JP2014039138A - Signal abnormality detection device, and communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a signal abnormality detection device and communication device capable of detecting abnormality of a signal with instantaneous fluctuation in a circuit for processing the signal, with a simple configuration.SOLUTION: A signal abnormality detection device 51 comprises: a power information acquisition unit 61 for acquiring an index value of power of a signal transmitted or received by a target device at each timing; a comparison unit 62 for comparing the index value acquired by the power information acquisition unit 61 with an evaluation threshold; a plurality of accumulation units 65, 66, and 67 for accumulating the index value acquired by the power information acquisition unit 61 for a predetermined period; an assignment unit 64 for making the accumulation unit 65, 66, or 67 selected from the plurality of accumulation units 65, 66, and 67 on the basis of a comparison result by the comparison unit 62 start accumulation; and a division unit 69 and an abnormality detection unit 70 for detecting abnormality of the signal on the basis of an accumulation result by the accumulation unit 65, 66, or 67.

Description

  The present invention relates to a signal abnormality detection device and a communication device, and more particularly, to a signal abnormality detection device and a communication device that detect excessive power of a circuit in a target device.

  In order to perform high-speed communication, a broadband signal is inevitably required. Communication systems such as W-CDMA (Wide Band Code Division Multiple Access) and OFDM (Orthogonal Frequency Division Multiplex) have been developed in accordance with such requirements.

  In a wireless communication apparatus that employs these communication methods, overpower detection of an amplifier or the like may be performed. The purpose of overpower detection is, for example, to deal with legal regulations or to prevent damage due to thermal stress inside the equipment.

  Here, in a configuration for amplifying a broadband signal, the amplified signal is a signal with instantaneous fluctuation. For this reason, when operating an amplifier whose output power is defined, it is necessary to measure the average power of the amplifier. Similarly, when checking whether or not the output power from the amplifier is appropriate, it is necessary to measure not the instantaneous power but the average power.

  A wideband signal handled in the communication system as described above has a characteristic that a ratio of average power to peak power is large. For this reason, in order to perform measurement of average power, detection of excessive output, and the like, some calculation function is required.

  That is, in order to measure the power of a wideband signal, fluctuations in instantaneous power must be averaged. For example, in OFDM, it is known that the PAPR (Peak to Average Power Ratio) is close to 10 dB. For this reason, the average power cannot be determined based on whether or not the instantaneous power exceeds the specified power.

  As an example of a method for calculating such average power, for example, “Waveform Data Processing for Scientific Measurement”, CQ Publisher, Shigeo Minami, pp.86-97, April 1986 (Non-patent Document 1) ) Discloses a recursive moving average calculation algorithm using an average value of a plurality of samples in equation (5-15).

"Waveform data processing for scientific measurement", CQ Publisher, Shigeo Minami, pp.86-97, April 1986

  However, when calculating the average power using the algorithm described in Non-Patent Document 1, there is a problem that a storage area for holding instantaneous power for a plurality of samples is required and the circuit scale becomes large. .

  The present invention has been made to solve the above-described problems, and its object is to detect a signal abnormality that can be detected with a simple configuration in a circuit that processes a signal with instantaneous fluctuation. It is to provide a detection device and a communication device.

  (1) In order to solve the above problem, a signal abnormality detection device according to an aspect of the present invention acquires power information for acquiring an index value of power at each timing of a signal transmitted or received by a target device. A comparator for comparing the index value acquired by the power information acquisition unit with the evaluation threshold, and for accumulating the index value acquired by the power information acquisition unit for a predetermined time. Based on a plurality of accumulation units, a comparison result by the comparison unit, a accumulation control unit for causing the accumulation unit selected from the plurality of accumulation units to start accumulation, and a accumulation result by the accumulation unit And an abnormality detection unit for detecting an abnormality of the signal.

  As described above, when calculating the moving average or the like by using the comparison result between the index value that is the feature amount of the target signal and the evaluation threshold, and selecting the timing for starting the accumulation of the index value in each accumulation unit Therefore, it is possible to detect signal abnormality with a simple configuration having a small number of storage devices without preparing storage devices for the number of samples required.

  (2) Preferably, the accumulation control unit does not cause the other accumulation units to start the accumulation until a predetermined time elapses after the accumulation unit starts the accumulation, regardless of a comparison result by the comparison unit. .

  With such a configuration, since the next accumulation is not started until another accumulation unit has elapsed since a certain accumulation unit has started accumulation, the range in which the index value accumulation periods overlap can be reduced.

  (3) Preferably, the abnormality detection unit compares the accumulated result with an accumulated result threshold value, and detects an abnormality of the signal based on a magnitude relationship between the accumulated result and the accumulated result threshold value. The evaluation threshold value and the cumulative result threshold value are the same value.

  Thus, by setting the evaluation threshold value and the cumulative result threshold value to the same value, for example, the comparison condition of the index value and the evaluation threshold value in the comparison unit, and the average value and cumulative value of the cumulative result in the abnormality detection unit The result threshold comparison condition can be matched.

  As a result, since a signal that is not determined to be abnormal by the comparison unit is often not determined to be abnormal by the abnormality detection unit, it is possible to suppress the index value corresponding to the signal from being meaninglessly accumulated in the accumulation unit.

  In addition, since the accumulating unit does not operate while the index value is continuously received, when the signal that is determined to be abnormal by the comparing unit is received, all of the plural accumulating units are performing accumulation processing. It is possible to avoid the occurrence of a situation in which it is impossible to start a cumulative process.

  (4) Preferably, the abnormality detection unit compares the accumulated result with an accumulated result threshold value, and detects an abnormality of the signal based on a magnitude relationship between the accumulated result and the accumulated result threshold value. The accumulation control unit causes the accumulation unit to start accumulation when the comparison result by the comparison unit indicates that the index value is greater than the evaluation threshold value. Greater than the result threshold.

  As described above, since the evaluation threshold value is larger than the cumulative result threshold value, it can be expected that there is an increased possibility that a signal abnormality is detected based on the magnitude relationship between the cumulative result and the cumulative result threshold value. The probability that the accumulating unit operates when no signal abnormality is detected can be reduced.

  (5) Preferably, the abnormality detection unit compares the accumulated result with an accumulated result threshold value, and detects an abnormality of the signal based on a magnitude relationship between the accumulated result and the accumulated result threshold value. The accumulation control unit causes the accumulation unit to start accumulation when the comparison result by the comparison unit indicates that the index value is smaller than the evaluation threshold value. Less than the result threshold.

  As described above, since the evaluation threshold value is smaller than the cumulative result threshold value, it can be expected that there is an increased possibility that a signal abnormality is detected based on the magnitude relationship between the cumulative result and the cumulative result threshold value. The probability that the accumulating unit operates when no signal abnormality is detected can be reduced.

  (6) Preferably, the abnormality detection unit monitors the accumulation result by the accumulation unit before the predetermined time elapses, and detects the abnormality of the signal based on the monitoring result.

  With such a configuration, if the accumulation result satisfies the detection condition in the abnormality detection unit at a timing before the predetermined time has elapsed after the index value accumulation is started, whether or not the accumulation result satisfies the detection condition. As compared with the configuration in which the signal is determined after the elapse of a predetermined time, the abnormality of the signal can be detected at an earlier timing.

