JP2022028419A - Signal processor, signal processing method, and signal processing system - Google Patents

Abstract

To provide a signal processor that suppresses deterioration of observation accuracy as compared with before.SOLUTION: A signal processor includes a receiving section, a first generation section, a first compression section, a second generation section, a second compression section, a detection section, a calculation section, and an interference removal section. The receiving section acquires a reception signal based on a reflection wave to a transmission wave, the first generation section generates a first reference signal on the basis of interference wave data, the first compression section pulse compresses the reception signal with the first reference signal to generate a first compression signal, the second generation section generates a second reference signal on the basis of transmission wave data, the second compression section pulse compresses the reception signal with the second reference signal to generate a second compression signal, the detection section detects interference on the basis of an output value of the first compression signal, the calculation section calculates an interference range of the second compression signal on the basis of a position of interference detected in the first compression signal, and the interference removal section modifies the second compression signal within the interference range of the second compression signal.SELECTED DRAWING: Figure 1

Description

Embodiments of the present invention relate to signal processing devices, signal processing methods, and signal processing systems.

In recent years, damage caused by local meteorological phenomena such as guerrilla rainstorms and tornadoes has increased. Therefore, there is a great need for a weather radar used to predict the occurrence of the phenomenon in advance. In particular, the phased array type weather radar has a shorter observation time of about 30 seconds than the conventional parabolic type weather radar, and it is possible to observe the three-dimensional structure of rain clouds, so early detection of this phenomenon is realized. Expected to do.

However, in terms of interference, phased array weather radars are more problematic than traditional parabolic weather radars. The phased array weather radar uses a fan beam having a wider transmission beam width than the parabolic weather radar. Therefore, when a phased array weather radar is used, the frequency of interference occurs higher than when a parabola weather radar is used, and there is a concern that the accuracy of meteorological observation will deteriorate.

To solve this problem, a technique has been proposed to suppress the deterioration of the observation accuracy based on the signal by detecting and removing the component related to the interference from the signal based on the reflected wave from the observation target. A technology that further suppresses the deterioration of the water is desired.

JP-A-2019-219315 Japanese Patent No. 5355322

Shoichiro Fukao and one other person, "Radio Remote Sensing of Meteorology and Atmosphere", Kyoto University Press, March 2005, <http://hdl.handle.net/2433/49766>

The signal processing apparatus according to the embodiment of the present invention suppresses deterioration of observation accuracy as compared with the conventional case.

The signal processing device as one aspect of the present invention includes a receiving unit, a first generation unit, a first compression unit, a second generation unit, a second compression unit, a detection unit, a calculation unit, and an interference removing unit. The receiving unit acquires a received signal based on the reflected wave with respect to the transmitted wave, the first generation unit generates a first reference signal based on the interference wave data, and the first compression unit pulses the received signal with the first reference signal. The first compression signal is generated by compression, the second generation unit generates a second reference signal based on the transmitted wave data, and the second compression unit pulse-compresses the received signal with the second reference signal and second. A compressed signal is generated, the detection unit detects interference based on the output value of the first compressed signal, and the calculation unit calculates the interference range in the second compressed signal based on the position of the interference detected in the first compressed signal. Then, the interference removing unit corrects the second compressed signal within the interference range of the second compressed signal.

The block diagram of the signal processing apparatus which concerns on 1st Embodiment. The figure explaining a plurality of first compression signals. The figure explaining the calculation of the interference range. The figure explaining the 1st example of the calculation of a correlation function. The figure explaining the 2nd example of the calculation of a correlation function. The figure explaining the adjustment of PRF. The figure which shows the improvement of the accuracy of the calculated parameter. The figure which shows an example of the schematic flow chart of the whole processing of a signal processing apparatus. The block diagram of the signal processing apparatus of the 2nd Embodiment. The block diagram of the signal processing apparatus of the 3rd Embodiment. The block diagram of the signal processing apparatus of 4th Embodiment. The block diagram of the signal processing apparatus of the 5th Embodiment. The block diagram of the signal processing apparatus of the 6th Embodiment. The block diagram of the signal processing apparatus of 7th Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment)
FIG. 1 is a block diagram of a signal processing device according to the first embodiment. The signal processing device 1 according to the present embodiment includes a receiving unit 101, an interference wave data storage unit 102, a first reference signal generation unit 103, a first pulse compression unit 104, a transmission wave data storage unit 105, and a first unit. 2. A reference signal generation unit 106, a second pulse compression unit 107, an interference detection unit 108, an interference range calculation unit 109, an interference elimination unit 110, and a parameter calculation unit 111 are provided.

The signal processing device 1 of the present embodiment is used for observation using radio waves. Generally, when a radar device transmits a radio wave, the radio wave hits some object and a reflected wave is generated. From the received signal based on the reflected wave, the signal processing device 1 has parameters related to the reflected wave, for example, received power, speed, speed width in the single polarization radar, and Z _DR (in addition to them in the double polarization radar). Radar reflection factor difference), ρhv (interpolar correlation coefficient), φ _DP (polarity phase difference) are calculated. These parameters are used as observation data for the object, and the state of the object is estimated. It is assumed that the signal processing device 1 of the present embodiment even calculates the parameters.

However, in the present embodiment, the radio wave is also transmitted from another radar device or the like, and the influence of the radio wave, that is, the interference is included in the received signal. Therefore, the signal processing device 1 removes the interference from the radar device on the interference side, and suppresses a decrease in the accuracy of the calculated parameter.

Hereinafter, the radio wave transmitted by the predetermined radar device will be referred to as "transmitted wave". The received signal analyzed by the signal processing device 1 is based on the reflected wave with respect to the transmitted wave. Further, a radio wave different from the transmitted wave and causing interference included in the reflected wave is referred to as an "interference wave".

The transmitted wave and the interference wave are both modulated pulse signals (chirp signals), but it is assumed that the pulse length and the frequency sweep width of the chirp are different from each other.

The signal processing device 1 may be a part of a radar device that transmits radio waves, or may be a device having a housing different from the radar device. For example, the radar device that has transmitted the radio wave may receive the reflected wave, and the received signal based on the reflected wave may be transmitted to the signal processing device 1 installed in a place different from the radar device such as a data center.

It is assumed that the signal processing device 1 has obtained data on the transmitted wave and the interference wave in advance. The data shows, for example, the pulse length, modulation frequency width, amplitude, phase, etc. of the transmitted wave and the interfering wave. The signal processing device 1 may obtain these data directly from the radar device that transmits the transmitted wave and the radar device that transmits the interference wave. Alternatively, it may be obtained from a database server that manages these data. Alternatively, the administrator of the signal processing device 1 may generate these data. It is preferable that the accuracy of the data is as high as possible because it affects the accuracy of the detected parameters.

