JP2011223504A - Radio communication apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To address an issue that a mobile station which is travelling across different coverage areas served by different communication systems needs to have multiple receivers supporting the respective communication systems and such a mobile station would fail to communicate with a relevant communication system if a receiver supporting the communication system breaks down.SOLUTION: A radio communication apparatus 7, which communicates with a first communication system and a second communication system using the respective communication methods, comprises: a storage unit 11 for storing a program for each of the first communication system and the second communication system; a radio unit 12 having a receiver for demodulating a received signal using a read program; and a control unit 15 for monitoring a state of communication with at least one of the first and second communication systems, which is in communication with the apparatus, and switching an operating mode depending on the state of communication so as to operate the radio unit 12 accordingly.

Description

  The present invention relates to a mobile station that moves between different systems in a mobile radio communication system, and an operation mode control method for the mobile station.

  The wireless communication system described in Patent Document 1 is provided for a base station employing a digital wireless system, a base station employing an analog wireless system, and both sides where a vehicle travels, and provided for a digital system and an analog base station, respectively. It is composed of a leaky coaxial cable (LCX) that carries transmission radio waves from a base station or transmission radio waves from a mobile station. At the boundary between the zone covered by the digital base station and the zone covered by the analog base station, the mobile station switches the radio system.

  The mobile station detects the pilot signal (identification signal) by the antenna, demultiplexer, distributor, analog receiver and digital receiver that receive radio waves leaking from the LCX, analog transmitter and digital transmitter, analog receiver If the digital transmitter is disabled, the switch is controlled, the digital transmitter is connected to the duplexer, and if the digital receiver cannot detect the base station identification signal (identification signal), the switch is controlled to A control unit for connecting the transmitter to the duplexer is provided.

  When a mobile station exists in an area of a digital radio system and moves toward an analog radio system, when the mobile station enters a zone boundary, the mobile station includes a base included in a transmission radio wave frame of a base station that employs the digital radio system. The station identification signal cannot be detected. In this case, the mobile station releases frame synchronization with the base station, controls the changeover switch, and connects the analog transmitter to the duplexer. Further, when the mobile station moves to the area of the analog radio system, the analog receiver detects the pilot signal (identification signal) included in the transmission wave of the base station, thereby establishing synchronization with the base station and Communication is possible.

  On the other hand, when the mobile station exists in the area of the analog radio system and moves toward the digital radio system, when the mobile station enters the zone boundary, the mobile station includes the pilot included in the transmission wave of the base station adopting the analog radio system. When the signal (base station identification signal) cannot be detected, the synchronization with the base station is canceled, the changeover switch is controlled, and the digital transmitter is connected to the duplexer. Further, when the mobile station moves to the area of the digital wireless system, the digital receiver detects the base station identification signal included in the frame of the transmission radio wave of the base station, thereby establishing frame synchronization with the base station, Communication becomes possible.

JP 2001-267777 A

  Since a receiver mounted on a mobile station can be demodulated with respect to one system, when a mobile station travels between different systems, it is necessary to mount a receiver corresponding to each system on the mobile station. However, when a failure occurs in a receiver mounted on the mobile station, there is a problem that the mobile station cannot receive a signal transmitted from the base station in a system corresponding to the failed receiver.

  A wireless communication apparatus according to the present invention includes a program that enables communication with a first communication system and a second communication apparatus that communicate with a first communication system and a second communication system that have different communication methods. A storage unit storing a program enabling communication with the communication system, a wireless unit including a receiver that performs demodulation processing of a received signal using the program read from the storage unit, and a first communication system Among the programs stored in the storage unit, the program corresponding to the communication system that is not currently communicating is monitored according to the communication state. The control part which switches to the state of this and operates a radio | wireless part is provided.

  A wireless communication apparatus according to the present invention includes a program that enables communication with a first communication system and a second communication apparatus that communicate with a first communication system and a second communication system that have different communication methods. A storage unit storing a program enabling communication with the communication system, a wireless unit including a receiver that performs demodulation processing of a received signal using the program read from the storage unit, and a first communication system Among the programs stored in the storage unit, the program corresponding to the communication system that is not currently communicating is monitored according to the communication state. Since a control unit for operating the radio unit is provided, even a mobile station not equipped with multiple receivers corresponding to different communication systems The period state by a predetermined time detected by switching the operation mode may correspond to a plurality of communication systems.

1 is a block diagram showing a radio communication system according to Embodiment 1 of the present invention. It is a block diagram which controls the mobile station receiver and receiver of this invention. It is a block diagram which shows the structure of the receiver and control part which are mounted in the receiving rack on the mobile station of this invention. It is a block diagram which shows the structure of the receiver and control part which are mounted in the receiving rack on the mobile station of this invention. It is a flowchart which shows the process of the radio | wireless communication apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the process of the radio | wireless communication apparatus which concerns on Embodiment 2 of this invention.

