JP2011015359A - Repeater system and control method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect abnormal oscillation caused by loop interference without deteriorating communication quality.SOLUTION: A repeater system for repeating a radio frequency (RF) signal to be transmitted and received between a base station and a mobile station, includes: an amplifier for amplifying the received RF signal, a detector for measuring the input level of the received RF signal; and a memory for storing a preset over-input threshold. Only when the input level measured by the detector is equal to or higher than the over-input threshold during operation of the amplifier, whether the oscillation is abnormal or not is determined.

Description

  The present invention relates to a repeater device used in a mobile communication system, and more particularly to a repeater device that detects abnormal oscillation and a control method thereof.

  In recent years, mobile communication systems using cellular phones and the like have become widespread. In a mobile communication system, a repeater device that amplifies and transmits a radio frequency signal is used so that it can be used in the back of buildings or underground where radio waves are difficult to reach. The repeater device amplifies the downlink radio frequency signal transmitted from the base station and transmits the amplified signal to the mobile station, amplifies the uplink radio frequency signal transmitted from the mobile station, and transmits the amplified signal to the base station.

  However, if the gain of the amplifier of the repeater device remains constant, even if a strong signal is input, the signal is amplified and exceeds the processing capability of the receiver. It has a function of adjusting the gain according to.

  In general, since a repeater device amplifies a received signal and transmits it at the same frequency, the transmitted signal may wrap around the receiving antenna and cause abnormal oscillation. Further, due to restrictions on installation of the apparatus, abnormal oscillation also occurs when the gain of the amplifier is higher than the isolation between the transmitting and receiving antennas. Further, even when the repeater device is not oscillating abnormally, abnormal oscillation may occur due to a change in the gain of the repeater device in operation. If abnormal oscillation occurs, the amplifier cannot operate normally, which may cause a failure of the apparatus, which affects the communication system.

  As a technology related to a repeater device that detects such abnormal oscillation, the transmission signal frequency is slightly offset from the reception signal frequency and transmitted, and the offset frequency component included in the reception signal is detected, so that the transmission antenna and the reception signal are detected. A technique for detecting an abnormal oscillation by measuring the amount of sneaking of a radio wave with an antenna is disclosed (for example, Patent Document 1). Further, a technique for detecting abnormal oscillation based on a difference in reception level between when the transmission from the repeater device is operated and when the transmission is stopped using the radio wave idle time is disclosed (for example, Patent Document 2). ).

JP 7-30473 A US2005 / 00118949A1

  However, in the technique described in Patent Document 1, transmission is performed by offsetting the frequency of the transmission signal from the frequency of the reception signal in order to detect abnormal oscillation, which is different from the original transmission signal and the signal is disturbed. As a result, the communication quality may be deteriorated.

  In addition, in the technique described in Patent Document 2, since the transmission from the repeater device is stopped every time an abnormal oscillation is detected, a state in which communication is impossible occurs frequently, and the influence on the communication system is great. There is an inconvenience.

  In addition, when there is a mobile station that emits a signal with high signal strength near the repeater device during abnormal oscillation detection operation, the input level of the received signal exceeds the input limit of the detector, and abnormal oscillation detection operation is performed. There is a problem that sometimes abnormal oscillation cannot be detected.

  The present invention has been made in view of the above-described problems, and it is an object of the present invention to provide a repeater device that solves or reduces these problems and a control method therefor.

  The present invention relates to a repeater device that relays a radio frequency signal transmitted and received between a base station and a mobile station, an amplifier that amplifies the received radio frequency signal, and a detector that measures an input level of the received radio frequency signal And a memory for storing a preset over-input threshold value, and the amplifier only when the input level measured by the detector during operation of the amplifier is greater than or equal to the over-input threshold value And whether or not the oscillation is abnormal is determined.