The internal configuration of the signal processing device 1 shown in FIG. 1 will be described. Note that FIG. 1 shows the components necessary for eliminating interference and improving the accuracy of the detected parameters, and other components are omitted. That is, the signal processing device 1 may include other components. For example, when the signal processing device 1 is a radar device, it includes a transmission unit that transmits a transmitted wave. In addition, each component may be grouped or subdivided. For example, the components surrounded by the dotted line in FIG. 1 may be combined into one processing unit. Further, the interference wave data storage unit 102 and the transmission wave data storage unit 105 may be combined into one storage unit.

The receiving unit 101 receives a received signal based on the reflected wave. As described above, the received signal may be transmitted from the radar device, or the receiving unit 101 may receive the reflected wave and convert it into a received signal. Further, as described above, since the reflected wave is interfered with, the received signal includes a signal based on the reflected wave and a signal based on the interference wave. Hereinafter, the signal based on the reflected wave will be referred to as a desired signal, and the signal based on the interference wave will be referred to as an interference signal.

The interference wave data storage unit 102, the first reference signal generation unit 103, and the first pulse compression unit 104 perform processing for generating a compressed signal used for detecting an interference signal included in the received signal. conduct. The interference wave data storage unit 102 stores data related to the above-mentioned interference wave. The first reference signal generation unit 103 generates a first reference signal having a correlation with the interference signal by using the data related to the interference wave. The first pulse compression unit 104 pulse-compresses the received signal with the first reference signal. The received signal pulse-compressed by the first reference signal is referred to as a first compressed signal.
The pulse-compressed first compressed signal can be defined as a voltage value in a complex number format. Further, the power value can be obtained by squaring the absolute value of the first compressed signal and dividing by an appropriate impedance. Hereinafter, the voltage value or the power value is also referred to as an output value.

Since there is a correlation between the first reference signal and the interference signal, when the received signal is pulse-compressed by the first reference signal, the pulse width of the received signal is narrowed and the gain of the component of the interference signal included in the received signal is improved. do. As a result, the first compressed signal has a peak (extreme value) in which the power value suddenly rises in the portion including the interference signal. That is, the waveform of the first compressed signal is a steep pulse waveform. This facilitates the presence / absence of interference and the detection of the interference position. The generation of the first compressed signal may be performed by a known method of pulse compression.

The pulse compression may be performed by any of a frequency modulation method, a code modulation method, and the like. It may be performed by correlation processing on the time axis. Alternatively, pulse compression may be performed by performing multiplication by Fourier transform on the frequency axis and performing inverse Fourier transform on the multiplication result. Further, the position of the peak of the compressed signal generated by pulse compression can be freely set in any modulation method within a range including the interference signal.

Further, the transmitted wave data storage unit 105, the second reference signal generation unit 106, and the second pulse compression unit 107 perform processing for generating a compressed signal used for parameter calculation. The transmission wave data storage unit 105 stores the data related to the transmission wave described above. The second reference signal generation unit 106 uses the data related to the transmitted wave to generate a second reference signal having a correlation with the desired signal. The second pulse compression unit 107 pulse-compresses the received signal with the second reference signal. The received signal pulse-compressed by the second reference signal is referred to as a second compressed signal.
The pulse-compressed second compressed signal can be defined as a voltage value in complex number format. Further, the power value can be obtained by squaring the absolute value of the second compressed signal and dividing by an appropriate impedance.

Since there is a correlation between the second reference signal and the desired signal, when the received signal is pulse-compressed by the second reference signal, the pulse width of the received signal is narrowed and the gain of the component of the desired signal contained in the received signal is improved. do. It is assumed that the second reference signal is adjusted so that the pulse width of the second compressed signal is narrowed to the extent that the desired distance resolution is satisfied and the range side lobe is below the desired level. The generation of the second compressed signal may also be performed by a known method of pulse compression.

The interference detection unit 108 detects interference based on the power value of the first compressed signal. For example, when the first compressed signal contains a power value larger than a predetermined threshold value, it may be determined that the first compressed signal contains an interference signal. Further, a predetermined threshold value may be used as the average power of a plurality of first compressed signals generated so far. In radar observation, the transmitted wave is repeatedly transmitted in a short period of time, and the received signal is also repeatedly received in a short period of time. Therefore, a plurality of first compressed signals corresponding to the plurality of received signals are generated. Therefore, the average power value can be calculated from these plurality of first compressed signals. Further, the predetermined threshold value may be an evaluation value calculated based on the power value of the first compressed signal. Depending on the setting of the evaluation value, it is determined that the first compressed signal contains an interference signal not only when it is equal to or more than a predetermined threshold value or larger than a predetermined threshold value but also when it is equal to or less than a predetermined threshold value or smaller than a predetermined threshold value. In some cases.

FIG. 2 is a diagram illustrating a plurality of first compressed signals. Graphs 2A, 2B, 2C, and 2N, some of which project in the Z-axis direction, are shown. These graphs show the waveform of the first compressed signal due to the received signals received at different time points. Graph 2A shows the waveform of the first compressed signal based on the first received signal, graph 2B shows the waveform of the first compressed signal based on the second received signal, and graph 2C shows the waveform of the first compressed signal based on the third received signal. The waveform of the compressed signal is shown, and graph 2N shows the waveform of the first compressed signal based on the Nth received signal (N means an integer and is 4 or more in FIG. 2). The number of the first compressed signal is the same as the number of transmissions of the transmitted wave, and in other words, it can be said to be the number of observations (the number of hits) for the observation target.

Since the transmission cycle of the transmitted wave is constant, the length of the waveform of each first compressed signal in the X-axis direction is the same. The position of the waveform in the X-axis direction is described as the observation time r. Further, the peak of the power value of the first compressed signal described above corresponds to the protruding portion of these graphs. In the example of FIG. 2, the peak of the second first compressed signal is at the observation time r _x1 and the peak of the third first compressed signal is at the observation time r _x2 . When the peak positions are different in each first compressed signal in this way, the peak can be recognized by comparing with the average of the power values of each first compressed signal in the same observation time. For example, the difference between the average of the power values at the observation time r _x1 of the first compressed signal from the first to the Nth and the power value at the observation time r _x1 of the second first compressed signal is compared with the others. Since it is so large, it is easy to see that the second first compressed signal has a peak at the observation time r _x 1.

The interference range calculation unit 109 calculates the interference range in the second compressed signal based on the position of the interference detected in the first compressed signal.

FIG. 3 is a diagram illustrating the calculation of the interference range. FIG. 3A shows an interference signal included in the received signal. The interference signal exists from the observation time _rs0 to _re . That is, the interference range in the received signal is from the observation time _{r s} 0 to the observation time r _e . However, unlike FIG. 3A, the actual interference signal is included in the received signal, so that the interference range of the received signal cannot be determined from the received signal.

It should be noted that the interference range is different for the received signal, the first compressed signal, and the second compressed signal. In the present embodiment, the parameter is calculated using the second compressed signal, so that the second compressed signal is used. It is necessary to find the interference range of the compressed signal.

