JP2007163406A - Radar reception pulse separator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radar reception pulse separator capable of selection-extracting only a pulse train signal having a desired PRI (Pulse Repetition Interval) out of the pulse train signals, and capable of sounding a speaker based on the pulse train signal, even when the pulse train signals having the specified PRIs of a plurality of targets are received overlappedly. <P>SOLUTION: The pulse train signals transmitted from radar systems in the plurality of targets are received by a reception circuit 1 and are digitized by an A/D converter 2, a digital PRI detection-selecting part 3 selection-outputs thereafter the second digital pulse train signal having the desired target PRI out of the first digital pulse train signals digitized therein, and a speaker driving circuit 4 pulse-expands to sound the speaker 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a radar reception pulse separation device that receives a pulse train signal transmitted from a radar device or the like and converts it into sound.

  The pulse train signal transmitted from the radar device or the like is received by the receiving circuit of the radar reception pulse separation device, and the characteristics of this pulse train signal are extracted and compared with the known features of the pulse train signal transmitted by the desired target. If the speaker is made to sound when the two match, it can be known by listening to the sound produced by the speaker that the desired target has entered the monitored area of the radar reception pulse separation device. Such a radar reception pulse separation device is also called an acoustic filter device. For example, a target such as an aircraft that transmits a pulse train signal of a specific PRI (Pulse Repetition Interval) from a mounted radar device is within an airspace control range. It is possible to recognize with the ear that it has invaded, and it is also possible to recognize what the target is from the pitch of the sound.

  Therefore, in the conventional radar reception pulse separation device, the pulse train signal transmitted from the radar device or the like is received by the receiving circuit, the analog processing is performed by the PRI measuring unit or the like comprising an analog circuit, and the characteristics of the received pulse train signal For example, a PRI is detected, and when the PRI matches a known desired target PRI, it is determined that the desired target has been detected (see, for example, Patent Document 1). If the speaker is sounded using this determination result, it can be recognized by the ear.

Japanese Patent Laid-Open No. 10-38999 (pages 2 and 3, FIG. 1)

  As described above, the conventional radar reception pulse separation device described in Patent Document 1 uses an analog circuit to identify a desired target equipped with a radar device that transmits a pulse train signal having a specific PRI. Since the identification processing is performed by, for example, an aircraft enters a territorial airspace at the same time, such as a plurality of targets each equipped with a radar device that transmits a pulse train signal having a specific PRI, However, it is difficult to selectively extract only pulse train signals having a specific target PRI from the pulse train signals.

  The present invention has been made to solve the above-described problems. Even if a plurality of pulse train signals having a specific PRI are received in an overlapping manner, the desired target is identified from the pulse train signals. It is an object of the present invention to provide a radar reception pulse separation device that can selectively extract only a pulse train signal having the PRI and sound a speaker based on the pulse train signal.

  A radar reception pulse separation device according to the present invention receives a pulse train signal transmitted from a plurality of target radar devices having a specific PRI by a receiving circuit, digitizes the pulse train signal by an A / D converter, The PRI detection / selection unit selects and outputs a second digital pulse train signal having a desired target specific PRI from the first digital pulse train signals output from the A / D converter, and the speaker drive circuit The second digital pulse train signal is subjected to pulse expansion in order to sound a speaker.

  According to the present invention, since the received pulse train signal is digitized, a digital pulse train signal having a desired target PRI is selected and outputted, so that pulse train signals having a plurality of target specific PRIs overlap. Can be selected and extracted from the pulse train signal, and only a pulse train signal having a specific PRI of a desired target can be selected and a speaker can be sounded based on the pulse train. There is an effect that a desired target can be identified.

  Hereinafter, the radar reception pulse separation device according to the embodiment of the present invention will be described with respect to a case where pulse train signals from a plurality of targets each equipped with a radar device each transmitting a pulse train signal having a specific PRI are received.

Embodiment 1 FIG.
FIG. 1 is a schematic configuration diagram of Embodiment 1 of a radar reception pulse separation device according to the present invention.

  The radar reception pulse separation device simultaneously receives a radio frequency reception signal (RXRF) obtained by modulating a pulse train signal transmitted from a plurality of targets each equipped with a radar device that transmits a pulse train signal having a specific PRI by a receiving circuit 1. The pulse train signal received, processed and demodulated is digitized by the A / D converter 2 to obtain a first digital pulse train signal.

  Next, the digital PRI detection selection unit 3 selects and outputs a second digital pulse train signal having a desired target PRI from the first digital pulse train signals. The second digital pulse train signal output from the digital PRI detection / selection unit 3 is subjected to pulse expansion by the speaker driving circuit 4 so as to have a time interval in which the speaker can be driven in order to sound the speaker, and the speaker 5 Sounds at a height corresponding to the desired target PRI.

  The digital PRI detection / selection unit 3 detects the PRI included in the first digital pulse train signal, determines whether or not the detected PRI matches the desired target PRI, and selects it if it matches. A PRI detection unit that outputs a signal, and whether or not to pass a pulse train included in the first digital pulse train signal based on the selection signal output from the PRI detection unit, and has a desired target PRI It comprises a selection pulse train pass filter that passes only the second digital pulse train signal.

