JP4986765B2 - Wireless communication system - Google Patents

Description

  The present invention relates to a radio communication system such as a train radio system, and more particularly, to a radio communication system that realizes securing a wide communication area and selecting an appropriate frequency.

For example, in a mobile radio communication system such as a train radio system, there is a mode in which one call is serviced by a plurality of base station apparatuses when the service area is long on the line and the mobile station apparatus does not deviate from the determined range.
In such a service configuration, if the same frequency is used in all base station apparatuses, downlink radio waves from a plurality of base station apparatuses interfere with each other, resulting in a section where communication is impossible. .
In order to solve this problem, radio interference is avoided by assigning two frequencies to downlink radio waves and using different frequencies between adjacent base station apparatuses. In this case, the mobile station device needs to be equipped with two radio devices as an example, and as another example, the frequency needs to be changed when the reception level is monitored and becomes equal to or less than a threshold value.

Among these methods, in the case of using means for installing two radio devices, the number of facilities is doubled, so there are cases where the cost and space are not allowed. In particular, in commercial mobile communication systems, the number of mobile station devices is large relative to the number of ground stations, and there are many cases in which a mounting space cannot be secured. In many cases, a simple means for switching the frequency is used.
In addition, there is a situation that you want to make a communication area even in places where sufficient reception level is not obtained such as both ends of the area or shadows of buildings, and in the worst case you can hear audio even if noise, interference or distortion is mixed It is difficult to raise the threshold value higher because it is preferred.

FIG. 3 shows a configuration example of the mobile radio communication system.
In FIG. 3, for the sake of convenience of explanation, the same reference numerals are given to components that are substantially the same as those shown in FIG. There is no intention to limit it to unnecessary.
The line control device 1 performs various call control and line control. FIG. 3 shows a transmission circuit. The voice input from the microphone 11 for inputting voice is amplified by an amplifier (amplifier) 12, and the low-pass filter 13 that cuts off the voice band (generally 300 Hz or less on a telephone line) is excluded. On the other hand, when radio wave interference occurs, a low frequency tone signal for reducing the beat is generated from the tone generator 14, and the high-pass filter 15 excludes the influence outside the voice band. Then, the audio signal from the low-pass filter 13 and the low-frequency tone signal from the high-pass filter 15 are combined and transmitted to the base station apparatuses 2a, 2b, and 2d.

  Each base station apparatus 2a, 2b, 2d has the same configuration, and each has a cover area. The signals received from the line control device 1 are separated into audio signals and low-frequency tone signals by the high-pass filters 21a to 21c and the low-pass filters 24a to 24c, respectively, and the audio signals are amplified by the amplifiers (amplifiers) 22a to 22c. The low frequency tone signal is amplified by amplifiers (amplifiers) 25a to 25c. These audio signals and low-frequency tone signals are converted into high-frequency signals by the transmission circuits 23a to 23c and then transmitted (wireless transmission) from the antennas 26a to 26c to the space.

  At this time, if all the base station devices 2a, 2b, and 2d use the same frequency, radio wave interference occurs in the section between them, making it difficult to talk. For example, in a system that can use abundant frequency resources such as a cellular phone system, three to four frequencies are used to prevent radio wave interference between adjacent base station apparatuses.

  However, a system that constructs an area on a line, such as a train radio system, may execute system construction by repeating two waves due to its configuration. In such a case, the base station apparatus shares a single frequency. In this method, although there is interference of the next adjacent (one jump), it is possible to prevent interference between adjacent base station devices causing extremely large interference, and change the frequency in the interference area with the next adjacent base station device. Therefore, a relatively high quality line can be provided. In the example of FIG. 3, the base station device 2a and the base station device 2d use the same frequency (f1), and the base station device 2b uses a different frequency (f2).