  (7) In order to solve the above problem, a communication apparatus according to an aspect of the present invention includes a communication unit for transmitting or receiving a signal and a signal abnormality detection unit for detecting abnormality of the signal. The communication apparatus, wherein the signal abnormality detection unit is acquired by a power information acquisition unit for acquiring an index value of power at each timing of a signal transmitted or received in the communication device, and the power information acquisition unit A comparison unit for comparing the index value and the evaluation threshold value, a plurality of accumulation units for accumulating the index value acquired by the power information acquisition unit for a predetermined time, and the comparison unit Based on the comparison result, an accumulation control unit for causing the accumulation unit selected from the plurality of accumulation units to start accumulation, and an abnormality of the signal based on the accumulation result by the accumulation unit. And a fault detection unit for knowledge.

  As described above, when calculating the moving average or the like by using the comparison result between the index value that is the feature amount of the target signal and the evaluation threshold, and selecting the timing for starting the accumulation of the index value in each accumulation unit Therefore, it is possible to detect signal abnormality with a simple configuration having a small number of storage devices without preparing storage devices for the number of samples required.

  (8) Preferably, the signal abnormality detection unit detects an abnormality of the transmitted signal, and the communication device further transmits the signal when the signal abnormality detection unit detects the abnormality. A circuit protection unit for stopping the operation of the circuit is provided.

  With such a configuration, when a signal abnormality is detected, the operation of the circuit that transmits the signal is stopped, so that the circuit can be prevented from being damaged by excessive power.

  (9) Preferably, the signal abnormality detection unit detects an abnormality of the received signal, and the communication device further detects the occurrence of the abnormality when the signal abnormality detection unit detects the abnormality. An alarm unit for outputting alarm information to be shown is provided.

  With such a configuration, for example, when a signal abnormality is detected by receiving a radio signal with excessive power from a certain radio terminal device, alarm information can be notified to the main device that controls the radio terminal device. .

  For example, the main body device transmits a radio signal with appropriate transmission power to the radio terminal device, so that the communication device can receive a radio signal of normal power from the radio terminal device.

  For example, when a signal abnormality is detected by receiving a high-power radio signal such as an illegal radio wave, alarm information can be notified to the communication unit in the communication device.

  The communication unit can prevent the receiving circuit from being damaged by excessive power, for example, by reducing the amplification factor of the amplifier in its own receiving circuit or setting it to zero.

  According to the present invention, it is possible to detect an abnormality of a signal in a circuit that processes a signal with instantaneous fluctuation with a simple configuration.

It is a figure which shows the structure of the radio | wireless communication apparatus which concerns on the 1st Embodiment of this invention. It is a figure which shows the structure of the remote radio head which concerns on the 1st Embodiment of this invention. It is a figure which shows the structure of the transmission part in the remote radio head which concerns on the 1st Embodiment of this invention. It is a figure which shows the structure of the electric power abnormality detection part which concerns on the 1st Embodiment of this invention. It is a figure which shows the structure of the accumulation part in the electric power abnormality detection part which concerns on the 1st Embodiment of this invention. It is a figure which shows an example of the start timing of the accumulation process of the index value of electric power which concerns on the 1st Embodiment of this invention, and the selection timing of an accumulation result. It is a figure which shows the structure of the remote radio head which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structure of the receiving part in the remote radio head which concerns on the 2nd Embodiment of this invention. It is a figure which shows the structure of the electric power abnormality detection part which concerns on the 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<First Embodiment>
FIG. 1 is a diagram showing a configuration of a wireless communication apparatus according to the first embodiment of the present invention.

  Referring to FIG. 1, wireless communication device 201 includes one or more remote radio heads 101 and a main device 102.

  The remote radio head 101 is an apparatus in which a part that transmits and receives a radio signal is independent from a radio base station apparatus used in mobile communication. The remote radio head 101 is attached to an antenna pole 104 installed on the roof of a building. An antenna 103 is attached to the antenna pole 104.

  The remote radio head 101 converts a wireless signal received from the wireless terminal device 301 via the antenna 103 into a digital signal and outputs the digital signal to the main device 102 via the optical fiber 105. Further, the remote radio head 101 converts a digital signal received from the main body apparatus 102 via the optical fiber 105 into a radio signal and transmits the radio signal to the radio terminal apparatus 301 via the antenna 103.

  FIG. 2 is a diagram showing the configuration of the remote radio head according to the first embodiment of the present invention.

  Referring to FIG. 2, remote radio head 101 includes an interface unit 80, a communication unit 90, a power abnormality detection unit (signal abnormality detection device and signal abnormality detection unit) 51, and a circuit protection unit 92. Communication unit 90 includes a transmission unit 93 and a reception unit 94.

  The interface unit 80 reproduces an I signal and a Q signal, which are electrical signals, from the optical signal received from the main device 102 via the optical fiber 105 and outputs the I signal and the Q signal to the communication unit 90. Each of the I signal and the Q signal includes amplitude information, and is hereinafter also referred to as a transmission-side digital signal.

  The communication unit 90 converts the transmission-side digital signal received from the interface unit 80 into an analog signal, transmits a radio signal generated based on the converted analog signal via the antenna 103, and transmits from the transmission side received from the interface unit 80. A digital signal is output to the power abnormality detection unit 51.

  In addition, the communication unit 90 reproduces an I signal and a Q signal, which are electrical signals, from the radio signal received via the antenna 103 and outputs the I signal and the Q signal to the interface unit 80. Each of the I signal and the Q signal includes amplitude information, and is hereinafter also referred to as a receiving-side digital signal.

  The interface unit 80 converts the reception-side digital signal received from the communication unit 90 into an optical signal, and transmits the converted optical signal to the main device 102 via the optical fiber 105.

  The power abnormality detection unit 51 detects an abnormality of the radio signal transmitted from the communication unit 90 based on the transmission-side digital signal received from the communication unit 90. Details of signal abnormality detection processing in the power abnormality detection unit 51 will be described later.

  The power abnormality detection unit 51 outputs abnormality detection information to the circuit protection unit 92 when detecting an abnormality of the wireless signal transmitted from the communication unit 90.

  When the circuit protection unit 92 receives the abnormality detection information from the power abnormality detection unit 51, the circuit protection unit 92 stops the transmission of the wireless signal by controlling the operation of the circuit in the communication unit 90. Details of the wireless signal transmission stop process will be described later.

  FIG. 3 is a diagram showing a configuration of a transmission unit in the remote radio head according to the first embodiment of the present invention.

  Referring to FIG. 3, transmission unit 93 includes a digital frequency conversion unit 81, digital / analog converters (DACs) 82 and 83, a quadrature modulation unit 84, and a high power amplifier 85.

  The digital frequency conversion unit 81 converts the baseband I signal and Q signal received from the interface unit 80 into an IF (Intermediate Frequency) band signal by an operation using a rotation matrix, and converts the converted I signal and The Q signal is output to the digital / analog converters 82 and 83, respectively.

  The digital / analog converters 82 and 83 convert the I signal and Q signal, which are digital signals received from the digital frequency converter 81, into analog signals and output the analog signals to the quadrature modulator 84.

  The quadrature modulation unit 84 performs quadrature modulation on the I and Q signals, which are analog signals received from the digital / analog converters 82 and 83, converts the signals into RF (Radio Frequency) band signals, and outputs the signals to the high power amplifier 85. .

  High power amplifier 85 amplifies the signal received from quadrature modulation unit 84 and outputs the amplified signal to antenna 103. The amplification factor of the high power amplifier 85 is controlled by the circuit protection unit 92.

  The power abnormality detection unit 51 detects excessive power in the remote radio head 101, for example, excessive output from the high power amplifier 85, based on the I signal and Q signal received from the interface unit 80.

  When detecting the excessive output, the power abnormality detection unit 51 outputs abnormality detection information to the circuit protection unit 92.

  As indicated by the dotted arrows, the power abnormality detection unit 51 may be configured to detect excessive power in the remote radio head 101 based on the I signal and the Q signal received from the digital frequency conversion unit 81. .