FIG. 3B shows the first compressed signal of the received signal shown in FIG. 3A. In FIG. 3B, the first compressed signal is generated so as to peak at the start point of the range including the interference signal in the received signal, that is, at the observation time _rs0 . Since the power of the first compressed signal exceeds the threshold value _P0 , the interference detection unit 108 determines that the first compressed signal contains the interference signal. The interference range calculation unit ₁₀₉ can recognize the observation time r s 0, which is the start point of the interference range in the first compressed signal, from the peak. Further, as described above, the pulse length of the interference signal coincides with the pulse length of the first reference signal. Assuming that the pulse length of the interference wave is LI, the interference range calculation unit 109 has the observation time r _e , which is the end point of the interference range in the first compressed signal, being the observation time of r _s0 + _LI (r _{e =} ). r _s0 + _LI ) can be recognized.

In the first compressed signal, the interference range starts not only from the observation time _r s 0 to the observation time _{r e} but also from a time point before the observation time r s 0. Specifically, the power value of the first compressed signal rises under the influence of the interference signal from the observation time _rs0 to the observation time before the pulse length _LI of the interference wave. Therefore, the interference range in the first compressed signal is a range of a length of 2 _LI from the observation time _rs0 - _LI to the observation time _rs0 + _LI .

FIG. 3C shows the interference range in the second compressed signal calculated by the interference range calculation unit 109. The waveform of the second compressed signal is omitted. Even in the second compressed signal, the interference range starts not only from the observation time r _s0 to the observation time r _e but also from a time point before the observation time r _s0 . Specifically, _assuming that the pulse length of the transmitted wave is L s, the power value of the second compressed signal is affected by the interference signal from the observation time before the pulse length L _s of the transmitted wave from the observation time _rs0 . Receive and rise. Therefore, the interference range in the second compressed signal is the range of the length _{L s} + _LI from the observation time r _s0 −L _s to the observation time r _s0 + LI. In FIG. 3C, the observation time from the observation time _rs 0 to the observation time before the pulse length L _s of the transmitted wave is expressed as _rs 1, and the interference range in the second compressed signal is from the observation time _rs 1. It can be said that it is up to _re .

As described above, the interference range is the interference in the second compressed signal from the pulse length of the first reference signal and the pulse length of the second reference signal with reference to the position of the interference detected in the first compressed signal. Calculate the range. In FIG. 3, the peak of the first compressed signal is set as the starting point of the interference range of the received signal, but the peak of the first compressed signal may be arbitrarily determined. For example, when the peak of the first compressed signal is set to be the center of the interference range of the received signal, the interference range calculation unit 109 sets the observation time as early as _LI / 2 from the peak to the interference range of the received signal. The start point may be set, and the observation time delayed by _LI / 2 from the peak may be set as the end point of the interference range of the received signal.

In addition, in FIG. 3C, the position and length of the calculated interference range may be further adjusted. For example, considering that there are actually hardware fluctuations, it is conceivable to further expand the calculated interference range. Further, when the amplitude waveform of the interference signal is not a perfect rectangle and an amplitude taper is provided, even if the calculated interference range is narrowed a little, it is within the margin of observation accuracy required for the signal processing device 1. It is possible that it will fit. Therefore, the interference range in the second compressed signal calculated by the interference range calculation unit 109 does not always exactly match the range traced back from the observation time r _e to the length _LI + L _s .

In addition, the interference signals may be overlapped with each other with a time delay. In consideration of such a case, the observation time point when the power value exceeds a predetermined threshold value may be set as the head position of the interference signal instead of the peak value of the power. In FIG. 3B, it is shown that the observation time point exceeding the threshold value P ₀ is the observation time _point about _Lv before the observation time r s 0. When the observation time is set as the head position of the interference signal, the observation time r _s2 about L _s + L _v from the observation time _rs 0 shown in FIG. 3C is the interference range of the second compressed signal. It becomes the starting point, and the length of the interference range is L _s + L _v + _LI . As described above, the head position of the interference signal is not limited to the peak value of the power.

Further, depending on the strength of the interference signal, the A / D converter for realizing the receiving unit 101 is saturated, and the response of the desired signal to the movement of the observation target is delayed due to the influence of the filter for realizing the receiving unit 101. Sometimes. Even in such a case, the interference range may be adjusted. The end point of the interference range may be shifted later by the time required for the delay of the response to converge.

The first compressed signal may include a plurality of peaks. In other words, the first compressed signal may have a plurality of peaks in the range from the start point to the end point of the observation time (from r ₀ to r _max in FIG. 2). In such a case, the interference range for each peak may be calculated, and the logical sum thereof may be calculated as the final interference range.

The interference removing unit 110 corrects the second compressed signal in the interference range of the second compressed signal. For example, the second compressed signal may not exist in the interference range of the second compressed signal. Alternatively, the voltage value within the interference range of the second compressed signal may be set to an invalid value such as 0 or NaN (Not a Number).

Alternatively, the voltage value within the interference range of the second compressed signal may be replaced with another voltage value. For example, interference is not detected from the third first compressed signal, interference is detected from the fourth first compressed signal, and the interference range of the third second compressed signal is set to the observation time _{r s} 1 to re. In this case, the interference removing unit 110 sets the voltage value of the fourth second compressed signal at at least one observation time within the range of the observation time _rs1 to _re of the third second compressed signal. It may be replaced with the voltage value at the observation time. For example, if the response time of the motion of the observation target is sufficiently large with respect to the sampling interval by the transmission cycle (Pulse Recognition Frequency) of the transmitted wave, each voltage value of the received signal is each of the received signals in the previous transmission cycle. Since the voltage value is substantially the same as the voltage value, such replacement with the voltage value of the second compressed signal in the past may be performed. Further, in the above example, when interference is not detected from the past first compressed signal, the current second compressed signal is based on the transition of the voltage value including the phase information of each past first compressed signal. The voltage value when it is considered that no interference has been received may be estimated, and at least one of the voltage values within the interference range of the second compressed signal this time may be replaced with the estimated value.

By replacing the voltage value in the interference range of the second compressed signal with a plausible numerical value in this way, it is possible to prevent the number of populations from decreasing in the correlation processing or the averaging processing described later. Further, in some cases, it is possible to reduce variations in observation errors due to variations in desired signals, noise, and the like.

The parameter calculation unit 111 calculates parameters related to the reflected wave based on the second compressed signal processed by the interference removing unit. Parameters related to the reflected wave include, for example, received power, velocity, velocity width, Z _DR (radar reflection factor difference), ρhv (correlation coefficient between polarizations), φ _DP (phase difference between polarizations), and the like.

Further, the parameter calculation unit 111 may calculate the parameter after performing the correlation processing or the averaging processing based on the second compressed signal. The received signal used for the correlation processing or the averaging processing may be appropriately selected. All the second compressed signals acquired so far by the parameter calculation unit 111 may be used, or only two, the second compressed signal acquired most recently and the second compressed signal acquired before that. May be used. Alternatively, a plurality of the second compressed signals acquired so far may be randomly selected or selected based on predetermined conditions. Further, the second compressed signal that does not satisfy the predetermined condition may not be selected.