  Therefore, after digitizing the received pulse train signal, the PRI detection unit determines whether or not it matches the desired target PRI, and if it matches, the selected pulse train pass filter selectively outputs the result to obtain the desired target PRI. It is possible to emit a sound with a corresponding height.

FIG. 2 shows a synchronous digital PRI detection / selection unit 3a for detecting a desired target PRI by performing parallel synchronization processing on the first digital pulse train signal as the digital PRI detection / selection unit 3 in the schematic configuration diagram of FIG. 1 is a configuration diagram of a radar reception pulse separation device using a radar. FIG. The same reference numerals as those in FIG.

In FIG. 2, a synchronous digital PRI detection / selection unit 3a includes a parallel synchronization processing unit 6 having a plurality of detection circuits that perform synchronization detection on the output of the A / D converter 2 and output a synchronization detection signal; A PRI detection / determination unit 7 that detects a PRI based on synchronization detection signals output from a plurality of detection circuits, further determines whether the PRI is a desired target PRI, and outputs a selection signal if the PRI is a desired target PRI. A second detector having a desired target PRI from the first digital pulse train signal output from the A / D converter 2 based on the selection signal output from the PRI detection determination unit 7. And a selected pulse train pass filter 8 for selecting and outputting the pulse train signal.

Next, the operation of the radar reception pulse separation device shown in FIG. 2 will be described. FIG. 3 is an operation waveform diagram for explaining the operation of the radar reception pulse separation device using the synchronous digital PRI detection / selection unit 3a .

FIG. 3A shows a first digital pulse train signal digitized by the A / D converter 2 of FIG. 2, and the radio frequency reception signal of the pulse train signal transmitted from the radar device of the target A and the target As an example, the radio frequency reception signal of the pulse train signal transmitted from the radar device of B is simultaneously received by the reception circuit 1, demodulated by reception processing, and then digitized by the A / D converter 2. Here, it is assumed that the desired target is the target B, and the second digital pulse train signal having the PRI of the target B is selected from the first digital pulse train signals by the synchronous digital PRI detection / selection unit 3a. The output waveform selected and output is shown in FIG.

When the target A and the target B enter the monitoring range of the radar reception pulse separation device almost simultaneously, the radio frequency reception signal obtained by modulating the pulse train signal transmitted from the radar device of the target A and the radar device of the target B are transmitted. The radio frequency reception signal obtained by modulating the modulated pulse train signal is simultaneously overlapped and received and demodulated by the receiving circuit 1, digitized by the A / D converter 2, and the target A pulse train signal and the target B pulse train signal. A first digital pulse train signal as shown in FIG. 3A is input to the synchronous digital PRI detection / selection unit 3a .

  Next, the rising edge of the first digital pulse train signal is detected by a plurality of detection circuits provided in the parallel synchronization processing unit 6. The detection circuit is set with a desired target PRI value according to an instruction from the operator. As shown in FIG. 3A, after detecting the first rise a-1, the PRI starts from that point. Each time elapses, the presence or absence of the pulse rise is checked in the range of the rise gate width, and it is detected that synchronization is detected when the pulse rise is detected. (Here, it is assumed that it is set to four times as an example.) When the synchronization is detected continuously, the operation is performed so as to output a synchronization detection signal.

  That is, among the waveforms of the first digital pulse train signal in FIG. 3A, the first pulse trains a-1, b-1, which start with the pulse of the target A and the pulse of the target A and B-1, When the first detection circuit of the plurality of detection circuits detects the rising edge of the pulse a-1 with respect to a-2, b-2,..., the first detection circuit is set by the operator. Every time the PRI time elapses, the presence or absence of the rising of the pulse is monitored within the range of the rising gate width, and if the rising is detected, the synchronization is detected and the number of synchronizations is counted. In the target a-2, since there is no rising edge of the pulse, the first detection circuit does not detect synchronization. In FIG. 3A, the first detection circuit can detect a rising edge at a-6, but if the detection circuit does not detect the first rising edge continuously, Reset is done without counting the number of synchronizations.

  On the other hand, for the next pulse train b-1, a-2, b-2, a-3. When the second detection circuit detects the rise of the pulse, the second detection circuit monitors the rise of the pulse within the range of the rise gate width every time the PRI time set by the operator elapses. Is detected, the number of synchronizations is counted. Since b-2 of target B has a rising edge of the pulse, the second detection circuit detects the synchronization and counts the number of synchronizations as one. Similarly, in the target B, b-3, b-4, and b-5, the second detection circuit counts the number of synchronizations, and detects that the predetermined number of times is continuously detected. Output a signal. Based on the synchronization detection signal output from the second detection circuit, the PRI detection determination unit 7 matches the detected PRI included in the first digital pulse train signal with the desired target PRI set by the operator. It is determined that a selection signal is output.

  Next, based on the selection signal output from the PRI detection determination unit 7, the selection pulse train pass filter 8 selects a desired digital pulse train signal set by the operator from the first digital pulse train signal output from the A / D converter 2. The second digital pulse train signal having the PRI of the target B is selectively passed to output a second digital pulse train signal as shown in FIG.