In the mobile station device 4 in the area, signals transmitted from the base station devices 2a, 2b, and 2d are received by the antenna 31, and the received signal is demodulated into sound by the detection circuit 32. At this time, a reception frequency to be used is determined by a CPU (Central Processing Unit) 101, and when waiting, the CPU 101 periodically changes the frequency to determine whether there is an incoming call.
On the other hand, once the incoming call is detected, the received voice is amplified by the voice amplification circuit 33 and broadcast from the speaker 38 via the switch (SW) 37. The switch 37 is controlled by the CPU 101, and the opening / closing thereof is performed on the basis of the case where both sides recognize “incoming call” based on the detection result by the TSQ detection unit 34 and the detection result by the NSQ detection unit 35. That is, when it is determined that there is an incoming call in both TSQ and NSQ, the switch 37 is closed (turned on) and the sound is output from the speaker 38, and in other cases, the switch 37 is opened ( The output from the speaker 38 is cut off.

Here, in TSQ detection, a process of detecting that radio waves are correctly received based on the presence of a predetermined tone signal in the demodulated signal is performed. In NSQ detection, noise in the demodulated signal is detected. And a process of detecting reception of radio waves with noise reduction is performed.
In general, whether or not to use TSQ differs depending on the system, the operator, and the like.

In such a system, for example, when the mobile station device 4 exists in the vicinity of the base station device 2a and moves to the area of the base station device 2b, the reception level of the mobile station device 4 decreases with the progress. Then, the CPU 101 determines “no reception” (incoming call detection off) by NSQ detection, and switches the frequency to the detection circuit 32.
In general, NSQ detects incoming calls even with extremely weak radio waves in order to widen the reception area. It is technically difficult to increase the determination of NSQ, and the reception area is narrowed. Further, although TSQ has a clear determination basis of tone, it cannot determine the signal strength.

JP 2001-102999 A JP-A-11-289576

As described above, in the conventional mobile radio communication system, the mobile station device 4 keeps the adjacent base station until the radio wave of the base station device (for example, the base station device 2a) selected at the timing of entering the call falls below the threshold value. Even if the radio wave of the station device (for example, the base station device 2b) is sufficient, switching was not possible. For this reason, even if the mobile station apparatus 4 is in a state where communication is difficult due to interference with the next adjacent base station apparatus (for example, the base station apparatus 2d), the base station apparatus (for example, the base station apparatus 2a) ) Will continue to be selected. On the other hand, when the threshold value is raised, there is a drawback that communication cannot be performed in a weak electric field region.
Thus, the conventional technique has a problem that there is a trade-off relationship between securing a large area and selecting an appropriate frequency.

  The present invention has been made in view of such conventional circumstances, and an object of the present invention is to provide a wireless communication system capable of ensuring a wide communication area and selecting an appropriate frequency.

In order to achieve the above object, the present invention has the following configuration in a radio communication system in which a plurality of base station apparatuses and mobile station apparatuses communicate by radio.
That is, each of the plurality of base station apparatuses includes a base station wireless communication unit. The base station wireless communication means uses two frequencies so that adjacent base station apparatuses use different frequencies for wireless communication, and one skipped (next adjacent) base station apparatus uses the same frequency for wireless communication. Different frequencies are assigned alternately.
In addition, one or more of the plurality of base station apparatuses include tone signal phase control means. This tone signal phase control means reverses the phase of a tone signal transmitted wirelessly by the base station wireless communication means to the mobile station apparatus in a single base station apparatus that uses the same frequency for wireless communication. In addition, the phase of the tone signal is controlled.
The mobile station apparatus includes mobile station radio communication means, tone signal detection means, and frequency switching control means. The mobile station wireless communication means can switch between the two different frequencies for use. The tone signal detecting means detects the presence / absence of the tone signal included in the signal received by the mobile station wireless communication means. The frequency switching control means is used for radio communication by the mobile station radio communication means when the tone signal detection means detects the absence of the tone signal (that is, when the tone signal is not detected). Switch the frequency to be used.

  Therefore, the phase of the tone signal transmitted wirelessly from two skipped base station apparatuses is reversed, so that an area where radio waves from these two base station apparatuses interfere, that is, between these two base station apparatuses. In an area where the radio wave from a certain base station apparatus is strong, the tone signals from these two base station apparatuses are canceled and are not detected. For example, the mobile station apparatus determines one of these two base station apparatuses and its frequency. Switching from the state of wireless communication using the base station device between these two base station devices to use the frequency for wireless communication, that is, the base station device between these two base station devices Can be switched to wireless communication. Thereby, for example, it is possible to realize a wide communication area and appropriate frequency selection as compared with the conventional case.

