WO2022180676A1 - Dispositif radio - Google Patents

Dispositif radio Download PDF

Info

Publication number
WO2022180676A1
WO2022180676A1 PCT/JP2021/006839 JP2021006839W WO2022180676A1 WO 2022180676 A1 WO2022180676 A1 WO 2022180676A1 JP 2021006839 W JP2021006839 W JP 2021006839W WO 2022180676 A1 WO2022180676 A1 WO 2022180676A1
Authority
WO
WIPO (PCT)
Prior art keywords
interference
fft
unit
frequency
wireless device
Prior art date
Application number
PCT/JP2021/006839
Other languages
English (en)
Japanese (ja)
Inventor
順一 西田
Original Assignee
株式会社日立国際電気
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社日立国際電気 filed Critical 株式会社日立国際電気
Priority to JP2023501706A priority Critical patent/JPWO2022180676A1/ja
Priority to PCT/JP2021/006839 priority patent/WO2022180676A1/fr
Publication of WO2022180676A1 publication Critical patent/WO2022180676A1/fr

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B17/00—Monitoring; Testing
    • H04B17/30—Monitoring; Testing of propagation channels
    • H04B17/309—Measuring or estimating channel quality parameters

Definitions

  • the present invention relates to a radio device used, for example, in air traffic control, and more particularly to a radio device capable of quickly and accurately detecting the presence or absence of interference.
  • Air traffic control uses AM modulation as its radio communication system, and in the event of interference, the receiving side will experience distorted voices and abnormal noises.
  • AM modulation As its radio communication system, and in the event of interference, the receiving side will experience distorted voices and abnormal noises.
  • a relative level difference of 20 dB or more between signals in a state of interference a weak signal is suppressed by a strong signal, and abnormal noise may not be recognized, making it difficult to detect interference.
  • Patent Document 1 a received signal output from an ADC is converted to a baseband frequency, converted to an optimum sampling rate, windowed, and then subjected to FFT (Fast Fourier Transform) processing.
  • FFT Fast Fourier Transform
  • the conventional radio equipment since air traffic controllers judge the presence or absence of interference by listening with their ears, there is a problem that the detection accuracy is low and there is a possibility of missing something.
  • the conventional wireless device has a problem that it is not possible to notify the degree of danger according to the degree of interference.
  • Patent Document 1 does not describe that FFT is performed by overlapping processing to shorten the time required to detect interference and improve detection accuracy.
  • the present invention has been made in view of the above-mentioned actual situation, and provides a wireless device capable of detecting the presence or absence of interference quickly and with high precision, and furthermore, notifying the degree of risk according to the degree of interference to improve safety. intended to provide
  • the present invention which solves the problems of the conventional example, is a wireless device that detects interference that occurs on the receiving side when a plurality of wireless devices simultaneously transmit radio waves at the same frequency in one wireless communication area.
  • a windowing unit that performs windowing on the received signal to optimize the result of subsequent Fast Fourier Transform (FFT) processing
  • a rate conversion unit that outputs frames including a number of samples while overlapping them with a certain number of samples, an FFT unit that fast Fourier transforms the signal output from the rate conversion unit to a frequency-level relationship, and an FFT unit.
  • an interference detector that detects peak power of the output carrier, determines an interference state based on the number of detected peaks, and detects interference.
  • the present invention has an interface unit for acquiring time information by the NTP protocol or GPS in the above wireless device.
  • a storage device is connected to store interference state data when interference is detected by the interference detection unit.
  • a computer device that reads and displays interference state data from the storage device is connected.
  • the computer device when the computer device receives data indicating that the interference state is present, it displays a warning indicating that the degree of danger is small and starts timing, If it continues for a longer time, a warning is displayed indicating that the danger is high.
  • the present invention is the above wireless device that increases the number of samples in one frame of FFT processing and increases the number of overlaps.
  • the wireless device described above includes a window processing unit, an FFT unit, and an interference detection unit for each of a plurality of frequencies corresponding to a plurality of wireless communication areas.
  • a wireless device that detects interference generated on the receiving side by a plurality of wireless devices simultaneously transmitting radio waves at the same frequency in one wireless communication area.
  • a windowing unit that performs windowing to optimize the result of Fourier transform (FFT) processing, and a rate-converting signal output from the windowing unit to a higher frequency so that frames containing a specific number of samples are
  • a rate conversion section that outputs while overlapping the number of samples, an FFT section that fast Fourier transforms the signal output from the rate conversion section to the relationship between frequency and level, and a peak power of the carrier output from the FFT section.