  The circuit protection unit 92 stops the transmission of the radio signal by controlling the operation of the circuit in the communication unit 90.

  Specifically, the high power amplifier 85 may be thermally damaged by excessive power if the state where the average power of the output signal is equal to or greater than a predetermined value continues for a predetermined time or longer. When the circuit protection unit 92 receives abnormality detection information indicating excessive power from the power abnormality detection unit 51, the circuit protection unit 92 lowers the amplification factor of the high power amplifier 85 or sets it to zero. Thereby, the remote radio head 101 reduces the transmission power of the radio signal or stops the transmission of the radio signal, and prevents the high power amplifier 85 from being damaged by heat.

  Hereinafter, a detailed configuration and operation of the power abnormality detection unit 51 that detects excessive power in the transmission unit 93 will be described as an example.

  FIG. 4 is a diagram showing a configuration of the power abnormality detection unit according to the first embodiment of the present invention.

  FIG. 5 is a diagram showing a configuration of the accumulating unit in the power abnormality detecting unit according to the first embodiment of the present invention.

  Referring to FIG. 4, power abnormality detection unit 51 includes power information acquisition unit 61, comparison unit 62, timer unit 63, allocation unit (cumulative control unit) 64, accumulation units 65, 66, 67, A selection unit 68, a division unit (abnormality detection unit) 69, and an abnormality determination unit (abnormality detection unit) 70 are included. Note that two or four or more accumulation units may be included.

  Referring to FIG. 5, accumulating units 65, 66, 67 include an adder circuit 54, a counter 52, and a register 53.

  Referring to FIG. 4 again, the power information acquisition unit 61 acquires an index value of power at each timing of a signal transmitted in the target device (hereinafter also referred to as a target signal), that is, the instantaneous of the target signal. The index value of a typical power.

  Here, the target device is the remote radio head 101, and the target signal is a transmission side digital signal, that is, an I signal and a Q signal. Moreover, each said timing is a timing (henceforth an acquisition timing) when the power information acquisition part 61 samples the index value of electric power, for example.

More specifically, the power index value is, for example, the amplitude of the target signal, that is, the size of the envelope. The magnitude of the envelope is expressed by the square root of the square sum of the amplitude of the I signal and the amplitude of the Q signal. In terms of mathematical expressions, Sqrt (I ^ 2 + Q ^ 2), that is, √ (I ² + Q ² ), where I is the amplitude of the I signal and Q is the amplitude of the Q signal.

  The power information acquisition unit 61 calculates the envelope size based on the I signal and the Q signal, and outputs the calculated envelope size to the comparison unit 62 and the allocation unit 64 at each acquisition timing.

  The comparison unit 62 compares the power index value acquired by the power information acquisition unit 61 with the evaluation threshold value Pth1, and outputs comparison result information indicating the comparison result to the timer unit 63.

  Specifically, the comparison unit 62 compares the magnitude of the envelope received from the power information acquisition unit 61 with the evaluation threshold value Pth1, and the magnitude of the envelope is greater than the evaluation threshold value Pth1. In this case, the comparison result information is output to the timer unit 63.

  Based on the comparison result information in the comparison unit 62, the timer unit 63 outputs an accumulation start signal that is a control signal to the allocation unit 64.

  More specifically, upon receiving the comparison result information from the comparison unit 62, the timer unit 63 outputs a cumulative start signal to the allocation unit 64, and measures a predetermined standby time (hereinafter also referred to as standby time Tw). Start the timer. The waiting time Tw will be described later.

  In addition, the timer unit 63 does not output a cumulative start signal to the allocating unit 64 even when receiving the comparison result information from the comparing unit 62 when the timer has not expired, that is, when the waiting time Tw has not elapsed. That is, once outputting the cumulative start signal to the allocating unit 64, the timer unit 63 does not output the next cumulative start signal to the allocating unit 64 at least until the standby time Tw elapses.

  Hereinafter, before describing the operation of the allocating unit 64, the operation of the accumulating units 65, 66, and 67 will be described.

  Referring to FIG. 5, when accumulating units 65, 66 and 67 receive an index value of power such as the size of an envelope from allocating unit 64, accumulating unit 65 accumulates the index value for a predetermined time by the following operation.

  More specifically, the adding circuit 54 adds the size of the envelope received from the assigning unit 64 and the value held in the register 53, and outputs the addition result to the register 53.

  When the register 53 receives the set signal, which is a control signal, from the assignment unit 64, the register 53 resets its value to zero. In addition, the register 53 updates the value held by itself to the value received from the adder circuit 54 at every acquisition timing at which the power information acquisition unit 61 acquires the size of the envelope. That is, the register 53 holds the cumulative result of the envelope size received from the assigning unit 64.

  When the counter 52 receives the set signal from the assigning unit 64, the counter 52 sets its own count value to a predetermined initial value.

  Then, the counter 52 decrements its own count value at every acquisition timing, and outputs a count end signal to the assigning unit 64 when its own count value becomes zero.

  The accumulating units 65, 66, and 67 may accumulate the size of the envelope received from the allocating unit 64 at each acquisition timing, or may be accumulated after thinning out the size of the envelope at each acquisition timing. Also good.

  Referring to FIG. 4 again, when allocation unit 64 receives the accumulation start signal from timer unit 63, allocation unit 64 accumulates the size of the envelope received from power information acquisition unit 61 among accumulation units 65, 66, and 67. Select the cumulative part to be used.

  Specifically, when receiving the accumulation start signal from the timer unit 63, the allocating unit 64 grasps the accumulation unit that has not performed accumulation processing based on the count end signal received from each accumulation unit. Then, the assigning unit 64 selects any of the accumulating units that are not performing the accumulating process.

  For example, when selecting the accumulating unit 65, the allocating unit 64 outputs a set signal to the accumulating unit 65, resets the value of the register 53 in the accumulating unit 65 to zero, and sets the count value of the counter 52 to an initial value.

  Allocation unit 64 outputs the size of the envelope received from power information acquisition unit 61 to accumulation unit 65 until it receives a count end signal from accumulation unit 65.

  That is, the accumulators 65, 66, and 67 receive a set signal from the allocator 64 and set an initial value as the count value of their counter 52 until a predetermined time from when the count value becomes zero (hereinafter referred to as accumulator). Also, the magnitude of the envelope received from the assigning unit 64 is accumulated in its own adder circuit 54 and register 53.

  Note that the standby time Tw in the timer unit 63 is generally set to a value obtained by dividing the cumulative time Ta by the number of the cumulative units 65, 66, and 67, for example.

  By setting the waiting time Tw as described above, at least one of the accumulating units 65, 66, and 67 among the accumulating units 65, 66, and 67 expires when the timer operating in the timer unit 63 expires. The accumulation process is not performed.

  That is, at the timing when the allocating unit 64 receives the accumulation start signal from the timer unit 63, at least one of the accumulating units 65, 66, and 67 can be in a state in which no accumulating process is performed.

  Thereby, the power abnormality detection unit 51 can shorten the section in which the power index value cannot be sampled.

  The selection unit 68 outputs the value selected based on the magnitude relationship between the values of the register 53 in the accumulation units 65, 66, and 67 to the division unit 69.

  Specifically, the selection unit 68 selects the maximum value of the value of the register 53 in the accumulation units 65, 66, and 67 for each acquisition timing, and outputs the selected maximum value to the division unit 69.

  FIG. 6 is a diagram illustrating an example of the start timing of the power index value accumulating process and the selection timing of the accumulating result according to the first embodiment of the present invention.

