JP4875530B2 - Wireless communication system - Google Patents

Description

The present invention relates to a radio communication system having a base station and a mobile station, and more particularly to a radio communication system for measuring the received electric field strength of radio waves between a base station and a mobile station.

In general, when measuring the performance and radio quality of base station and mobile station radio devices in a radio communication system, the base station moves by transmitting a radio wave from the base station and sending back a response. It measures the quality of the radio equipment of the station.
For example, in the case of measurement of radio waves in a train radio system, it is composed of a control station, a plurality of base stations, and a train (mobile station) that moves along a track. From the base station based on a command from the control station A radio wave is transmitted, and a mobile station that has received the radio wave returns data related to radio quality such as received electric field strength (RSSI) and BER together with the status of each device of the mobile station (for example, failure status).
Then, the base station aggregates the returned data to obtain statistical data.

As a conventional radio communication system for trains, for example, there is Patent Literature 1.

JP 2003-163954 A

However, in the wireless communication system as described above, since replies are sent from a plurality of mobile stations, it is necessary to predetermine a reply timing for each mobile station, and it takes time to collect and analyze data. there were.
Also, in a train radio system in which the mobile station is moving on the track, there is an area where the reply from the mobile station cannot be received by the base station due to the influence of tunnels or building shadows, and the data cannot be identified. was there.

The present invention has been made in view of such conventional circumstances, and can efficiently collect and analyze data even when a base station receives replies from a plurality of mobile stations. An object of the present invention is to provide a wireless communication system capable of performing effective data collection and analysis even in an area where a reply from the base station cannot be received.

In order to solve the above-described conventional problems, the invention according to claim 1 is composed of at least one base station and a plurality of mobile stations, and the base station and the mobile station are connected by a wireless line. The mobile station that has received the transmission of the base station is a wireless communication system in which various information of the mobile station is transmitted and received by the base station and stored together with received electric field strength in a storage means, The station measures the received electric field strength even when the transmission from the mobile station is not received after a predetermined time has elapsed after transmitting the data to the mobile station and a detection unit that detects the received electric field strength wherein by controlling the detection unit, in association with the transmission and reception data between the detected received field strength the mobile station and a data processing means for processing to be stored in the storage means, stored in said storage means as the reception was Characterized by comprising an analysis means for performing analysis on the basis of the the field intensity the transmitted and received data.

The invention described in claim 2 for solving the above problems is a wireless communication system according to claim 1, receiving electric field strength stored in said storage means, the detector is Jo Tokoro It is the average value of the received electric field intensity detected at a predetermined sampling timing during the period.

In order to solve the above-mentioned conventional problems, the invention according to claim 3 is the wireless communication system according to claim 1 or 2, wherein the mobile station is mounted on a train moving on a track. The mobile station transmits an ID and location information of the mobile station as response data of the data from the base station, and the analysis means transmits the transmission from the mobile station to the base station. Analysis is performed including a case where no signal is received, and the received electric field strength in the line is analyzed .

According to the present invention, it is possible to efficiently collect and analyze data even when the base station receives replies from a plurality of mobile stations, and for areas where replies from the mobile station cannot be received by the base station. It is possible to provide a wireless communication system capable of performing effective data collection and analysis.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 5 shows a configuration example of a radio communication system according to the embodiment of the present invention.
This radio communication system is an example of a train radio communication system, and includes a control station 51, a plurality of base stations 52-1 to 5-n, and mobile stations 54-1 to n (trains).
The control station 51 and each of the base stations 52-1 to n are connected by a wired line, and the base stations 52-1 to n and the mobile stations 54-1 to n are connected by radio waves.
The control station 51 communicates with each mobile station 54-1 to n through control of the radio line or the like or through each base station 52-1 to n, and at the time of performance measurement, It communicates with the mobile station via the base station to start data measurement and acquire and manage measurement data.
That is, the base stations 52-1 to n perform wireless communication with the mobile stations 54-1 to n in accordance with an instruction from the control station 51, and perform data measurement, data measurement instruction to the mobile station, and the like.
The mobile stations 54-1 to n perform wireless communication with the base stations 52-1 to n, and measure data according to instructions from the base stations 52-1 to n.
Then, measurement data is collected and analyzed for each base station, and the control station stores data for each base station.