Here, various numbers may be used as the number of base station apparatuses and the number of mobile station apparatuses, respectively.
In addition, the plurality of base station apparatuses are arranged, for example, along the movement path of the mobile station apparatus, and the mobile station apparatus sequentially changes the base station apparatus as a communication partner as the movement path moves.

Various signals may be used as the tone signal. For example, a signal that can be separated from a signal (communication signal) originally intended for communication in the mobile station apparatus is used.
Further, the tone signal phase control means may control the phase of the tone signal in an arbitrary manner, and may be provided in an arbitrary base station apparatus. As an example, when looking at an array of one base station apparatus using the same frequency, every other base station apparatus is provided with means (tone signal phase control means) for inverting the phase of the tone signal. Can be used.

  In the mobile station apparatus, various methods for detecting the presence or absence of a tone signal may be used. For example, the level of a received tone signal is equal to or higher than a predetermined threshold (or a predetermined level). If a tone signal is detected, the received tone signal level is below (or below) a predetermined threshold value. Can be used to detect the absence of a tone signal.

  Further, in the mobile station apparatus, for example, frequency switching processing based on a tone signal may be performed, and frequency switching processing by another method may be performed. As a frequency switching process by another method, for example, when information on noise level is detected and the noise level is equal to or higher than a predetermined threshold (or exceeds a predetermined threshold) If the method of switching the frequency at the same time or the level of the original communication signal is detected and the level is below a predetermined threshold (or less than the predetermined threshold), the frequency It is possible to use a technique for performing a switching process.

The radio communication system according to the present invention has the following configuration as an example configuration.
That is, the radio communication system is a train radio system. The mobile station apparatus is mounted on a train.
The plurality of base station devices are arranged along a travel route of the train and communicate with the mobile station device mounted on the train by radio.
The wireless communication system includes a line control device.
The line control apparatus includes line control communication means for transmitting a voice signal and a tone signal to each of the plurality of base station apparatuses.
Each of the plurality of base station apparatuses processes the audio signal and the tone signal received from the line control apparatus and wirelessly transmits them by the base station wireless communication means.

Therefore, in the train radio system, for example, it is possible to realize a wide communication area and appropriate frequency selection as compared with the conventional system.
Here, as a traveling route of a train, for example, a track is used, and in the case of a subway, a tunnel can also be used.
In addition, various contents may be used as the contents of processing performed on the audio signal and tone signal in each base station apparatus. For example, processing such as filtering, amplification, and frequency conversion is used. In addition, a process of controlling the phase of the tone signal (for example, inversion) can be used.

  As described above, according to the wireless communication system of the present invention, two different frequencies are alternately assigned to a plurality of base station apparatuses, and a tone signal is transmitted in a single base station apparatus using the same frequency. For example, compared with the conventional case, the mobile station device switches the frequency used for wireless communication (that is, the base station device as the communication partner) triggered by the disappearance of the tone signal from the base station device. Thus, it is possible to ensure a wide communication area and select an appropriate frequency.

Embodiments according to the present invention will be described with reference to the drawings.
FIG. 1 shows a configuration example of a mobile radio communication system according to an embodiment of the present invention.
The mobile radio communication system of this example includes a line control device 1, a plurality of base station devices 2 a, 2 b, 2 c, and a mobile station device 3. Each base station apparatus 2a, 2b, 2c is connected to the line control apparatus 1 via a wired cable, for example.
Here, for example, there are more base station apparatuses, but in this example, three base station apparatuses 2a, 2b, and 2c arranged in succession are shown.
For example, although there are a plurality of mobile station apparatuses, one mobile station apparatus 4 is shown in this example.