  The speaker drive circuit 4 performs pulse expansion on the second digital pulse train signal output from the selected pulse train pass filter 8 so as to have a time interval capable of driving the speaker, and the speaker 5 corresponds to the PRI of the desired target B. Sounds high.

  In the above, the case where the desired target B to be identified from the target A has entered the monitoring range of the radar reception pulse separation device has been described as an example. However, if the target has a specific PRI, the number of targets is further increased. It goes without saying that even if the frequency increases, it is possible to emit a sound having a height corresponding to the PRI of the desired target B by the operation of the same radar reception pulse separation device.

  As described above, after the received pulse train signal is digitized, the synchronization detection is performed by the parallel synchronization processing unit having a plurality of detection circuits to detect the PRI, and when it is determined that it matches the desired target PRI, Since the pulse train signal having the target PRI is selectively output, the pulse is expanded and the speaker is sounded, even if a plurality of targets simultaneously enter the monitoring range of the radar reception pulse separation device, the desired target can be selected from among them. And a sound having a height corresponding to a desired target PRI can be produced in real time.

  By the way, the received pulse train signal is digitized, and once stored in the memory unit, the stored digital pulse train signal is read out and detected in synchronization by a single synchronization processing unit. If the PRI detection determination unit determines whether or not it matches the desired target PRI, it is not necessary to provide a plurality of detection circuits, and the circuit configuration can be simplified.

4 temporarily stores a predetermined amount of the first digital pulse train signal in the memory unit as the digital PRI detection / selection unit 3 in the schematic configuration diagram of FIG. 1, and each pulse train of the predetermined amount of signal is stored in the memory unit. It is a block diagram of a radar reception pulse separation device using a synchronous digital PRI detection / selection unit 3b provided with a memory unit 9 for detecting a desired target PRI by performing synchronous detection for each pulse train with respect to an input. . The same reference numerals as those in FIG.

In FIG. 4, a synchronous digital PRI detection / selection unit 3b having a memory unit temporarily stores a predetermined amount of the first digital pulse train signal that is the output of the A / D converter 2. And, for each pulse train input of this predetermined amount of signal, synchronous detection is performed for each pulse train, and a synchronization detection signal is output when it is continuously detected that synchronization is performed a predetermined number of times or more. A single synchronization processing unit 10 having a detection circuit, and when the synchronization detection signal is output from the detection circuit, it is determined that the PRI included in the first digital pulse train signal matches the desired PRI It comprises a memory-compatible PRI detection / determination unit 11 that outputs a signal and outputs an instruction signal for storing the next predetermined amount of signal in the memory unit 9 after the determination of the predetermined amount of signal is completed. .

Since the synchronous digital PRI selection unit 3b including the memory unit is configured as described above, a plurality of detection circuits are not required, and thus cannot be operated in real time. There is an effect that a PRI detection selection unit can be realized.

Embodiment 2. FIG.
In the radar reception pulse separation apparatus according to the first embodiment, the case of using a synchronous digital PRI detection / selection unit and a synchronous digital PRI detection / selection unit including a memory unit has been described. However, there are a plurality of PRI detection units. It is also possible to use an FIR circuit control type digital PRI detection / selection unit configured by using a parallel FIR processing unit including a FIR (Finite Impulse Response) circuit. Here, the finite impulse response means that the output signal when an impulse is input converges to 0 in a finite time, and the FIR circuit is a circuit that functions as a so-called FIR filter.

FIG. 5 shows a digital PRI detection / selection unit 3 in the schematic configuration diagram of FIG. 1, which selects a desired target PRI by performing parallel FIR processing on the first digital pulse train signal. It is a block diagram of the radar receiving pulse separation apparatus using the part 3c . The same reference numerals as those in FIG.

In FIG. 5, an FIR circuit control type digital PRI detection / selection unit 3c adds a plurality of delay units, a plurality of multipliers, and outputs of these multipliers to the output of the A / D converter 2. A plurality of FIR circuits that perform FIR processing and output addition processing results, and perform PRI detection based on the addition processing results output from the plurality of parallel FIR processing units 12 and the plurality of FIR circuits. It is determined whether it is a target PRI or not, and if it is a desired target PRI, a selection signal is outputted and a FIR circuit controlled PRI detection determination unit 13 for setting and controlling the multiplication value of each multiplier of the FIR circuit. A desired one of the first digital pulse train signals output from the A / D converter 2 based on the selection signal output from the PRI detection unit and the FIR circuit control type PRI detection determination unit 13 And a selection pulse train pass filter 8 which selects the second pulse train signal having a target of PRI outputs.

Next, the operation of the radar reception pulse separation device shown in FIG. 5 will be described. FIG. 6 is an operation explanatory diagram for explaining the operation of the radar reception pulse separation device using the digital PRI detection / selection unit 3c controlled by the FIR circuit.