  In the repeater device according to the present invention, the memory further stores a preset abnormal oscillation detection threshold value, and whether or not the abnormal oscillation has occurred is determined by the detector during operation of the amplifier. When the value obtained by subtracting the input level measured by the detector while the amplifier is stopped is equal to or greater than the abnormal oscillation detection threshold value, the abnormal oscillation is determined. It is characterized by.

  In the repeater apparatus according to the present invention, the memory further stores a preset number of retries, and the detection is performed while the amplifier is stopped from the input level measured by the detector during the operation of the amplifier. When the value obtained by subtracting the input level measured by the measuring device is less than the abnormal oscillation detection threshold value, the amplifier is operated to determine whether or not the excessive input and the abnormal oscillation occur until the number of retries. It is characterized by repetition.

  In the repeater device according to the present invention, the determination as to whether or not there is excessive input and abnormal oscillation is performed every time a predetermined period elapses.

  In the repeater device according to the present invention, the determination as to whether or not there is excessive input and abnormal oscillation is performed when a gain of the repeater device is changed.

  The present invention detects over-input while the amplifier is performing an amplification operation, and stops the amplification of the amplifier and detects abnormal oscillation only when it is determined that the input is over-input. When it is expected to operate normally, the amplification operation of the amplifier is not stopped by the abnormal oscillation detection operation, so that deterioration of communication quality due to frequent stop can be avoided. Moreover, since the present invention detects abnormal oscillation by measuring the input level of the received radio frequency signal, there is no need to offset the frequency of the signal, and this does not cause a reduction in communication quality. .

  In addition, if abnormal oscillation cannot be detected even if the input level of the received radio frequency signal is excessive, if detection of abnormal oscillation is retried for a predetermined number of times, for example, a strong wireless near the repeater device Abnormal oscillation detection omissions can be reduced in the case of excessive input temporarily due to the presence of a mobile station that emits a frequency signal.

  In addition, if the determination as to whether there is excessive input or abnormal oscillation is made periodically, abnormal oscillation can be detected without delay, and the influence on communication can be minimized.

  Furthermore, if abnormal oscillation is detected when the gain of the repeater device is changed, it is possible to immediately cope with abnormal oscillation that may occur due to the gain change, which is given to communication between the base station and the mobile station in this case. The impact can be minimized.

FIG. 1 shows a schematic configuration of a repeater apparatus according to an embodiment of the present invention and an entire mobile communication system including the repeater apparatus. FIG. 2 shows a configuration of the control unit 16 included in the repeater device according to the embodiment of the present invention. FIG. 3 shows an image of an abnormal oscillation detection parameter stored in the memory 21 of the repeater device according to the embodiment of the present invention. FIG. 4 shows a flowchart of an over-input and abnormal oscillation detection procedure by the repeater device of FIG. FIG. 5 shows a flowchart of the procedure for changing the abnormal oscillation detection parameter stored in the memory 21 of the repeater device. FIG. 6 shows a flowchart for explaining the operation when the gain is changed by the repeater apparatus 1.

  Hereinafter, embodiments of an electronic device according to the present invention will be described with reference to the drawings.

  FIG. 1 shows a schematic configuration of a repeater apparatus according to an embodiment of the present invention and an entire mobile communication system including the repeater apparatus. The mobile communication system includes a repeater device 1, a base station 2, and a mobile station 3. The mobile station 3 is a mobile phone or other communication terminal. For example, the mobile station 3 may be a portable communication terminal such as a PDA (Personal Digital Assistance) or a computer device such as a personal computer. The configurations of the base station 2 and the mobile station 3 shown in FIG. 1 are well known to those skilled in the art, and details thereof are omitted.

  The repeater apparatus 1 includes first and second duplexers 10 and 13, first and second detectors 11 and 14, first and second amplifiers 12 and 15, and a control unit 16. The repeater apparatus 1 amplifies the radio frequency signal received from the base station 2 and transmits it to the mobile station 3, amplifies the radio frequency signal received from the mobile station 3, and transmits it to the base station 2. Moreover, the repeater apparatus 1 changes and sets the gain of an amplifier regularly so that transmission power may become an appropriate value.