記号ｒは、観測時間を表す。記号Ｎは、相関処理に用いる第２圧縮信号の総数（トータルのヒット数）を表す。記号ｎは、１以上でＮ以下の整数であって、第２圧縮信号の番号（ヒット数）を表す。記号ｘは、相関を調べる対象の値を表す。ここでは、第２圧縮信号の複素数形式の電圧値が該当する。つまり、ｘ［ｎ］［ｒ］は、ｎ番目の第２圧縮信号の観測時間ｒにおける電圧値を示す。記号＊は複素共役を表す。記号ｍは、積算される二つの第２圧縮信号の番号のずれ（ヒット数のラグ）を表す。ここでは、記号ｍの値は０または１とする。ｍ＝０のときは、ｎ番目の第２圧縮信号の観測時間ｒにおける電圧値とその複素共役とが積算される。ｍ＝１のときは、ｎ番目の第２圧縮信号の観測時間ｒにおける電圧値の複素共役と、ｎ＋１番目の第２圧縮信号の観測時間ｒにおける電圧値と、が積算される。記号Ｒ_ｍは、ラグがｍのときの相関関数を表す。こうして、各観測において得られた複数の第２圧縮信号の相関を考慮することにより、一つの第２圧縮信号から得たときよりも、パラメータのばらつきを低減することができる。 For the correlation processing, for example, the following equation can be used.

The symbol r represents the observation time. The symbol N represents the total number of second compressed signals (total number of hits) used for correlation processing. The symbol n is an integer of 1 or more and N or less, and represents the number (number of hits) of the second compressed signal. The symbol x represents the value to be examined for correlation. Here, the voltage value in the complex number format of the second compressed signal is applicable. That is, x [n] [r] indicates the voltage value at the observation time r of the nth second compressed signal. The symbol * represents the complex conjugate. The symbol m represents a deviation (lag in the number of hits) between the numbers of the two second compressed signals to be integrated. Here, the value of the symbol m is 0 or 1. When m = 0, the voltage value at the observation time r of the nth second compressed signal and its complex conjugate are integrated. When m = 1, the complex conjugate of the voltage value at the observation time r of the nth second compressed signal and the voltage value at the observation time r of the n + 1th second compressed signal are integrated. The symbol R _m represents a correlation function when the lag is m. In this way, by considering the correlation of the plurality of second compressed signals obtained in each observation, it is possible to reduce the variation in parameters as compared with the case of obtaining from one second compressed signal.

However, the above equation (1) does not consider the correction in the interference range of the second compressed signal. The second compressed signal whose observation time r is within the interference range and whose voltage value is corrected at the observation time r can be excluded from the calculation of the above equation (1). Further, the coefficient 1 / (Nm) for the average processing in the equation (1) is also modified.

FIG. 4 is a diagram illustrating a first example of calculation of a correlation function. FIG. 4 shows a case where the voltage value at the observation distance r of the third (n = 3) second compressed signal is corrected to 0 or an invalid value. In this case, the modified x [3] [r] and x ^* [3] [r] should not be used for the correlation processing. Therefore, it is shown that the integration using any of these is removed from the formula for the correlation function.

In the calculation of the correlation function R ₀ , one integration is deleted. Therefore, the coefficient used to calculate the correlation function R ₀ was 1 / (N-m) in the equation (1), but since the integration is reduced by one, it becomes 1 / {(N-m) -1}. Since m = 0, it becomes 1 / (N-1). In FIG. 4, the number of accumulated data to be deleted is shown as d _num .

In the calculation of the correlation function _R1 , there are two integrations containing the modified x [3] [r] or x ^* [3] [r]. Therefore, the coefficient used to calculate the correlation function R ₀ is 1 / {(Nm) -d _num } = 1 / (N-1-2) = because the integration is reduced by two and m = 1. It becomes 1 / (N-3).

In this way, it is preferable to match the coefficient with the effective integrated number to improve the calculation accuracy of the correlation functions R ₀ and R ₁ . When the _nb second compressed signals out of the N second compressed signals are removed or the invalid value is processed, as a result, when the correlation function _R0 is calculated, the averaging is performed. The coefficient for this is replaced with 1 / (N-n _b ), and when the correlation function _R1 is calculated, the coefficient may be replaced with 1 / (N-1-2 × n _b ).

FIG. 5 is a diagram illustrating a second example of calculation of the correlation function. FIG. 5 shows a case where the voltage value at the observation distance r of the third (n = 3) second compressed signal is excluded and the fourth and subsequent numbers are shifted forward by one. That is, since the third second compressed signal has disappeared, the fourth second compressed signal is the third, and the fifth second compressed signal is the fourth.

In the calculation of the correlation function R ₀ , there is no integration to be deleted. However, the coefficient used to calculate the correlation function R ₀ was 1 / (Nm) in the above equation, but since the third second compressed signal disappeared and the total number decreased by one, N Is replaced with N-1, and becomes 1 / {(N-1) -m}, and since m = 0, it becomes 1 / (N-1).

In the calculation of the correlation function R ₁ , the integration of x ^* [2] [r] × x [3] [r] is deleted. x [3] [r] is x [4] [r] before the number is changed. Therefore, the integration of x ^* [2] [r] × x [3] [r] is x ^* [2] [r] × x [4] [r] before the number change, and the integration of adjacent numbers is performed. is not it. Therefore, the integration is deleted. The integration of x ^* [3] [r] × x [4] [r] is x ^* [4] [r] × x [5] [r] before the number change, and the integration of adjacent numbers is performed. Is. Therefore, the total is not deleted. As a result, the coefficient used for the calculation of the correlation function R ₁ is 1 / {(N-1) -m-1} because the total number of integrations is N-1 and the integration is further reduced by one, and m = 1. Since there is, it becomes 1 / (N-3).

In this way, when the correlation function _R1 is calculated when the voltage value in the interference range is excluded from the _nb second compressed signals out of the N second compressed signals, it is for averaging. The coefficient may be replaced with 1 / (N-1-2 × n _b ). As a result, the coefficient matches the effective integration number, so that the calculation accuracy of the correlation function R ₁ is improved.

As described above, when the correlation processing is performed by excluding the modified second compressed signal, it is preferable that the modified second compressed signal is small. However, when the pulse repetition frequency (PRF: Pulse Repetition Frequency) of the interference wave and the pulse repetition frequency of the transmission wave completely match, interference occurs at almost the same observation time (position). Therefore, even if an attempt is made to calculate the correlation function at the observation time r, most of the second compressed signals are corrected at the observation time r, and there is almost no second compressed signal that can be used to calculate the correlation function. It is possible. Therefore, even if the correlation processing is performed, the accuracy of the calculated parameters may not be improved.

