Repeater device and repeater device control method

Abstract

To provide a repeater device that can quickly perform gain adjustment according to change of an installation environment.SOLUTION: A repeater device comprises: an amplification section; an amplitude fluctuation and synchronous detection section; and a control section. The amplification section amplifies a radio signal received by a first antenna using an amplifier, and adjusts gain using an attenuator. The amplitude fluctuation and synchronous detection section generates periodic amplitude fluctuation for the radio signal transmitted from a second antenna transmitting the radio signal having gain adjusted using a preset value for the attenuator. The amplitude fluctuation and synchronous detection section detects whether or not an electromagnetic wave radiated from the second antenna wraps around the first antenna. The control section reduces gain of the attenuator when it is determined that the electromagnetic wave radiated from the second antenna wraps around the first antenna on the basis of a synchronous detection signal.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a repeater device and a method for controlling a repeater device. [Background technology]

[0002] 2. Description of the Related Art In a mobile communication system, there is a repeater device for relaying radio waves transmitted and received between a base station and a mobile station.

[0003] For example, Patent Document 1 discloses a radio relay device that uses an amplifier to amplify a radio frequency signal received by a receiving antenna and retransmits the signal from a transmitting antenna at the same frequency as the received radio frequency signal.

[0004] Patent Document 2 describes that abnormal oscillation caused by sneak interference is detected without degrading communication quality. The repeater device in Patent Document 2 includes an amplifier, a detector, and a memory. The amplifier amplifies a received radio frequency signal. The detector measures the input level of the received radio frequency signal. The memory stores a preset over-input threshold. The repeater device stops the amplifier and determines whether or not there is abnormal oscillation only if the input level measured by the detector while the amplifier is operating is equal to or greater than the over-input threshold.

[0005] Patent Document 3 describes that a service is provided to users with maximum gain without causing oscillation, while suppressing degradation of service quality, without complicating the circuit configuration. The repeater device in Patent Document 3 has first and second antennas. The repeater device amplifies a signal received by the first antenna and transmits the amplified signal from the second antenna. The repeater device also amplifies a signal received by the second antenna and transmits the amplified signal from the first antenna. If the power level of the signal received by the first antenna is equal to or lower than a predetermined first threshold, the repeater device determines whether oscillation has occurred based on the power level of the signal received by the second antenna. The repeater device determines a new gain for amplifying the signal received by the second antenna based on the result of the determination. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 141825 / 1983 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-015359 [Patent Document 3] Japanese Patent Application Laid-Open No. 2011-114545 Summary of the Invention [Problem to be solved by the invention]

[0007] Repeater devices are required to be able to adjust the gain used for amplification for relaying to keep up with changes in the environment (radio wave propagation environment) where the device is installed, in order to prevent problems that arise as a result of the relayed radio waves being deflected, such as service interruptions due to oscillation.

[0008] For example, a repeater device is installed in a space where radio waves are difficult to reach, such as an underground area, and the repeater device emits amplified radio waves to expand the communication area. However, due to changes in the installation environment, for example, changes in nearby structures, the radio wave environment, such as reflection, can change, which can cause problems such as oscillation. More specifically, radio waves can get between a first antenna that transmits and receives radio waves to and from a base station and a second antenna that transmits and receives radio waves to and from a mobile station, causing abnormal oscillation.

[0009] To address this issue, the first antenna is given directivity and the two antennas are installed with a certain distance between them. Alternatively, the gain is adjusted during the initial setup of the repeater device to prevent abnormal oscillation before the repeater device is put into operation.

[0010] Alternatively, as disclosed in Patent Document 2, measures have been taken to measure the input level of a received signal, set an over-input threshold in advance, and detect abnormal oscillation based on whether the input level measured by a detector while the amplifier is operating exceeds the over-input threshold.Alternatively, as disclosed in Patent Document 3, measures have been taken such as determining whether the level of a downlink signal transmitted from a base station to a mobile station is equal to or lower than a threshold, and adjusting the gain when the mobile station (user) is not using the signal.

[0011] However, these technical measures are insufficient. For example, in the example of Patent Document 2, it is only possible to detect a malfunction when abnormal oscillation actually occurs and excessive input occurs. In addition, in Patent Document 3, gain adjustment is only possible when there is no mobile device present, and it is not possible to quickly respond to changes in the installation environment during actual operation.

[0012] A main object of the present invention is to provide a repeater device and a repeater device control method that contribute to enabling rapid gain adjustment in response to changes in the installation environment. [Means for solving the problem]

[0013] According to a first aspect of the present invention, there is provided a repeater device comprising: an amplifier unit that amplifies a radio signal received by a first antenna using an amplifier and adjusts the gain using an attenuator; an amplitude fluctuation and synchronous detection unit that uses a set value for the attenuator to cause periodic amplitude fluctuations in a radio signal transmitted from a second antenna that transmits the gain-adjusted radio signal, and generates a synchronous detection signal for detecting whether or not radio waves radiated from the second antenna have entered the first antenna; and a control unit that reduces the gain of the attenuator when it is determined based on the synchronous detection signal that radio waves radiated from the second antenna have entered the first antenna.

