Signal processing device and signal processing method

Abstract

To provide a signal processing device that can comprehensively present arrival bearing and electromagnetic wave specification information of a pulse signal.SOLUTION: A signal processing device comprises: an arrival bearing measurement unit; a pulse interval analysis unit; a generation unit; and a display control unit. The arrival bearing measurement unit measures arrival bearing of a wireless band pulse signal. The pulse interval analysis unit analyzes a pulse interval of a pulse signal time-sequence to generate a coordinate point distribution pattern that reflects pulse signal specification. The generation unit generates a symbol visually representing the specification from the coordinate point distribution pattern. The display control unit generates image data visually representing a frequency and arrival bearing of the pulse signal, and superposes the symbol on the image data to display the same on a display.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE The present invention relates to a signal processing device and a signal processing method. [Background technology]

[0002] The interferometer method, or MUSIC method, is known as a technique for measuring the direction of arrival of radio waves. The interferometer method is a method for measuring the direction of arrival of a single signal based on the phase difference between signals received by multiple antenna elements. The MUSIC method performs eigenvalue decomposition of the correlation matrix of the received signal, and can measure the directions of arrival of multiple signals. The directions of arrival of radio waves measured using these methods are visualized, for example, in a graph showing direction vs. intensity, and displayed on a monitor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-028447 A Summary of the Invention [Problem to be solved by the invention]

[0004] With existing technology, it was possible to grasp the direction of arrival of a received signal by displaying the direction versus strength, but it was not possible to grasp other information at a glance. For this reason, other information related to the signal specifications had to be analyzed separately at a later stage and output separately. Also, when multiple received signals were mixed within the reception bandwidth, it was not possible to distinguish and display them by frequency, for example. For these reasons, the information was not easily viewable, and a solution was desired.

[0005] Therefore, an object of the present invention is to provide a signal processing device and a signal processing method capable of comprehensively presenting the arrival direction of a pulse signal and radio wave specification information. [Means for solving the problem]

[0006] According to an embodiment, a signal processing device includes an arrival direction measurement unit, a pulse interval analysis unit, a generation unit, and a display control unit. The arrival direction measurement unit measures the arrival direction of a pulse signal in a radio band. The pulse interval analysis unit analyzes pulse intervals in a time series of the pulse signal to generate a coordinate point distribution pattern reflecting specifications of the pulse signal. The generation unit generates a symbol that visually represents the specifications from the coordinate point distribution pattern. The display control unit generates image data that visually represents the frequency and arrival direction of the pulse signal, and displays the image data on a display device by superimposing the symbol on the image data. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a functional block diagram showing an example of a signal processing device according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing an example of a time-intensity graph of a staggered modulated received pulse signal. [Diagram 3] FIG. 3 is a diagram showing an example of a coordinate point distribution pattern generated from the received pulse signal of FIG. [Figure 4] FIG. 4 is a diagram for explaining the conversion process performed by the display conversion unit 3. As shown in FIG. [Diagram 5] FIG. 5 is a diagram showing an example of a direction versus frequency display of a received pulse signal. [Figure 6] FIG. 6 is a diagram showing an example of a display to which a band-pass filter is applied. [Figure 7] FIG. 7 is a diagram showing an example of an enlarged display. [Figure 8] FIG. 8 is a flowchart showing an example of a processing procedure of the signal processing device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Next, an embodiment will be described with reference to the drawings. In the following, signal processing related to a pulse signal in a radio band will be described.

[0009] 1 is a functional block diagram showing an example of a signal processing device according to an embodiment. The signal processing device includes a receiving antenna 1, a receiving unit 10, a pulse interval analyzer 2, a display converter 3, a radio wave arrival direction measuring unit 4, a display controller 5 connected to a display unit 7, and an operation unit 6 including a mouse, a keyboard, etc. 1, a radio band pulse signal captured by a receiving antenna 1 becomes a received pulse signal after undergoing reception processing by a receiving section 10. The received pulse signal is sent to a pulse interval analyzer 2 and a radio wave arrival direction measuring section 4.