  The first duplexer 10 inputs / outputs and distributes the radio frequency signal received from the base station 2 and the radio frequency signal transmitted to the base station 2, and the second duplexer 13 receives the radio frequency signal received from the mobile station 3. Input / output and distribution of radio frequency signals to be transmitted to the mobile station 3. The first detector 11 measures the input level of the radio frequency signal received from the base station 2, and the second detector 14 measures the input level of the radio frequency signal received from the mobile station 3. The first amplifier 12 amplifies the radio frequency signal received from the base station 2, and the second amplifier 15 amplifies the radio frequency signal received from the mobile station 3. The amplifiers 12 and 15 are configured so that a threshold value that does not perform an amplification operation is set in advance for a signal that can be normally communicated, and the amplification operation is appropriately performed. However, the present invention is not limited to this.

  FIG. 2 shows the configuration of the control unit 16. The control unit 16 includes a CPU 20, a memory 21, and a USB port 22 for communicating with the PC 30, and controls the detectors 11 and 14 and the amplifiers 12 and 15. The memory 21 stores parameters used for abnormal oscillation detection processing. Further, the control unit 16 changes and sets the gain of the amplifier so that the transmission power becomes an appropriate value. This gain change and setting is a method well known to those skilled in the art, and may be performed by an AGC (Automatic Gain Control) function of the control unit 16 or the like, but is not limited thereto.

  FIG. 3 shows an image of the abnormal oscillation detection parameter stored in the memory 21. The abnormal oscillation detection parameter includes a monitoring time 211, an over-input threshold 212, a retry count 213, and an abnormal oscillation detection threshold 214. Specifically, the monitoring time 211 is a monitoring cycle for executing a monitoring operation for determining whether or not there is an excessive input and abnormal oscillation. The over-input threshold 212 is a threshold for determining whether or not the input level of the received radio frequency signal is over-input. The number of retries 213 is the number of times to retry the operation of detecting excessive input and abnormal oscillation when abnormal oscillation is not detected even though the received radio frequency signal is excessive input. The abnormal oscillation detection threshold value 214 is an input level (first measured value) of the received radio frequency signal measured when the amplifier is operated and an input of the received radio frequency signal when the amplifier is stopped. This is a threshold value for determining whether or not there is abnormal oscillation from the difference (comparison value) of the level (second measured value). These oscillation detection parameters are set to values that allow the repeater device to operate normally when the repeater device is installed in the mobile communication system. You may make it change suitably according to an operating condition. These oscillation detection parameters may be changed from the PC 30 via the USB 22, the CPU 20, or by remote control.

  Next, with reference to FIG. 4, an operation in which the repeater apparatus in FIG. 1 detects an abnormal oscillation by monitoring an uplink radio frequency signal to the base station 2 will be described.

  FIG. 4 shows a flowchart of an over-input and abnormal oscillation detection procedure by the repeater device of FIG. In FIG. 4, the control unit 16 first determines whether or not the amplifier 15 is performing an amplification operation (step 100). If the amplifier 15 is not performing an amplification operation (step 100: NO), abnormal oscillation does not occur, and the detection of abnormal oscillation is terminated.

  When the amplifier 15 is performing an amplification operation (step 100: YES), the input level (first measured value) of the uplink radio frequency signal received from the mobile station 3 is measured by the detector 14 (step 101). Then, it is determined whether or not the first measurement value exceeds the over-input threshold value stored in the memory 21 (step 102). If the first measurement value does not exceed the over-input threshold value (step 102: NO), the abnormal oscillation detection is terminated because no abnormal oscillation has occurred.