The line control device 1 includes a microphone 11, an amplifier 12, a low-pass filter (LPF) 13, a tone generator 14, and a high-pass filter (HPF) 15 as a transmission circuit. Yes.
The base station apparatus 2a and the base station apparatus 2b adjacent to the base station apparatus 2a have the same configuration, and include high-pass filters (HPF) 21a and 21b, amplifiers (amplifiers) 22a and 22b, and transmission circuits 23a and 23b. , Low pass filters (LPF) 24a and 24b, amplifiers 25a and 25b, and antennas 26a and 26b.

The base station device 2c is adjacent to the base station device 2b and has a positional relationship of one jump (next adjacent) as viewed from the base station device 2a.
The base station apparatus 2c includes a high-pass filter (HPF) 21c, an amplifier (amplifier) 22c, a transmission circuit 23c, a low-pass filter (LPF) 24c, a phase inverting amplifier (phase inverting amplifier) 27, an amplifier (Amplifier) 25c and an antenna 26c are provided.
Here, in this example, the same frequency is used in one base station apparatus that is skipped, and different frequencies are used in adjacent base station apparatuses. Specifically, the base station apparatus 2a and the base station In the device 2c, the frequency (f1) is used for wireless communication with the mobile station device 3, and in the base station device 2b, the frequency (f2) is used for wireless communication with the mobile station device 3. Note that (f1) and (f2) are different frequencies.

  The mobile station device 3 includes an antenna 31, a detection circuit 32, a voice amplification circuit 33, a TSQ (tone squelch) detection unit 34, an NSQ (noise squelch) detection unit 35, a CPU 36, a switch (SW) 37, A speaker 38 is provided. In this example, the mobile station device 3 includes one radio device and has a function of switching the frequency used for radio communication between (f1) and (f2).

An example of a schematic operation performed in the mobile radio communication system of the present example is shown.
The line control device 1 performs various call control and line control.
The voice input from the microphone 11 for inputting voice is amplified by an amplifier (amplifier) 12, and the low-pass filter 13 that cuts off the voice band (generally 300 Hz or less on a telephone line) is excluded. On the other hand, when radio wave interference occurs, a low frequency tone signal for reducing the beat is generated from the tone generator 14, and the high-pass filter 15 excludes the influence outside the voice band. Then, the audio signal from the low-pass filter 13 and the low-frequency tone signal from the high-pass filter 15 are combined and transmitted to the base station apparatuses 2a, 2b, and 2c.
Here, the tone signal (tone squelch signal) is a signal that can be detected on the reception side by being superimposed outside the call band of the transmission wave.

Each base station apparatus 2a, 2b, 2c has a cover area.
The base station device 2a and the base station device 2b perform the following processing.
The signal received from the line control device 1 is separated into a sound signal and a low frequency tone signal by the high-pass filters 21a and 21b and the low-pass filters 24a and 24b, respectively, and the sound signals are amplified by amplifiers 22a and 22b. The low frequency tone signal is amplified by amplifiers (amplifiers) 25a and 25b. These audio signals and low-frequency tone signals are converted into high-frequency signals by the transmission circuits 23a and 23b, and then transmitted (wireless transmission) from the antennas 26a and 26b to the space.

In the base station device 2c, the following processing is performed.
The signal received from the line control device 1 is separated into a voice signal and a low-frequency tone signal by the high-pass filter 21c and the low-pass filter 24c, respectively. The audio signal is amplified by an amplifier (amplifier) 22c. The low frequency tone signal is amplified by being phase-inverted by a phase-inverting amplifier (phase-inverting amplifier) 27 and then amplified by an amplifier (amplifier) 25c. These audio signals and low-frequency tone signals are converted into high-frequency signals by the transmission circuit 23c and then transmitted (wireless transmission) from the antenna 26c to the space.
As described above, the base station apparatus 2c is configured with substantially the same circuit as the base station apparatuses 2a and 2b, but the phase inversion amplifier 27 explicitly inverts the phase of the low frequency tone signal. It has the composition to make it.

  In the mobile station device 3 in the area, signals transmitted from the base station devices 2 a to 2 c are received by the antenna 31, and the received signal is demodulated into sound by the detection circuit 32. At this time, the reception frequency to be used is determined by the CPU 36, and when waiting, the CPU 36 periodically changes the frequency to determine whether there is an incoming call.

