodiment is configured such that the direction of the high-speed antenna 11 of the high-speed base station 10 is adjusted by the antenna direction adjuster 50, as shown in FIG. The antenna direction adjuster 50 has, for example, a moving mechanism and a servo motor for changing the direction of the high-speed antenna 11, and changes the direction of the high-speed antenna 11 through the moving mechanism according to the drive control of the servo motor. adjust. The antenna direction adjuster 50 is driven and controlled by the server 30 to adjust the direction of the high speed antenna 11 within a set range.

  The server 30 adjusts the direction of the high-speed antenna 11 within the set range via the antenna direction adjuster 50 when there is a lot of data loss in the received data received by the high-speed wireless communication unit 13. By such automatic antenna adjustment by the server 30, the communication area 110 by the high-speed antenna 11 changes as compared to the case shown in FIG. 4 as shown in FIG. Therefore, it is possible to improve the reception state of the high speed base station 10 and reduce the data loss of the received data received by the high speed wireless communication unit 13.

  In short, with the system of this embodiment, the direction of the high-speed antenna 11 can be automatically adjusted within the set range, and in particular, the reception state by wireless communication with the moving body 40 during high-speed traveling is improved. In addition, it is possible to obtain received data with little data loss. This makes it possible to perform stable wireless communication, regardless of the type of mobile object.

  In the present embodiment, the automatic direction adjustment function of the high-speed antenna 11 has been described. However, the present invention is not limited to this, and a configuration in which the direction of the normal antenna 21 is automatically adjusted within the set range can be realized.

[Fourth Embodiment]
FIG. 6 is a diagram for explaining the configuration and operation of a wireless communication system according to the fourth embodiment. Note that the basic configuration of the system is the same as that of the system according to the first embodiment shown in FIG.

  In the present embodiment, as shown in FIG. 6, for example, a road 41 such as a racetrack is divided into a plurality of ranges, and a plurality of high-speed base stations 10A to 10D having communication areas 110A to 110D covering each range are provided. It is a deployed system. Each of these high-speed base stations 10 </ b> A to 10 </ b> D has a high-speed antenna 11, a mixer 12, a high-speed wireless communication unit 13, and a data processing unit 14, and transmits each received data to the server 30.

  In the present embodiment, the server 30 turns on the operation of the high-speed wireless communication unit 13 of the high-speed base station that covers the communication area corresponding to the range in which the moving body 40 is traveling. In addition, the server 30 turns off the operation of the high-speed wireless communication unit 13 of the high-speed base station that covers a communication area outside the range in which the moving body 40 is traveling.

  Specifically, for example, the server 30 enables the wireless communication function of the high-speed base station 10D that covers the communication area 110D corresponding to the range in which the moving body 40 is traveling. That is, the server 30 turns on the operation of the high-speed wireless communication unit 13 of the high-speed base station 10D, and acquires the reception data from the moving body 40. The server 30 collects in real time various information such as the moving state of the moving body 40 that is traveling at high speed, that is, the position, posture, and moving speed of the moving body, from the received data received by the high speed base station 10D.

  Here, based on the moving speed information included in the received data, the server 30 predicts the time when the moving body 40 passes through the communication area 110D and enters the next communication area 110A as shown in FIG. When the mobile unit 40 passes through the communication area 110D and goes out of the area 110D, the server 30 outputs pause information to the high-speed wireless communication unit 13 of the high-speed base station 10D and turns it off. As a result, the high-speed wireless communication unit 13 of the high-speed base station 10 </ b> D enters a standby state until the mobile body 40 approaches next and receives an instruction from the server 30.

  On the other hand, the server 30 outputs activation information to the high-speed wireless communication unit 13 of the high-speed base station 10A and turns it on immediately before the moving body 40 passes through the communication area 110D and enters the communication area 110A. As a result, the server 30 provides various information such as the position, posture, and moving speed of the moving body 40 traveling at high speed in real time from the received data received by the high-speed wireless communication unit 13 of the high-speed base station 10A. collect.

  As described above, in the system according to the present embodiment, among the plurality of high-speed base stations 10A to 10D, high-speed wireless communication of a high-speed base station having a communication area in which wireless communication with the mobile unit 40 is effective. The unit 13 is turned on, and the high-speed wireless communication units 13 of the other high-speed base stations are turned off. That is, the high-speed wireless communication unit 13 in the communication area through which the moving body 40 has passed temporarily cancels a channel (wireless communication frequency) necessary for wireless communication and makes it wait. On the other hand, a channel necessary for wireless communication is set for the high-speed wireless communication unit 13 in the communication area immediately before the mobile object 40 enters and wireless communication is started.

  By such on / off control for the high-speed base stations 10A to 10D, only the high-speed wireless communication unit 13 necessary for wireless communication is operated, and the high-speed wireless communication unit 13 that does not require wireless communication is dedicated unnecessarily. Such a situation can be avoided. Therefore, particularly when performing wireless communication with a plurality of mobile units having different travel positions, the high-speed wireless communication unit 13 of the high-speed base station that is turned off is newly required for wireless communication with the mobile unit. Wireless communication can be effectively performed by setting a channel. In other words, when the high-speed wireless communication unit 13 that does not require wireless communication is occupied, it may not be possible to immediately perform wireless communication with a new mobile body with a different channel. Such a situation can be avoided. As a result, the plurality of high-speed wireless communication units 13 can be effectively used without waste.