[0014] According to a second aspect of the present invention, there is provided a repeater device control method that includes an amplifier that amplifies a radio signal received by a first antenna and adjusts the gain of a radio signal transmitted from a second antenna using an attenuator, and that uses a set value for the attenuator to cause periodic amplitude fluctuations in the radio signal transmitted from the second antenna, generates a synchronous detection signal for detecting whether or not the radio waves radiated from the second antenna have entered the first antenna, and reduces the gain of the attenuator when it is determined based on the synchronous detection signal that the radio waves radiated from the second antenna have entered the first antenna. [Effects of the Invention]

[0015] According to each aspect of the present invention, a repeater device and a control method for a repeater device are provided that contribute to enabling rapid gain adjustment in response to changes in the installation environment. Note that the effects of the present invention are not limited to those described above. The present invention may achieve other effects instead of or in addition to the effects described above. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a diagram for explaining an outline of an embodiment. [Figure 2] FIG. 2 is a diagram showing an example of a schematic configuration of the mobile communication system according to the first embodiment. [Figure 3] FIG. 3 is a diagram showing the internal configuration of the repeater device according to the first embodiment. [Figure 4] 4A and 4B are diagrams showing an example of the internal configuration of the amplifier according to the first embodiment. [Figure 5] FIG. 5 is a diagram illustrating an example of the internal configuration of the amplitude fluctuation and synchronous detection unit according to the first embodiment. [Figure 6] FIG. 6 is a diagram illustrating an example of the internal configuration of the control unit according to the first embodiment. [Figure 7] FIG. 7 is a diagram for explaining the amplitude fluctuation and the operation of the synchronous detection unit according to the first embodiment. [Figure 8] FIG. 8 is a flowchart showing an example of the operation of the repeater device according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] First, an overview of one embodiment will be described. Note that the reference numerals in the drawings are added to each element for convenience as an example to facilitate understanding, and the description of this overview is not intended to be limiting in any way. Furthermore, unless otherwise specified, the blocks shown in each drawing represent functional units, not hardware units. Connection lines between blocks in each drawing include both bidirectional and unidirectional lines. Unidirectional arrows are used to schematically indicate the flow of main signals (data) and do not exclude bidirectionality. Note that in this specification and drawings, elements that can be similarly described may be assigned the same reference numerals to avoid redundant explanation.

[0018] A repeater device 100 according to one embodiment includes an amplifier 101, an amplitude fluctuation and synchronous detection unit 102, and a control unit 103 (see FIG. 1). The amplifier 101 amplifies a radio signal received by a first antenna using an amplifier and adjusts the gain using an attenuator. The amplitude fluctuation and synchronous detection unit 102 uses a setting value for the attenuator to cause periodic amplitude fluctuations in a radio signal transmitted from a second antenna that transmits the gain-adjusted radio signal. The amplitude fluctuation and synchronous detection unit 102 detects whether radio waves radiated from the second antenna have leaked into the first antenna. If the control unit 103 determines, based on the synchronous detection signal, that radio waves radiated from the second antenna have leaked into the first antenna, it reduces the gain of the attenuator.

[0019] The repeater device 100 relays radio frequency signals transmitted and received between base stations and mobile stations used in mobile communications such as mobile phones and smartphones. The repeater device 100 has a first antenna for transmitting and receiving radio waves to and from the base station and a second antenna for transmitting and receiving radio waves to and from the mobile station. The repeater device 100 has a function for periodically varying (periodically varying slightly) the gain of the transmission wave directed to the mobile station. The repeater device 100 also detects the level of interference of the radio waves emitted from the second antenna by performing synchronous detection (synchronous detection) on the reception level from the first antenna at the above-mentioned varying period. The repeater device 100 optimizes the transmission gain from the repeater device 100 according to the detected interference level, thereby enabling rapid gain adjustment in response to changes in the installation environment. In other words, a repeater device 100 is provided that enables system operation with gain that is free of interference from the second antenna.

[0020] Specific embodiments will be described in more detail below with reference to the drawings.

[0021] [First embodiment] The first embodiment will be described in more detail with reference to the drawings.

[0022] [System Configuration] Fig. 2 is a diagram showing an example of a schematic configuration of a mobile communication system according to the first embodiment. Referring to Fig. 2, the mobile communication system includes a repeater device 10, a base station 30, and a mobile station 40.

[0023] The repeater device 10 amplifies and transmits radio frequency signals to enable mobile communications inside buildings, underground, and other locations where radio waves are difficult to reach. The repeater device 10 amplifies downlink radio frequency signals transmitted from the base station 30 and transmits them to the mobile station 40. The repeater device 10 amplifies uplink radio frequency signals transmitted from the mobile station 40 and transmits them to the base station 30.

[0024] The base station 30 is a device for connecting the mobile station 40 to a mobile line.

[0025] Examples of the mobile station 40 include mobile terminal devices such as smartphones, mobile phones, game consoles, and tablets, as well as computers (personal computers, laptop computers). Alternatively, the mobile station 40 may be an IoT (Internet of Things) terminal, an MTC (Machine Type Communication) terminal, or the like that transmits radio waves. However, the transmitting terminal is not intended to be limited to these examples. In the present disclosure, a "mobile station" may be any device that transmits radio waves.

[0026] Next, the devices included in the mobile communication system according to the first embodiment will be described in detail.

[0027] [Repeater device] 3 is a diagram showing the internal configuration of the repeater device 10 according to the first embodiment. The repeater device 10 receives radio waves for communication with the base station 30 at an antenna 11 (first antenna) on the base station side. The repeater device 10 also transmits radio waves from the antenna 11 to the base station 30. The antenna 11 receives downstream radio signals.

[0028] The duplexer 12 connected to the antenna 11 separates the transmitted and received radio waves. After separating the transmitted and received radio waves, the duplexer 12 inputs the radio waves from the base station 30 (hereinafter referred to as a downlink signal or a downlink wireless signal) to the amplifier 13.

[0029] The amplifier 13 amplifies the radio wave of the downstream radio signal. The amplifier 13 amplifies the radio signal received by the antenna 11 using an amplifier (described later) and adjusts the overall gain using an attenuator. The amplifier 13 outputs the amplified downstream radio signal to the duplexer 14.