  With reference to FIG. 6, the timing of each operation in the comparison unit 62, the timer unit 63, the allocation unit 64, the accumulation units 65, 66, 67, and the selection unit 68 will be described.

  FIG. 6A illustrates an example of a change over time in the size of the envelope that the comparison unit 62 receives from the power information acquisition unit 61 as an index value of power.

  As shown in FIG. 6A, the size of the envelope is as follows: time Tt1 from time tas1 to time tf1, time Tt2 from time tas2 to time tf2, and time Tt3 from time tas4 to time tf3. In this case, it becomes larger than the evaluation threshold Pth1.

  The comparison unit 62 outputs comparison result information to the timer unit 63 at each acquisition timing at time Tt1, time Tt2, and time Tt3.

  FIG. 6B shows an example of the time change of the timer operation in the timer unit 63. Hereinafter, the operation timing in the timer unit 63 will be described in time series with reference to FIG.

  As shown in FIG. 6B, when the timer unit 63 receives the comparison result information from the comparison unit 62 at time tas1, the timer unit 63 outputs an accumulation start signal to the allocation unit 64 and starts the operation of the timer. The timer is operated for Tw. Then, even if the timer unit 63 receives the comparison result information from the comparison unit 62 before the timer expires, the timer unit 63 does not output the accumulation start signal to the allocation unit 64.

  The timer unit 63 receives the comparison result information from the comparison unit 62 at each acquisition timing from time tas1 to time tf1.

  Since the time Tw is longer than the time Tt1, the timer unit 63 does not receive the comparison result information from the comparison unit 62 at time tc1, which is the timing when the timer expires. Therefore, the timer unit 63 stands by until the next comparison result information is received from the comparison unit 62.

  Next, when receiving the comparison result information from the comparison unit 62 at time tas2, the timer unit 63 outputs an accumulation start signal to the allocation unit 64 and starts the timer operation, and operates the timer for the time Tw.

  Once the timer unit 63 outputs the accumulation start signal to the allocation unit 64, the timer unit 63 does not output the next accumulation start signal to the allocation unit 64 at least until the timer expires.

  The timer unit 63 receives the comparison result information from the comparison unit 62 at each acquisition timing from time tas2 to time tf2.

  Since the time Tw is shorter than the time Tt2, the timer unit 63 receives the comparison result information from the comparison unit 62 at each acquisition timing even after the time tc2 when the timer expires. For this reason, the timer unit 63 outputs a cumulative start signal to the allocating unit 64 and starts the timer operation at time tas3 slightly delayed from time tc2, and operates the timer for the time Tw.

  Next, since the time tc3 when the timer expires is later than the time tf2 when the magnitude of the envelope becomes Pth1 or less, the timer unit 63 does not receive the comparison result information from the comparison unit 62 at the time tc3. Therefore, the timer unit 63 waits until the next comparison result information is received from the comparison unit 62 after the time tc3 when the timer expires.

  Next, upon receiving the comparison result information from the comparison unit 62 at time tas4, the timer unit 63 outputs an accumulation start signal to the allocation unit 64 and starts the timer operation, and operates the timer for a time Tw.

  In addition, the timer unit 63 receives comparison result information from the comparison unit 62 at each acquisition timing from time tas4 to time tf3.

  Since the time Tw is longer than the time Tt3, the timer unit 63 does not receive the comparison result information from the comparison unit 62 at time tc4 when the timer expires. Therefore, the timer unit 63 stands by until the next comparison result information is received from the comparison unit 62.

  FIG. 6C shows an example of the operation timing of the accumulation process in the accumulation units 65, 66, and 67. 6D shows an example of the time change of the values R65, R66, and R67 of the register 53 in the accumulation units 65, 66, and 67, and the timing of the selection process in the selection unit 68.

  Hereinafter, with reference to (C) and (D) of FIG. 6, the timing of each operation in the allocating unit 64, the accumulating units 65, 66, 67 and the selecting unit 68 will be described in time series.

  When the allocation unit 64 receives the accumulation start signal from the timer unit 63 at time tas1, for example, the allocation unit 64 selects the accumulation unit 65 and outputs a set signal to the accumulation unit 65.

  As shown in FIG. 6D, a situation is assumed in which, for example, the value R67 in the register 53 of the accumulator 67, that is, the accumulated result shows the maximum value at time tas1. The value R67 is held until the time tas3 when the accumulating unit 67 receives the set signal.

  Since the value R67 is the maximum value until time tao1, the selection unit 68 selects the value R67 until time tao1, and outputs the selected value R67 to the division unit 69.

  When the accumulation unit 65 receives the set signal from the allocation unit 64 at time tas1, as shown in FIGS. 6C and 6D, the accumulation unit 65 resets the value R65 of its own register 53 to zero, and then accumulates the accumulated time Ta. Accumulate the size of the envelope.

  Further, the selection unit 68 monitors the values R65, R66, and R67 of the register 53 of the accumulation units 65, 66, and 67, that is, the accumulation results for each acquisition timing, and compares the magnitude relationship of the accumulation results.

  A dotted line L65 shown in (D) of FIG. 6 shows a time change of the accumulation result obtained by accumulating the evaluation threshold value Pth1 from time tas1 to time tae1.

  Next, when the allocation unit 64 receives the accumulation start signal from the timer unit 63 at time tas2, for example, the allocation unit 64 selects the accumulation unit 66 and outputs a set signal to the accumulation unit 66.

  When the accumulation unit 66 receives the set signal from the allocation unit 64 at time tas2, as shown in (C) and (D) of FIG. 6, the accumulation unit 66 resets the value R66 of its own register 53 to zero, and then accumulates the accumulated time Ta. Accumulate the size of the envelope.

  A dotted line L66 shown in (D) of FIG. 6 shows a time change of the accumulation result obtained by accumulating the evaluation threshold value Pth1 from time tas2 to time tae2.

  Next, as shown in FIG. 6D, the selecting unit 68 determines that the value R65 in the register 53 of the accumulating unit 65 is greater than the values R66 and R67 of the register 53 of the accumulating units 66 and 67 at time tao1. Therefore, the value R65 is selected, and the selected value R65 is output to the division unit 69.

  Next, when the allocation unit 64 receives the accumulation start signal from the timer unit 63 at time tas3, for example, the allocation unit 64 selects the accumulation unit 67 and outputs a set signal to the accumulation unit 67.

  When the accumulation unit 67 receives the set signal from the allocation unit 64 at time tas3, as shown in (C) and (D) of FIG. 6, the accumulation unit 67 resets the value R67 of its own register 53 to zero, and then accumulates the accumulated time Ta. Accumulate the size of the envelope.

  A dotted line L67 shown in (D) of FIG. 6 shows a time change of the accumulation result obtained by accumulating the evaluation threshold value Pth1 from time tas3 to time tae3.

  Next, as shown in FIG. 6D, the accumulating unit 65 holds the value R65 in its own register 53 until the time tas4 at which the next set signal is received after completing the accumulating process at the time tae1.

  Next, as shown in FIG. 6D, the selection unit 68 determines that the value R66 in the register 53 of the accumulation unit 66 is greater than the values R65 and R67 of the register 53 of the accumulation units 65 and 67, for example, at time tao2. Since it becomes a value, the value R66 is selected, and the selected value R66 is output to the division unit 69.

  Next, as shown in FIG. 6D, the accumulating unit 66 holds the value R66 in its own register 53 until it receives the next set signal after completing the accumulating process at time tae2.

  Next, when the allocation unit 64 receives the accumulation start signal from the timer unit 63 at time tas4, for example, the allocation unit 64 selects the accumulation unit 65 and outputs a set signal to the accumulation unit 65.

