JP2010193336A - Mobile station and radio communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problem: when any one antenna of a mobile station is located within a radio interference area that can be made in the boundary of neighboring base stations, normal demodulation at a receiver is disabled and radio communication cannot be performed. <P>SOLUTION: The mobile station comprises: a plurality of antennas 10 or the like, for receiving radio signals from base stations 1, 4; a receiver 14 capable of performing diversity reception for demodulating radio signals received by the plurality of antennas 10 or the like; a detection means for detecting the moving state of a train 8 that is a present station; and an antenna selector 16 and a high-frequency switch 17 included in a selection means for selecting which one of radio signals received by the plurality of antennas 10 or the like is to be demodulated at the receiver 14 in accordance with the moving state detected by the detection means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a mobile station that communicates with a base station and that can be suitably used for a train radio communication system that is a radio communication system in which a plurality of base stations communicate with each other via a leaky coaxial cable, and the mobile station A wireless communication system comprising:

  FIG. 4 is an example of a configuration diagram of a wireless communication system provided with a conventional mobile station described in Patent Document 1. A train 8 serving as a mobile station is used to improve reception performance as described in Patent Document 1. Diversity is received by the antennas 10, 11, 12, and 13, and communication with the base stations 1 and 4 is performed.

JP 2000-49683 A

  The wireless communication system shown in FIG. 4 has adjacent base stations 1 and 4, is connected to the base station 1, is connected to the leaky coaxial cables 2 and 3 for transmitting and receiving radio waves, and the base station 4, Leaky coaxial cables 5 and 6 for transmitting and receiving radio waves, a train 8 for receiving radio waves via the leaky coaxial cables 2, 3, 5 and 6, and aerial lines 10, 11, 12, 13 provided with the train 8 And a receiver 14 that receives the output from the antennas 10 to 13 and demodulates the radio wave, and a line connection device 15 that receives the output from the receiver 14 and controls wireless communication. In addition, there is a radio wave interference section 7 that can be formed at the boundary between the base station 1 and the base station 4.

  Next, the operation will be described. The base station 1 can wirelessly communicate with the train 8 via the leaky coaxial cables 2 and 3, and the base station 4 can also wirelessly communicate with the train 8 via the leaky coaxial cables 5 and 6. However, when the radio wave interference section 7 is formed at the zone boundary between the adjacent base station 1 and the base station 4, and any one of the antennas 10, 11, 12, 13 of the train 8 is applied to the radio wave interference section 7, the receiving unit 14 is It becomes impossible to demodulate normally and wireless communication using the line control device 15 becomes impossible.

  A wireless communication system including a conventional mobile station has a train aerial line (aerial lines 10 and 11 in FIG. 4) in a wireless interference section formed at the boundary between adjacent base stations (base stations 1 and 4 in FIG. 4). , 12, 13), the receiving unit cannot correctly demodulate and wireless communication cannot be performed. When a train that is a mobile station is traveling at a high speed, a momentary interruption occurs and there is no significant effect on wireless communication, but the train stops or runs at a low speed, and one of the train's antennas interferes with the radio. When in the section, there was a problem that communication was not possible until the train moved and all the aerial lines were out of the radio interference section.

  The present invention has been made to solve the above problems, and provides a mobile station capable of communicating even when a train serving as a mobile station stops or travels at a low speed, and a radio communication system including the mobile station. For the purpose.

  A mobile station according to the present invention detects a plurality of antennas that receive radio signals from a base station, a diversity reception receiver that demodulates radio signals received by the plurality of antennas, and a moving state of the own station Detecting means; and selecting means for selecting which of the radio signals received by the plurality of antennas is demodulated by the receiving unit in accordance with the movement state detected by the detecting means.