[0030] The duplexer 14 is connected to an antenna 15 (second antenna) that outputs radio waves directed to the mobile station 40. The duplexer 14 outputs the downlink signal received from the amplifier 13 to the antenna 15. The antenna 15 transmits radio waves corresponding to the downlink radio signal whose gain has been adjusted by the amplifier 13.

[0031] Radio waves (hereinafter referred to as uplink signals or uplink radio signals) traveling from the mobile station 40 to the base station 30 are received by the antenna 15. A received signal corresponding to the radio waves (received radio waves) received by the antenna 15 is input to the duplexer 14. The duplexer 14 outputs an uplink signal corresponding to the received radio waves to the amplifier 16.

[0032] The amplifier 16 amplifies the upstream signal and outputs the amplified upstream signal to the duplexer 12.

[0033] The duplexer 12 transmits from the antenna 11 a radio wave corresponding to the upstream signal received from the amplifier 16 .

[0034] 4A and 4B, the internal configurations of the amplifier 13 and the amplifier 16 will be described. Figures 4A and 4B are diagrams showing an example of the internal configurations of the amplifier 13 and the amplifier 16 according to the first embodiment.

[0035] 4A, the amplifying unit 13 includes an amplifier 201a, an attenuator 202a, and a control circuit 203a. The amplifier 201a receives a signal corresponding to the downstream radio wave from the duplexer 12 and amplifies the signal at a predetermined amplification factor (gain). The attenuator 202a attenuates the output of the amplifier 201a and outputs the attenuated signal to the duplexer 14. The control circuit 203a is a circuit that controls the operations of the amplifier 201a and the attenuator 202a.

[0036] The control circuit 203a controls the amplifier 201a and the attenuator 202a in accordance with an "amplifier control signal" received from the outside. The amplifier control signal is a signal for controlling the operation of the amplifier 13.

[0037] The amplifier control signal includes information for controlling activation and deactivation of the amplification operation (AMP (Amplifier) ​​control information) and information regarding the amplification factor (gain) (ATT (Attenuator) setting value).

[0038] The control circuit 203a controls the activation (ON) and deactivation (OFF) of the amplifier 201a using the AMP control information. The control circuit 203a sets the gain of the attenuator 202a using an ATT setting value (ATT setting signal). The ATT setting value may be an analog signal or a digital signal. For example, the control circuit 203a switches the internal resistance of the attenuator 202a based on the ATT setting value.

[0039] Fig. 4B is a diagram showing an example of the internal configuration of the amplifier unit 16. As shown in Fig. 4B, the amplifier unit 16 includes an amplifier 201b, an attenuator 202b, and a control circuit 203b. The operation of the amplifier unit 16 can be the same as that of the amplifier unit 13, and therefore a description thereof will be omitted.

[0040] Returning to Fig. 3, detector 17 is a detector that detects the level of a downstream signal. Detector 17 detects the reception level of a radio signal received by antenna 11. Detector 17 outputs a detected signal that includes the reception level of the downstream signal. Detector 17 is connected to control unit 18 and amplitude fluctuation and synchronous detection unit 19.

[0041] The amplitude fluctuation and synchronous detection unit 19 is a module for performing amplitude fluctuation and synchronous detection of the downlink signal. The amplitude fluctuation and synchronous detection unit 19 causes periodic amplitude fluctuations in the radio signal transmitted from the antenna 15, using a setting value set in the attenuator 202a of the amplifier 13. The amplitude fluctuation and synchronous detection unit 19 also generates a synchronous detection signal for detecting whether the radio wave emitted from the antenna 15 is leaking into the antenna 11.

[0042] The amplitude fluctuation and synchronous detection unit 19 receives the above-described amplifier control signal from the control unit 18. In particular, the amplitude fluctuation and synchronous detection unit 19 receives the amplifier control signal supplied to the amplifier 13 that amplifies the downstream signal.

[0043] The amplitude variation and synchronous detection unit 19 changes (processes and converts) the ATT setting value of two control signals (AMP control information and ATT setting value) included in the amplifier control signal. More specifically, the amplitude variation and synchronous detection unit 19 changes the ATT setting value so as to impart slight amplitude variation to the radio waves of the downstream signal. The amplitude variation and synchronous detection unit 19 changes the ATT change value included in the amplifier control signal using a "reference signal" supplied from the control unit 18.

[0044] In the following description, the ATT setting value changed (generated) by the amplitude fluctuation and synchronous detection unit 19 will be referred to as the "amplitude fluctuation ATT setting value."

[0045] The amplitude fluctuation and synchronous detection unit 19 outputs an amplifier control signal including an amplitude fluctuation ATT setting value that imparts a slight amplitude fluctuation to the downlink signal to the amplifier 13. The format of the amplifier control signal supplied to the amplifier 13 is the same as the amplifier control signal output by the control unit 18. The amplifier control signal supplied to the amplifier 13 differs from the amplifier control signal output by the control unit 18 in that it includes an ATT setting signal whose setting value changes periodically (changes in a short time).

[0046] The amplifier 13 applies minute amplitude fluctuation to the downstream signal in accordance with the amplitude fluctuation ATT setting value included in the amplifier control signal.

[0047] Furthermore, the amplitude fluctuation and synchronous detection unit 19 outputs a synchronous detection output (synchronous detection signal) synchronized with the reception level (detection output) of the detector 17 and the reference signal to the control unit 18. That is, the synchronous detection output is a signal synchronized with the reference signal used when changing the ATT setting value.

[0048] Based on the synchronous detection output, the control unit 18 detects whether or not the radio waves of the downstream signal, the amplitude of which has been slightly changed in the amplifier unit 13, are radiated from the antenna 15 and the radiated radio waves are leaking into the antenna 11. The control unit 18 will be described in more detail later.

[0049] The initial setting unit 20 stores initial setting values ​​and the like for the repeater device 10. The initial setting unit 20 is configured by a device such as a ROM (Read Only Memory).