  In the present embodiment, the on / off control for the high-speed base stations 10A to 10D has been described. However, the present invention is not limited to this, and it can be applied to the on / off control when a plurality of normal base stations are arranged. it can.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

The block diagram for demonstrating the structure of the radio | wireless communications system regarding the 1st Embodiment of this invention. The flowchart for demonstrating operation | movement of the radio | wireless communications system regarding this embodiment. 9 is a flowchart for explaining the operation of the wireless communication system according to the second embodiment. The figure for demonstrating the effect of the radio | wireless communications system regarding 3rd Embodiment. The figure for demonstrating the partial structure of the radio | wireless communications system regarding 3rd Embodiment. The figure for demonstrating the structure and operation | movement of the radio | wireless communications system regarding 4th Embodiment.

Explanation of symbols

10, 10A to 10D ... high speed base station, 11 ... high speed antenna (second antenna),
12 ... mixer, 13 ... high speed wireless communication unit (second wireless communication device),
14 ... Data processing unit, 20 ... Normal base station,
21 ... Diversity antenna (first antenna), 22 ... Mixer 23 ... Normal wireless communication unit (first wireless communication device), 24 ... Data processing unit,
30: Server.

Claims (11)

A first antenna for performing wireless communication with a mobile body, and a first wireless communication device that generates reception data by processing radio waves received by the first antenna;
A second antenna for performing wireless communication with a mobile body that moves at a speed higher than a set speed, and a second wireless communication device that generates reception data by processing radio waves received by the second antenna When,
The same wireless communication channel is set for the first wireless communication device and the second wireless communication device, and the mobile unit is connected to one of the first wireless communication device and the second wireless communication device. And a control means for acquiring valid received data received by the wireless communication. The first antenna is a diversity antenna.
The second antenna is a high-speed antenna having directivity characteristics or gain characteristics different from those of the first antenna, and relatively excellent reception characteristics by wireless communication with a moving body that moves at high speed. The wireless communication system according to claim 1. The first wireless communication apparatus uses a diversity antenna as the first antenna, and a first wireless communication unit that processes radio waves received by the first antenna, and the first wireless communication First data processing means for generating received data from the output signal of the unit;
The second wireless communication apparatus uses a high-speed antenna having a directivity characteristic or gain characteristic different from that of the first antenna as the second antenna, and processes a radio wave received by the second antenna. 2. The wireless communication according to claim 1, comprising: two wireless communication units; and second data processing means for generating reception data from an output signal of the second wireless communication unit. system. The control means includes
A data determination unit that employs received data with a relatively small amount of data loss by comparing each received data acquired from the first wireless communication device and the second wireless communication device. The wireless communication system according to any one of claims 1 to 3. The control means includes
Means for calculating a moving speed of the moving body based on received data acquired from the first wireless communication device;
When the moving speed is equal to or higher than a set speed, the second wireless communication device is activated to set the same channel as the wireless communication channel set in the first wireless communication device, and the second wireless communication The wireless communication system according to any one of claims 1 to 3, further comprising means for acquiring received data output from the apparatus as valid received data. An adjustment mechanism for adjusting the direction of the second antenna;
When the control means obtains valid received data in which the data loss amount is within an allowable range in the reception data output from the second wireless communication device, the control unit is configured to perform the above processing based on the data loss amount of the reception data 6. The wireless communication system according to claim 1, further comprising a unit that controls an adjustment mechanism to adjust a direction of the second antenna. 7. Base stations having the second wireless communication device are arranged at a plurality of locations, each base station has a different wireless communication area as a receivable wireless communication area,
The control means stops the reception function by the second antenna for the base station corresponding to the radio communication area through which the mobile body has passed, and the base station in the radio communication area corresponding to the movement range of the mobile body The wireless communication system according to any one of claims 1 to 3, further comprising means for activating a reception function by the second antenna. The mobile body has means for transmitting data indicating position information,
The control means obtains information relating to a moving state such as a position and a moving speed of the moving body based on reception data from the moving body received by the first wireless communication apparatus or the second wireless communication apparatus. The wireless communication system according to any one of claims 1 to 7, further comprising a collecting unit. A first antenna for performing wireless communication with a mobile body, and a first wireless communication apparatus that generates reception data by processing radio waves received by the first antenna, and is faster than a set speed Wireless communication having a second antenna for performing wireless communication with a moving mobile body, and a second wireless communication device for processing radio waves received by the second antenna and generating reception data A wireless communication method applied to a system,
Setting the same wireless communication channel for the first wireless communication device and the second wireless communication device;
Executing a procedure including a step of selecting and acquiring valid received data from received data received by wireless communication with the mobile unit from the first wireless communication device or the second wireless communication device. And a wireless communication method. The obtaining step includes
10. The method includes comparing received data acquired from the first wireless communication device and the second wireless communication device and adopting received data with a relatively small amount of data loss. The wireless communication method described in 1. A first antenna for performing wireless communication with a mobile body, and a first wireless communication apparatus that generates reception data by processing radio waves received by the first antenna, and is faster than a set speed Wireless communication having a second antenna for performing wireless communication with a moving mobile body, and a second wireless communication device for processing radio waves received by the second antenna and generating reception data A wireless communication method applied to a system,
Calculating a moving speed of the moving body based on received data acquired from the first wireless communication device;
When the moving speed is equal to or higher than a set speed, activating the second wireless communication device and setting the same channel as the wireless communication channel set in the first wireless communication device;
And a step of acquiring received data output from the second wireless communication device as valid received data.

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