FIG. 1 shows a block diagram of a mobile station of a wireless communication system according to an embodiment of the present invention.
This figure shows the details of the radio devices of the mobile stations 54-1 to n in FIG. 5 described above. The radio wave transmitted from the base station 52 is received by the antenna 11, and the transmission and reception are separated by the duplexer 12. The receiver 14 receives the radio wave, the data demodulator 15 demodulates the data, and the signal processor 16 performs control according to the contents of the data.
On the other hand, the signal processing unit 16 processes vehicle information and the like according to the content of the data transmitted from the base station apparatus based on the information of the vehicle data 17 of each part of the train, and generates transmission data by the data generation unit 18 to transmit the data. The device 13 performs radio modulation and transmits the signal from the antenna 11 via the duplexer 12.
The contents of the vehicle data 17 include, for example, the position of the vehicle, the open / close state of the door in the vehicle, the power supply state, the air conditioning state, and the like.

FIG. 2 shows a block diagram of a base station of the wireless communication system according to the embodiment of the present invention.
This figure shows the details of the radio apparatuses of the base stations 52-1 to 52-n in FIG. 5 described above. The data processing unit 26 generates response request data for the mobile station 54, and the data modulation unit 28 transmits the transmission data. Is wirelessly modulated by the transmitter 23 and transmitted from the antenna 21 via the duplexer 22.
On the other hand, the signal from the mobile station apparatus is demodulated by the receiver 24 through the duplexer 22 from the antenna 21, demodulated by the data demodulator 25, and processed by the data processor 26.

When data transmitted from the mobile station is received, the data processing unit 26 controls the reception voltage level detection unit 29 to start detecting the reception electric field strength (RSSI), and the reception power level pressure detection unit 29 An average value of RSSI during data reception is calculated, and the result is converted into predetermined data by the digital conversion unit 30, and the predetermined data is requested to the mobile station, response data, and received voltage level data. The information is shared with the operation management data 27 and recorded. Based on the recorded data, statistical processing and editing in units of mobile stations are performed for each base station, and statistical processing and editing in units of track position information are performed.
Statistical processing and editing will be described later.

FIG. 3 shows an operation timing chart of transmission / reception data of the base station of the radio communication system according to the embodiment of the present invention.
In this figure, (a) is the base station transmission timing, (b) is the base station transmission (request data), (c) is the base station reception timing, (d) is the mobile station reply (response data), (E) shows the reception voltage level (RSSI) detection timing of the base station.
During the timing shown in (a), the base station transmits request data to the mobile station as shown in (b) as a base station transmission radio wave.
Then, the base station sets a time for receiving the transmission of the mobile station shown in (c), and the mobile station transmits the response data to the base station as shown in (d).
Then, the reception voltage level (RSSI) of the base station is detected by the reception voltage level detector 29 at the timing of receiving data from the mobile station as shown in (e), and the average value of these sample timings is calculated. Record.
The sample timing shown in (e) is set so as to be received after a predetermined time (t) has elapsed after transmitting the request data from the base station shown in (b).

The RSSI and various data recorded by the base station are stored in the storage unit inside the base station, or output to the control station 51 and stored in the storage unit of the control station.
The stored received voltage level can be easily analyzed by associating and recording request data and response data.
Regardless of the reception state at the base station device, after transmission from the base station (predetermined time t), the reception voltage level at the time when the mobile station is transmitting is detected, for example, to receive transmission from the mobile station. It is possible to analyze the radio wave propagation situation including when it is not possible.
For example, in response to request data from the base station, the response data includes the mobile station ID (that is, the train-specific code), the mobile station location information, and the status information of various devices in the train. Thus, the RSSI at which position in the entire track can be grasped from the mobile station ID and the position information, and further, the analysis including the case where the base station does not receive can be performed.
In addition, by associating with train operation information, it is possible to grasp a difference from where the train should originally be.
Note that the data classification shown in (b) and (d) in FIG. 5 is an image of data sampling timing and data contents.