  FIG. 6A shows the first digital pulse train signal digitized by the A / D converter 2 of FIG. 5, and the radio frequency reception signal of the pulse train signal transmitted from the radar device of the target C and the target An example is a case where a radio frequency reception signal of a pulse train signal transmitted from a radar device of D is simultaneously received by the reception circuit 1, demodulated by reception processing, and then digitized by the A / D converter 2. Here, it is assumed that the desired target is the target C.

  FIG. 6B shows an FIR circuit based on the configuration and operation of the FIR circuit and the addition processing result output from the FIR circuit for each pulse train input of the first digital pulse train signal of FIG. FIG. 10 is an operation explanatory diagram for explaining the operation of the control type PRI detection determination unit 13.

  The FIR circuit is a ladder circuit in which a plurality of delay devices 14 connected in series and a plurality of multipliers 15 connected in parallel are arranged in a ladder shape for each pulse train input of the first digital pulse train signal. And an addition processing unit 16 that adds the outputs of a plurality of multipliers 15.

  The delay unit 14 gives a delay of a predetermined unit time to the input pulse train. The multiplier 15 is set and controlled by the FIR circuit control type PRI detection determination unit 13 so as to set a multiplication value corresponding to the PRI of the target C. FIG. 6B shows an example in which the PRI of the target C is a time interval with four delay devices 14 sandwiched therebetween, that is, a time interval four times the unit time of the delay device 14. Multiplier value 1 is set to multipliers 15 on both sides of one delay unit 14, and multiplier value 0 is set to the three inner multipliers 15 sandwiched therebetween.

  6B, four delay devices 14 are arranged on the left side of the drawing corresponding to the PRI of the target C, but in order to simplify the description in the drawing, For the three PRIs on the right side, only one delay unit 14 and one multiplier 15 are illustrated where four delay units 14 are arranged, and the remaining three delay units 14 are connected to the three PRI units. The multiplier 15 is omitted from the illustration. Actually, for any PRI of the target C, a ladder circuit is formed by arranging four delay devices 14 and four multipliers 15 connected to the delay devices 14 respectively.

  Further, the FIR circuit control type PRI detection determination unit 13 determines that the PRI included in the first digital pulse train signal is a desired target when the addition processing result output from the addition processing unit 16 of the FIR circuit exceeds a predetermined threshold. And a threshold value judgment unit 17 for judging that the two coincide with the PRI, and an output unit 18 for outputting a selection signal to the selection pulse train pass filter 8 shown in FIG.

  Therefore, even if the target D pulse trains d-1, d-2,... In FIG. 6A are input to the FIR circuit, the PRI of the target D is four times the unit time of the delay unit 14. Therefore, the addition result obtained by multiplying each pulse of the pulse train delayed by the delay unit 14 by the multiplication value by the multiplier 15 and adding the output of the multiplier 15 by the addition processing unit 16 exceeds a predetermined threshold value. In this case, the threshold determination unit 17 does not determine that the PRI included in the first digital pulse train signal matches the PRI of the desired target C, but the pulse train c− of the target C in FIG. When 1, c-2, c-3, c-4, c-5,... Are input to the FIR circuit, the PRI of the target A is exactly four times the unit time, so the addition processing result Exceeds a predetermined threshold value, and the threshold value judgment unit 17 It is determined that the PRI to be included in the scan sequence signal matches the PRI of the desired target C, the selection signal from the output unit 18 is output. The single operation of the FIR circuit is as described above.

As shown in FIG. 5, the PRI detection unit of the FIR circuit control type PRI detection selection unit 3c includes a parallel FIR processing unit 12 having a plurality of FIR circuits, and each of the first digital pulse train signals. Each FIR circuit corresponding to each pulse train performs FIR processing, and each FIR circuit outputs each addition processing result.

The operation of the FIR circuit-controlled PRI detection selection unit 3c will be described in detail below with reference to FIGS.

  Among the waveforms of the first digital pulse train signal shown in FIG. 6A, the first pulse trains c-1, d-1, c- that start with the c-1 pulse of the target C and comprise the pulses of the target C and the target D are shown. .., D-2..., The first FIR circuit of the plurality of FIR circuits performs FIR processing, and c-1, c-2, c-3, c, which are target C pulse trains. -4... Are added from the first FIR circuit. Since this is a pulse train of the desired target C, the result of this addition processing exceeds a predetermined threshold value, so that the threshold value judgment unit 17 judges that the PRI included in the first digital pulse train signal matches the PRI of the desired target C. Then, a selection signal is output from the output unit 18.

  Next, the selection pulse train pass filter 8 is configured to output the first digital pulse train signal output from the A / D converter 2 based on the selection signal output from the output unit 18 of the FIR circuit control type PRI detection determination unit 13. The second digital pulse train signal having the PRI of the desired target C is selectively passed through, the speaker driving circuit 4 performs pulse expansion, and the speaker 5 emits a sound having a height corresponding to the PRI of the desired target C. .

  On the other hand, among the waveforms of the first digital pulse train signal shown in FIG. 6A, the next pulse trains d-1, c-2 including the target C and the pulse of the target D, starting from the pulse d-1 of the target D, The second FIR circuit performs FIR processing on d-2, c-3,..., and the result of addition processing for d-1, d-2,. However, since this is not a desired target, the addition processing result does not exceed the threshold value.