[0050] The display unit 21 displays (outputs) the status of the repeater device 10 and various setting states. The display unit 21 includes a device (output device) such as a liquid crystal panel. The display unit 21 functions as an "output unit" that outputs the operating status of its own device (the repeater device 10). The display unit 21 may include, for example, a touch panel type operation unit, and output user operation inputs to the operation unit to the control unit 18.

[0051] For example, the control unit 18 may control the display mode of the display unit 21 to present (output) to the user a status display (operating status) of the repeater device 10 using at least part of the data representing various signals described later with reference to the example shown in Fig. 7. In this case, the status display of the repeater device 10 displayed by the display unit 21 may be in the form of, for example, each chart shown in Fig. 7.

[0052] The control unit 18 may also readably record various signals in a memory (for example, memory 402 described later). In this case, the memory may record the various signals in association with time, for example. The control unit 18 may then read from the memory data indicating the states of the various signals corresponding to a period designated by the user using the operation unit. Furthermore, the control unit 18 may display the states of the various signals during the designated period on the display unit 21 as the operating status of the repeater device 10 based on the read data. The period designated by the user here may be a past period or a future period.

[0053] Next, the configuration of the amplitude variation and synchronous detection unit 19 will be described with reference to Fig. 5. Fig. 5 is a diagram showing an example of the internal configuration of the amplitude variation and synchronous detection unit 19 according to the first embodiment.

[0054] The amplitude variation and synchronous detection unit 19 generates a synchronous detection signal based on the detection signal and the reference signal output by the detector 17. More specifically, the amplitude variation and synchronous detection unit 19 generates the synchronous detection signal using an adder 301.

[0055] The adder 301 receives an amplifier control signal (a control signal transmitted from the control unit 18 to the amplifier unit 13) and a reference signal from the control unit 18. The adder 301 adds a signal to the ATT setting value based on the reference signal in order to cause a slight amplitude fluctuation in the radio wave of the downlink signal.

[0056] For example, adder 301 adds a reference signal to the ATT setting value, or adds a signal generated from the reference signal (for example, a signal obtained by converting the voltage of the reference signal) to the ATT setting value. Amplitude fluctuation and synchronous detection unit 19 outputs an amplifier control signal including the output of adder 301 (amplitude fluctuation ATT setting value) to amplifier 13.

[0057] A high-pass filter (HPF) 302 is applied to the output (demodulated signal or detected signal) of the detector 17. The high-pass filter 302 receives the detected signal output by the detector 17. The high-pass filter 302 cuts out the DC component of the detected signal. The high-pass filter 302 outputs the detected signal from which the DC component has been removed (a reception level or detection level that does not include a DC component) to an inverting amplifier 303 and a switch 304.

[0058] Here, consider a case where radio waves generated using a reference signal and amplified by an amplitude fluctuation ATT setting value are emitted from antenna 15, and the radio waves are routed around to antenna 11. In this case, since the reference signal is a signal with a predetermined period, the radio waves received by antenna 11 contain AC components and pass through high-pass filter 302.

[0059] The amplitude fluctuation and synchronous detection unit 19 generates a synchronous detection signal by switching between the detection signal and a signal obtained by inverting the detection signal based on the reference signal and outputting the signal. The amplitude fluctuation and synchronous detection unit 19 realizes this switching using a switch 304.

[0060] Switch 304 outputs the detected signal or the inverted detected signal to low pass filter (LPF) 305. Switch 304 switches internally in accordance with the reference signal (in accordance with the timing of the reference signal), and outputs the detected signal or the inverted detected signal to low pass filter 305.

[0061] The low-pass filter 305 outputs the smoothed synchronous detection output to the control unit 18. The low-pass filter 305 smooths the synchronous detection output from the switch 304 to shape it into a continuous waveform.

[0062] Next, the configuration of the control unit 18 will be described with reference to Fig. 6. Fig. 6 is a diagram showing an example of the internal configuration of the control unit 18 according to the first embodiment.

[0063] The CPU (Central Processing Unit) 401 is a device for monitoring and controlling the status of the repeater device 10. The CPU 401 performs various calculations to realize the functions of the repeater device 10.

[0064] The memory 402 stores programs executed by the CPU 401 and information, parameters, and the like required for the operation of the repeater device 10. The memory 402 may also readably record data representing various signals related to past operations of the repeater device 10. In this case, the memory 402 or a portion thereof may be a removable recording medium such as a memory card. For example, the repeater device 10 may be provided with an interface (not shown) for external input / output, and the control unit 18 may output data stored in the memory 402 to the outside.

[0065] The clock circuit 403 generates clocks and timing signals required by the CPU 401 .

[0066] The control unit 18 (CPU 401) can adjust the gain of each of the amplifier unit 13 and the amplifier unit 16 by changing the settings of the attenuator 202a included in the amplifier unit 13 and the attenuator 202b included in the amplifier unit 16.

[0067] Furthermore, the CPU 401 can cause slight amplitude fluctuations in the downstream signal output from the amplifier 13 by outputting an amplifier control signal to the amplifier 13 via the amplitude fluctuation and synchronous detection unit 19 described above.

[0068] The control unit 18 (CPU 401) outputs a first amplifier control signal including an ATT setting value to be set in the attenuator 202a of the amplifier 13 to the amplitude variation and synchronous detection unit 19. The amplitude variation and synchronous detection unit 19 generates an amplitude variation ATT setting value, the setting value to be set in the attenuator 202a that changes periodically, based on the ATT setting value and a reference signal whose amplitude changes periodically. The amplitude variation and synchronous detection unit 19 outputs a second amplifier control signal including the generated amplitude variation ATT setting value to the amplifier 13.