Therefore, the signal processing device 1 has the position of the interference detected in the plurality of first compressed signals with respect to at least one of the interfering side and the interfering side so that the PRFs of the interfering side and the interfering side do not match. Instructions regarding the change of PRF may be given depending on whether or not they match. The interfered side is, for example, a transmission unit when the signal processing device 1 is a radar device. By shifting the PRFs on the interfering side and the interfering side to some extent, it is possible to prevent the observation time at which interference occurs from always being the same. As a result, it is possible to prevent a situation in which the voltage value of most of the plurality of second compressed signals used for calculating the correlation function is corrected for interference elimination at the observation time r, and the effect of the correlation processing can be sufficiently obtained. be able to.

FIG. 6 is a diagram illustrating the adjustment of PRF. FIG. 6A shows a received signal when the PRFs on the interfering side and the interfering side match. In FIG. 6A, each first compressed signal has a peak at the observation time point r _x . In this case, there is no second compressed signal that has not been corrected at the time of observation r _x , and the correlation function cannot be calculated. FIG. 6B shows a case where the PRFs on the interfering side and the interfering side are shifted. In FIG. 6B, only the first received signal has a peak at the observation time point r _x . In this case, only the first second compressed signal is excluded, and the correlation function can be calculated from the second to Nth compressed signals.

The amount of PRF to be shifted may be appropriately determined. However, the upper limit of PRF is related to the maximum observation distance of the radar, and the lower limit of PRF is related to the maximum observation speed. Therefore, it is necessary to determine the PRF in consideration of the requirements required for the radar. In addition, the frequency of interference may also have an allowable upper limit. It is necessary to determine the PRF in consideration of the conditions related to such interference.

In order to expand the speed range to be detected, there is a method called stagger that switches between a plurality of PRFs. In the case of switching a plurality of PRFs such as a stagger, there may be a PRF commonly used on the interfering side and the interfered side, but the signal processing device 1 receives the interfering wave during the period of receiving the interfering wave. It is necessary to give instructions regarding the change of PRF so that the side and the interfered side do not use a common PRF. Further, by acquiring information on the PRFs on the interfering side and the interfering side, instructions regarding changing the PRF may be given depending on whether or not the PRFs on the interfering side and the interfering side match.

The observation parameters are calculated using the correlation function _Rm obtained from the above correlation processing. For example, in the case of a weather radar that uses a single polarization for the transmitted wave, observation parameters such as received power, velocity, and velocity range can be calculated. For example, in the case of a weather radar that uses two polarizations for the transmitted wave, Z _DR (radar reflection factor difference) and ρhv (phase relationship between polarizations) are calculated by calculating the correlation function of the power difference and phase difference between the polarizations. Observation parameters for double polarization such as number) and φ _DP (phase difference between polarizations) can also be calculated.

記号Ｐ［ｒ］は観測時間ｒにおける反射波の電力を、記号Ｖ［ｒ］は観測時間ｒにおける反射波の速度を、記号Ｗ［ｒ］は観測時間ｒにおける反射波の速度幅を表す。また、記号λは波長［ｍ］を、Ｎ_ｏは平均ノイズ電力を、ＰＲＩ（Ｐｕｌｓｅ Ｒｅｐｅｔｉｔｉｏｎ Ｉｎｔｅｒｖａｌ）はパルス繰り返し間隔を表す。 For example, the observed parameters of received power, velocity, and velocity width in the weather radar are expressed below using the correlation functions R ₀ and R ₁ of the equation (1). Therefore, the calculation accuracy of the correlation functions R ₀ and R ₁ is directly linked to the calculation accuracy of the observation parameters.

The symbol P [r] represents the power of the reflected wave at the observation time r, the symbol V [r] represents the velocity of the reflected wave at the observation time r, and the symbol W [r] represents the velocity width of the reflected wave at the observation time r. Further, the symbol λ represents the wavelength [m], No represents the average noise power, and _PRI (Pulse Repetition Interval) represents the pulse repetition interval.

In this way, the parameter calculation unit 111 may calculate the correlation function of the plurality of second compressed signals from the plurality of second compressed signals, and calculate the parameter based on the calculated correlation function.

The parameters calculated in this embodiment are more accurate than the conventional method. FIG. 7 is a diagram showing an improvement in the accuracy of the calculated parameters. The estimation error of the parameter calculated by performing the correlation processing by the signal processing apparatus 1 of this embodiment is shown. The estimation error is an error between the parameter value estimated when the interference is included and the parameter value estimated when the interference is not included. Further, as a comparison, although the interference is detected by pulse compression as in the present embodiment, the interference is removed from the received signal to generate a desired signal, and the parameter is calculated based on the generated desired signal. Shows the error.

The simulation conditions are as follows.
S / N = 20 dB (S: received signal level, N: noise level)
-I / N = 50 dB (I: interference signal level, N: noise level)
・ Total number of hits = 90
・ PRF ratio (interfering side / interfered side) = approx. 0.8

In the example of FIG. 7, it can be seen that the estimation error of the signal processing device is smaller than the estimation error of the conventional method in each parameter such as the received power, and the accuracy is improved. Similar results are obtained even if the simulation conditions such as the level of the received signal and the level of the interference signal are changed.

Next, the flow of processing by each component will be described. FIG. 8 is a diagram showing an example of a schematic flowchart of the overall processing of the signal processing apparatus. It should be noted that this flowchart is an example, and the order of processing is not limited as long as the required processing result can be obtained. For example, in FIG. 8, the processes performed in parallel may be performed in order. Further, the processing result of each processing is sequentially stored in a storage unit (not shown), and each component may obtain the processing result by referring to the storage unit.

First, the first reference signal generation unit 103 generates a first reference signal based on the data related to the interference wave stored in the interference wave data storage unit 102 (S101), and the second reference signal generation unit 106 generates the transmission wave data. A second reference signal is generated based on the data related to the transmitted wave stored in the storage unit 105 (S102). In addition, each of these processes may be executed at the time when the data regarding the interference wave and the transmission wave is acquired.

After that, the receiving unit 101 receives the received signal based on the reflected wave (S103). In response to this, the first compressed signal generation unit pulse-compresses the received signal with the first reference signal to generate the first compressed signal (S104). When the first compressed signal is generated, the interference detection unit 108 detects the interference based on the power value of the first compressed signal (S105). Then, the interference range calculation unit 109 determines the interference range of the second compressed signal using the pulse length of the interference wave and the pulse length of the transmission wave with reference to the position of the detected interference (S106). .. In this way, while the processing of S104 to S106 is performed, the second compressed signal generation unit pulse-compresses with the second reference signal to generate the second compressed signal (S107).

When the second compressed signal is generated and the interference range of the second compressed signal is determined, the interference removing unit 110 corrects the voltage value within the determined interference range of the generated second compressed signal (S108). ). Then, it is confirmed whether or not the second compressed signal has been processed by a predetermined number or more, and if it has not been processed (NO in S109), the reception of the next received signal is awaited. Then, the next received signal is received, and the processes from S104 to S108 are performed again. In this way, the processed second compressed signal is accumulated. The second compressed signal may be stored in a storage unit (not shown).