  As described above, the FIR circuit corresponding to each pulse train of the first digital pulse train signal performs the FIR processing, and the FIR circuit when the addition processing result of any of the plurality of FIR circuits exceeds a predetermined threshold value. Since the selection signal is output from the control-type PRI detection / determination unit 13, even if a plurality of targets enter the monitoring area of the radar reception pulse separation device at the same time, a desired target is identified from them. Thus, there is an effect that a sound having a height corresponding to a desired target PRI can be played in real time.

  By the way, the received pulse train signal is digitized, and once stored in the memory unit, the stored digital pulse train signal is read out, and FIR processing is performed by a single FIR processing unit. If the FIR circuit control type PRI detection / determination unit determines whether or not it matches the desired target PRI, it is not necessary to provide a plurality of FIR circuits, and the circuit configuration can be simplified.

7 includes a single FIR processing unit 19 and a memory-compatible FIR circuit-controlled PRI detection determination unit 20 instead of the PRI detection unit including the single synchronization processing unit 10 and the memory-compatible PRI detection determination unit 11 of FIG. Configuration diagram of a radar reception pulse separating apparatus using a PRI detection unit and a digital PRI detection selection unit 3d of the FIR circuit control type that includes a memory unit 9 that temporarily stores a predetermined amount of the first digital pulse train signal. It is. The same reference numerals as those in FIG.

In FIG. 7, an FIR circuit control type digital PRI detection / selection unit 3d having a memory unit temporarily stores a predetermined amount of the first digital pulse train signal that is the output of the A / D converter 2. Unit 9, a single FIR processing unit 19 having a single FIR circuit that performs an FIR process for each pulse train and outputs an addition processing result for each pulse train input of the predetermined amount of signal, When the addition processing result of the FIR circuit exceeds a predetermined threshold value, it is determined that the PRI included in the first digital pulse train signal matches the desired target PRI, and a selection signal is output to determine a predetermined amount of signal. After the operation is completed, an instruction signal for storing the next predetermined amount of signal is output to the memory unit, and the multiplication value of each multiplier of the single FIR circuit is set and controlled. And a and RI detection determining unit.

Since the FRI circuit control type digital PRI selection unit 3d having a memory unit is configured as described above, a plurality of FIR circuits are not required, and thus cannot be operated in real time, but a simple circuit configuration. Thus, the digital PRI detection / selection unit can be realized.

Embodiment 3 FIG.
The radar reception pulse separation device of the first embodiment uses a synchronous digital PRI detection selection unit, and the laser reception pulse separation device of the second embodiment uses an FIR circuit control type digital PRI detection selection unit. However, it is also possible to use an FFT-type digital PRI detection / selection unit in which the PRI detection unit is configured by using a parallel FFT processing unit including a plurality of FFT (Fast Fourier Transform) circuits. is there.

FIG. 8 shows a digital PRI detection / selection unit 3 in the schematic configuration diagram of FIG. 1. The first digital pulse train signal is subjected to parallel FFT processing, and the peak of the obtained periodogram is detected to obtain a desired target PRI. It is a block diagram of the radar receiving pulse separation apparatus using the FFT type digital PRI detection selection part 3e to detect. The same reference numerals as those in FIG.

In FIG. 8, the FFT digital PRI detection / selection unit 3 e performs an FFT process on the output of the A / D converter 2 and includes a plurality of FFT processing units 21 having a plurality of FFT circuits that output a periodogram. An amplitude peak detection unit 22 for detecting the peak of each periodogram output from the FFT circuit of the above, and calculating a PRI only for a peak that exceeds the threshold among the peaks detected by the amplitude peak detection unit 22, It is determined whether or not this PRI is a desired target PRI, and if it is a desired target PRI, a PRI detection unit including a frequency peak type PRI detection determination unit 23 that outputs a selection signal, and a frequency peak type PRI detection determination unit A second digital signal having a desired target PRI out of the first digital pulse train signal output from the A / D converter 2 based on the selection signal output from the A / D converter 2. And a selection pulse train pass filter 8 which selects and outputs the pulse train signal.

Next, the operation of the radar reception pulse separation device shown in FIG. 8 will be described. FIG. 9 is an operation waveform diagram for explaining the operation of the radar reception pulse separation device using the FFT type digital PRI detection / selection unit 3e .

  FIG. 9A shows the first digital pulse train signal digitized by the A / D converter 2 of FIG. 8, and the radio of the pulse train signal transmitted from the radar apparatus of the target E whose PRI is PRI1. The radio frequency reception signal and the radio frequency reception signal of the pulse train signal transmitted from the radar apparatus of the target F whose PRI is PRI2 are simultaneously received by the reception circuit 1 and demodulated by the reception process, and then the A / D converter 2 The case where it is digitized is taken as an example. Here, it is assumed that the desired target is the target E whose PRI is PRI1.

  FIG. 9B shows a periodogram obtained by performing FFT processing in the FFT circuit on the input of the FFT time range shown in the diagram of the first digital pulse train signal of FIG. 9A. .