  When the accumulation unit 65 receives the set signal from the allocation unit 64 at time tas4, as shown in (C) and (D) of FIG. 6, the accumulation unit 65 resets the value R65 of its own register 53 to zero, and then accumulates the accumulation time Ta. Accumulate the size of the envelope.

  Next, as shown in FIG. 6D, the accumulating unit 67 holds the value R67 in its own register 53 until the next set signal is received after completing the accumulating process at time tae3.

  Since the value R66 in the register 53 of the accumulating unit 66 is continuously larger than the values R65 and R67 of the register 53 of the accumulating units 65 and 67 after time tao2, as shown in FIG. After time tao2, the value R66 in the register 53 of the accumulating unit 66 is selected continuously, and the selected value R66 is output to the dividing unit 69.

  Referring back to FIG. 4, when division unit 69 receives the maximum value of the accumulation result from selection unit 68, division unit 69 uses the accumulated number of accumulation units 65, 66, and 67, that is, the initial value set in counter 52. The average value of the envelope size is calculated by dividing. Then, division unit 69 outputs the calculated average value to abnormality determination unit 70.

  The division unit 69 does not need to output a strict average value, and divides the maximum value received from the selection unit 68 by the number of accumulations in the accumulation units 65, 66, and 67 estimated based on the accumulation time Ta. Thus, an approximate average value may be calculated.

  The abnormality determination unit 70 compares the accumulation results in the accumulation units 65, 66, and 67 with the abnormality determination threshold value Ath1 that is the accumulation result threshold value, and determines the magnitude relationship between the accumulation result and the abnormality determination threshold value Ath1. Based on this, the abnormality of the signal transmitted in the target device is detected.

  Specifically, the abnormality determination unit 70 compares the average value obtained by dividing the cumulative result by the initial value in the division unit 69 with the abnormality determination threshold value Ath1, for example, the average value is the abnormality determination threshold value Ath1. If larger, it is detected that an abnormality has occurred in the signal transmitted in the target device.

  Then, the abnormality determination unit 70 outputs an excessive power alarm that is abnormality detection information to the circuit protection unit 92.

  The abnormality determination unit 70 compares the cumulative result directly received from the selection unit 68 without passing through the division unit 69 with the value obtained by multiplying the abnormality determination threshold value Ath1 by the initial value. When larger than the multiplied value, it may be detected that an abnormality has occurred in the signal transmitted in the target device. In this case, the division unit 69 in the power abnormality detection unit 51 can be omitted.

  Further, the abnormality determination unit 70 may use the cumulative number in the accumulation units 65, 66, and 67 estimated based on the accumulation time Ta instead of the initial value.

  The magnitude relationship between the evaluation threshold value Pth1 and the abnormality determination threshold value Ath1 is set as follows, for example. That is, the evaluation threshold value Pth1 and the abnormality determination threshold value Ath1 are set to the same value.

  For example, even if only an abnormality determination threshold value Ath1, that is, an index value of electric power equal to or less than the evaluation threshold value Pth1, is accumulated, the average value of the accumulated result is smaller than the abnormality determination threshold value Ath1, and is transmitted in the target device. An abnormality is not detected in the signal.

  In contrast, the power abnormality detection unit 51 starts accumulation when the power index value is larger than the abnormality determination threshold Ath1, so that while the normal signal continues to be transmitted in the target device, Do not accumulate index values.

  Thereby, the power abnormality detection unit 51 can suppress the meaningless accumulation process of the power index value in the accumulation units 65, 66, and 67 while the normal signal continues to be transmitted in the target device.

  Further, since the accumulating units 65, 66, and 67 do not operate while a normal signal continues to be transmitted in the target device, the power abnormality detection unit 51 determines that the signal changes from a normal signal to an abnormal signal. It is possible to avoid a situation in which the accumulating units 65, 66, and 67 are accumulating and the accumulation process cannot be started.

  That is, the power abnormality detection unit 51 can quickly start the accumulation process of the power index value when the signal changes from a normal signal to an abnormal signal.

  The magnitude relationship between the evaluation threshold value Pth1 and the abnormality determination threshold value Ath1 is set as follows, for example. That is, the evaluation threshold value Pth1 is set to a value larger than the abnormality determination threshold value Ath1.

  In this case, the power abnormality detection unit 51 starts accumulating the power index value based on the evaluation threshold value Pth1 greater than the abnormality determination threshold value Ath1. In this case, the average value of the accumulated results is highly likely to be a value larger than the abnormality determination threshold value Ath1.

  Thereby, it is possible to reduce the probability that the accumulating units 65, 66, and 67 operate when no signal abnormality is detected.

  By the way, as described above, since a wideband signal is accompanied by instantaneous fluctuations, it is necessary to obtain an average power, not an instantaneous power, in order to evaluate an output power of an amplifier or the like. The configuration described in Non-Patent Document 1 has a problem that a large number of flip-flops and memories are required to calculate the average power, resulting in an increase in circuit scale. For example, when calculating the average of 100 instantaneous power values, a large-capacity memory for storing 100 instantaneous power values is required.

  On the other hand, in the power abnormality detection unit according to the first embodiment of the present invention, the power information acquisition unit 61 acquires a power index value at each timing of a signal transmitted in the target device. The comparison unit 62 compares the index value acquired by the power information acquisition unit 61 with the evaluation threshold value Pth1. The accumulation units 65, 66, and 67 accumulate the index value acquired by the power information acquisition unit 61 during the accumulation time Ta. The allocating unit 64 causes the accumulating unit 65, 66, or 67 selected from the accumulating units 65, 66, and 67 to start accumulating based on the comparison result by the comparing unit 62. The abnormality determination unit 70 and the division unit 69 detect signal abnormality based on the accumulation results of the accumulation units 65, 66, and 67.

  In this way, by using the comparison result between the index value, which is the feature quantity of the target signal, and the evaluation threshold value Pth1, the configuration is used to select the timing for starting the accumulation of the index value in each accumulating unit 65, 66, 67. It is possible to detect a signal abnormality with a simple configuration having a small number of storage devices without preparing storage devices for the number of samples necessary for calculating an average or the like.

  Further, in the power abnormality detection unit according to the first embodiment of the present invention, the allocation unit 64 performs the comparison by the comparison unit 62 until the accumulation time Ta elapses after the accumulation units 65, 66, and 67 start accumulation. Regardless of the result, the other accumulation units 65, 66, or 67 are not allowed to start accumulation.

  With such a configuration, since the next accumulation is not started until another accumulation unit 65, 66 or 67 starts accumulation until the accumulation time Ta elapses, the range in which the accumulation periods of the index values overlap is set. Can be small.

  In the power abnormality detection unit according to the first embodiment of the present invention, abnormality determination unit 70 and division unit 69 compare the accumulated result with abnormality determination threshold value Ath1, and determine the accumulated result and the abnormality determination threshold. A signal abnormality is detected based on the magnitude relationship with the value Ath1. Here, abnormality determination threshold value Ath1 is set to the same value as evaluation threshold value Pth1.

  In this way, by setting the evaluation threshold value Pth1 and the abnormality determination threshold value Ath1 to the same value, for example, the comparison condition of the index value and the evaluation threshold value Pth1 in the comparison unit 62 and the cumulative result in the abnormality determination unit 70 And the comparison condition of the cumulative result threshold value Ath1 can be matched.

  Thus, since a signal that is not determined to be abnormal by the comparison unit 62 is often not determined to be abnormal by the abnormality determination unit 70, the index values corresponding to the signal are accumulated meaninglessly in the accumulation units 65, 66, and 67. Can be suppressed.