FIG. 4 shows an example of a schematic diagram of a measurement result of received data by the base station of the wireless communication system according to the embodiment of the present invention.
FIG. 7 shows an example of a memory table in which received data from each mobile station is processed and stored by the data processing unit of the base station.
In FIG. 4, for example, the base station 52-1 records and records two mobile stations (mobile station 54-1 and mobile station 54-n, RSSI of data received from a train). -1 is transmitted in each frequency band of channel 1 (CH1, for example, 460 MHz), and the mobile station 54-n is transmitted in each frequency band of channel 2 (CH2, for example, 450 MHz). The RSSI value is measured and pointed at the interval.
As shown in FIG. 7, the RSSI value is stored together with the train ID, position information, and received time. At that time, each mobile station device, for example, the open / closed state of a door, the state of an air conditioner, a power source, etc. You may remember.
The RSSI value is theoretically large when close to the base station, and small when far away. However, the RSSI changes in a complex manner due to the influence of shielding objects such as buildings around the track and the tunnel. To do.

In this figure, the circle mark (◯) is the reception RSSI of the mobile station 54-1 by CH1, and the triangle mark (Δ) is the reception of the mobile station 54-n by CH1.
A dotted line in each mark indicates that the reception level is a predetermined level or less (no reception level).
The mobile station 54-1 (◯) has two waveform peaks, and the two peaks are left-right symmetric, that is, reciprocate along the track.
The mobile station 54-n has moved one way on the track.

FIG. 6 shows an example of a schematic diagram of received RSSI statistical data by the base station of the wireless communication system according to the embodiment of the present invention.
The solid line shows the average value of the reception level statistics of the received electric field strength (RSSI) at each position of the track on which the train moves.
The reception level has dropped to zero at two places, and this position is, for example, a building shadow or a tunnel, that is, a position where reception from a mobile station is not performed.
Also, the third point from the left of the circle mark, the third point from the right, and the third point from the left of the triangle mark have RSSI slightly lower than the distance equivalent due to the influence of the building or the like.

Comparing the measurement result of the received data in FIG. 4 described above with FIG. 6, both the CH1 (circle mark) and CH2 (triangle mark) values of RSSI are almost the same as the statistical data as the line is moved. It becomes.
And it can grasp | ascertain from a measurement result that a some mobile station becomes the value of substantially the same RSSI in the same position, and RSSI shows the substantially same value by the position of a train.
Therefore, for example, if a threshold value is set for each position information in RSSI, and the RSSI is out of the threshold value, an error based on the failure of the radio device itself or information including error information of each mobile station Whether it is based on information or the like is calculated at the base station, and this is output to the control station 51 for display.

Based on the above, the base station 52-1 detects and stores the position information and the received electric field strength of the mobile stations 54-1 and 54-2 over a predetermined time, and stores the received received electric field strength and the respective movements. Accumulate and statistics station location information.
When the base station 52-1 detects the position information and the received electric field strength of each of the mobile stations 54-1 and 54-2 with the passage of a predetermined time, the base station 52-1 sets the received electric field strength of the position information of each mobile station. By comparing with the statistical RSSI, it can be determined whether or not there is an abnormality.
This determination can be made by the data processing unit 26 of the base station or by the control station.

According to the embodiment of the present invention, a data processing unit is provided in the base station, the received voltage level during data reception is detected, and the averaged value is digitally converted and recorded together with the communication data by the data processing unit. Analyzes such as statistical processing.
Further, in the data processing unit of the base station apparatus, after the transmission from the base station apparatus, the received voltage level when a preset time has passed is detected, and the averaged value is digitally converted and the data processing unit Since it is recorded together with the communication data, it can be analyzed even when it is not received from the mobile station.
That is, the data processing unit 26 starts the detection and detects for a certain period of time at the reception voltage level detection unit 29 after a predetermined time has elapsed after transmitting desired data to the mobile station 54. Then, the reception power level pressure detection unit 29 calculates the average value of the reception voltage level, converts the result into data by the digital conversion unit 30, and converts the data into request data and response data to the mobile station. And the received voltage level data are associated with each other, and the operation management data 27 and the information are shared and recorded to enable statistical processing and editing according to the mobile station unit, the location information unit, and the like.