When a predetermined number or more of the second compressed signals have been processed (YES in S109), the parameter calculation unit 111 calculates the parameters related to the reflected wave based on the second compressed signal (S110). The correlation function may be calculated using a plurality of second compressed signals to calculate the parameters, or the parameters may be calculated from a single second compressed signal. The flow ends in this way.

In the above flow, the first reference signal and the second reference signal are created before the reception of the received signal, but they may be created after the reception signal is received. Further, the parameters of the reference signal created in advance may be adjusted according to the observation status of the reflected wave, the power value of the received signal, and the like.

As described above, according to the signal processing device 1 of the present embodiment, the interference range of the second pulse compressed signal pulse-compressed using the data related to the transmitted wave is calculated, and the interference range of the second pulse compressed signal is related to the interference range. Correct the value. As a result, it is possible to suppress a decrease in accuracy as compared with the case where the value related to the interference range is corrected from the received signal instead of the second pulse compressed signal.

As described above, the configuration of the signal processing device 1 shown in FIG. 1 is an example, and the components that perform processing other than those described above are omitted, and the components are grouped together. It may be subdivided or subdivided. Therefore, the configuration of the signal processing device 1 can be variously modified depending on various circumstances such as the application, processing load, and convenience of the signal processing device 1. Some embodiments are introduced below.

(Second embodiment)
As described above, the voltage value within the interference range of the second compressed signal is corrected by the interference removing unit 110, but there are a plurality of correction methods. Therefore, the interference removing unit 110 may be provided for each correction method. FIG. 9 is a block diagram of the signal processing device of the second embodiment. In the second embodiment, the interference removing unit 110 shown in the second embodiment corrects the voltage value within the interference range of the second compressed signal by different methods, that is, the first interference removing unit 110A and the second interference. It is separated into the removal unit 110B. Although it is divided into two in FIG. 9, it may be divided into three or more depending on the correction method to be implemented.

Further, in the example of FIG. 9, the parameter calculation unit 111 is also divided according to the division of the interference removing unit 110. In FIG. 9, the first parameter calculation unit 111A calculates the parameter based on at least the second compressed signal calculated by the first interference removing unit 110A, and at least the second compressed signal calculated by the second interference removing unit 110B is used. Based on this, the second parameter calculation unit 111B calculates the parameters. Further, the determination unit 112 that makes a determination to adopt either the parameter calculated by the first parameter calculation unit 111A or the parameter calculated by the second parameter calculation unit 111B as the processing result of the signal processing device 1. It is shown.

The conditions for determination by the determination unit 112 may be appropriately determined. For example, suppose that the first interference removing unit 110A replaces the voltage value within the interference range of the second compressed signal in which interference is detected with a voltage value within the interference range of the second compressed signal in which interference is not detected. Further, it is assumed that no interference is detected in the second compressed signal at the first time point and interference is detected in the second compressed signal at the second time point, and the PRI is shorter than the correlation time calculated from the observation speed range. .. In such a case, the determination unit 112 may adopt the parameter calculated by the first parameter calculation unit 111A, in other words, the parameter related to the second compressed signal processed by the first interference removal unit 110A. .. By doing so, it is possible to reduce the variation in observation error. The correlation time τ _c is obtained by the following equation using the wavelength λ and the velocity width σ _v .

Further, for example, it is assumed that the second interference removing unit 110B considers that the voltage value within the interference range of the second compressed signal in which the interference is detected does not exist. Also, it is assumed that the observation interval is sufficiently larger than the correlation time. In such a case, the determination unit 112 may adopt the parameter calculated by the second parameter calculation unit 111B, in other words, the parameter related to the second compressed signal processed by the second interference removal unit 110B. .. In such a case, since the correlation between the second compressed signals is small, the direct influence of the interference signal itself can be removed without replacing the voltage value.

Although the speed range of the parameter is used to obtain the correlation time, the speed range calculated by either the first parameter calculation unit 111A or the second parameter calculation unit 111B may be used, or both speeds may be used. The calculation result using the width may be used as the speed width for obtaining the correlation time.

(Second and third embodiments)
In the previous embodiments, pulse compression is performed in order to remove the interference signal included in the received signal and which cannot be discriminated. However, processing for detecting and removing other interference signals may be performed. For example, when the reflected wave is also affected by an interference wave which is an unmodulated pulse signal, the influence can be removed without pulse compression.

FIG. 10 is a block diagram showing a signal processing device according to a third embodiment. In the third embodiment, a pre-interference detection unit 113 that detects interference with the received signal before pulse compression is performed, and a pre-interference removal unit that removes interference with the received signal before pulse compression is performed. 114 and.

For example, the unmodulated pulse signal has a pulse width as small as 1/10 to 1 / several 100 or less as compared with the modulated pulse signal. Therefore, it is possible to detect and remove an unmodulated pulse signal by a conventional method of detecting and removing a signal having a small pulse width.

FIG. 11 is a block diagram showing a signal processing device according to a fourth embodiment. As shown in FIG. 10, in the third embodiment, the received signal from which interference has been removed in advance is transmitted to the first pulse compression unit 104 and the second pulse compression unit 107, but in the fourth embodiment, the received signal is transmitted to the first pulse compression unit 104 and the second pulse compression unit 107. , A received signal that has not been preliminarily removed from interference is transmitted to the first pulse compression unit 104. Since the second compressed signal is used for parameter calculation, it is preferable that the received signal used for generating the second compressed signal contains as little interference as possible. On the other hand, since the first compressed signal is used for interference detection, if there is no problem in the accuracy of interference detection, the received signal used for generating the first compressed signal is preliminarily removed from interference. It doesn't have to be. In addition, in order to avoid false detection of interference as much as possible, the third embodiment is preferable.

(Fifth Embodiment)
FIG. 12 is a block diagram showing a signal processing device according to a fifth embodiment. In the fifth embodiment, the receiving unit 101 is divided into a first receiving unit 101A and a second receiving unit 101B, and the first filter 115A and the second filter 115B are connected to each.

In this embodiment, it is assumed that the carrier frequencies of the reflected wave and the interference wave are different. The antenna for receiving the reflected wave may be an antenna independent for each frequency or an antenna common to all frequencies. Further, in the present embodiment, the type of radar that transmits the transmitted wave and the interference wave is not particularly limited, and may be, for example, a parabolic type or a phased array type.

The first receiving unit 101A acquires the received signal and further frequency-converts the received signal at the center frequency of the interference wave. The second receiving unit 101B acquires the received signal and further frequency-converts the received signal at the center frequency of the transmitted wave. In frequency conversion, the components of the reference frequency are efficiently extracted. That is, the baseband signal is extracted. Therefore, the first receiving unit 101A mainly extracts the interference signal as the baseband signal, and the second receiving unit 101B mainly extracts the desired signal as the baseband signal.

The first filter 115A and the second filter 115B attenuate components other than the baseband signal. Therefore, when the received signal passes through the first filter 115A, the components of the desired signal are further attenuated. This further improves the accuracy of interference detection. Further, when the received signal passes through the second filter 115B, the component of the interference signal is further attenuated. This improves the accuracy of the calculated parameters.