  • an interference detector that detects interference by judging the state of interference based on the number of detected peaks. can be improved, and the presence or absence of interference can be determined quickly and with high accuracy.
  • the wireless device since the wireless device is connected to a storage device for storing data of the interference state when interference is detected by the interference detection unit, the data of the interference state can be used for analysis. There is an effect that can be done.
  • the wireless device since the wireless device is connected to a computer device that reads and displays interference state data from a storage device, there is an effect that the state of interference can be notified by display.
  • the computer device when the computer device receives data indicating an interference state, it displays a warning indicating that the degree of danger is low and starts timing, and the interference state continues longer than a specific time. Since the above wireless device displays an alarm indicating that the degree of danger is high in the event of interference, the degree of danger is reported in accordance with the degree of interference, thereby enhancing safety.
  • the noise floor can be reduced and the detection accuracy can be further improved.
  • the radio apparatus is provided with a window processing unit, an FFT unit, and an interference detection unit for each of a plurality of frequencies corresponding to a plurality of radio communication areas, interference in a plurality of radio communication areas can be prevented. There is an effect that the presence or absence can be detected.
  • FIG. 2 is an explanatory diagram showing a configuration example of the present wireless device
  • 3 is a configuration block diagram of a receiving device 4
  • FIG. 4 is a flowchart showing processing in the interference detection device
  • FIG. 4 is an explanatory diagram showing an outline of overlap processing in the interference detection device
  • FIG. 4 is an explanatory diagram showing a waveform example (1) when interference is detected
  • FIG. 10 is an explanatory diagram showing a waveform example (2) when interference is detected;
  • a radio apparatus includes an interference detection device that detects the presence or absence of interference that occurs on the receiving side when a plurality of radio devices transmit using the same frequency.
  • the window processing unit performs window processing for optimally performing subsequent FFT processing on the received signal having the carrier frequency as the center frequency, and the rate conversion unit converts the output signal from the window processing unit to a higher frequency.
  • Rate conversion is performed on the frequency, frames including a specific number of samples are output while being overlapped, and the FFT unit performs FFT processing on the signal output from the rate conversion unit on a frame-by-frame basis, and outputs the relationship between the frequency and the level.
  • the interference detection section detects peaks of the carrier output from the FFT section, and when a plurality of peaks are detected, determines that there is an interference state. The time required to detect the presence or absence of interference can be shortened, and the number of FFT points can be increased to improve the detection accuracy.
  • this wireless device detects interference, it outputs a warning indicating that there is interference and starts measuring the duration. It is a thing, and it can alert
  • this wireless device is equipped with the above-described interference detection device for each frequency corresponding to a plurality of wireless communication areas, and can detect the presence or absence of interference in a plurality of wireless communication areas.
  • FIG. 1 is an explanatory diagram showing a configuration example of this wireless device.
  • this wireless device includes an antenna 1, a GPS (Global Positioning System) antenna 2, a high frequency section 3, a receiver 4, a network device 5, and a personal computer. ) 6 and an external storage device 7 .
  • GPS Global Positioning System
  • Antenna 1 transmits and receives radio signals to and from a radio device (radio station) mounted on an aircraft.
  • the GPS antenna 2 receives GPS signals from a plurality of GPS satellites and outputs GPS received signals to the receiving device 4 .
  • the receiving device 4 acquires position information and time information based on the GPS reception signal.
  • the high frequency unit 3 performs frequency conversion and amplification associated with transmission and reception of radio signals. Specifically, the high frequency section 3 amplifies the radio signal from the antenna 1 , down-converts it to an IF signal, and outputs it to the receiving device 4 . It also converts the IF signal from the receiving device 4 into a high frequency signal and outputs it to the radio antenna 1 .
  • the receiving device 4 includes a demodulator, demodulates the received signal, and outputs the received audio to a speaker.
  • the receiver 4 of this wireless device is equipped with an interference detection device that detects the presence or absence of interference in the received signal, detects the presence or absence of interference in the input received signal, and outputs the result to the personal computer 6. .
  • the interference detection device will be described later.
  • the receiving device 4 has a GPS interface unit that acquires time information based on the GPS reception signal from the GPS antenna 2 . Then, time information is attached to the detection result of the interference detection device, and the result is output to the personal computer 6 or the external storage device 7, which will be described later.