Now, the operation of the FFT-type PRI detection / selection unit 3e will be described in detail below with reference to FIGS.

  9B obtained by FFT processing by the FFT circuit of the parallel FFT processing unit 21, which is set to input a signal in the FFT time range on the time axis shown in FIG. 9A. In the periodogram thus obtained, peaks are obtained at the reciprocal frequency position of PRI1 which is the PRI of the target E and the reciprocal frequency position of PRI2 which is the PRI of the target F. The frequency position and intensity of the periodogram peak are detected by the amplitude peak detection unit 22. In this example, the frequency peak type PRI detection determination unit 23 determines that the frequency position peak corresponding to PRI1 has exceeded a predetermined threshold. Therefore, the PRI is calculated only for this peak by obtaining the reciprocal of the frequency value of this peak, and since this PRI (= PRI1) matches PRI1 which is the PRI of the desired target E, the first digital It is determined that the PRI included in the pulse train signal matches the PRI of the desired target E, and a selection signal is output. Subsequent operations are the same as those in the first and second embodiments.

  By the way, there is a problem that the intensity of the peak appearing in the periodogram varies depending on how the FFT time range is set with respect to the input of the first digital pulse train signal. In FIG. 9B, since the desired target is E, the desired target could be identified. However, if the desired target is F, the corresponding peak exceeds a predetermined threshold value. Cannot be identified.

  Therefore, as shown in FIG. 8, a parallel FFT processing unit 21 having a plurality of FFT circuits is provided, and the first digital pulse train signal is divided into a plurality of time ranges, that is, FFT time ranges, corresponding to each time range. The first digital pulse train signals to be input are respectively input to the FFT circuits in which the time ranges are set, and the respective periodograms are output from the respective FFT circuits.

  Therefore, since the radar reception pulse separation device according to the third embodiment includes the parallel FFT processing unit 21 having a plurality of FFT circuits having different FFT time ranges, regardless of the magnitude of the desired target PRI value, It is possible to reliably identify the desired goal.

  As described above, after the received pulse train signal is digitized, the first digital pulse train signal is divided into a plurality of time ranges, and the pulse train of each time range is subjected to FFT by a plurality of FFT circuits corresponding to each time range. The PRI is calculated only for a peak that exceeds a predetermined threshold among the peaks detected in the obtained periodogram, and when it is determined that it matches the PRI of the desired target, the PRI of the desired target is calculated. Since the pulse train signal is selectively output, the pulse is expanded and the speaker is sounded, even if multiple targets enter the monitoring range of the radar reception pulse separation device at the same time, the desired target is identified from among them There is an effect that a sound having a height corresponding to a desired target PRI can be played in real time.

Embodiment 4 FIG.
In the radar reception pulse separation device according to the third embodiment, the case where the PRI detection unit uses a parallel FFT processing unit including a plurality of FFT circuits has been described. However, the parallel autocorrelation processing in which the PRI detection unit includes a plurality of autocorrelation circuits is illustrated. It is also possible to use an autocorrelation type digital PRI detection / selection unit configured by using a unit.

FIG. 10 shows a digital PRI detection / selection unit 3 in the schematic configuration diagram of FIG. 1, which performs parallel autocorrelation processing on the first digital pulse train signal and detects the peak of the obtained autocorrelogram. It is a block diagram of a radar reception pulse separation device using an autocorrelation type digital PRI detection selection unit 3f for detecting PRI. The same reference numerals as those in FIG.

In FIG. 10, the autocorrelation type digital PRI detection / selection unit 3 f performs parallel autocorrelation processing including a plurality of autocorrelation circuits that perform autocorrelation processing on the output of the A / D converter 2 and output an autocorrelogram. Unit 24, amplitude peak detection unit 22 for detecting the peak of each autocorrelogram output from a plurality of autocorrelation circuits, and for peaks exceeding the threshold among the peaks detected by amplitude peak detection unit 22 A PRI detection unit comprising a time peak type PRI detection determination unit 25 that calculates a PRI only, determines whether the PRI is a desired target PRI, and outputs a selection signal if the PRI is a desired target PRI, A desired target P is selected from the first digital pulse train signals output from the A / D converter 2 based on the selection signal output from the time peak PRI detection determination unit 25. And a selection pulse train pass filter 8 which selects the second pulse train signal having an I output.

Next, the operation of the radar reception pulse separation device shown in FIG. 10 will be described. FIG. 11 is an operation waveform diagram for explaining the operation of the radar reception pulse separation device using the autocorrelation type digital PRI detection / selection unit 3f .

  FIG. 11A shows the first digital pulse train signal digitized by the A / D converter 2 of FIG. 10, and the radio of the pulse train signal transmitted from the radar device of the target G whose PRI is PRI3. The frequency reception signal and the radio frequency reception signal of the pulse train signal transmitted from the target H radar apparatus whose PRI is PRI4 are simultaneously received by the reception circuit 1 and demodulated by the reception processing, and then the A / D converter 2 The case where it is digitized is taken as an example. Here, it is assumed that the desired target is the target G whose PRI is PRI3.