[0010] The pulse interval analyzer 2 as a pulse interval analyzer analyzes the pulse intervals of the time series of the pulse signal to generate a coordinate point distribution pattern (pattern) reflecting the characteristics of the pulse signal. That is, the pulse interval analyzer 2 converts data obtained from the received pulse signal into a unique pattern representing each characteristic. For example, according to the technology disclosed in Patent Document 1, the pulse interval analyzer 2 measures the forward pulse interval time and the backward pulse interval time for each received pulse. Then, coordinate points are plotted on a two-dimensional coordinate space with the forward pulse interval time (Pre-PI) as the X-axis (first coordinate axis) and the backward pulse interval time (Post-PI) as the Y-axis (second coordinate axis). A distribution of coordinate points is obtained from a received pulse signal including a plurality of received pulses.

[0011] FIG. 2 is a diagram showing an example of a time-intensity graph of a staggered received pulse signal. Suppose seven pulses of approximately constant intensity (Pulse Amplitude: PA) are observed in a certain time window. In FIG. 2, five types of pulse intervals (Pulse Intervals: PI) are observed, and each PI is given the subscripts 1 to 5 and is referred to as PI. 1 ~PI 5 It is expressed as:

[0012] Fig. 3 is a diagram showing an example of a coordinate point distribution pattern generated from the received pulse signal in Fig. 2. For example, the second pulse from the left in Fig. 2 is Pre-PI=PI 1 ,Post-PI=PI 2Therefore, it is plotted at the leftmost point (the hatched square) in Figure 3. If other pulses are plotted in the same way, a coordinate point distribution pattern that shows the characteristics of the pulse signal can be obtained.

[0013] Errors occur in the pulse interval time of the received pulse signal due to fluctuations on the transmitter side and the measurement accuracy on the receiver side (mainly the receiving unit 10). Even if pulse signals are emitted based on the same specification information, errors in the pulse interval time may result in a coordinate point distribution pattern with different coordinate positions.

[0014] Returning to Fig. 1, the radio wave arrival direction measurement unit 4 as an arrival direction measurement unit measures the arrival direction of the pulse signal. That is, the radio wave arrival direction measurement unit 4 measures the direction of the received pulse signal within the reception bandwidth by, for example, the interferometer method or the MUSIC method. The pulse signal to be the target of the direction measurement may be either a single signal or multiple signals.

[0015] The display converter 3 as a generator generates symbols visually expressing the parameters of each pulse signal from the coordinate point distribution pattern output from the pulse interval analyzer 2. That is, the display converter 3 converts the coordinate point distribution pattern to generate symbols for display. The conversion process will be explained using equations.

[0016] The display converter 3 expresses the set P of coordinate point distribution patterns obtained by the pulse interval analyzer 2 as shown in equation (1).

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[0017] Since each coordinate point distribution pattern 1 has a different display position and range in the XY coordinate space, the symbol sizes will also vary if left as is. Therefore, in this embodiment, the symbol sizes are unified by normalization.

[0018] FIG. 4 is a diagram for explaining the conversion process by the display conversion unit 3. The display conversion unit 3 normalizes all of the coordinate point distribution patterns 《1》 by moving the origin according to the average value of all pulse intervals in the pattern and by scaling according to the difference between the maximum and minimum values ​​of the pulse intervals. For each coordinate point distribution pattern, an average point M corresponding to the average value of all pulse intervals can be taken, and normalization is performed based on this point M. For scaling, the difference between the maximum and minimum values ​​may be further multiplied by a coefficient. Then, the display conversion unit 3 rotates the normalized pattern 45° counterclockwise around the origin to create a symbol pattern for display. That is, the display conversion unit 3 performs normalization processing of the coordinate point distribution pattern and coordinate axis rotation processing.