[0069] The CPU 401 generates a reference signal for generating the amplitude fluctuation based on a timing signal generated by the clock circuit 403. The reference signal is a signal whose amplitude changes periodically. The CPU 401 outputs the generated reference signal to the amplitude fluctuation and synchronous detection unit 19.

[0070] [Base station, mobile station] Detailed explanations regarding the configurations and operations of the base station 30 and the mobile station 40 will be omitted, as these devices are obvious to those skilled in the art and are not directly related to the disclosure of this application.

[0071] [Explanation of operation] First, the operation of the amplitude fluctuation and synchronous detection unit 19 will be described with reference to FIG.

[0072] The amplitude fluctuation and synchronous detection unit 19 receives the reference signal 501 generated by the control unit 18. The reference signal 501 is a signal that causes a slight amplitude fluctuation in the radio wave transmitted from the antenna 15 and performs synchronous detection synchronized with the fluctuation.

[0073] The amplitude fluctuation and synchronous detection unit 19 generates an ATT setting value for causing slight amplitude fluctuations in the downlink signal based on the reference signal 501. The amplitude fluctuation and synchronous detection unit 19 adds the reference signal (a signal for causing slight amplitude fluctuations in the downlink radio wave) to the ATT setting value supplied to the downlink signal amplifier 13 to generate an amplitude fluctuation ATT setting value. The amplitude fluctuation and synchronous detection unit 19 outputs an amplifier control signal including the generated amplitude fluctuation ATT setting value to the amplifier 13.

[0074] The amplitude fluctuation ATT setting value causes the gain of the amplifier 13 to undergo amplitude fluctuation 502. That is, the antenna 11 outputs a downstream radio wave with a slight amplitude fluctuation.

[0075] The amplitude fluctuation and synchronous detection unit 19 receives the detection output (detection signal 503) from the detector 17. The detector 17 detects the radio waves received from the antenna 11, and outputs the detection signal whose reception level changes to the control unit 18 and the amplitude fluctuation and synchronous detection unit 19.

[0076] Here, if the radio wave radiated from antenna 15 leaks into antenna 11, an AC component synchronized with the reference signal that is the basis for the slight amplitude fluctuation appears, as shown in detection signal 503 in Fig. 7. On the other hand, if the radio wave radiated from antenna 15 does not leak into antenna 11, no AC component such as that shown in detection signal 503 in Fig. 7 appears.

[0077] The amplitude fluctuation and synchronous detection unit 19 removes the DC component from the detection output from the detector 17 by passing it through a high-pass filter 302. As a result, an HPF output 504 shown in FIG.

[0078] Furthermore, amplitude fluctuation and synchronous detection unit 19 inverts the detection signal (HPF output 504 from which the DC component has been cut) using inverting amplifier 303 to generate inverted detection signal 505. Inverted detection signal 505 is input to switch 304.

[0079] The amplitude fluctuation and synchronous detection unit 19 uses the switch 304 to switch between the HPF output 504 and the inverted detection signal 505. The switch 304 performs this switching based on a reference signal. Specifically, the switch 304 outputs the upper input (HPF output 504) when the reference signal 501 is "H," and outputs the lower input (inverted detection signal 505) when the reference signal 501 is "L."

[0080] The amplitude fluctuation and synchronous detection unit 19 inputs the output of the switch 304 to a low-pass filter 305 for smoothing. The smoothed detection output is output from the amplitude fluctuation and synchronous detection unit 19 as a synchronous detection signal (synchronous detection output) 506.

[0081] If the radio wave sent from the antenna 15 is leaking into the antenna 11, the control unit 18 can observe (monitor) the amount of leakage based on the synchronous detection signal output by the amplitude fluctuation and synchronous detection unit 19.

[0082] Specifically, as shown in Fig. 7, if radio waves transmitted from antenna 15 are leaking into antenna 11, the reception level of the detection signal obtained while reference signal 501 is "H" increases. On the other hand, if radio waves transmitted from antenna 15 are not leaking into antenna 11, the reception level of the detection signal does not increase even when reference signal 501 is "H". As a result, if radio waves transmitted from antenna 15 are leaking into antenna 11, the signal level of synchronous detection signal 506 increases. On the other hand, if radio waves transmitted from antenna 15 are not leaking into antenna 11, the signal level of synchronous detection signal 506 does not increase. Control unit 18 detects radio wave leakage from changes in synchronous detection signal 506 that occur depending on whether or not such radio wave leakage is occurring.

[0083] Next, a description will be given of the overall operation of the repeater device 10. Fig. 8 is a flowchart showing an example of the operation of the repeater device 10 according to the first embodiment.

[0084] After the power is turned on, the repeater device 10 performs initial settings required for the device's operation (step S01). Specifically, the control unit 18 reads out various setting values ​​from the initial setting unit 20.

[0085] For example, the control unit 18 performs settings related to the reference signal required for the amplitude fluctuation and the operation of the synchronous detection unit 19 (for example, the amplitude and period of the signal). Alternatively, the control unit 18 reads out a threshold value for determining whether or not there is leakage of radio waves from the antenna 15 to the antenna 11 (a threshold value for determining leakage of the radio waves from the synchronous detection output) from the initial setting unit 20. In the following description, the threshold value for determining leakage of radio waves is referred to as a "leakage determination threshold value."

[0086] Alternatively, the control unit 18 reads out a threshold value required for determining whether the amplifier units 13 and 16 are active or inactive (on or off) from the initial setting unit 20. In the following description, the threshold value used for determining whether the amplifier units 13 and 16 are active or inactive is referred to as an "activation threshold." Alternatively, the control unit 18 reads out the initial setting gain values ​​(ATT initial setting values) of the amplifier units 13 and 16, the maximum settable gain value, and the like from the initial setting unit 20.