  FIG. 11B shows an autocorrelation obtained by performing autocorrelation processing by an autocorrelation circuit on the input of the autocorrelation processing time range shown in the diagram of the first digital pulse train signal of FIG. Shows the program.

The operation of the autocorrelation type PRI detection selection unit 3f will be described below with reference to FIGS.

  11 obtained by autocorrelation processing by the autocorrelation circuit of the parallel autocorrelation processing unit 24 set to input a signal in the time range of autocorrelation processing on the time axis shown in FIG. In the autocorrelogram shown in (b), peaks are obtained at the time position of PRI3 which is the PRI of the target G and the time position of PRI4 which is the PRI of the target H. The time position and intensity of the peak of the autocorrelogram are detected by the amplitude peak detection unit 22, but in this example, the time peak type PRI detection determination unit 25 sets a predetermined threshold value for the peak of the time position corresponding to PRI3. Since this is exceeded, the PRI is calculated only for this peak as the time value of this peak itself, and since this PRI (= PRI3) coincides with the PRI3 of the desired target G, the first It is determined that the PRI included in the digital pulse train signal matches the PRI of the desired target G, and a selection signal is output. Subsequent operations are the same as those in the third embodiment.

  By the way, the intensity of the peak appearing in the autocorrelogram is determined by how the autocorrelation processing time range is set with respect to the input of the first digital pulse train signal, as in the periodogram of the third embodiment. There is a problem of fluctuating depending on.

  Therefore, as shown in FIG. 10, a parallel autocorrelation processing unit 24 having a plurality of autocorrelation circuits is provided, and the first digital pulse train signal is divided into a plurality of time ranges, that is, autocorrelation processing time ranges. The first digital pulse train signals corresponding to the time ranges are inputted to the autocorrelation circuits corresponding to the respective time ranges, and the respective autocorrelograms are outputted from the respective autocorrelation circuits.

  Therefore, the radar received pulse separation apparatus according to the fourth embodiment includes the parallel autocorrelation processing unit 24 having a plurality of autocorrelation circuits having different autocorrelation time ranges, so that the desired target PRI value can be increased or decreased. Regardless, it is possible to reliably identify the desired goal.

  As described above, after the received pulse train signal is digitized, the first digital pulse train signal is divided into a plurality of time ranges, and each time train pulse train is divided into a plurality of autocorrelation circuits corresponding to each time range. The autocorrelation processing is performed, and the PRI is calculated only for the peaks exceeding the predetermined threshold among the peaks detected in the obtained autocorrelogram, and when it is determined that it matches the PRI of the desired target, the desired target Since the pulse train signal having the PRI of the above is selectively output, the pulse is expanded and the speaker is sounded, even if a plurality of targets enter the monitoring area of the radar reception pulse separation device at the same time, a desired target can be selected from them. There is an effect that a sound having a pitch corresponding to the desired target PRI can be played in real time.

  By the way, in the first to fourth embodiments, the reception circuit simultaneously receives radio frequency reception signals obtained by modulating pulse train signals transmitted from a plurality of targets each equipped with a radar device that transmits a pulse train signal having a specific PRI. Although only the case where the A / D conversion is performed on the pulse train signal that has been subjected to reception processing and demodulated has been described, the radio frequency reception signal is down-converted to an intermediate frequency by the reception circuit, and the reception signal of the intermediate frequency is converted to A Even if the radar reception pulse separation device is configured to perform digital signal processing by performing D / D conversion, a desired target is identified from a plurality of targets and a sound having a height corresponding to the PRI of the desired target is real-time. Needless to say, a similar effect can be obtained.

1 is a schematic configuration diagram of Embodiment 1 of a radar reception pulse separation device according to the present invention. FIG. It is a block diagram of the radar receiving pulse separation apparatus using the synchronous digital PRI detection selection part 3a . It is an operation | movement waveform diagram for demonstrating operation | movement of the radar receiving pulse separation apparatus using the synchronous digital PRI detection selection part 3a . 3 is a configuration diagram of a radar reception pulse separation device using a synchronous digital PRI detection / selection unit 3b including a memory unit 9. FIG. It is a block diagram of a radar reception pulse separation device using an FIR circuit control type digital PRI detection and selection unit 3c . It is operation | movement explanatory drawing for demonstrating operation | movement of the radar receiving pulse separation apparatus using the digital PRI detection selection part 3c of a FIR circuit control type. 2 is a configuration diagram of a radar reception pulse separation device using an FIR circuit control type digital PRI detection selection unit 3d including a memory unit 9. FIG. It is a block diagram of the radar receiving pulse separation apparatus using the FFT type digital PRI detection selection part 3e . It is an operation waveform diagram for explaining the operation of the radar reception pulse separation device using the FFT type digital PRI detection / selection unit 3e . It is a block diagram of a radar receiving pulse separation apparatus using a digital PRI detection selection portion 3f of the autocorrelation equation. It is an operation waveform diagram for explaining the operation of the radar reception pulse separation device using the autocorrelation type digital PRI detection / selection unit 3f .