  In addition, since the accumulating units 65, 66, and 67 do not operate while the index value is continuously received, all of the accumulating units 65, 66, and 67 are received when the comparison unit 62 receives a signal determined to be abnormal. Occurrence of a situation where a new accumulation process cannot be started because the accumulation process is being performed can be avoided.

  In the power abnormality detection unit according to the first embodiment of the present invention, abnormality determination unit 70 and division unit 69 compare the accumulated result with abnormality determination threshold value Ath1, and determine the accumulated result and the abnormality determination threshold. A signal abnormality is detected based on the magnitude relationship with the value Ath1. Then, when the comparison result by the comparison unit 62 indicates that the index value is larger than the evaluation threshold value Pth1, the allocation unit 64 causes the accumulation unit 65, 66, or 67 to start accumulation. Here, the evaluation threshold value Pth1 is larger than the abnormality determination threshold value Ath1.

  Thus, when the evaluation threshold value Pth1 is larger than the abnormality determination threshold value Ath1, there is an increased possibility that a signal abnormality is detected based on the magnitude relationship between the accumulated result and the abnormality determination threshold value Ath1. Since it can be expected, it is possible to reduce the probability that the accumulating units 65, 66, and 67 operate when no signal abnormality is detected.

  In the power abnormality detection unit according to the first embodiment of the present invention, the abnormality determination unit 70 and the division unit 69 monitor the accumulation results by the accumulation units 65, 66, and 67 before the accumulation time Ta elapses. Then, the abnormality of the signal is detected based on the monitoring result.

  With such a configuration, when the accumulation result satisfies the detection condition in the abnormality determination unit 70 and the division unit 69 at the timing before the accumulation time Ta elapses after the index value accumulation starts, the accumulation result is detected. Compared with the configuration in which whether or not the condition is satisfied is determined after the cumulative time Ta has elapsed, a signal abnormality can be detected at an earlier timing.

  In the communication apparatus according to the first embodiment of the present invention, the signal abnormality detection unit 51 detects an abnormality of the transmitted signal. Then, when an abnormality is detected by the signal abnormality detection unit 51, the circuit protection unit 92 stops the operation of the circuit that transmits the signal.

  With such a configuration, when a signal abnormality is detected, the operation of the circuit that transmits the signal is stopped, so that the circuit can be prevented from being damaged by excessive power.

In the power abnormality detection unit according to the first embodiment of the present invention, the power information acquisition unit 61 acquires the size of the envelope of the I signal and the Q signal, that is, √ (I ² + Q ² ). Although there is, it is not limited to this. The power information acquisition unit 61 may be configured to acquire an index value of power at each timing of the target signal. For example, the power information acquisition unit 61 may be configured to acquire the power values of the I signal and the Q signal, that is, (I ² + Q ² ). For example, the configuration may be such that (I ² + Q ² ) ⁿ is obtained.

  Further, although the power abnormality detection unit according to the first embodiment of the present invention is configured to detect excessive power of a circuit in its own wireless communication device 201, the present invention is not limited to this. The power abnormality detection unit 51 may be a separate device that detects excessive power of another device. For example, the power abnormality detection unit 51 may be configured to detect excessive power of a wireless communication device that is another device.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Second Embodiment>
The present embodiment relates to a signal abnormality detection device that detects an abnormality of a signal received in a wireless communication device, as compared with the signal abnormality detection device according to the first embodiment. The contents other than those described below are the same as those of the communication apparatus according to the first embodiment.

  FIG. 7 is a diagram showing a configuration of a remote radio head according to the second embodiment of the present invention.

  Referring to FIG. 7, the remote radio head 111 is different from the remote radio head 101 according to the first embodiment in that a power abnormality detection unit (signal abnormality detection device and signal abnormality detection) is used instead of the power abnormality detection unit 51. Part) 55 and an alarm part 91 instead of the circuit protection part 92.

  The communication unit 90 converts the transmission-side digital signal received from the interface unit 80 into an analog signal, and transmits a radio signal generated based on the converted analog signal via the antenna 103.

  In addition, the communication unit 90 reproduces a reception-side digital signal that is an electrical signal from the radio signal received via the antenna 103, and outputs it to the power abnormality detection unit 55 and the interface unit 80.

  The power abnormality detection unit 55 detects an abnormality of the radio signal received by the communication unit 90 based on the reception-side digital signal received from the communication unit 90. Details of the signal abnormality detection process in the power abnormality detection unit 55 will be described later.

  When detecting an abnormality in the radio signal received by the communication unit 90, the power abnormality detection unit 55 outputs alarm information indicating that the abnormality has occurred to the alarm unit 91.

  When the alarm unit 91 receives alarm information from the power abnormality detection unit 55, the alarm unit 91 transmits the received alarm information to the main body device 102 via the interface 80, for example.

  FIG. 8 is a diagram showing the configuration of the receiving unit in the remote radio head according to the second embodiment of the present invention.

  Referring to FIG. 8, reception unit 94 includes a digital frequency conversion unit 71, analog / digital converters (ADC) 72 and 73, an orthogonal demodulation unit 74, and a low noise amplifier 75.

  The low noise amplifier 75 amplifies the RF band radio signal received via the antenna 103 and outputs the amplified radio signal to the orthogonal demodulation unit 74.

  The quadrature demodulator 74 performs quadrature demodulation on the radio signal received from the low noise amplifier 75 to convert it into an I signal and a Q signal that are analog signals in the IF band, and outputs them to the analog / digital converters 72 and 73.

  Analog / digital converters 72 and 73 convert the I signal and the Q signal, which are analog signals received from quadrature demodulation unit 74, into digital signals and output them to digital frequency conversion unit 71.

  The digital frequency conversion unit 71 frequency-converts the IF signal and Q signal in the IF band received from the analog / digital converters 72 and 73 into a baseband signal by an operation using a reverse rotation matrix, and converts the converted I signal. The signal and the Q signal are output to the interface unit 80 and the power abnormality detection unit 55.

  Based on the I signal and the Q signal received from the digital frequency conversion unit 71, the power abnormality detection unit 55 detects, for example, excessive power in the wireless terminal device 301 that has transmitted the wireless signal. As indicated by the dotted arrows, the power abnormality detection unit 55 detects underpower of the wireless signal in the wireless terminal device 301 based on the I signal and the Q signal received from the analog / digital converters 72 and 73. It may be configured to.

  Hereinafter, a detailed configuration and operation of the power abnormality detection unit 55 that detects underpower is shown as an example.

  FIG. 9 is a diagram illustrating a configuration of a power abnormality detection unit according to the second embodiment of the present invention.

  Referring to FIG. 9, the power abnormality detection unit 55 includes a comparison unit 56 instead of the comparison unit 62 and a selection unit instead of the selection unit 68 as compared with the power abnormality detection unit 51 according to the first embodiment. 57 and an abnormality determination unit 58 instead of the abnormality determination unit 70.

  The power information acquisition unit 61 acquires an index value of power at each timing of a signal received by the target device (hereinafter also referred to as a target signal), that is, acquires an instantaneous power index value of the target signal. To do. Here, the target device is the remote radio head 111, and the target signals are reception-side digital signals, that is, I signals and Q signals. Moreover, each said timing is a timing which the power information acquisition part 61 samples the index value of electric power, for example.

  The power information acquisition unit 61 calculates the envelope size based on the I signal and the Q signal, and outputs the calculated envelope size to the comparison unit 56 and the allocation unit 64 at each acquisition timing.

  The comparison unit 56 compares the power index value acquired by the power information acquisition unit 61 with the evaluation threshold value Pth2, and outputs comparison result information indicating the comparison result to the timer unit 63.