  • the time information is acquired from the GPS reception signal here, it may be provided with a network interface section for acquiring the time information of NTP (Network Time Protocol) from the network signal.
  • NTP Network Time Protocol
  • this wireless device is also provided with a transmission device that modulates the input transmission sound and outputs it to the high frequency unit 3, the illustration is omitted here.
  • the receiving device 4 may be configured as a transmitting/receiving device so as to perform modulation/demodulation associated with transmission and reception.
  • the network device 5 connects the receiving device 4 to the network.
  • the personal computer 6 and the external storage device 7 are connected via the network device 5.
  • the network device 5 is connected to an external network such as the Internet. good too.
  • the personal computer 6 is a terminal operated by an operator such as an air traffic controller, and displays warnings and warnings indicating the presence or absence of interference and the degree of interference based on information (interference state data) on interference from the receiving device 4. do.
  • a speaker for outputting received voice and a microphone for inputting transmitted voice are also provided.
  • the external storage device 7 stores information relating to interference output from the receiving device 4, and outputs the stored information upon request from the personal computer 6. By accumulating data in the external storage device 7, it is possible to analyze the state of interference.
  • FIG. 2 is a configuration block diagram of the receiving device 4.
  • the receiving device 4 demodulates the received signal and outputs a received voice, and also detects the presence or absence of interference with respect to a narrow-band signal centered on a predetermined carrier frequency.
  • the receiving device 4 includes an ADC (Analog Digital Converter) 11, a frequency converter 12, a first rate converter (rate converter (1)) 13, and a second rate converter.
  • ADC Analog Digital Converter
  • rate conversion section (2) 14, window processing section 15, third rate conversion section (rate conversion section (3)) 16, FFT section 17, interference detection section 18, and power detection section 19 , a demodulator 21 and a DAC (Digital Analog Converter) 22 .
  • the portion including the second rate conversion section 14, the window processing section 15, the third rate conversion section 16, the FFT section 17, the interference detection section 18, and the power detection section 19 is used for interference detection. become a device.
  • a band-pass filter that passes a narrow band around a predetermined carrier frequency is provided in the preceding stage of the ADC 11 .
  • the ADC 11 converts an IF frequency analog signal or an orthogonalized baseband frequency analog signal into a digital signal.
  • the frequency converter 12 converts the IF frequency digital signal into a baseband frequency. However, when a digital signal having an orthogonalized baseband frequency is input, the frequency conversion unit 12 can be omitted.
  • the first rate conversion unit 13 converts the baseband frequency signal into an optimal sampling rate (for example, 1 MHz) for demodulation processing.
  • the demodulator 21 amplifies or attenuates the signal output from the first rate converter 13 to an appropriate level, and then performs AM demodulation.
  • the DAC 22 converts the demodulated digital signal into an analog signal and outputs audio.
  • the second rate conversion unit 14 further converts the input signal into a sampling rate (for example, 24 kHz) suitable for subsequent window processing.
  • the window processing unit 15 processes the signal output from the second rate conversion unit 14 using a window function so as to optimize the FFT result in the latter stage.
  • the third rate conversion unit 16 converts the FFT frame containing the number of samples, which is the unit of FFT processing, into the optimal sampling rate (for example, 200 MHz) for FFT processing, and outputs the signal output from the window processing unit 15. do. At that time, the third rate conversion unit 16 outputs frames while overlapping a preset number of samples.
  • the third rate conversion section 16 corresponds to the rate conversion section described in the claims.
  • the frequency resolution of the FFT is adjusted to such an extent that the fluctuation of the transmission frequency of the radio can be identified, and the FFT processing is performed to calculate the relationship between the frequency and the reception level.
  • the FFT unit 17 performs FFT processing on the basis of the input FFT frame and converts it into a relationship between frequency and level. Thereby, the power level peak at the carrier frequency is detected.
  • the FFT section 17 of this wireless device outputs the FFT processing result for each of the overlapped FFT frames. A plurality of FFT frames containing the same sample are subjected to FFT processing by overlapping, thereby improving detection accuracy and preventing interference from being overlooked.
  • the interference detection unit 18 detects the presence or absence of interference by detecting the number of power peaks based on the relationship between the frequency and the level from the FFT unit 17 . Specifically, if there is one peak, it is determined that there is no interference, and if there are two or more peaks, it is determined that there is interference.
  • the interference detection unit 18 inputs the power value of the peak power (peak power value) in the FFT processing result from the power detection unit 19 described later, and if the peak power value is less than a preset threshold, is not detected as a peak.