However, in terms of frequency spectrum, the interference signal is usually not a line spectrum but a broad spectrum. Although the interference signal can be attenuated by a certain amount or more by passing through the second filter 115B, the component of the interference signal is included even in the pass band (baseband band) of the desired signal due to the spread of the spectrum. Therefore, the interference component caused by the spread of the spectrum cannot be completely suppressed by the second filter 115B alone. Therefore, as in the previous embodiments, it is preferable to perform highly accurate interference detection using pulse compression with the first reference signal. That is, even when the carrier frequencies of the reflected wave and the interference wave are different, the interference detection by the pulse compression of the present embodiment is effective.

Further, in the present embodiment, even if the interference is detected based on the first compressed signal, it may occur that the second compressed signal does not include the interference signal. In that case, it can be dealt with by adjusting the level of the threshold value for determining the presence or absence of interference in the interference detection unit 108. The threshold value is determined in consideration of the difference in gain between the level timetables of the first receiving unit 101A and the second receiving unit 101B, the spread of the spectrum of the interference signal, and the like. When different antennas are connected to the first receiving unit 101A and the second receiving unit 101B, the difference in gain of these antennas is also taken into consideration.

(Sixth Embodiment)
FIG. 13 is a block diagram showing a signal processing device according to a sixth embodiment. In the present embodiment, the signal processing device 1 further includes a learning unit 116.

Until now, in order to detect interference from the received signal by pulse compression, the first reference signal was generated based on the data related to the interference wave. That is, it is necessary to obtain data on the interference wave in advance. However, the parameters of the interference wave may be changed. In that case, the data related to the changed parameter must be obtained before the change, but it is assumed that the parameter change cannot be recognized in advance. Further, even if the existence of the interference wave cannot be recognized in advance, it is difficult to remove the interference until the existence of the interference wave and the source of the interference wave are recognized.

Therefore, in the present embodiment, the learning unit 116 generates a model based on a neural network for extracting data related to the interference wave or a signal having a strong correlation with the interference wave from the received signal by machine learning. For example, machine learning may be performed on the neural network using the received signal received in the past as input data and the data related to the interference wave or the first reference signal generated in the past corresponding to the received signal as the correct answer data. In other words, the neural network parameters are optimized based on the received signal received in the past and the data related to the interference wave or the first reference signal generated in the past corresponding to the received signal. The network may be a model that generates data about interference waves or a first reference signal from a received signal.

Further, after the model is generated, the first reference signal may be generated from the received signal by using the model without using the data related to the interference wave. The model may be stored in the interference data storage unit.

(7th Embodiment)
FIG. 14 is a block diagram showing a signal processing device according to a seventh embodiment. The seventh embodiment is configured assuming a case where two polarizations of horizontal polarization (H polarization) and vertical polarization (V polarization) are used as a transmission wave. A dual polarization weather radar corresponds to a device that uses horizontally polarized waves (H polarization) and vertically polarized waves (V polarization) as transmitted waves.

In the present embodiment, the components other than the parameter calculation unit 111 are set as one set (one system), and the signal processing device 1 includes a set 117A for horizontal polarization and a set 117B for horizontal polarization. The processing in each set 117 is the same as before, and the second compressed signal in which the voltage value in the interference range is corrected is output from each set 117. The parameter calculation unit 111 calculates the correlation function between the horizontal polarization and the vertical polarization based on the second compression signal from each set 117, and calculates the parameter for the double polarization.

As described above, the components of the signal processing device 1 may be put together, and in the present embodiment, the first reference signal generation unit 103 and the second reference item generation unit 106 may be common to each set 117. good. Further, in FIG. 14, an antenna 118A for receiving the reflected wave of horizontal polarization and an antenna 118B for receiving the reflected wave of vertical polarization are shown, but the reflected wave is received by one antenna. The received signal may be divided into a horizontally polarized component and a vertically polarized component by a polarization separator. Further, also in this embodiment, the type of radar that transmits the transmitted wave and the interference wave is not particularly limited, and may be, for example, a parabolic type or a phased array type.

The degree of interference with horizontal polarization and vertical polarization is not always the same. When interference is detected from only one of both sets 117 depending on the level of polarization, the state of radio wave propagation, etc., the calculation result of the interference range in both sets 117 may be different. Conversely, when interference is detected from only one of both sets 117, it is considered that the polarization of the other set 117 also contains interference that has not reached the detected level. Therefore, the logical sum of the interference ranges calculated in both sets 117 may be used as the overall interference range. In that case, each set 117 informs the other set 117 of the calculated interference range. Thereby, the interference not detected in one of both sets 117 can be included in the interference range. Then, by performing the interference removal in the entire interference range, it is possible to perform the interference removal without any omission.

The components of the signal processing device 1 of the present embodiment may be realized by dedicated hardware such as an IC (Integrated Circuit) on which a processor or the like is mounted. For example, the signal processing device 1 includes a receiving circuit that realizes a receiving unit 101, a memory or storage that realizes a storage unit such as an interference wave data storage unit 102 and a transmission wave data storage unit 105, and other components such as, for example. It may include one or more processing circuits (processors) that realize the above-mentioned processing unit. Further, the processing circuit may be realized by a more detailed dedicated circuit. Alternatively, the components may be realized using software (program). When software (program) is used, in the embodiment described above, for example, a general-purpose computer device is used as basic hardware, and a processor such as a central processing unit (CPU: Central Processing Unit) mounted on the computer device is used. It can be realized by executing the program.

Also, the terms used in this embodiment should be broadly interpreted. For example, the term "processor" may include general purpose processors, central processing units (CPUs), microprocessors, digital signal processors (DSPs), controllers, microcontrollers, state machines, and the like. In some circumstances, the "processor" may refer to an application-specific integrated circuit, field programmable gate array (FPGA), programmable logic circuit (PLD), and the like. "Processor" may refer to a combination of processing devices such as multiple microprocessors, a combination of DSPs and microprocessors, and one or more microprocessors that work with a DSP core.

As another example, the term "memory" may include any electronic component capable of storing electronic information. "Memory" includes random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable PROM (EEPROM), and non-volatile. It may refer to random access memory (NVRAM), flash memory, magnetic or optical data storage. These can be read by the processor. If the processor reads and writes information to the memory, or both, then the memory can be said to communicate electrically with the processor. The memory may be integrated into the processor, again, it can be said that the memory is electrically communicating with the processor.

It should be noted that the present invention is not limited to the above embodiment as it is, and at the implementation stage, the components can be modified and embodied within a range that does not deviate from the gist thereof. In addition, various inventions can be formed by an appropriate combination of the plurality of components disclosed in the above-described embodiment. For example, some components may be removed from all the components shown in the embodiments. In addition, components across different embodiments may be combined as appropriate.