  If the first measurement value exceeds the over-input threshold (step 102: YES), it is determined that the input is over-input. In this case, the control unit 16 stops the amplification operation of the amplifier 15 (step 103), and again measures the input level (second measured value) of the uplink radio frequency signal received from the mobile station 3 by the detector 14. (Step 104). Subsequently, a value (comparison value) obtained by subtracting the second measurement value from the first measurement value stored in the memory 21 is calculated, and this comparison value is calculated from the abnormal oscillation detection threshold value stored in the memory 21 in advance. Is also larger (step 105). If the comparison value is larger than the abnormal oscillation detection threshold (step 105: YES), it is determined that the oscillation is abnormal (step 106). If it is determined that the oscillation is abnormal, the control unit keeps the amplification operation of the amplifier 15 stopped. After the abnormal oscillation is detected, an alarm sound may be emitted or the lamp may be turned on in a state where the amplification operation is stopped to notify the surroundings of the abnormal oscillation.

  If the comparison value is smaller than the abnormal oscillation detection threshold (step 105: NO), the amplification operation of the amplifier 15 is restarted (step 107). Subsequently, the number of abnormal oscillation detection operations is counted up (step 108), and it is determined whether or not the count value is less than the number of retries previously stored in the memory 21 (step 109). If the count value is less than the number of retries (step 109: YES), the steps from step 101 are repeated.

  If the number of retries has been reached (step 109: NO), it is determined that there is no abnormal oscillation, and the abnormal oscillation detection operation is terminated. After the abnormal oscillation detection operation is completed, the abnormal oscillation detection operation is performed again after the monitoring time has elapsed, and the abnormal oscillation is periodically inspected.

  As described above, in the present invention, only when an excessive input is detected, the amplification operation of the amplifier is stopped and the presence or absence of abnormal oscillation is confirmed. Therefore, abnormal oscillation is appropriately suppressed while minimizing the influence on communication. Can be detected. In addition, when an excessive input is detected, the detection of abnormal oscillation is repeated a predetermined number of times, so that for example, there is a failure to detect abnormal oscillation when there is a terminal that temporarily emits strong radio waves near the repeater device. Can be reduced.

  Next, a method for changing the abnormal oscillation detection parameter will be described with reference to FIG. FIG. 5 is a flowchart of the procedure for changing the abnormal oscillation detection parameter stored in the memory 21 of the repeater device. In FIG. 5, first, when the administrator operates the PC 30 and requests the CPU 20 to change the oscillation detection parameter via the USB port 22, the CPU 20 detects this (step 200).

  When the oscillation detection parameter change request is received (step 200: YES), the CPU 20 changes the oscillation detection parameter stored in the memory 21 (step 201). Subsequently, the CPU 20 notifies the PC 30 of a response of completion of the oscillation detection parameter change via the USB port 22 (step 202). When the oscillation detection parameter is changed, the repeater device performs an abnormal oscillation detection operation based on the changed oscillation detection parameter.

  As described above, in the present invention, since the transmission detection parameter can be changed as appropriate, it can be set so as to efficiently detect abnormal oscillation in accordance with the operation status and installation environment of the repeater device.

  Next, another embodiment of the control method of the repeater device according to the present invention will be described with reference to FIG. The repeater device 1 is configured to detect an excessive input or abnormal oscillation when the gain is changed, and the other components are the same as those in the first embodiment described above. FIG. 6 is a flowchart for explaining the operation of detecting excessive input and abnormal oscillation when the gain of the amplifier 15 is changed by the repeater device 1.

  First, the repeater apparatus 1 determines whether or not the amplifier 15 is performing an amplification operation in determining whether or not the current gain is appropriate (step 300). When the amplifying operation is not performed (step 300: NO), the gain is not changed, and neither the excessive input nor the abnormal oscillation detecting operation is performed.

  When the amplification operation is being performed (step 300: YES), the detector 11 measures the input level of the downlink received radio frequency signal (step 301). The controller 16 calculates a gain to be set in the amplifier 12 based on the measured input level value (step 302). Subsequently, it is determined whether or not the currently set gain value is different from the calculated gain value (step 303). When the currently set gain value is the same as the calculated gain value (step 303: NO), the gain is not changed, and the over-input and abnormal oscillation detection operations are not performed.