  Specifically, the comparison unit 56 compares the magnitude of the envelope received from the power information acquisition unit 61 with the evaluation threshold value Pth2, and the magnitude of the envelope is smaller than the evaluation threshold value Pth2. In this case, the comparison result information is output to the timer unit 63.

  The timer unit 63 outputs an accumulation start signal to the allocation unit 64 based on the comparison result information in the comparison unit 56.

  More specifically, when receiving the comparison result information from the comparison unit 56, the timer unit 63 outputs an accumulation start signal to the allocation unit 64, and starts a timer to measure the standby time Tw.

  In addition, the timer unit 63 does not output a cumulative start signal to the allocating unit 64 even when receiving the comparison result information from the comparing unit 56 when the timer has not expired, that is, when the waiting time Tw has not elapsed. That is, once outputting the cumulative start signal to the allocating unit 64, the timer unit 63 does not output the next cumulative start signal to the allocating unit 64 at least until the standby time Tw elapses.

  When the allocation unit 64 receives the accumulation start signal from the timer unit 63, the allocation unit 64 selects an accumulation unit that accumulates the size of the envelope received from the power information acquisition unit 61 from among the accumulation units 65, 66, and 67.

  Specifically, when receiving the accumulation start signal from the timer unit 63, the allocating unit 64 grasps the accumulation unit that has not performed accumulation processing based on the count end signal received from each accumulation unit. Then, the assigning unit 64 selects any of the accumulating units that are not performing the accumulating process.

  For example, when selecting the accumulating unit 65, the allocating unit 64 outputs a set signal to the accumulating unit 65, resets the value of the register 53 in the accumulating unit 65 to zero, and sets the count value of the counter 52 to an initial value.

  Allocation unit 64 outputs the size of the envelope received from power information acquisition unit 61 to accumulation unit 65 until it receives a count end signal from accumulation unit 65.

  That is, the accumulating units 65, 66, and 67 accumulate the magnitude of the envelope received from the allocating unit 64 in the adder circuit 54 and the register 53 during the accumulating time Ta.

  The selection unit 57 outputs the value selected based on the magnitude relationship of the values of the register 53 in the accumulation units 65, 66, and 67 to the division unit 69.

  Specifically, the selection unit 57 selects the minimum value of the register 53 in the accumulation units 65, 66, and 67 for each acquisition timing, and outputs the selected minimum value to the division unit 69.

  When the division unit 69 receives the minimum value of the accumulation result from the selection unit 57, the division unit 69 divides the minimum value by the number of times accumulated in the accumulation units 65, 66, and 67, that is, the initial value set in the counter 52. The average value of the size of is calculated. Then, the dividing unit 69 outputs the calculated average value to the abnormality determining unit 58.

  The division unit 69 does not need to output a strict average value, and divides the minimum value received from the selection unit 57 by the number of accumulations in the accumulation units 65, 66, and 67 estimated based on the accumulation time Ta. Thus, an approximate average value may be calculated.

  The abnormality determination unit 58 compares the accumulation results in the accumulation units 65, 66, and 67 with the abnormality determination threshold value Ath2, which is a cumulative result threshold value, and determines the magnitude relationship between the accumulation result and the abnormality determination threshold value Ath2. Based on this, the abnormality of the signal received in the target device is detected.

  Specifically, the abnormality determination unit 58 compares the average value obtained by dividing the cumulative result by the initial value in the division unit 69 with the abnormality determination threshold value Ath2, and the average value is, for example, the abnormality determination threshold value Ath2. If smaller, it is detected that an abnormality has occurred in the signal received by the target device.

  Then, the abnormality determination unit 58 outputs an underpower alarm that is abnormality detection information to the warning unit 91.

  The abnormality determination unit 58 compares the cumulative result directly received from the selection unit 57 without going through the division unit 69 with the value obtained by multiplying the abnormality determination threshold value Ath2 by the initial value. If the value is smaller than the multiplied value, it may be detected that an abnormality has occurred in the signal received by the target device. In this case, the division unit 69 in the power abnormality detection unit 55 can be eliminated.

  Further, the abnormality determination unit 58 may use the cumulative number in the accumulation units 65, 66, and 67 estimated based on the accumulation time Ta instead of the initial value.

  The magnitude relationship between the evaluation threshold value Pth2 and the abnormality determination threshold value Ath2 is set as follows, for example. That is, the evaluation threshold value Pth2 and the abnormality determination threshold value Ath2 are set to the same value.

  For example, even if only the power determination index value equal to or higher than the abnormality determination threshold value Ath2, that is, the evaluation threshold value Pth2, is accumulated, the average value of the accumulated result is larger than the abnormality determination threshold value Ath2, and is thus received by the target device. An abnormality is not detected in the signal.

  On the other hand, the power abnormality detection unit 55 starts accumulation when the power index value is smaller than the abnormality determination threshold value Ath2, so that while the normal signal continues to be received in the target device, the power abnormality detection unit 55 Do not accumulate index values.

  Thereby, the power abnormality detection unit 55 can suppress the meaningless accumulation process of the power index values in the accumulation units 65, 66, and 67 while the normal signal is continuously received in the target device.

  Further, since the accumulating units 65, 66, and 67 do not operate while a normal signal is continuously received in the target device, the power abnormality detection unit 55 determines that the signal changes from a normal signal to an abnormal signal. It is possible to avoid a situation in which the accumulating units 65, 66, and 67 are accumulating and the accumulation process cannot be started.

  That is, the power abnormality detection unit 55 can promptly start accumulation processing of the power index value when the signal changes from a normal signal to an abnormal signal.

  The magnitude relationship between the evaluation threshold value Pth2 and the abnormality determination threshold value Ath2 is set as follows, for example. That is, the evaluation threshold value Pth2 is set to a value smaller than the abnormality determination threshold value Ath2.

  In this case, the power abnormality detection unit 55 starts accumulating the power index value based on the evaluation threshold value Pth2 having a value smaller than the abnormality determination threshold value Ath2. In this case, it is highly possible that the average value of the accumulated results is smaller than the abnormality determination threshold value Ath2.

  Thereby, it is possible to reduce the probability that the accumulating units 65, 66, and 67 operate when no signal abnormality is detected.

  Further, the power abnormality detection unit 55 may be configured to detect excessive power, for example, to detect excessive power of a circuit that amplifies a signal input from another device to the wireless communication device 201. In this case, the remote radio head 111 includes, for example, the power abnormality detection unit 51 instead of the power abnormality detection unit 55, thereby detecting excessive power in the low noise amplifier 75 that amplifies the radio signal received by the wireless communication device 201, for example. To do.

  Since other configurations and operations are the same as those of the signal abnormality detection device according to the first embodiment, detailed description thereof will not be repeated here.

  As described above, in the power abnormality detection unit according to the second embodiment of the present invention, the power information acquisition unit 61 acquires the index value of power at each timing of the signal received by the target device. The comparison unit 56 compares the index value acquired by the power information acquisition unit 61 with the evaluation threshold value Pth2. The accumulation units 65, 66, and 67 accumulate the index value acquired by the power information acquisition unit 61 during the accumulation time Ta. The allocating unit 64 causes the accumulating unit 65, 66, or 67 selected from the accumulating units 65, 66, and 67 to start accumulating based on the comparison result by the comparing unit 56. The abnormality determination unit 58 and the division unit 69 detect signal abnormality based on the accumulation results of the accumulation units 65, 66, and 67.

  In this way, by using the comparison result between the index value, which is the feature quantity of the target signal, and the evaluation threshold value Pth2, the timing for starting the accumulation of the index value in each of the accumulating units 65, 66, and 67 is selected. It is possible to detect a signal abnormality with a simple configuration having a small number of storage devices without preparing storage devices for the number of samples necessary for calculating an average or the like.