  On the other hand, once the incoming call is detected, the received voice is amplified by the voice amplification circuit 33 and broadcast from the speaker 38 via the switch (SW) 37. The switch 37 is controlled by the CPU 36, and the opening / closing thereof is performed on the basis of the case where “there is an incoming call” is recognized on the basis of the detection result by the TSQ detection unit 34 and the detection result by the NSQ detection unit 35. That is, when it is determined that there is an incoming call in both TSQ and NSQ, the switch 37 is closed (turned on) and the sound is output from the speaker 38, and in other cases, the switch 37 is opened ( The output from the speaker 38 is cut off.

  Here, in TSQ detection, a process of detecting that radio waves are correctly received based on the presence of a predetermined tone signal in the demodulated signal is performed. In NSQ detection, noise in the demodulated signal is detected. And a process of detecting reception of radio waves with noise reduction is performed.

  Further, the CPU 36 performs control for frequency switching on the detection circuit 32 on the condition that NSQ detection interruption (incoming call detection off) is determined based on the detection result by the NSQ detection unit 35, and the TSQ detection unit. On the condition that TSQ detection interruption (incoming call detection off) is determined based on the detection result by 34, control for frequency switching is performed on the detection circuit 32. Thus, in this example, the frequency (f1) and (f2) used for radio | wireless communication are switched on condition of NSQ detection interruption or TSQ detection interruption.

With reference to FIG. 2, the frequency switching operation performed by the mobile station apparatus 3 in the mobile radio communication system of the present example will be described in detail.
In FIG. 2, three base station apparatuses 2a, 2b, and 2c and from the vicinity of the base station apparatus 2a to the vicinity of the base station apparatus 2c via the vicinity of the base station apparatus 2b (from the left in FIG. 2) The mobile station device 3 is moving (to the right).
Further, as the incoming radio wave level in the mobile station apparatus 3, an incoming radio wave level 41a from the base station apparatus 2a, an incoming radio wave level 41b from the base station apparatus 2b, and an incoming radio wave level 41c from the base station apparatus 2c are shown. . The horizontal direction represents the position, and the vertical direction represents the level.

Also, NSQ threshold value 1 (T1) and NSQ threshold value 2 (T2) are shown as examples of threshold levels for determining NSQ detection interruption set in the mobile station apparatus 3. . Depending on the NSQ threshold level set in the mobile station apparatus 3, the size (range) of the area in which wireless communication is possible is determined.
FIG. 2 shows an area range (T3) determined by the NSQ threshold value 1 and an area range (T4) determined by the NSQ threshold value 2. In the NSQ threshold value setting method and NSQ detection method of this example, the area range is wider when the NSQ threshold value is lower, and the area range is narrower when the NSQ threshold value is higher.

  FIG. 2 also shows NSQ detection cutoff point (T5) corresponding to the case where NSQ threshold value 1 is set and NSQ detection cutoff point (T6) corresponding to the case where NSQ threshold value 2 is set. In these respects, the mobile station apparatus 3 switches the frequency. In this example, the mobile station apparatus 3 is accommodated by the base station apparatus 2a, and the incoming radio wave level 41a from the base station apparatus 2a is used.

  Here, as is clear from the above, when the NSQ threshold value 1 is used, the area can be widened, but the radio wave level from the adjacent base station apparatus 2b is sufficient. The frequency is not switched up to the point (T5). On the other hand, when the NSQ threshold value 2 is used, the frequency is switched at the point (T6), but the area becomes narrow.

  Further, FIG. 2 shows an area where the D / U (desired wave-to-interference wave ratio) is insufficient, that is, an interference area between the next adjacent base station devices (in this example, the base station device 2a and the base station device 2c) ( T7) is shown. In this interference area (T7), if the NSQ threshold value 1 is used due to the lack of D / U, the sound quality is extremely deteriorated even if there is a reception level.