  When the currently set gain value is different from the calculated gain value (step 303: YES), the gain of the amplifier 12 is reset (step 304), and the above-described over-input and abnormal oscillation detection operation is started.

  Specifically, the input level (first measured value) of the uplink radio frequency signal received from the mobile station 3 is measured by the detector 14 (step 305), and the first measured value is stored in the memory 21. It is determined whether or not the over-input threshold is exceeded (step 306). If the first measurement value does not exceed the over-input threshold (step 306: NO), the over-input and abnormal oscillation detection operation is terminated.

  When the first measured value exceeds the overinput threshold (step 306: YES), it is determined that the input is overinput. In this case, the control unit 16 stops the amplification operation of the amplifier 15 (step 307), and again measures the input level (second measured value) of the uplink radio frequency signal received from the mobile station 3 by the detector 14. (Step 308). Subsequently, a value (comparison value) obtained by subtracting the second measurement value from the first measurement value stored in the memory 21 is calculated, and the comparison value is larger than the abnormal oscillation detection threshold value stored in the memory 21 in advance. It is determined whether it is larger (step 309). If the comparison value is greater than the abnormal oscillation detection threshold (step 309: YES), it is determined that there is abnormal oscillation (step 310). If it is determined that the oscillation is abnormal, the amplification operation of the amplifier 15 is stopped. After the abnormal oscillation is detected, an alarm sound may be emitted or the lamp may be turned on in a state where the amplification operation is stopped to notify the surroundings of the abnormal oscillation.

  If the comparison value is smaller than the abnormal oscillation detection threshold (step 309: NO), the amplification operation of the amplifier 15 is restarted (step 311). Subsequently, the number of abnormal oscillation detection operations is counted up (step 312), and it is determined whether the number of abnormal oscillation detection operations is less than the number of retries previously stored in the memory 21 (step 313). If it is less than the retry count (step 313: YES), the steps from step 305 are repeated.

  If the number of retries has been reached (step 313: NO), it is determined that there is no abnormal oscillation, the counter value is reset, and the abnormal oscillation detection operation is terminated.

  As described above, when the gain of the amplifier is changed, if the presence or absence of abnormal oscillation is confirmed, the occurrence of abnormal oscillation when the gain change is not appropriate can be detected quickly and dealt with.

  Although several examples of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and can be realized as various modifications and changes.

  For example, in the above-described embodiment, the monitoring operation in the repeater device is performed periodically or at the time of gain change. However, these are combined and added periodically, and further, an operation for detecting over-input and abnormal oscillation at the time of gain change is performed. May be performed.

  In the embodiment described above, a configuration has been described in which abnormal oscillation is detected using only uplink radio frequency signals in order to minimize the influence on the base station and reduce the influence on the mobile communication system. On the other hand, since the downlink radio frequency signal only affects some mobile stations, over-input and abnormal oscillation are not detected, but may be performed as necessary. Similarly, in the above-described embodiment, the detection operation of over-input and abnormal oscillation at the time of changing the gain of the amplifier for the downlink radio frequency signal is shown. However, the operation is performed when the gain of the amplifier for the uplink radio frequency signal is changed. May be.

  The present invention is applied to, for example, a mobile communication system and can be used for a communication business.

DESCRIPTION OF SYMBOLS 1 Repeater apparatus 2 Base station 3 Mobile station 10 1st duplexer 11 1st detector 12 1st amplifier 13 2nd duplexer 14 2nd detector 15 2nd amplifier 16 Control part 20 CPU
21 Memory 22 USB port 30 PC
211 Monitoring time 212 Over-input threshold 213 Retry count 214 Abnormal oscillation detection threshold

Claims (13)