[0019] Returning to FIG. 1, the display control unit 5 generates image data visually representing the frequency and arrival direction of the pulse signal, and displays the symbol generated by the display conversion unit 3 on the display unit 7 by superimposing it on the image data. That is, the display control unit 5 plots the arrival direction and frequency of the pulse signal on a polar coordinate graph to generate image data in an orientation versus frequency display. Here, the polar coordinate graph is a graph in which the orientation is the angular coordinate axis and the frequency is the radial coordinate axis. That is, the display control unit 5 displays the symbol of the coordinate point distribution pattern output by the display conversion unit 3 in association with the arrival direction of each pulse signal plotted on the orientation versus frequency display.

[0020] Fig. 5 is a diagram showing an example of the direction versus frequency display of the received pulse signal. Fig. 5 shows an example in which the number of patterns is 3. The display control unit 5 generates image data of the direction versus frequency display by distinguishing between multiple (three) pulse signals mixed within the reception bandwidth.

[0021] The azimuth vs. frequency display is a polar coordinate system display (polar graph), with the angular coordinate axis (5) defined as azimuth and the radial coordinate axis (6) defined as frequency. The domain of azimuth is (7), and the domain of frequency is (8). Note that (9) and (10) are the upper and lower limits of frequency within the reception bandwidth, respectively.

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[0022] Each coordinate point distribution pattern has an arrival direction and frequency, which are superimposed on the direction vs. frequency display as shown in Fig. 5. The coordinate point distribution pattern is specific to a pulse signal, and its symbol represents the signal specification information (pulse interval (PI) or pulse width (PD), etc.) obtained by the pulse interval analyzer 2. By plotting these on a common direction vs. frequency display, the user can visually and comprehensively check information corresponding to signal waveforms that require individual analysis for all directions within the reception bandwidth.

[0023] Returning to Fig. 1, the operation unit 6 accepts a frequency band designated by the user. In response to this designation, the display control unit 5 updates the direction vs. frequency display. For example, if it is desired to display only the target signal on the display unit 7 while excluding unnecessary signals, a band pass filter is applied to the display result to limit the frequency range.

[0024] FIG. 6 is a diagram showing an example in which frequency ranges "11" and "12" are hidden by a band-pass filter.

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[0025] The hatched areas in Fig. 6 are the areas cut out corresponding to 《11》 and 《12》. A ~f B Only the symbols of the pulse signal in the frequency range are selectively displayed.

[0026] The application of the band pass filter may be specified by the user via a GUI (Graphical User Interface) on a dedicated screen. Alternatively, the frequency range may be specified by inputting a file that describes the frequency range in advance. In addition, when received pulse signals of different frequencies are mixed in the same direction, the frequency domain may be expanded and detailed.

[0027] Returning to Fig. 1, the operation unit 6 accepts a frequency range designated by the user. Then, the display control unit 5 changes the scale of the radial coordinate axis in the azimuth vs. frequency display in association with the designated frequency range, thereby realizing the expansion / contraction of the frequency domain related to the display.

[0028] Figure 7 shows an example of an enlarged display. For example, you can enlarge the frequency range by specifying a base point with a left click of the mouse, and then dragging the mouse along the radius from this base point to select the area. In Figure 7, the area with diagonal hatching is enlarged, which allows you to see more detailed information without overlapping between symbols.

[0029] Fig. 8 is a flowchart showing an example of a processing procedure of a signal processing device according to an embodiment. In Fig. 8, the signal processing device measures the arrival direction of a pulse signal in a radio band (step S2), and generates image data visually representing the frequency and arrival direction of the pulse signal based on the result (step S2).

[0030] Meanwhile, the signal processing device analyzes the pulse intervals of the time series of the pulse signal (step S3) and generates a coordinate point distribution pattern that reflects the specifications of the pulse signal (step S4).Then, the signal processing device converts the coordinate point distribution pattern to generate a symbol that visually represents the specifications of the pulse signal (step S5).Then, the signal processing device superimposes the symbol on the image data of step S2 (step S6) and displays it on the display unit 7 (step S7).