Embodiment 1 FIG.
FIG. 1 shows a mobile communication system according to the present invention. FIG. 1 shows an example in which the mobile station 7 travels between three communication systems having different systems. In the communication system 1 (first communication system) in the figure, 1a is a central station, 2a is a control station, 3a, 3b and 3c are base stations under the control station 2a, and 4a is a transmission radio wave and movement of the base station 3a. Leakage coaxial cable (hereinafter referred to as LCX) that carries transmission radio waves from the station 7, 4 b is the transmission radio wave of the base station 3 b, LCX that carries the transmission radio waves from the mobile station 7, 4 c is the transmission radio wave of the base station 3 c and The LCX carries transmission radio waves from the mobile station 7. In the communication system 2 (second communication system) in the figure, 1b is a central station, 2b is a control station, 3d, 3e, and 3f are base stations under the control station 2b, 4d is a transmission radio wave and movement of the base station 3d. LCX and 4e that carry transmission radio waves from the station 7, LCX and 4f that carry transmission radio waves from the base station 3e and mobile station 7, and 4x that carry transmission radio waves from the base station 3f and mobile station 7, respectively. Similarly, in the communication system 3, 1 c is a central station, 2 c is a control station, 3 g, 3 h, 3 i are base stations under the control station 2 c, 4 g is a transmission wave of the base station 3 g and transmission from the mobile station 7 LCX and 4h for carrying radio waves are LCX for carrying the transmission radio waves of the base station 3h and transmission radio waves from the mobile station 7, and 4i are LCXs for carrying the transmission radio waves of the base station 3i and the transmission radio waves from the mobile station 7. 5 is a system boundary between the communication systems 1 and 2, 6 is a system boundary between the communication systems 2 and 3, and 7 is a mobile station.

  FIG. 2 shows a receiver and a control unit in a receiving rack mounted on the mobile station. 8 is an antenna mounted on the mobile station 7, 9 is a frequency conversion unit that converts a signal input from the antenna to the receiver from an RF band signal to an IF band signal, and 10 is a signal output from 9 that is converted from an analog signal to a digital signal. An A / D converter for conversion, 11 is a ROM (storage unit) storing program data for performing demodulation processing, and 12 is a demodulation processing unit (wireless) for demodulating a signal from the A / D converter 10 by software radio. 13), MPU set by the demodulating processor 12 and MPU set by the demodulating processor 12, 14 is an upper I / F that is an interface between signals inside and outside the receiver, and 15 is a control that controls the receiver. Part. The mobile station shown in FIG. 2 is provided with a program corresponding to the entire system to communicate, and by switching the state of the program, the frequency and demodulation method used according to different communication systems without changing the hardware configuration Other signal processing methods can be changed. That is, it is a software defined radio that can support various systems simply by switching the operation mode (state) of software.

  Next, the operation when the mobile station 7 moves through the three communication systems shown in FIG. 1 when the mobile station has one receiver will be described. FIG. 5 is a flowchart showing processing of the wireless communication apparatus according to Embodiment 1 of the present invention. First, it is assumed that the mobile station 7 is moving from the area of the system 1 toward the system 2. In the communication system 1, the mobile station 7 receives signals transmitted from the base stations 3a, 3b, and 3c and is ready for demodulation. The mobile station 7 is located in the area of the communication system 1, starts communication with the communication system 1 (step 1 in FIG. 5), and receives from the communication system 1 without any problem (step 2 in FIG. 5). .

  When the mobile station 7 is located in the area of the communication system 1, the mobile station 7 is synchronized with the communication system 1 (YES in step 3 in FIG. 5). When the mobile station 7 enters the system boundary 5 which is the boundary between the communication systems 1 and 2, the receiver cannot demodulate and goes out of synchronization (NO in step 3 in FIG. 5). When the communication system 2 is further entered from the system boundary 5, the asynchronous state between the mobile station 7 and the communication system 1 continues. Here, if the control unit 15 of the mobile station 7 detects that the asynchronous state of the receiver has continued for a certain time (YES in step 4 in FIG. 5), the setting of the operation mode of the receiver is changed from the operation setting of the communication system 1 to the communication system. (2) (Step 5).

  In the above description, an example in which the mobile station 7 has moved from the communication system 1 to the communication system 2 has been described. However, when synchronization with the communication system 2 cannot be established, the operation mode of the receiver is changed from the communication system 2 to the communication system. The operation mode is switched to the third operation mode to try to synchronize. That is, the mobile station 7 further changes the setting of the operation mode of the receiver when the asynchronous state continues for a certain period of time, and changes the operation mode until the synchronization state is reached. Specifically, the change of the operation mode means that the program data stored in the ROM 11 is expanded from the MPU 13 onto the memory of the radio unit (demodulation processing unit 12) when the receiver is activated, and a predetermined communication system is included in the program. However, this means that the state in the program is changed via the MPU 13 in accordance with an instruction from the control unit 15.