In a repeater device that relays radio frequency signals transmitted and received between a base station and a mobile station,
An amplifier for amplifying the received radio frequency signal;
A detector for measuring an input level of the received radio frequency signal;
A memory for storing a preset over-input threshold, and the amplifier is stopped only when the input level measured by the detector during operation of the amplifier is equal to or greater than the over-input threshold. And determining whether or not there is abnormal oscillation.   2. The repeater device according to claim 1, wherein the memory further stores a preset abnormal oscillation detection threshold value, and whether or not the abnormal oscillation is detected is determined by the detector during operation of the amplifier. When the value obtained by subtracting the input level measured by the detector while the amplifier is stopped is equal to or greater than the abnormal oscillation detection threshold value, the abnormal oscillation is determined. A repeater device characterized by that.   3. The repeater apparatus according to claim 2, wherein the memory further stores a preset number of retries, and when the amplifier is stopped from the input level measured by the detector during operation of the amplifier. When the value obtained by subtracting the input level measured by the detector is less than the abnormal oscillation detection threshold, the amplifier is operated to determine whether or not the excessive input and the abnormal oscillation are detected. Repeater device characterized by repeating up to a number of times.   4. The repeater device according to claim 1, wherein the determination as to whether or not there is an excessive input and abnormal oscillation is performed every elapse of a predetermined period.   5. The repeater apparatus according to claim 1, wherein the determination as to whether or not there is an excessive input and abnormal oscillation is performed when a gain of the repeater apparatus is changed. 6.   A method of controlling a repeater device that relays a radio frequency signal transmitted and received between a base station and a mobile station, wherein the repeater device measures an input level of the received radio frequency signal, and, if necessary, An amplifier for amplifying the received radio frequency signal; and a memory for storing a preset over-input threshold; wherein the method measures the input level measured by the detector during operation of the amplifier. The abnormal oscillation detection method is characterized by determining whether or not an abnormal oscillation occurs by stopping the amplifier only when the value is equal to or greater than the over-input threshold.   7. The method according to claim 6, wherein the memory further stores a preset abnormal oscillation detection threshold value, and whether or not the abnormal oscillation is detected is determined by the detector during operation of the amplifier. This is performed by determining that the oscillation is abnormal when a value obtained by subtracting the input level measured by the detector while the amplifier is stopped is equal to or greater than the abnormal oscillation detection threshold value from the measured input level. An abnormal oscillation detection method characterized by the above.   8. The method of claim 7, wherein the memory further stores a preset number of retries, and from the input level measured by the detector during operation of the amplifier during the shutdown of the amplifier. When the value obtained by subtracting the input level measured by the detector is less than the abnormal oscillation detection threshold value, the amplifier is activated to determine whether or not the excessive input and the abnormal oscillation are present. The abnormal oscillation detection method characterized by repeating until.   9. The method according to any one of claims 6 to 8, wherein the determination as to whether or not there is an excessive input and abnormal oscillation is performed every elapse of a predetermined period.   10. The method according to any one of claims 6 to 9, wherein the determination as to whether the input is excessive or abnormal oscillation is performed when a gain of the repeater device is changed.   In a program for controlling a repeater device that relays a radio frequency signal transmitted and received between a base station and a mobile station, the repeater device amplifies the received radio frequency signal, and an input level of the received radio frequency signal And a memory for storing a preset over-input threshold, and the program is configured such that the input level measured by the detector during operation of the amplifier is the over-input. A program that causes the repeater device to execute a procedure for stopping the amplifier and determining whether or not an abnormal oscillation occurs only when a threshold value is exceeded.   12. The program according to claim 11, wherein the memory further stores a preset abnormal oscillation detection threshold value, and whether or not the abnormal oscillation is detected is determined by the detector during operation of the amplifier. This is performed by determining that the oscillation is abnormal when a value obtained by subtracting the input level measured by the detector while the amplifier is stopped is equal to or greater than the abnormal oscillation detection threshold value from the measured input level. A program characterized by that.   13. The program according to claim 12, wherein the memory further stores a preset number of retries, and the input level measured by the detector during operation of the amplifier during the stop of the amplifier. When the value obtained by subtracting the input level measured by the detector is less than the abnormal oscillation detection threshold value, the amplifier is activated to determine whether or not the excessive input and the abnormal oscillation are present. A program characterized by repeating until.

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