  According to the present invention, in the mobile station, a plurality of antennas that receive radio signals from the base station, a diversity receiving receiver that demodulates radio signals received by the plurality of antennas, and the movement state of the own station Detecting means for detecting, and selecting means for selecting which of the radio signals received by the plurality of antennas is demodulated in the receiving unit according to the movement state detected by the detecting means. Therefore, when the mobile station is stopped or moving at low speed, the selection means selects an antenna that can be demodulated normally, so that either antenna is in the radio wave interference section and is demodulated normally. Even if it is not possible, the possibility of wireless communication is increased.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows the radio | wireless communications system by Embodiment 1 of this invention. It is a block diagram which shows the radio | wireless communications system by Embodiment 2 of this invention. It is a block diagram which shows the radio | wireless communications system by Embodiment 3 of this invention. It is a block diagram which shows the conventional radio | wireless communications system.

<A. Embodiment 1>
<A-1. Configuration>
Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is an example of a wireless communication system including a train 8 which is a mobile station to which the present invention is applied. In the figure, the mobile station has adjacent base stations 1 and 4 and is connected to the base station 1 to transmit radio waves. Leakage coaxial cables 2 and 3 that receive signals and base station 4 are connected to leaky coaxial cables 5 and 6 that transmit and receive radio waves, and radio waves (radio signals) via leaky coaxial cables 2, 3, 5, and 6 ), The aerial lines 10, 11, 12, 13 provided with the train 8, the receiving unit 14 that receives the output from the aerial lines 10 to 13 and demodulates the radio wave (radio signal), and the receiving unit 14 Of the aerial lines 10 to 13 using the line connection device 15 that receives the output from the radio and controls the wireless communication, the synchronization information from the receiving unit 14 and the speed information of the train 8 from the detection means (not shown). The antenna selection unit 16 for instructing the selection and the antenna selection unit 16 Select aerial 10-13 in the instruction, in which and a high-frequency switch 17 for connecting and disconnecting the connection between the antenna 10 to 13 and the receiver 14. In addition, there is a radio wave interference section 7 at the boundary between the base station 1 and the base station 4 where wireless communication cannot be performed due to radio wave interference between the base stations.

<A-2. Operation>
Next, the operation will be described. Base station 1 can wirelessly communicate with train 8 via leaky coaxial cables 2 and 3, and base station 4 can also wirelessly communicate with train 8 via leaky coaxial cables 5 and 6. However, when the radio wave interference section 7 is formed at the zone boundary between the base station 1 and the base station 4 and any one of the antennas 10, 11, 12, 13 of the train 8 is applied to the radio wave interference section 7, the receiving unit 14 is normally operated. Demodulation becomes impossible and wireless communication using the line control device 15 becomes impossible.

  In the train 8 which is a mobile station, the antenna selection unit 16 included in the selection unit receives the signal when the detection unit (not shown) detects that the train 8 is stopped or moving at a low speed using the speed information. When the synchronization information output by the unit 14 is monitored and it is determined that it cannot be demodulated normally, the antennas 10 to 13 that can be normally demodulated by the receiving unit 14 are selected for the high-frequency switch 17 included in the selection means. Instruct. The antenna selection unit 16 monitors the synchronization information output from the reception unit 14 and repeats the selection of the antennas 10 to 13 until it can be confirmed that demodulation is normally performed.

  Also, the antenna selection unit 16 monitors the speed information from the detection means, and when it is detected that the train 8 is moving at a certain speed or higher, the selection of the antennas 10 to 13 is stopped, and the antennas 10 to 13 are set. All are connected to the receiver 14.

<A-3. Effect>
According to the first embodiment of the present invention, in a mobile station, a plurality of antennas 10 and the like that receive radio signals from the base stations 1 and 4 and diversity reception that demodulates radio signals received by the plurality of antennas 10 and the like. Any of the possible receivers 14, detection means for detecting the movement state of the train 8 as its own station, and any of the radio signals received by the plurality of antennas 10 according to the movement state detected by the detection means By including the antenna selection unit 16 and the high-frequency switch 17 included in the selection means for selecting whether to demodulate in the unit 14, when the train 8 is stopped or traveling at a low speed, the antenna selection unit 16 Since the high frequency switch 17 is instructed to select an antenna that can be demodulated normally, any one of the antennas 10 to 13 is in the radio wave interference section 7 and cannot be demodulated normally. Even if, more likely to continue wireless communication.