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reception circuit 2 A / D converter 3 Digital PRI detection selection part 4 Speaker drive circuit 5 Speaker

Claims (8)

A receiving circuit for receiving transmission pulse train signals of a plurality of radar devices each transmitting a pulse train signal of a specific PRI;
An A / D converter that digitizes the received transmission pulse train signal and outputs a first digital pulse train signal;
A digital PRI detection / selection unit that selects a desired PRI signal from the first digital pulse train signal and outputs it as a second digital pulse train signal;
A speaker driving circuit that performs pulse expansion to ring the second digital pulse train signal;
A radar received pulse separation device comprising: The digital PRI detection selection unit
A PRI detection unit that determines whether or not the PRI included in the first digital pulse train signal matches a desired PRI, and outputs a selection signal if they match,
A selection pulse train pass filter that selects and passes a second digital pulse train signal included in the first digital pulse train signal based on the selection signal;
The radar received pulse separation device according to claim 1, wherein The PRI detector
A detection circuit that performs synchronization detection for each pulse train with respect to each pulse train input of the first digital pulse train signal, and outputs a synchronization detection signal when it is continuously detected that synchronization is performed a predetermined number of times or more. A plurality of parallel synchronization processing units corresponding to each of the pulse trains;
A PRI detection determination unit that determines that the PRI included in the first digital pulse train signal matches a desired PRI when the synchronization detection signal is output from any of the detection circuits, and outputs a selection signal;
The radar reception pulse separation device according to claim 2, comprising: The PRI detector
A memory unit for temporarily storing a predetermined amount of the first digital pulse train signal;
Single detection that outputs synchronous detection signal when synchronous detection is performed for each pulse train and synchronization is performed more than a predetermined number of times for each pulse train input of the predetermined amount of signal A single synchronization processor having a circuit;
When the synchronization detection signal is output, it is determined that the PRI included in the first digital pulse train signal matches the desired PRI, and a selection signal is output, and after the determination of the predetermined amount of signal is completed A memory-compatible PRI detection / determination unit for outputting an instruction signal for storing a next predetermined amount of signal in the memory unit;
The radar reception pulse separation device according to claim 2, comprising: The PRI detector
A ladder circuit in which a plurality of delay devices connected in series and a plurality of multipliers connected in parallel are arranged in a ladder shape with respect to each pulse train input of the first digital pulse train signal; and the plurality of multiplications An addition processing unit for adding the outputs of the multipliers, and for each pulse train, an FIR circuit that performs multiplication processing by the plurality of multipliers and addition processing by the adders and outputs an addition processing result is provided for each pulse train. A corresponding parallel FIR processing unit;
When the addition processing result of any of the FIR circuits exceeds a predetermined threshold, it is determined that the PRI included in the first digital pulse train signal matches the desired target PRI, and a selection signal is output. An FIR circuit-controlled PRI detection / determination unit for setting and controlling a multiplication value of each multiplier of the FIR circuit;
The radar reception pulse separation device according to claim 2, comprising: The PRI detector
A memory unit that temporarily stores a predetermined amount of the first digital pulse train signal, and a plurality of multipliers that are connected in parallel to each pulse train input of the predetermined amount of signals. And a delay circuit arranged in a ladder shape, and an addition processing unit that adds the outputs of the multipliers, a multiplication process by the plurality of multipliers and an addition process by the adders for each pulse train And a single FIR processing unit having a single FIR circuit that outputs the addition processing result;
When the result of the addition processing exceeds a predetermined threshold, it is determined that the PRI included in the first digital pulse train signal matches the desired target PRI, a selection signal is output, and the predetermined amount of signal is determined. Is output, the memory unit outputs an instruction signal for storing the next predetermined amount of signal to the memory unit, and sets and controls the multiplication value of each multiplier of the single FIR circuit. A circuit-controlled PRI detection determination unit;
The radar reception pulse separation device according to claim 2, comprising: The PRI detector
An FFT circuit that divides the first digital pulse train signal into a plurality of time ranges with respect to the input of the first digital pulse train signal, performs FFT processing on the pulse trains in the respective time ranges, and outputs a periodogram, A plurality of parallel FFT processing units corresponding to the time range of
An amplitude peak detector for detecting the peak of the periodogram;
Of the detected peaks, the PRI is calculated only for a peak that exceeds a predetermined threshold, and when the PRI matches a desired target PRI, the PRI included in the first digital pulse train signal is the target. A frequency peak type PRI detection / determination unit that outputs a selection signal.
The radar reception pulse separation device according to claim 2, comprising: The PRI detector
An autocorrelation circuit that divides the first digital pulse train signal into a plurality of time ranges with respect to the input of the first digital pulse train signal, and outputs an autocorrelogram by performing autocorrelation processing on the pulse train in each time range A plurality of parallel autocorrelation processing units corresponding to the respective time ranges;
An amplitude peak detector for detecting the peak of the autocorrelogram;
Of the detected peaks, the PRI is calculated only for a peak that exceeds a predetermined threshold, and when the PRI matches a desired target PRI, the PRI included in the first digital pulse train signal is the target. A time peak PRI detection / determination unit that outputs a selection signal.
The radar reception pulse separation device according to claim 2, comprising:

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