  On the other hand, in this example, by using the phase inverting amplifier 27 of the base station device 2c, the low-frequency tone signal is transmitted between the next adjacent base station devices (in this example, the base station device 2a and the base station device 2c). The phases are reversed from each other. In this case, in the interference area (T7), among the interfering signals, the tone signal used for TSQ detection is lost or extremely small. For this reason, the state where the tone signal is detected by TSQ disappears at the point (T8), and the mobile station apparatus 3 can switch the frequency at this point (T8) by the TSQ detection interruption.

In the case of this example, for example, the point of frequency switching due to the TSQ detection interruption is the moving direction of the mobile station device 3 (in the right direction in FIG. 2) rather than the point (T6) that is the ideal point of frequency switching. However, when the NSQ threshold value 1 is used, it is preferable that the frequency can be switched before the frequency switching point (T5) due to NSQ detection interruption (left side in FIG. 2).
In this example, using this, for example, the NSQ threshold value is set to a low value (NSQ threshold value 1 in this example) to secure the area size, and TSQ detection interruption is used. Appropriate frequency switching can be realized.

  As described above, in the mobile radio communication system of this example, for example, a base station apparatus using the frequency (f1), a base station apparatus using the frequency (f2), a base station apparatus using the frequency (f1), and a frequency The base station apparatus using (f2) is alternately arranged for two different frequencies, such as a base station apparatus using..., And the same frequency is used for each frequency. The phase of the tone signal emitted from one base station apparatus (next adjacent) that uses one is reversed (inverted). That is, when only the base station apparatuses using the same frequency are viewed, the phases of tone signals emitted from the base station apparatuses are alternately inverted.

Thereby, in the interference area between the next adjacent base station apparatuses (for example, those using the frequency (f1)), the mutual tone signals are canceled and the adjacent base station apparatuses (for example, the frequency (f2) are used). The signal at the frequency of the one to be performed becomes relatively large. In such an interference area, the mobile station apparatus 3 detects the TSQ detection interruption by canceling the tone signals of the frequency (f1) between the next adjacent base station apparatuses and detecting the TSQ adjacent to the adjacent base station. A different frequency (f2) used by the device is switched to use for wireless communication.
Moreover, in this example, the mobile station apparatus 3 can set a threshold value for detecting NSQ detection interruption to a relatively low value to ensure a wide range of areas in which wireless communication is possible.

  As a configuration example, in a train radio system to which the configuration of this example is applied, a line control device 1, a plurality of base station devices 2a, 2b, 2c connected to the line control device 1, a plurality of base station devices 2a, 2b, 2c has a mobile station device 3 mounted on a train moving in an area on the line, and a plurality of base station devices 2a, 2b, 2c are arranged on the line and have two frequencies ( By using f1) and (f2) to alternately change the use frequency, radio wave interference between adjacent base station apparatuses is prevented. Further, the tone signal is transmitted from the line control device 1 and transmitted by inverting the phase of the tone signal between the adjacent base station devices, and the mobile station device 3 appropriately sets the frequency to be used in response to the disappearance of the tone signal. Switch.

  In this way, in this example, the tone signal is distributed from the line control device 1 to all the base station devices 2a, 2b, 2c, and the tone signal received from the line control device 1 between the next adjacent base station devices 2a, 2c is By making the phase inversion relationship with each other, the tone signal disappears in an area where radio interference between the next adjacent base station apparatuses 2a and 2c occurs, that is, an area where the radio wave of the adjacent base station apparatus 2b is sufficiently high. By causing the frequency change by triggering the disappearance of the tone signal at the initiative of the mobile station apparatus 3, it is possible to select an appropriate frequency with simple equipment.

  Therefore, in this example, a plurality of base station apparatuses 2a, 2b, and 2c and two transmission waves (f1) and (f2) are used to cover a single transmitter and a plurality of base station apparatuses 2a, 2b, and 2c. In the mobile radio communication system that communicates with the mobile station apparatus 3 that moves in the area to be transmitted, the tone signal is intentionally interfered between the next adjacent base station apparatuses 2a and 2c, and the mobile station apparatus 3 responds to the TSQ detection interruption. By performing frequency switching, appropriate frequency switching can be realized while ensuring a sufficiently wide area.