[0031] As described above, in this embodiment, the arrival direction of the received pulse signal captured by the receiving antenna 1 is measured using a method such as the MUSIC method, and plotted on a polar coordinate graph of direction versus frequency. Meanwhile, a coordinate point distribution pattern of the received pulse signal is obtained by pulse interval analysis, and a symbol of a standardized size is generated. Then, the symbol is displayed superimposed on the plot position of the pulse signal on the polar coordinate graph.

[0032] This makes it possible to visually present to the user the arrival directions of the mixed pulse signals and the radio wave specification information. Therefore, it is possible to provide a signal processing device and a signal processing method capable of comprehensively presenting the arrival directions of the pulse signals and the radio wave specification information.

[0033] It should be noted that the present invention is not limited to the above embodiment. For example, a notch filter may be used in place of the band pass filter used in the process shown in FIG.

[0034] In addition, by registering a coordinate point distribution pattern that has been identified in advance as a template in a database, it is possible to compare the coordinate point distribution pattern obtained by analyzing the received signal. In other words, a table in which the coordinate point distribution pattern of a known signal is associated with template data and registered is stored in a database, and it is possible to determine whether the received pulse signal is known or unknown based on a comparison between the coordinate point distribution pattern obtained by analyzing the received pulse signal and the template data.

[0035] That is, based on the data prepared in advance, it is possible to determine whether the signal is known or unknown and convert it into a numerical value using a method such as pattern matching. If these determination results are also displayed superimposed on the direction vs. frequency display, the information presented to the user can be further enhanced.

[0036] Although the embodiment has been described, this embodiment is presented as an example and is not intended to limit the scope of the invention. This novel embodiment can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. This embodiment and its modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0037] 1...receiving antenna, 2...pulse interval analyzer, 3...display conversion section, 4...radio wave arrival direction measurement section, 5...display control section, 6...operation section, 7...display section, 10...receiving section.

Claims

1. an arrival direction measurement unit for measuring an arrival direction of a pulse signal in a radio band; a pulse interval analysis unit that analyzes pulse intervals of the time series of the pulse signal to generate a coordinate point distribution pattern that reflects the parameters of the pulse signal; a generating unit that generates a symbol visually representing the parameter from the coordinate point distribution pattern; a display control unit that generates image data visually representing the frequency of the pulse signal and the arrival direction, and superimposes the symbol on the image data and displays it on a display device.

2. 2. The signal processing device according to claim 1, wherein the display control unit plots the arrival azimuth and frequency of the pulse signal on a polar coordinate graph having azimuth as an angular coordinate axis and frequency as a radial coordinate axis, to generate the image data in azimuth versus frequency display.

3. The signal processing device according to claim 1 , wherein the display control unit generates the image data by distinguishing between a plurality of pulse signals that are mixed within a reception bandwidth.

4. Further comprising an operation unit for accepting a frequency band designated by a user, The signal processing device according to claim 1 , wherein the display control unit superimposes a symbol corresponding to the specified frequency band on the image data and displays the symbol on the display device.

5. Further comprising an operation unit for accepting a frequency range designated by a user, The signal processing device according to claim 2 , wherein the display control unit varies a scale of the radial coordinate axis in the azimuth versus frequency display in association with the specified frequency range.

6. a database storing a table in which coordinate point distribution patterns of known signals and template data are registered in correspondence with each other; 2. The signal processing device according to claim 1, further comprising a determination unit that determines whether the pulse signal is known or unknown based on a comparison between the generated coordinate point distribution pattern and the template data.

7. A step of measuring an arrival direction of a pulse signal in a radio band by a signal processing device; a step in which the signal processing device analyzes pulse intervals of a time series of the pulse signal to generate a coordinate point distribution pattern reflecting the parameters of the pulse signal; generating, by the signal processing device, a symbol visually representing the parameter from the coordinate point distribution pattern; a step of generating image data visually representing the frequency and the direction of arrival of the pulse signal by the signal processing device; and a step of the signal processing device superimposing the symbol on the image data and displaying the image data on a display device.

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