  Moreover, according to Embodiment 1 concerning this invention, in a mobile station, a detection means detects a movement state from the speed information of the train 8 which is a mobile station, and an antenna selection part based on the detected movement state 16, and the radio signals of the antennas 10 to 13 that can be demodulated by the receiving unit 14 can be selected. Therefore, wireless communication can be continued.

  Further, according to the first embodiment of the present invention, in the mobile station, the antenna selection unit 16 included in the selection unit receives the signal when the train 8 serving as the mobile station is stopped or is moving at a predetermined speed or less. By selecting a radio signal that can be demodulated in the section 14, when any of the antennas 10 to 13 is in the radio wave interference section 7 and cannot be demodulated normally when the train 8 is stopped or traveling at a low speed However, there is a high possibility that wireless communication can be continued.

  Further, according to the first embodiment of the present invention, when the antenna selection unit 16 included in the selection unit determines that the reception unit 14 cannot normally demodulate, the radio signal that can be demodulated by the reception unit 14 The antenna selection unit 16 can instruct the high-frequency switch 17 to select the radio signals of the antennas 10 to 13 that can be demodulated by the reception unit 14. Therefore, wireless communication can be continued.

  Further, according to the first embodiment of the present invention, in the mobile station, the selecting means includes the high frequency switch 17 that selects a radio signal to be output to the receiving unit 14 from the radio signals received by the plurality of antennas 10 to 13. By providing, the antenna selection unit 16 can instruct the high frequency switch 17 and select the radio signals of the antennas 10 to 13 that can be demodulated by the reception unit 14. Therefore, wireless communication can be continued.

  Moreover, according to Embodiment 1 concerning this invention, in the radio | wireless communications system, it arrange | positioned along the predetermined path | route which can carry out radio | wireless communication with the train 8 which moves along the predetermined path | routes, such as a track | line, for example By providing the plurality of base stations 1 and 4, for example, even when any of the antennas 10 to 13 is located in the radio wave interference section 7 generated at the boundary between the base station 1 and the base station 4, the antenna selection unit 16 is From the speed information of the train 8, it is possible to select radio signals from the antennas 10 to 13 that can be demodulated by the receiving unit 14, and it is possible to continue radio communication.

  Further, according to the first embodiment of the present invention, in the radio communication system, the plurality of base stations 1 and 4 and the train 8 are leaky coaxial cables 2, 3, 5, and 5 arranged along a predetermined route. By performing wireless communication via 6, it is possible to receive radio waves from the leaky coaxial cables 2, 3, 5, and 6 disposed along a predetermined route at the antennas 10 to 13 and perform wireless communication.

<B. Second Embodiment>
<B-1. Configuration>
FIG. 2 is an example of a radio communication system including a train 8 which is a mobile station according to Embodiment 2 of the present invention. In the figure, the receiving unit 14 selects the receiving antennas 10 to 13 in accordance with an instruction from the antenna selecting unit 16. Selective demodulation means (not shown) having the function of Other components are the same as those in FIG. 1 of the first embodiment. However, in the second embodiment, the high-frequency switch 17 that is a component of the first embodiment is not used.

<B-2. Operation>
In the first embodiment, the antennas 10 to 13 are selected in the high-frequency switch 17 according to the instruction of the antenna selection unit 16. However, in the second embodiment, the reception unit 14 includes selective demodulation means, so that selective demodulation is performed. The radio signal to be demodulated in the means can be selected.

  Similarly to the first embodiment, when the antenna selection unit 16 included in the selection unit detects that the train 8 is stopped or moving at a low speed from the speed information from the detection unit, the antenna selection unit 16 of the reception unit 14 The reception unit 14 instructs to select the antennas 10 to 13 that can be demodulated normally.