According to the present invention, the data processing unit is provided in the base station apparatus to control the detection of the reception voltage level, and the data and the detection voltage level are related to each other. Since it is recorded in reception by the station device, transmission / reception data can be related, and statistical processing and analysis can be simplified.
Furthermore, since the reception voltage level is detected after a predetermined time after the request data is transmitted from the base station, each data and the detection voltage level are set even if the transmission (response) from the mobile station is not received by the base station. It can be related and stored.
This means that the received voltage level and received data can be recorded when a received voltage of a set level or higher is detected in the past. For example, in an area where the radio wave is weak, whether data transmission / reception is not possible, It does not occur that it is not possible to determine whether or not it has been received.

Here, the configurations of the radio communication system, the control station, the base station, and the mobile station according to the present invention are not necessarily limited to those described above, and various configurations may be used.
The present invention can also be provided as, for example, a method or method for executing the processing according to the present invention, a program for realizing such a method or method, or a recording medium for recording the program. It is also possible to provide various devices and systems.
The application field of the present invention is not necessarily limited to the above-described fields, and the present invention can be applied to various fields.

As various processes performed in the radio communication system, the control station, the base station, and the mobile station according to the present invention, the processor is stored in a ROM (Read Only Memory) in a hardware resource including a processor, a memory, and the like. A configuration controlled by executing the control program may be used, and for example, each functional unit for executing the processing may be configured as an independent hardware circuit.
Further, the present invention can be grasped as a computer-readable recording medium such as a floppy (registered trademark) disk or a CD (Compact Disc) -ROM storing the control program, or the program (itself). The processing according to the present invention can be performed by inputting the program from the recording medium to the computer and causing the processor to execute the program.

1 shows a block diagram of a mobile station of a wireless communication system according to an embodiment of the present invention. 1 shows a block diagram of a base station of a wireless communication system according to an embodiment of the present invention. 2 shows an operation timing chart of transmission / reception data of a base station of a wireless communication system according to an embodiment of the present invention. An example of the schematic diagram of the measurement result of the received data by the base station of the radio | wireless communications system which concerns on embodiment of this invention is shown. 1 shows a configuration example of a wireless communication system according to an embodiment of the present invention. An example of the schematic diagram of the statistics data of the reception RSSI by the base station of the radio | wireless communications system which concerns on embodiment of this invention is shown. An example of a memory table in which received data from each mobile station is processed and stored in the data processing unit of the base station is shown.

Explanation of symbols

11, 21: Antenna, 12, 22: Duplexer, 13, 23: Transmitter, 14, 24: Receiver, 15, 25: Data demodulator, 16: Signal processor, 17: Vehicle data, 18, 28: Data generation unit, 29: reception voltage level detection unit, 30: digital conversion unit, 26: data processing unit, 27: operation management data, 51: statistical station, 52 (52-1 to n): base station, 54 (54 −1 to n): Mobile station.

Claims (3)

The mobile station is composed of at least one base station and a plurality of mobile stations, and is connected between the base station and the mobile station via a radio channel, and the mobile station that has received the transmission of the base station It transmits various information, which a radio communication system in which a base station stored in the storage means together with the received field strength is received,
The base station detects a received electric field strength, and after transmitting data to the mobile station, after a preset time has elapsed, even if the transmission from the mobile station is not received, the received electric field strength is Data processing means for controlling the detection unit to measure and performing processing for storing the received electric field strength detected and the transmission / reception data with the mobile station in association with each other in the storage means;
Wireless communication system comprising the analysis means for performing analysis on the basis of said received electric field strength stored in the storage means and the received data. Reception field strength to be stored in the storage unit, the detecting unit, Jo Tokoro period, radio according to claim 1, characterized in that an average value of the reception field intensity detected at a predetermined sampling timing Communications system. The mobile station is a radio device mounted on a train moving on a track,
The mobile station transmits the mobile station ID and location information as response data of the data from the base station,
The analysis unit according to claim 1 or 2, wherein the analysis unit analyzes the case where the base station does not receive transmission from the mobile station, and analyzes the received electric field strength in the line. Wireless communication system.

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