  • the threshold value of the peak power value for detecting the peak is set according to the radio wave reception condition (radio wave condition), and the setting can be changed by an external signal from the personal computer 6 or the like.
  • Power detection section 19 detects the power of the signal from FFT section 17 and outputs the peak power value to interference detection section 18 . Also, when interference occurs, depending on the power difference between the modulated waves, a beat (waveform oscillation) occurs. You may Specifically, the power detection unit 19 receives the signal output from the first rate conversion unit 13, detects the power value of the signal, and detects the power difference between the two modulated waves from the beat variation amount. and output to the personal computer 6 or the like as an interference level. Then, the operator of the personal computer 6 may make a final determination of the presence or absence of interference in combination with the interference presence/absence determination result from the interference detection section 18 .
  • FIG. 3 is a flow chart showing processing in the interference detection device.
  • the processing numbers (numbers following "S") in FIG. 3 correspond to the reference numerals of the constituent elements in FIG.
  • S11 the input signal is converted into a digital signal by the ADC 11 (S11), and It is converted to baseband frequency (S12).
  • the baseband frequency signal is rate-converted to a rate suitable for demodulation (rate conversion (1)) by the first rate conversion unit 13 (S13).
  • Rate conversion (2) (S14)
  • window processing is performed by the window processing unit 15 (S15).
  • the windowed signal is rate-converted to a rate suitable for FFT in the third rate conversion unit 16 (rate conversion (3)) (S16), and FFT-processed frame by frame in the FFT unit 17. , the relationship between frequency and level is output (S17).
  • interference detection processing is performed in the interference detection unit 18 (S18).
  • interference detection section 18 detects the number of peaks having a power value equal to or greater than a predetermined threshold based on the FFT result output from FFT section 17, and determines that the number of peaks is two. It is determined whether or not there are more than one (S181).
  • the interference detector 18 determines that there is interference, and outputs the result of "interference present" to the personal computer 6 and the external storage device 7 (S182). At that time, the interference detection unit 18 attaches the time information acquired from the GPS reception signal to the detection result of interference and outputs it. If the number of peaks is one in process 181, the interference detector 18 judges that there is no interference, adds time information to the result of "no interference", and outputs it to the personal computer 6 and the external storage device 7. (S183). In this way, the processing in the interference detection device of this radio device is performed.
  • FIG. 4 is an explanatory diagram showing an overview of overlap processing in the interference detection device.
  • FIG. 4 shows a case where the received signal shown in the upper part is subjected to overlap FFT processing.
  • the horizontal axis is time.
  • the third rate conversion unit 16 converts the rate to 200 MHz, cuts out a frame containing a predetermined number of samples by shifting it by a specific number of samples (here, one sample),
  • the frames are output to the FFT section 17 while being overlapped, and the FFT section 17 sequentially performs FFT processing from the input frame and outputs the result.
  • the FFT processing results of frame (2), frame (3), . . . are output with a delay.
  • This radio apparatus can detect interference even when the relative level difference between signals is 40 dB or more, and can prevent interference from being overlooked.
  • the personal computer 6 when interference is detected, the personal computer 6 outputs a warning or alarm to notify the operator.
  • the control section of the personal computer 6 outputs an alarm display of "warning" to the display section when "interference exists" is input from the interference detection section 18 of the receiving device.
  • a warning indicates a relatively low-risk interference condition.
  • the control unit of the personal computer 6 starts clocking, and outputs an alarm display of "warning" when the measured time exceeds a preset specific time.
  • a warning indicates a high-risk interference condition.
  • the controller of the personal computer 6 resets the measurement time when "no interference" is input.
  • air traffic controllers can know in real time that they are in a state of interference and the degree of interference, and can alert aircraft to prevent serious incidents. is possible.
  • the presence of interference can be recognized at a glance, it is possible to reduce oversights compared to distinguishing by ear, and furthermore, it is possible to reduce the burden on air traffic controllers.
  • the present wireless device provides information on interference from the receiving device 4 (date and time, reception status, presence/absence of interference, power value data, waveform data, etc.). ) is stored in the external storage device 7, the personal computer 6 or the analysis terminal can read the data from the external storage device 7 and perform detailed analysis.
  • the information on interference corresponds to the data on the interference state described in the claims. Also, as information about interference, various data in a non-interference state may be included.