<B-3. Effect>
According to the second embodiment of the present invention, in the mobile station, the selection unit includes the selection demodulation unit that is provided in the reception unit 14 and selectively demodulates the radio signal to be demodulated from the received radio signals. Thus, when the antenna selection unit 16 detects that the train 8 is stopped or moving at a low speed using the speed information from the detection means, the synchronization information output by the reception unit 14 is monitored and cannot be demodulated normally. If it is determined, the reception unit 14 is instructed to select the antennas 10 to 13.

  Therefore, it is possible to select a radio signal to be demodulated by the selective demodulation means without using the high frequency switch 17 in the first embodiment, and to obtain a train 8 that is a cheaper and more reliable mobile station. Can do.

<C. Embodiment 3>
<C-1. Configuration>
FIG. 3 is an example of a radio communication system provided with a train 8 which is a mobile station according to Embodiment 3 of the present invention. In FIG. 3, an antenna selection unit 16 monitors electric field information output from the reception unit 14 and detects it at a detection means. The speed of the train 8 is detected. Other components are the same as those in FIG. 1 of the first embodiment.

<C-2. Operation>
When the train 8 is traveling at a predetermined speed, the aerial lines 10, 11, 12, and 13 have an electric field with a constant period by the leaky coaxial cables 2, 3, 5, and 6 provided along the predetermined route. There are fluctuations. However, when the train 8 stops or travels at a low speed, the fluctuation is eliminated or has a very long cycle. By outputting the electric field fluctuation state from the receiving unit 14 and detecting it by a detecting means (not shown), it is possible to detect the moving state of the train without obtaining speed information.

  Thus, as in the first embodiment, the radio signal from the antennas 10, 11, 12, and 13 that can be normally demodulated by the receiving unit 14 is sent to the high frequency switch 17 by the antenna selecting unit 16 included in the selecting means. You can choose.

<C-3. Effect>
According to the third embodiment of the present invention, in the mobile station, the detecting means detects the movement state from the fluctuation of the electric field applied to the antennas 10 to 13, so that the antenna selecting unit 16 receives the receiving unit 14 based on the electric field information. It is possible to determine the radio signal that can be demodulated and to perform the same operation as in the first and second embodiments. Therefore, the speed information becomes unnecessary, and the same effect can be obtained in the train 8 that cannot connect the speed information.

  1, 4 base station, 2, 3, 5, 6 leaky coaxial cable, 7 radio wave interference section, 8 train, 10, 11, 12, 13 antenna, 14 receiver, 15 line connection device, 16 antenna selection unit, 17 high frequency switch.

Claims (9)

A plurality of antennas for receiving radio signals from the base station;
A receiver capable of diversity reception for demodulating radio signals received by the plurality of antennas;
Detecting means for detecting the moving state of the own station;
Selection means for selecting which of the radio signals received by the plurality of antennas is to be demodulated by the reception unit in accordance with the movement state detected by the detection means;
A mobile station comprising: The detecting means detects the moving state from speed information of the mobile station;
The mobile station according to claim 1. The detection means detects the movement state from a change in an electric field that the antenna receives.
The mobile station according to claim 1 or 2. The selection means performs the selection when the mobile station is stopped or in the moving state at a predetermined speed or less.
The mobile station in any one of Claims 1-3. The selection unit performs the selection when it is determined that the reception unit cannot correctly demodulate,
The mobile station in any one of Claims 1-4. The selection unit includes a high-frequency switch that selects the radio signal to be output to the reception unit from the radio signals received by the plurality of antennas.
The mobile station in any one of Claims 1-5. The selection unit includes a selection demodulation unit that is provided in the reception unit and selectively demodulates the radio signal to be demodulated from the received radio signals.
The mobile station in any one of Claims 1-5. The mobile station according to any one of claims 1 to 7, which moves along a predetermined route;
A plurality of base stations arranged along the predetermined route capable of wireless communication with the mobile station;
A wireless communication system comprising: The plurality of base stations and the mobile station communicate wirelessly via a leakage cable disposed along the predetermined path.
The wireless communication system according to claim 8.

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