[0087] The detector 17 detects the downstream radio wave (downstream signal) received by the antenna 11 from the base station 30, making it possible to measure the reception level of the downstream radio wave (step S02).

[0088] The control unit 18 performs threshold processing on the detection output (reception level) detected in step S02 (step S03). Specifically, the control unit 18 determines whether the detected reception level is equal to or greater than the activation threshold of the amplifier unit 13, etc.

[0089] If the reception level is equal to or higher than the activation threshold (step S03, Yes branch), the control unit 18 determines that a downstream radio wave has been received from the base station 30, and activates the amplifiers 13 and 16 (step S04).

[0090] On the other hand, if the reception level is lower than the activation threshold (step S03, No branch), the control unit 18 deactivates the amplifiers 13 and 16 (step S05). After that, the control unit 18 returns to the determination process of step S03.

[0091] The control unit 18 performs threshold processing on the amplitude fluctuation and the synchronous detection output output by the synchronous detection unit 19 (step S06). Specifically, it is determined whether the level (magnitude) of the synchronous detection signal is equal to or greater than the loop interference determination threshold.

[0092] If the level of the synchronous detection output is equal to or greater than the loop interference determination threshold (step S06, Yes branch), the control unit 18 determines that radio waves from the antenna 15 are looping into the antenna 11. In this case, the control unit 18 reduces the gains of the amplifiers 13 and 16 (increases the ATT setting value; step S07).

[0093] On the other hand, if the level of the synchronous detection output is smaller than the loop interference determination threshold (step S06, No branch), the control unit 18 determines that the radio waves from the antenna 15 are not looping to the antenna 11. In this case, the control unit 18 increases the gains of the amplifiers 13 and 16 (decreases the ATT setting value; step S08).

[0094] The control unit 18 waits for a predetermined period of time (step S09). After a predetermined appropriate waiting time has elapsed, the control unit 18 returns to step S02 and repeats the operations from step S02 to S09.

[0095] In this way, when it is determined based on the synchronous detection signal that the radio waves radiated from the antenna 15 have leaked into the antenna 11, the control unit 18 decreases the gain of the amplifier 13 (increases the attenuation amount of the attenuator 202a). On the other hand, when it is determined based on the synchronous detection signal that the radio waves radiated from the antenna 15 have not leaked into the antenna 11, the control unit 18 increases the gain of the amplifier 13 (decreases the attenuation amount of the attenuator 202a).

[0096] The control unit 18 repeats this process until radio wave leakage no longer occurs. By repeating this process, the control unit 18 can set the maximum gain at which radio wave leakage does not occur in the amplifier units 13 and 16. That is, the control unit 18 sets the upper limit gain setting value (ATT setting value) at which radio waves radiated from the antenna 15 do not leak into the antenna 11 in the attenuator 202a.

[0097] Note that, with regard to gain setting, control unit 18 starts with the initial gain setting value in step S01 during initial setting. After that, in the second and subsequent processing, control unit 18 starts processing from the current setting value and sequentially increases or decreases the gain. Control unit 18 searches for setting values ​​that exceed the loop threshold and setting values ​​that do not, depending on whether the gain is increased or decreased, to determine the upper limit gain setting value that does not exceed the loop detection threshold. Alternatively, when control unit 18 determines that radio wave loop will not occur even if the maximum gain value is set, it can set the maximum gain value in amplifier unit 13 and amplifier unit 16.

[0098] Alternatively, the control unit 18 may start the process from the maximum gain value and continue the process shown in Fig. 8 until the level of the synchronous detection output falls below the loop interference determination threshold. The control unit 18 may start the process with any set value as long as it can determine the upper limit gain set value that does not exceed the loop interference determination threshold.

[0099] Furthermore, for stable operation, the control unit 18 may set a gain for the amplifier units 13 and 16 that is obtained by subtracting a certain margin from the gain setting value determined by the above method.

[0100] 8, the repeater device 10 appropriately monitors the amount of radio waves from the antenna 15 that are routed back to the antenna 11, and adjusts the gains of the amplifiers 13 and 16. This adjustment provides the repeater device 10 that can quickly set the gain in response to environmental changes.

[0101] In the above embodiment, it has been described that the amplifier 16 for the uplink radio wave also operates in conjunction with the amplifier 13. However, by providing a detector or the like on the antenna 15 side for the uplink signal, a sleep function or the like that stops the amplification of the uplink when there is no uplink signal may be implemented in the repeater device 10. By using this sleep function, the repeater device 10 may control the amplifier 16 so that the gain is set to the same as that for the downlink when there is an uplink radio wave.

[0102] Furthermore, in the above embodiment, the explanation is given on the premise that the frequencies of the uplink radio waves and the downlink radio waves are different and can be distinguished, and that the necessary band can be detected by the detector 17. However, it goes without saying that it is also possible to extract and detect the necessary frequency using a filter or the like as needed.

[0103] In the above embodiment, the attenuator 202a built in the amplifier 13 is used to generate amplitude fluctuations in the downstream radio waves. However, the generation of the amplitude fluctuations may be achieved by other means. For example, the repeater device 10 may generate amplitude fluctuations using an amplitude modulator. However, as described above, the method of generating amplitude fluctuations using the attenuator 202a has many advantages in terms of circuit size, simplicity, etc., and is therefore preferable.

[0104] As described above, the repeater device 10 according to the first embodiment determines whether or not loop interference occurs in the radio waves emitted from the antenna 15 by synchronously detecting the reception level from the antenna 11. By determining whether or not loop interference occurs, the repeater device 10 can optimize the gain of the amplifier unit 16 to a transmission gain that does not cause loop interference. As a result, gain adjustment is completed quickly in response to changes in the installation environment of the repeater device 10. Furthermore, the repeater device 10 generates amplitude fluctuations using a simple configuration without using an amplitude modulator or the like. In other words, the repeater device 10 can be realized by adding an amplitude fluctuation and synchronous detection unit 19 to an existing configuration.