In the line control apparatus 1 of this example, the line control communication means is configured by the function of transmitting the audio signal and the tone signal to the base station apparatuses 2a to 2c using the processing units 11 to 15.
Further, in the base station apparatuses 2a to 2c of this example, the base station wireless communication means is configured by the function of performing wireless communication with the mobile station apparatus 3 using the transmission circuits 23a to 23c and the antennas 26a to 26c. The tone signal phase control means 27 is constituted by a function 27 for inverting the phase of the tone signal.
Further, in the mobile station device 3 of this example, mobile station wireless communication means is configured by the function of performing wireless communication with the base station devices 2a to 2c using the antenna 31 and the detection circuit 32, and the TSQ detection unit 34 receives the tone signal. The tone signal detecting means is configured by the function of detecting the presence or absence of the signal, and the frequency switching control means is configured by the function of the CPU 36 controlling the detection circuit 32 and switching the frequency used for wireless communication.

Here, the configuration of the system and apparatus according to the present invention is not necessarily limited to the configuration 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 systems and devices.
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.
In addition, as various processes performed in the system and apparatus according to the present invention, for example, the processor executes a control program stored in a ROM (Read Only Memory) in hardware resources including a processor and a memory. A controlled configuration may be used, and for example, each functional unit for executing the processing may be configured as an independent hardware circuit.
The present invention can also be understood as a computer-readable recording medium such as a floppy (registered trademark) disk or a CD (Compact Disc) -ROM storing the control program, and 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.

It is a figure which shows the structural example of the mobile radio | wireless communications system which concerns on one Example of this invention. It is a figure which shows an example of the operation | movement of frequency switching performed in a mobile radio | wireless communications system. It is a figure which shows the structural example of a mobile radio | wireless communications system.

Explanation of symbols

  1 ·· Line control device, 2a to 2d ·· Base station device, 3, 4 ·· Mobile station device, 11 ·· Mic, 12, 22a to 22c, 25a to 25c ·· Amplifier, 13, 24a to 24c ·· Low-pass filter 14.. Tone generator 15, 21 a to 21 c High-pass filter 23 a to 23 c Transmission circuit 26 a to 26 c 31 Antenna Antenna 27 Inverting amplifier 32・ Detection circuit 33 ・ ・ Sound amplifier circuit 34 ・ ・ TSQ detection unit 35 ・ ・ NSQ detection unit 36、101 ・ ・ CPU, 37 ・ ・ Switch 38 ・ ・ Speaker 41a ~ 41c ・ Incoming radio wave level ,

Claims (2)

In a wireless communication system in which a plurality of base station devices and mobile station devices communicate wirelessly,
Each of the plurality of base station apparatuses alternates between two different frequencies so that adjacent base station apparatuses use different frequencies for radio communication and one base station apparatus uses the same frequency for radio communication. A base station wireless communication means assigned to
One or more of the plurality of base station apparatuses are tone signals that are transmitted by radio from the base station radio communication means to the mobile station apparatus in a single base station apparatus that uses the same frequency for radio communication. Tone signal phase control means for controlling the phase of the tone signal so as to invert the phase of
The mobile station apparatus includes a mobile station radio communication unit capable of switching and using the two different frequencies, and a tone for detecting the presence / absence of the tone signal included in the signal received by the mobile station radio communication unit A signal detection means; and a frequency switching control means for switching a frequency used for radio communication by the mobile station radio communication means when the tone signal detection means detects the absence of the tone signal.
A wireless communication system. The wireless communication system according to claim 1, wherein
The radio communication system is a train radio system,
The mobile station device is mounted on a train,
The plurality of base station devices are arranged along the travel route of the train, and communicate with the mobile station device mounted on the train by radio,
The wireless communication system has a line control device,
The line control device comprises line control communication means for transmitting a voice signal and a tone signal to each of the plurality of base station devices,
Each of the plurality of base station devices processes the audio signal and the tone signal received from the line control device and wirelessly transmits the processed signal by the base station wireless communication unit.
A wireless communication system.

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