  • the timing at which the interference detection result changes from “no interference” to “interference present” is taken as the interference start date and time
  • the timing at which "interference is present” changes to “no interference” is taken as the interference end date and time to calculate the interference duration.
  • the duration of interference is also possible to determine the duration of interference by setting the timing at which two peaks start to be detected as the start of interference and the timing at which the number of peaks returns to one as the end of interference.
  • a history of interference may be displayed in a list so that the status of occurrence of interference can be understood at a glance.
  • FIG. 5 is an explanatory diagram showing a waveform example (1) when interference is detected
  • FIG. 6 is an explanatory diagram showing a waveform example (2) when interference is detected.
  • 5(1) to 6(6) show waveforms detected in a series of interference states in chronological order.
  • FIGS. 5 and 6 the upper figures are the FFT output results, and the horizontal axis is the frequency.
  • the lower diagram shows the observed frequency band, and the upper diagram shows the band in which the received signal was observed. Also, the scales of the horizontal axes in FIGS. 5 and 6 do not match.
  • the FFT result shows a power peak (first peak) at a specific frequency. This state has one peak and no interference.
  • the receiving side can confirm multiple AM-modulated carrier signals due to fluctuations in the original oscillation and Doppler shift.
  • This wireless device utilizes this fact to detect the peak power of the carrier signal, and if there are two or more peaks whose power value is equal to or greater than the threshold value, it is determined that there is interference.
  • the controller of the personal computer 6 starts measuring the interference time in this state and displays a warning indicating "interference".
  • the second peak due to the aircraft B increases and the interference state continues.
  • the first peak becomes smaller and the interference ends.
  • the interference detector 18 detects the end of interference when the power level of the first peak becomes less than a certain value.
  • the control unit of the personal computer 6 finishes counting the interference time.
  • aircraft B is transmitting and no interference occurs.
  • These waveform data can be displayed on the personal computer 6 in real time, and are also stored in the external storage device 7, so that the data can be read out and used for analysis at a later date.
  • FIG. 2 shows an example of a receiving device that detects the presence or absence of interference in one carrier frequency, it is also possible to adopt a configuration that detects the presence or absence of interference for a plurality of frequencies using RF direct sampling.
  • the multiple frequencies include, for example, carrier frequencies used in adjacent sectors.
  • the receiving device is configured to include filters that pass a plurality of different frequencies, ADCs corresponding to the filters, and interference detection devices corresponding to the ADCs. Then, each ADC converts the frequency that has passed through each filter into a digital signal, and the corresponding interference detection device detects the presence or absence of interference with respect to each input frequency and outputs it to the personal computer 6 .
  • the frequency is specified according to the interference detection device of the detection source, and the detection result, warning and alarm are displayed with the frequency attached.
  • the operation of each interference detection device is the same as the example described above. As a result, the presence or absence of interference can be simultaneously detected across a plurality of sectors by this wireless device, and the reliability of air traffic control in a wide area can be improved.
  • an interference detection device for detecting the presence or absence of interference that occurs on the receiving side when a plurality of wireless devices transmit using the same frequency
  • the window processing unit 15 Window processing for optimally performing subsequent FFT processing is performed on the received signal having the carrier frequency as the center frequency, and the rate conversion unit 16 rate-converts the output signal from the window processing unit 15 at a higher frequency, Frames including a specific number of samples are output while being overlapped
  • the FFT unit 17 performs FFT processing on the signal output from the rate conversion unit 16 on a frame-by-frame basis, outputs the relationship between frequency and level
  • the interference detection unit 18 However, the peak of the carrier output from the FFT unit 17 is detected, and when a plurality of peaks are detected, it is determined that there is an interference state. It is possible to shorten the time required for detection of , and increase the number of FFT points to improve the detection accuracy.
  • the controller of the personal computer 6 when the controller of the personal computer 6 receives data indicating that there is interference from the interference detector 18, it outputs a warning indicating that there is interference and starts measuring the duration. However, when the duration exceeds a certain period of time, an alarm is output to indicate that the degree of danger is high.
  • the present invention is suitable for radio equipment that can detect the presence or absence of interference quickly and accurately in air traffic control, and can notify the degree of risk according to the degree of interference to improve safety.