  Further, when the mobile station 7 enters the system boundary 6 between the communication system 2 and the communication system 3, the receiver becomes asynchronous. When the mobile station 7 enters the system 3 and the control unit 15 detects the asynchronous state of the receiver for a certain period of time, the control unit 15 changes the operation mode of the receiver until the operation mode of the system 1 or the system 3 is synchronized. . As described above, the wireless communication apparatus according to the present invention monitors the communication state with the communication system, particularly whether synchronization is established, and communicates stored in the ROM 11 when the asynchronous state continues for a certain period of time. By switching the state (operation mode) of the program corresponding to the entire system, the frequency, demodulation method, and other signal processing methods to be used are changed in accordance with communication systems having different methods without changing the hardware configuration. That is, even a mobile station not equipped with a plurality of receivers corresponding to different communication systems can detect a non-synchronized state and switch the operation mode of the receiver to support a plurality of communication systems.

Embodiment 2. FIG.
FIG. 3 shows the configuration of the receiver and the control unit in the receiving rack of the mobile station 7. An example of a case where a total of four receivers corresponding to the three communication systems shown in FIG. 1 and a spare receiver in preparation for failure of the receiver are mounted on the receiver rack is shown. The receiver 16 is a receiver for the communication system 1, the receiver 17 is a receiver for the communication system 2, the receiver 18 is a receiver for the communication system 3, the spare receiver 19 is a spare for the communication systems 1 to 3, The control unit 15 sets and controls not only the settings and control of the receivers 16 to 19 but also other transmission / reception devices. FIG. 6 is a flowchart showing processing of the wireless communication apparatus according to Embodiment 2 of the present invention.

  Usually, the operation when the mobile station moves from the system 1 to the system 3 when the receivers 16 to 19 are not malfunctioning will be described with reference to FIG. When the mobile station 7 exists in the area of the system 1, the mobile station 7 is receiving a signal from the base station 3a of the communication system 1 (step 2 in FIG. 6), and the receiver 16 is in a state synchronized with the communication system 1. It has become. In step 3 of FIG. 6, the control unit 15 determines the receiver that is synchronized among the receiver 16 for the communication system 1, the receiver 17 for the communication system 2, and the receiver 18 for the communication system 3. Do. In the description of this embodiment, the receiver 16 is in a synchronized state, and the control unit 15 determines that the synchronized receiver is the receiver 16 and exists in the area of the communication system 1. Since the mobile station 7 is in the area of the communication system 1, the mobile station 7 is set to the operation mode of the communication system 1.

  Further, when the mobile station 7 enters the system boundary 5, the receivers 16 to 19 are in an asynchronous state. When the mobile station 7 enters the area of the communication system 2, the receiver 17 is in a synchronized state. At this time, the control unit 15 determines that the synchronized receiver is the receiver 17 and exists in the area of the communication system 2. Then, the control unit 15 changes the operation mode of the communication system 1 to the operation mode of the communication system 2. Similarly, when the mobile station 7 enters the system boundary 6, the receivers 16 to 19 are in an asynchronous state. When the mobile station 7 enters the area of the communication system 3, the receiver 18 is in a synchronous normal state. At this time, the control unit 15 determines that the synchronized receiver is the receiver 18 and exists in the area of the communication system 3. Then, the control unit 15 changes the operation mode of the communication system 2 to the operation mode of the communication system 3.

  If any of the receivers 16 to 18 for the communication systems 1, 2, and 3 breaks down, the mobile station 7 cannot communicate with the base stations when moving between systems. In preparation for such a case, the mobile station 7 has a spare receiver 19 as a spare machine. Hereinafter, the operations of the spare receiver 19 and the control unit 15 will be described with reference to FIG. In step 3 of FIG. 6, the control unit 15 determines the receiver that is synchronized among the receiver 16 for the communication system 1, the receiver 17 for the communication system 2, and the receiver 18 for the communication system 3. Do. When the determination result in step 3 is the receiver 16 (step 4), in step 5, the standby receiver 19 is set to operate in the operation mode of the communication system 1. Similarly, when the determination result in step 3 is the receiver 17, in step 5, the standby receiver 19 is set to operate in the operation mode of the communication system 2, and the determination result in step 3 is received. In the case of the device 18, in step 5, the standby receiver 19 is set to operate in the operation mode of the communication system 3.