1 Signal processing device 101 Reception unit 102 Interference wave data storage unit 103 First reference signal generation unit 104 First pulse compression unit 105 Transmission wave data storage unit 106 Second reference signal generation unit 107 Second pulse compression unit 108 Interference detection unit 109 Interference range calculation unit 110 (110A, 110B) Interference removal unit 111 (111A, 111B) Parameter calculation unit 112 Judgment unit 113 Pre-interference detection unit 114 Pre-interference removal unit 115 (115A, 115B) Filter 116 Learning unit 117 (117A, 117B) ) Set (system)
118 (118A, 118B) Antenna

Claims (17)

A receiver that acquires a received signal based on the reflected wave with respect to the transmitted wave,
A first reference signal is generated based on the data on the interference wave that interferes with the reflected wave.
The received signal is pulse-compressed with the first reference signal to generate a first compressed signal.
A second reference signal is generated based on the data related to the transmitted wave.
The received signal is pulse-compressed with the second reference signal to generate a second compressed signal.
Interference is detected based on the output value of the first compressed signal, and
Based on the position of the interference detected in the first compressed signal, the interference range in the second compressed signal is calculated.
A processing unit that corrects the output value of the second compressed signal within the interference range, and
A signal processing device. The signal processing device according to claim 1, wherein the processing unit further determines the interference range based on the pulse length of the interference wave and the pulse length of the transmission wave. The signal processing according to claim 1 or 2, wherein the processing unit sets the start point of the interference range before the start point of the range including the interference signal in the received signal by the pulse length of the second compressed signal. Device. The processing unit generates the first compressed signal so that the output value of the first compressed signal becomes an extreme value at the start point of the range including the interference signal in the received signal.
The processing unit according to claim 1 or 2, wherein the processing unit sets the start point of the interference range before the time when the output value of the first compressed signal exceeds a predetermined value by the pulse length of the second compressed signal. Signal processing device. The signal processing device according to any one of claims 1 to 4, wherein the processing unit replaces an output value of the second compressed signal within the interference range with a predetermined value. The processing unit deletes the output value of the second compressed signal within the interference range, and the second compressed signal corresponding to the first compressed signal in which interference is not detected after the deleted second compressed signal. The signal processing apparatus according to any one of claims 1 to 4, wherein the serial number assigned to the output value within the interference range of the above is advanced. The processing unit sets the output value of the second compressed signal corresponding to the first compressed signal in which interference is detected within the interference range to the output value of the second compressed signal corresponding to the first compressed signal in which interference is not detected. The signal processing apparatus according to any one of claims 1 to 4, wherein the output value within the interference range or the calculated value based on the output value is replaced. The processing unit calculates parameters related to the reflected wave based on the modified second compressed signal.
The signal processing apparatus according to any one of claims 1 to 7. The processing unit calculates the correlation function of the plurality of second compressed signals from the plurality of second compressed signals generated from each of the plurality of received signals at different time points of reception, and reflects based on the calculated correlation function. The signal processing apparatus according to claim 8, wherein a parameter relating to a wave is calculated. The processing unit calculates the correlation function of the plurality of second compressed signals from the output values of the plurality of second compressed signals generated from each of the plurality of received signals having different reception time points, and the calculated correlation function. Calculate the parameters related to the reflected wave based on
Within the interference range, the output value of the second compressed signal is replaced with a predetermined value.
The signal processing device according to any one of claims 1 to 4, wherein in the calculation of the correlation function, the output value of the second compressed signal replaced with the predetermined value is omitted to calculate the correlation function. The processing unit calculates the correlation function of the plurality of second compressed signals from the output values of the plurality of second compressed signals generated from each of the plurality of received signals having different reception time points, and the calculated correlation function. Calculate the parameters related to the reflected wave based on
Within the interference range, the output value of the second compressed signal is deleted, and after the deleted second compressed signal, within the interference range of the second compressed signal corresponding to the first compressed signal for which interference was not detected. The serial number assigned to the output value of
Claims 1 to 4 for calculating the correlation function by omitting the integrated portion of the output value in which the assigned serial number is carried forward and the output value in which the assigned serial number is not carried forward in the calculation of the correlation function. The signal processing apparatus according to any one of the above. The processing unit calculates the parameters related to the reflected wave based on the corrected second compressed signal, and calculates the parameters.
The output value of the second compressed signal corresponding to the first compressed signal in which interference is detected within the interference range is determined.
(1) Replace with a predetermined value
(2) The output value of the second compressed signal within the interference range is deleted, and the second compressed signal corresponding to the first compressed signal in which interference is not detected after the deleted second compressed signal is used. Either carry up the serial number assigned to the output value within the interference range, or
(3) Replace with an output value within the interference range of the second compressed signal corresponding to the first compressed signal for which interference was not detected or a calculated value based on the output value.
Perform at least two of the above to generate multiple modified second compressed signals,
The signal processing apparatus according to any one of claims 1 to 4, wherein one of the plurality of modified second compressed signals is selected and the parameter is calculated. The signal processing device according to any one of claims 1 to 12, wherein the data regarding the interference wave is acquired from the source of the interference wave. Claims 1 to 13 generate a model for generating the data related to the interference wave or the first reference signal from the received signal by using the data related to the interference wave or the first reference signal as correct answer data. The signal processing apparatus according to any one of the above items. The processing unit determines whether or not the positions of interference detected in the plurality of first compressed signals match, or whether or not the pulse repetition frequency of the transmission wave and the pulse repetition frequency of the interference wave match. Depending on the information indicating that the pulse repetition frequency of the transmitted wave and the pulse repetition frequency of the interference wave match, the information regarding the change of the pulse repetition frequency of the transmission wave, or the pulse repetition frequency of the interference wave. The signal processing apparatus according to any one of claims 1 to 14, which outputs information regarding changes. The step of acquiring the received signal based on the reflected wave with respect to the transmitted wave,
A step of generating a first reference signal based on data on an interference wave that interferes with the reflected wave, and
A step of pulse-compressing the received signal with the first reference signal to generate a first compressed signal,
A step of generating a second reference signal based on the data related to the transmitted wave, and
A step of pulse-compressing the received signal with the second reference signal to generate a second compressed signal, and
A step of detecting interference based on the output value of the first compressed signal, and
A step of calculating the interference range in the second compressed signal based on the position of the interference detected in the first compressed signal, and
The step of modifying the second compressed signal within the interference range, and
A signal processing method comprising. A signal processing system including a first radar device that transmits a first radio wave and receives a reflected wave of the first radio wave, and a second radar device that transmits a second radio wave.
The first radar device is
A receiving unit that receives the reflected wave and acquires a received signal,
Based on the data related to the second radio wave, the first reference signal is generated.
The received signal is pulse-compressed with the first reference signal to generate a first compressed signal.
A second reference signal is generated based on the data related to the first radio wave.
The received signal is pulse-compressed with the second reference signal to generate a second compressed signal.
Interference is detected based on the output value of the first compressed signal, and
Based on the position of the interference detected in the first compressed signal, the interference range in the second compressed signal is calculated.
A processing unit that corrects the output value of the second compressed signal within the interference range, and
To prepare
Signal processing system.

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