Landscapes

  • Engineering & Computer Science (AREA)
  • Quality & Reliability (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Monitoring And Testing Of Transmission In General (AREA)

Abstract

La présente invention a pour objet de fournir un dispositif radio qui peut déterminer rapidement et avec une grande précision s'il existe une interférence radio quelconque et qui peut en outre envoyer une notification d'un risque en fonction du degré de l'interférence radio, ce qui permet d'améliorer la sécurité. La solution selon l'invention porte sur un dispositif radio qui détermine s'il existe une interférence radio quelconque se produisant sur un côté réception lorsqu'une pluralité d'appareils radio utilisent la même fréquence pour effectuer des transmissions. Une unité de traitement de fenêtre 15 soumet un signal reçu ayant une fréquence porteuse comme fréquence centrale à un traitement de fenêtre de façon à effectuer un traitement FFT suivant d'une manière optimale. Une unité de conversion de débit 16 effectue une conversion de débit du signal de sortie provenant de l'unité de traitement de fenêtre 15 par l'utilisation d'une fréquence élevée, ce qui permet de délivrer des trames comprenant un nombre particulier d'échantillons, tout en amenant les trames à se chevaucher mutuellement. Une unité FFT 17 effectue le traitement FFT du signal de sortie à partir de l'unité de conversion de débit 16 sur une base trame par trame, délivrant ainsi une relation entre la fréquence et le niveau. Une unité de détermination d'interférence radio 18 détecte les pics de porteuses délivrés par l'unité FFT 17, et détermine un état d'interférence radio lorsqu'une pluralité de pics sont détectés.
PCT/JP2021/006839 2021-02-24 2021-02-24 Dispositif radio WO2022180676A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2023501706A JPWO2022180676A1 (fr) 2021-02-24 2021-02-24
PCT/JP2021/006839 WO2022180676A1 (fr) 2021-02-24 2021-02-24 Dispositif radio