[0105] The functions of the repeater device 10 are realized, for example, by the CPU 401 executing a program stored in the memory 402. The program can be recorded on a computer-readable storage medium. The storage medium can be a non-transitory medium such as a semiconductor memory, a hard disk, a magnetic recording medium, or an optical recording medium. That is, the present invention can also be embodied as a computer program product. The program can be downloaded via a network or updated using a storage medium storing the program. Furthermore, the processing module can be realized by a semiconductor chip.

[0106] The repeater device 10 is equipped with a computer, and the functions of the repeater device 10 can be realized by causing the computer to execute a program. The repeater device 10 also executes a control method for the repeater device 10 by the program.

[0107] [Variations] The configuration, operation, etc. of the repeater device 10 described in the above embodiment are merely examples, and are not intended to limit the configuration, etc.

[0108] For example, in the above embodiment, the attenuator for setting the gain and the attenuator for realizing minute amplitude fluctuations are described as being the same in the amplifier 13. However, the amplifier 13 may include an attenuator for setting the gain of the amplifier 13 and an attenuator for providing minute amplitude fluctuations.

[0109] In the above embodiment, the amplitude fluctuation and "synchronous detection function" of the synchronous detection unit 19 are described as being implemented by hardware. However, synchronous detection may be implemented by performing filtering or the like through signal processing (arithmetic processing by software) on the output signal (detection output) of the detector 17. In other words, post-detection arithmetic processing may be implemented by software, without performing amplitude modulation in an analog circuit or signal extraction using a square-law detection circuit.

[0110] Furthermore, multiple repeater devices 10 may be connected in series in multiple stages. In this case, when a minute amplitude fluctuation with the same period is applied to each repeater device 10, it is impossible to distinguish whether the fluctuation is from the second antenna output of the repeater device itself or from the second antenna output of another repeater device 10 in the previous stage (closer to the base station). In such a case, the repeater device 10 performs synchronous detection at a predetermined amplitude fluctuation period before amplifying its own signal. If a detected output is obtained, the repeater device 10 changes the amplitude fluctuation period (for example, to half the period) and then activates its own amplifier. As a result, each repeater device 10 can distinguish between radio waves from the previous repeater device 10 and the radio waves from the second antenna, and can detect the amount of leakage from its own device's second antenna using the synchronous detection signal with the changed period.

[0111] In the flow charts (flowcharts, sequence diagrams) used in the above explanation, multiple steps (processes) are described in order, but the execution order of the steps executed in the embodiments is not limited to the order described. In the embodiments, the order of the illustrated steps can be changed to the extent that the content is not affected, such as by executing each process in parallel.

[0112] The above-described embodiments have been described in detail to facilitate understanding of the present disclosure, and it is not intended that all of the above-described configurations are required. Furthermore, when multiple embodiments are described, each embodiment may be used alone or in combination. For example, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of one embodiment with another configuration.

[0113] From the above explanation, it is clear that the present invention has industrial applicability, and the present invention is suitably applicable to a repeater device that relays radio waves.

[0114] Some or all of the above embodiments can be described as, but are not limited to, the following supplementary notes. [Appendix 1] an amplifier unit that amplifies a radio signal received by a first antenna with an amplifier and adjusts the gain with an attenuator; an amplitude fluctuation and synchronous detection unit that uses a set value for the attenuator to cause a periodic amplitude fluctuation in a radio signal transmitted from a second antenna that transmits the gain-adjusted radio signal, and that generates a synchronous detection signal for detecting whether or not radio waves radiated from the second antenna are leaking into the first antenna; a control unit that reduces a gain of the attenuator when it is determined based on the synchronous detection signal that the radio wave radiated from the second antenna has entered the first antenna; A repeater device comprising: [Appendix 2] The repeater device described in Appendix 1, wherein the control unit increases the gain of the attenuator when it is determined based on the synchronous detection signal that the radio waves radiated from the second antenna are not circling around to the first antenna. [Appendix 3] The repeater device according to claim 1 or 2, wherein the control unit sets the upper limit gain setting value in the attenuator so that radio waves radiated from the second antenna do not leak into the first antenna. [Appendix 4] the control unit outputs a first amplification unit control signal including an ATT (Attenuator) setting value to be set in the attenuator to the amplitude fluctuation and synchronous detection unit; A repeater device described in any one of Appendixes 1 to 3, wherein the amplitude fluctuation and synchronous detection unit generates an amplitude fluctuation ATT setting value whose setting value changes periodically based on the ATT setting value and a reference signal whose amplitude changes periodically, and outputs a second amplifier control signal including the generated amplitude fluctuation ATT setting value to the amplifier unit. [Appendix 5] 5. The repeater device according to claim 4, wherein the control unit generates the reference signal and outputs the generated reference signal to the amplitude fluctuation and synchronous detection unit. [Appendix 6] 6. The repeater device according to claim 5, wherein the amplitude fluctuation and synchronous detection unit generates the amplitude fluctuation ATT setting value by adding the reference signal to the ATT setting value. [Appendix 7] 7. The repeater device according to any one of claims 1 to 6, further comprising a detector that detects the reception level of the radio signal received by the first antenna. [Appendix 8] 7. The repeater device according to any one of claims 4 to 6, wherein the amplitude fluctuation and synchronous detection unit generates the synchronous detection signal based on the detection signal output by the detector and the reference signal. [Appendix 9] The repeater device described in Appendix 8, wherein the amplitude fluctuation and synchronous detection unit generates the synchronous detection signal by switching between and outputting the detection signal and a signal obtained by inverting the detection signal based on the reference signal. [Appendix 10] 10. The repeater device according to any one of claims 1 to 9, further comprising an output unit that outputs an operating status of the repeater device itself. [Appendix 11] 11. The repeater device according to claim 9, wherein the amplitude fluctuation and synchronous detection unit applies a high-pass filter to the detected signal. [Appendix 12] 12. The repeater device according to claim 1, wherein the radio signal is a downlink radio signal traveling from a base station to a mobile station. [Appendix 13] A repeater device having an amplifier that amplifies a radio signal received by a first antenna and adjusts the gain of a radio signal transmitted from a second antenna by an attenuator, using a setting value for the attenuator to cause a periodic amplitude variation in the radio signal transmitted from the second antenna; generating a synchronous detection signal for detecting whether or not the radio wave radiated from the second antenna has entered the first antenna; A repeater control method for reducing the gain of the attenuator when it is determined based on the synchronous detection signal that radio waves radiated from the second antenna are circling around the first antenna.