  In the power abnormality detection unit according to the second embodiment of the present invention, abnormality determination unit 58 and division unit 69 compare the accumulated result with abnormality determination threshold Ath2, and determine the accumulated result and the abnormality determination threshold. A signal abnormality is detected based on the magnitude relationship with the value Ath2. When the comparison result by the comparison unit 56 indicates that the index value is smaller than the evaluation threshold value Pth2, the allocation unit 64 causes the accumulation unit 65, 66, or 67 to start accumulation. Here, the evaluation threshold value Pth2 is smaller than the abnormality determination threshold value Ath2.

  As described above, when the evaluation threshold value Pth2 is smaller than the abnormality determination threshold value Ath2, there is an increased possibility that a signal abnormality is detected based on the magnitude relationship between the accumulated result and the abnormality determination threshold value Ath2. Since it can be expected, it is possible to reduce the probability that the accumulating units 65, 66, and 67 operate when no signal abnormality is detected.

  In the power abnormality detection unit according to the second embodiment of the present invention, the abnormality determination unit 58 and the division unit 69 monitor the accumulation results obtained by the accumulation units 65, 66, and 67 before the accumulation time Ta elapses. Then, the abnormality of the signal is detected based on the monitoring result.

  With such a configuration, when the accumulation result satisfies the detection condition in the abnormality determination unit 58 and the division unit 69 at the timing before the accumulation time Ta elapses after the index value accumulation starts, the accumulation result is detected. Compared with the configuration in which whether or not the condition is satisfied is determined after the cumulative time Ta has elapsed, a signal abnormality can be detected at an earlier timing.

  Further, in the communication device according to the second embodiment of the present invention, the signal abnormality detection unit 55 detects an abnormality of the received signal. When an abnormality is detected by the signal abnormality detection unit 55, the alarm unit 91 outputs alarm information indicating the occurrence of the abnormality.

  With such a configuration, for example, when a signal abnormality is detected by receiving a radio signal with excessive power from a certain radio terminal device 301, alarm information is notified to the main device 102 that controls the radio terminal device 301. be able to.

  For example, the main body device 102 causes the wireless terminal device 301 to transmit a wireless signal with appropriate transmission power, so that the remote radio head 111 can receive a wireless signal of normal power from the wireless terminal device 301. it can.

  For example, when a signal abnormality is detected by receiving a high-power radio signal such as an illegal radio wave, alarm information can be notified to the receiving unit 94.

  The receiving unit 94 can prevent the receiving circuit from being damaged due to excessive power, for example, by lowering or setting the gain of the low noise amplifier 75 in its own receiving circuit to zero.

  Note that the power abnormality detection unit according to the second embodiment of the present invention is configured to detect an underpower of a circuit in its own wireless communication device 201, but is not limited thereto. The power abnormality detection unit 55 may be a separate device that detects an underpower of another device. For example, the power abnormality detection unit 55 may be configured to detect underpower of a wireless communication device that is another device.

  In the communication apparatus according to the second embodiment of the present invention, the abnormality of the received signal is detected. However, the present invention is not limited to this. For example, the remote radio head 111 may further include a power abnormality detection unit 51 and a circuit protection unit 92 to detect an abnormality of a signal to be transmitted.

  The above embodiment should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

51, 55 Power abnormality detection unit (signal abnormality detection device and signal abnormality detection unit)
52 counter 53 register 54 addition circuit 61 power information acquisition unit 62, 56 comparison unit 63 timer unit 64 allocation unit (cumulative control unit)
65, 66, 67 Accumulation unit 68, 57 Selection unit 69 Division unit (abnormality detection unit)
70, 58 Abnormality determination unit (abnormality detection unit)
80 Interface unit 71, 81 Digital frequency conversion unit 72, 73 Analog / digital converter 74 Quadrature demodulation unit 75 Low noise amplifier 82, 83 Digital / analog converter 84 Quadrature modulation unit 85 High power amplifier 90 Communication unit 91 Alarm unit 92 Circuit protection Unit 93 Transmitter 94 Receiver 101, 111 Remote radio head 103 Antenna 102 Main unit 105 Optical fiber 201 Wireless communication device 301 Wireless terminal device

Claims (9)

A power information acquisition unit for acquiring an index value of power at each timing of a signal transmitted or received in the target device;
A comparison unit for comparing the index value acquired by the power information acquisition unit with an evaluation threshold;
A plurality of accumulating units for accumulating the index value acquired by the power information acquiring unit for a predetermined time;
An accumulation control unit for causing the accumulation unit selected from the plurality of accumulation units to start the accumulation based on a comparison result by the comparison unit;
A signal abnormality detection device comprising: an abnormality detection unit for detecting an abnormality of the signal based on the accumulation result by the accumulation unit.   2. The accumulation control unit according to claim 1, wherein the accumulation unit does not cause other accumulation units to start the accumulation until a predetermined time elapses after the accumulation unit starts the accumulation, regardless of a comparison result by the comparison unit. Signal abnormality detection device. The abnormality detection unit compares the accumulated result with an accumulated result threshold value, detects an abnormality of the signal based on a magnitude relationship between the accumulated result and the accumulated result threshold value,
The signal abnormality detection device according to claim 1, wherein the evaluation threshold value and the cumulative result threshold value are the same value. The abnormality detection unit compares the accumulated result with an accumulated result threshold value, detects an abnormality of the signal based on a magnitude relationship between the accumulated result and the accumulated result threshold value,
When the comparison result by the comparison unit indicates that the index value is larger than the evaluation threshold, the accumulation control unit causes the accumulation unit to start the accumulation,
The signal abnormality detection device according to claim 1, wherein the evaluation threshold value is larger than the cumulative result threshold value. The abnormality detection unit compares the accumulated result with an accumulated result threshold value, detects an abnormality of the signal based on a magnitude relationship between the accumulated result and the accumulated result threshold value,
When the comparison result by the comparison unit indicates that the index value is smaller than the evaluation threshold, the accumulation control unit causes the accumulation unit to start the accumulation,
The signal abnormality detection device according to claim 1, wherein the evaluation threshold is smaller than the cumulative result threshold.   The said abnormality detection part monitors the accumulation result by the said accumulation part before the said predetermined time passes, and detects abnormality of the said signal based on the monitoring result. The signal abnormality detection device described in 1. A communication unit for transmitting or receiving signals;
A communication apparatus comprising a signal abnormality detection unit for detecting abnormality of the signal,
The signal abnormality detection unit is
A power information acquisition unit for acquiring an index value of power at each timing of a signal transmitted or received in the communication device;
A comparison unit for comparing the index value acquired by the power information acquisition unit with an evaluation threshold;
A plurality of accumulating units for accumulating the index value acquired by the power information acquiring unit for a predetermined time;
An accumulation control unit for causing the accumulation unit selected from the plurality of accumulation units to start the accumulation based on a comparison result by the comparison unit;
A communication device including an abnormality detection unit for detecting an abnormality of the signal based on the accumulation result by the accumulation unit. The signal abnormality detection unit detects an abnormality of the transmitted signal,
The communication device further includes:
The communication device according to claim 7, further comprising a circuit protection unit for stopping an operation of a circuit that transmits the signal when the abnormality is detected by the signal abnormality detection unit. The signal abnormality detection unit detects an abnormality of the received signal,
The communication device further includes:
The communication device according to claim 7 or 8, further comprising an alarm unit for outputting alarm information indicating the occurrence of the abnormality when the abnormality is detected by the signal abnormality detection unit.

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