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2021/006839 WO2022180676A1 (fr) 2021-02-24 2021-02-24 Dispositif radio

Publications (1)

Publication Number Publication Date
WO2022180676A1 true WO2022180676A1 (fr) 2022-09-01

Family

ID=83047829

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2021/006839 WO2022180676A1 (fr) 2021-02-24 2021-02-24 Dispositif radio

Country Status (2)

Country Link
JP (1) JPWO2022180676A1 (fr)
WO (1) WO2022180676A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008061268A (ja) * 2007-09-28 2008-03-13 Toshiba Corp 携帯電話機
JP2012049768A (ja) * 2010-08-26 2012-03-08 Japan Radio Co Ltd 受信装置
WO2018092581A1 (fr) * 2016-11-16 2018-05-24 株式会社日立国際電気 Dispositif radio

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008061268A (ja) * 2007-09-28 2008-03-13 Toshiba Corp 携帯電話機
JP2012049768A (ja) * 2010-08-26 2012-03-08 Japan Radio Co Ltd 受信装置
WO2018092581A1 (fr) * 2016-11-16 2018-05-24 株式会社日立国際電気 Dispositif radio

Also Published As

Publication number Publication date
JPWO2022180676A1 (fr) 2022-09-01

Similar Documents

Publication Publication Date Title
CN108847907B (zh) 一种民航甚高频无线电干扰信号自动监测装置
KR100824990B1 (ko) 낙뢰 검출
US9826310B2 (en) Loudspeaker device and wireless communication system
KR950002442B1 (ko) 오디오 신호처리 시스템을 검사하기 위한 장치
JP5106417B2 (ja) 周期定常ツールボックスを使用するノイズに埋め込まれたテレビ信号の存在の検出
WO2004093025A1 (fr) Unite d'appel d'urgence
JP2000338234A (ja) 監視システム
GB2509847A (en) Apparatus for removing partial discharge noise and method for diagnosing partial discharge
US20220326366A1 (en) Detection device and detection system
WO2022180676A1 (fr) Dispositif radio
JP4249711B2 (ja) 無線通信システムにおける干渉検出
JPH06244768A (ja) Ｔｄｍａ移動通信装置のｒｆパワーレベルモニタ装置
WO2003102610A3 (fr) Procede et dispositif de detection dans le domaine frequentiel en fonction d'une mesure dans le domaine temporel
JP6647424B2 (ja) 無線機
US4683459A (en) Alarm system test annunciator
US7606543B1 (en) Signal quality indicator apparatus and method particularly useful for mobile telephones
KR101429451B1 (ko) 다채널 고층관측용 라디오존데 수신 장치
US11469832B2 (en) Control station device and alarm issue method for control station device
US7577412B2 (en) System and method for detecting narrow bandwidth signal content to determine channel occupancy
JP6437848B2 (ja) 受信解析装置
US20100198559A1 (en) Real time monitoring and control of communications networks and radio frequency distribution networks
AU2004305621B2 (en) Method for monitoring the time synchronisation of emitters in a common wave network
EP4028784B1 (fr) Procédé de mesure et d'affichage du rapport signal/bruit audio
Balint et al. HF Noise Measurement in the Western Part of Romania
JPH05161610A (ja) 緊急通報装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21927779

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2023501706

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21927779

Country of ref document: EP

Kind code of ref document: A1