[0115] The disclosures of the above-cited prior art documents are incorporated herein by reference. Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Those skilled in the art will understand that these embodiments are merely illustrative and that various modifications are possible without departing from the scope and spirit of the present invention. In other words, the present invention naturally includes various modifications and alterations that may be made by those skilled in the art in accordance with the entire disclosure, including the claims, and the technical concepts thereof. [Explanation of symbols]

[0116] 10 Repeater equipment 11 Antenna 12 Duplexer 13 Amplification section 14 Duplexer 15 Antenna 16 Amplification section 17 Detector 18 Control Unit 19 Amplitude fluctuation and synchronous detection section 20 Initial setting section 21 Display section 30 base station 40 Mobile Station 100 Repeater Device 101 Amplification section 102 Amplitude fluctuation and synchronous detection section 103 Control Unit 201a Amplifier 201b Amplifier 202a Attenuator 202b Attenuator 203a Control circuit 203b Control circuit 301 Adder 302 High Pass Filter 303 Inverting Amplifier 304 Switch 305 Low Pass Filter 401 CPU 402 memory 403 Clock Circuit 501 Reference signal 502 Amplitude Fluctuation 503 detection signal 504 HPF output 505 Inverted detection signal 506 Synchronous detection signal

Claims

1. an amplifier unit that amplifies a radio signal received by a first antenna with an amplifier and adjusts the gain with an attenuator; a detector that detects a reception level of a radio signal received by the first antenna and outputs a first signal including the reception level; a control unit that outputs a first amplifier control signal including an ATT (Attenuator) setting value to be set in the attenuator, and a reference signal whose amplitude changes periodically; a signal generator that uses the ATT setting value included in the first amplifier control signal and the reference signal to generate a second amplifier control signal that causes periodic amplitude fluctuations in a radio signal transmitted from a second antenna that transmits the gain-adjusted radio signal, and that uses the first signal and the reference signal to generate a second signal that is used to detect whether or not a radio wave radiated from the second antenna is leaking into the first antenna, and whose signal level changes depending on the reception level; Equipped with the control unit, when it is determined based on the signal level of the second signal that the radio wave radiated from the second antenna is circulating into the first antenna, reduces the gain of the attenuator; The signal generation unit generating an amplitude fluctuation ATT setting value in which the ATT setting value periodically changes based on the ATT setting value and the reference signal, generating the second amplification unit control signal including the generated amplitude fluctuation ATT setting value, and outputting the generated second amplification unit control signal to the amplification unit; A repeater device that generates the second signal by outputting the first signal when the amplitude of the reference signal is at a high level, and outputting a signal that is an inverted version of the first signal when the amplitude of the reference signal is at a low level.

2. The repeater device according to claim 1, wherein the control unit increases the gain of the attenuator when it is determined based on the second signal that the radio waves radiated from the second antenna are not circumventing the first antenna.

3. The repeater device of claim 1, wherein the control unit, when it is determined based on the second signal that the radio waves radiated from the second antenna are circulating into the first antenna, repeats the process of lowering the gain of the attenuator until it is determined that the radio waves radiated from the second antenna are not circulating into the first antenna, thereby setting the attenuator to an upper limit gain setting value at which the radio waves radiated from the second antenna do not circulate into the first antenna.

4. The repeater device according to claim 3 , wherein the signal generating unit generates the amplitude fluctuation ATT setting value by adding the reference signal to the ATT setting value.

5. The repeater device according to claim 1 , further comprising an output unit that outputs an operating status of the repeater device itself.

6. an amplifier unit that amplifies a radio signal received by a first antenna with an amplifier and adjusts the gain of a radio signal transmitted from a second antenna with an attenuator; a detector that detects a reception level of a radio signal received by the first antenna and outputs a first signal including the reception level, outputting a first amplifier control signal including an ATT (Attenuator) setting value to be set in the attenuator and a reference signal whose amplitude changes periodically; generating a second amplifier control signal that causes a periodic amplitude fluctuation in a radio signal transmitted from the second antenna that transmits the gain-adjusted radio signal, using the ATT setting value included in the first amplifier control signal and the reference signal; generating a second signal, using the first signal and the reference signal, for detecting whether or not the radio wave radiated from the second antenna has entered the first antenna, the second signal having a signal level that changes in accordance with the reception level; When it is determined based on the signal level of the second signal that the radio wave radiated from the second antenna is circulating into the first antenna, the gain of the attenuator is reduced; generating an amplitude fluctuation ATT setting value that periodically changes the ATT setting value based on the ATT setting value and the reference signal; generating the second amplifier control signal including the generated amplitude fluctuation ATT setting value; outputting the generated second amplifier control signal to the amplifier; A control method for a repeater device, which generates the second signal by outputting the first signal when the amplitude of the reference signal is at a high level, and outputting a signal that is an inverted version of the first signal when the amplitude of the reference signal is at a low level.

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