  Since the control unit 15 sets the standby receiver 19 to operate in an operation mode corresponding to the currently synchronized communication system, even if a failure occurs in the receiver 16, the standby receiver 19 is connected to the communication system 1. Since they are synchronized, it is possible to continue communication between the base station and the mobile station by switching from the receiver 16 to the spare receiver 19. Referring to FIG. 6, when detecting a failure in step 6, the control unit 15 determines in step 7 whether the failed receiver is currently in use, and the failed receiver is currently using it. If yes (YES in step 7), the standby receiver 19 is switched in step 8. If the faulty receiver is not currently in use (NO in step 7), no fault occurs in communication, and therefore switching to the spare receiver 19 is not performed.

  As described above, after moving from the area of the system where the mobile station is moving to the next system, the control unit 15 also sets the standby receiver 19 in synchronization with the receivers 16 to 18. If any of the receivers 16 to 18 fails, the control unit 15 switches to the spare receiver 19. Even if a failure occurs in the receivers 16 to 18 due to the operation of the spare receiver 19 and the control unit 15, the spare spare receiver 19 operates instead of the failed receiver, so that the base station-mobile Communication between stations becomes possible.

Embodiment 3 FIG.
In FIG. 3 of the above-described second embodiment, the receiver 19 is fixed and operated as a spare for the receivers 16 to 18. However, the spare receiver 19 breaks down and further receives signals corresponding to any of the systems 1 to 3. If the machine fails, communication between the base station and mobile station cannot be performed. In order to prevent this problem, an example of how to determine a spare receiver will be described.

  The receiver 20 in FIG. 3 is for the communication system 1, the receiver 21 is for the communication system 2, the receiver 22 is for the communication system 3, and the receiver 23 is a spare receiver for the communication systems 1-3.

  The communication system in which the mobile station 7 moves is shown in FIG. When the mobile station 7 is moving to the communication system 2 while the receiver 23 is out of order, the receiver 22 is reserved. When the mobile station 7 moves from the system 1 to the system 2 and the receiver 21 is synchronized, the control unit 15 sets the receiver 20 as a standby and the receiver 22 as a receiver for the system 3. When the mobile station 7 moves from the system 2 to the system 3 and the receiver 22 is in a synchronized state, the control unit 15 sets the receiver 20 as a receiver for the system 2 while the receiver 20 remains in the standby state.

  The case of moving to the communication system 3-1 in the opposite direction is also shown. When the mobile station 7 moves from the communication system 3 to the communication system 2 and the receiver 21 is in a synchronized state, the control unit 15 sets the receiver 22 as a spare and the receiver 20 as a reception for the system 1. Finally, when the mobile station 7 moves from the communication system 2 to the communication system 1 and the receiver 20 is synchronized, the control unit 15 keeps the receiver 22 spare and the receiver 21 remains set for the communication system 2. Set as.

  As described above, when the mobile station 7 sets a receiver for the communication system in the area where the mobile station 7 is moving, its backup, and the communication system of the next movement destination, reception for the communication system in the moving area Even if a machine breaks down, the control unit 15 can instantly switch to a spare receiver, and the time for disconnecting communication between the base station and the mobile station can be reduced.

1a, 1b, 1c central office, 2a, 2b, 2c control station,
3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, 3i base station,
4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h, 4i LCX
5, 6 System boundary, 7 Mobile station, 8 Antenna, 9 RF → IF converter 10 A / D converter, 11 ROM, 12 Demodulator, 13 MPU,
14 host I / F, 15 control unit,
16, 17, 18, 19, 20, 21, 22, 23 Receiver

Claims (3)

In a wireless communication apparatus that communicates with a first communication system and a second communication system having different communication methods,
A storage unit storing a program that enables communication with the first communication system and a program that enables communication with the second communication system;
A radio unit having a receiver that performs demodulation processing of a received signal using a program read from the storage unit;
The communication state of the first communication system and the second communication system with the communication system in communication is monitored, and the current communication among the programs stored in the storage unit according to the communication state A wireless communication apparatus comprising a control unit that switches to a program state corresponding to a communication system that is not connected to operate the wireless unit.   The control unit monitors the synchronization state with the communication system in communication, and if the state not synchronized with the communication system continues for a certain period of time, among the programs stored in the storage unit, the communication unit that is not currently communicating The wireless communication apparatus according to claim 1, wherein a corresponding operation mode is set. The wireless unit includes a first receiver that receives a signal from the first communication system, a second receiver that receives a signal from the second communication system, and the program read from the storage unit. A first communication system, comprising a spare receiver for receiving a signal from the second communication system;
The control unit sets the standby receiver to operate according to a program corresponding to a communication system that is currently communicating, and if a failure is detected, a receiver that receives a signal is set as the standby receiver. The wireless communication apparatus according to claim 1, wherein the wireless communication apparatus is changed.

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