Signal processing device, measurement device, and signal processing method

Abstract

The principal purpose of the present technology is to provide a signal processing device, a measurement device, and a signal processing method that involve a simple configuration but can still improve spatial resolution.　The present technology provides a signal processing device (100) that comprises a reception unit (1) that receives signals from objects (2: 21, 22), a reflection unit (3) that reflects the signals toward the objects or the reception unit, and a computation unit (4) that computes position information about the objects. The computation unit (4) computes the position information on the basis of the signals as received by the reception unit (1) and the positional relationship between the reception unit (1) and the reflection unit (3). The reflection unit (3) may selectively reflect the signals.

Description

Signal processing device, measuring device, and signal processing method

[0001] The technology according to the present disclosure (hereinafter also referred to as "the present technology") relates to a signal processing device, a measurement device, and a signal processing method.

[0002] In recent years, research and development has been conducted on technologies for measuring human biological information using radar signals, and technologies for measuring the distance between multiple points using wireless communication signals.

[0003] Radar signals can measure minute displacements based on phase changes, making it possible to detect displacements on the surface of a human body caused by breathing, heartbeat, and so on.

[0004] For example, Patent Document 1 discloses a signal processing device including "a reception processing unit that receives a response to a predetermined signal transmitted from a transmitting antenna, and a determination unit that determines the plurality of measurement targets based on responses to a plurality of signals corresponding to a second direction having a predetermined range different from a first direction having a predetermined range." It explains that this configuration makes it possible to distinguish and measure the plurality of measurement targets.

[0005] JP 2018-72171 A

[0006] When measuring the displacement of a human body surface using radar signals, it is necessary to improve the spatial resolution in order to measure the displacement of each nearby object with high accuracy. The spatial resolution obtained by radar includes, for example, range resolution and angular resolution. Range resolution is determined by the bandwidth of the radar signal, and angular resolution is determined by the number of antenna elements.

[0007] The bandwidth of radar signals is regulated by law, and increasing the number of antenna elements increases the size and cost of the equipment, making it difficult to improve spatial resolution. The same is true for wireless communications.

[0008] Therefore, a main object of the present technology is to provide a signal processing device, a measurement device, and a signal processing method that can improve spatial resolution while having a simple configuration.

[0009] The present technology provides a signal processing device including: a receiving unit that receives a signal from an object; a reflecting unit that reflects the signal toward the object or the receiving unit; and a computing unit that calculates position information regarding the object, wherein the computing unit calculates the position information based on the signal received by the receiving unit and a positional relationship between the receiving unit and the reflecting unit. The reflecting unit may selectively reflect the signal. The computing unit may select reflection or non-reflection from the reflecting unit based on a comparison result between the signal received by the receiving unit when the reflecting unit reflected the signal and the signal received by the receiving unit when the reflecting unit did not reflect the signal. The reflecting unit may be located farther from the object than the receiving unit. When the signal is a radar signal, the receiving unit may receive a first radar signal transmitted from a transmitting unit to an object and reflected by the object, the reflecting unit may reflect the first radar signal toward the object, and the calculating unit may calculate position information regarding the object based on the first radar signal, a second radar signal obtained by reflecting the first radar signal from the object, and a positional relationship between the receiving unit and the reflecting unit.The signal processing device may include a plurality of the receiving units, and the calculating unit may calculate the position information regarding the object based on the positional relationship between the respective receiving units and the first radar signal and the second radar signal received by the respective receiving units. When the signal is a wireless communication signal, the receiving unit is a first transceiver unit, and the object is a second transceiver unit, the first transceiver unit transmits the wireless communication signal toward the second transceiver unit, the second transceiver unit receives the wireless communication signal from the first transceiver unit and transmits a first wireless communication signal toward the first transceiver unit and the reflecting unit, the reflecting unit reflects the wireless communication signal from the second transceiver unit toward the first transceiver unit, and the calculating unit calculates position information regarding the second transceiver unit based on the first wireless communication signal, the second wireless communication signal reflected by the reflecting unit from the first wireless communication signal, and the positional relationship between the receiving unit and the reflecting unit.The signal processing device may include a plurality of the first transceivers, and the calculation unit may calculate position information regarding the object based on the positional relationship between the respective first transceivers and the first wireless communication signal and the second wireless communication signal received by each of the first transceivers. The signal processing device may include a plurality of the first transceivers, and the calculation unit may calculate position information regarding the object based on the time difference or phase difference, or both, between the first wireless communication signal and the second wireless communication signal received by each of the first transceivers. The reflecting unit may be configured to be positionally changeable and selectively reflect the signal, and the calculation unit may change the position of the reflecting unit based on a comparison result between the signal received by the receiving unit when the reflecting unit reflected the signal and the signal received by the receiving unit when the reflecting unit did not reflect the signal. The signal processing device may include a plurality of the reflecting units, and the calculation unit may calculate the position information based on the signal received by the receiving unit and the positional relationship between the receiving unit and each of the reflecting units. Each of the reflecting portions may selectively reflect the signal, and the calculating portion may calculate position information regarding the object based on a comparison result between a first signal received by the receiving portion when the reflecting portion reflects the signal and a second signal received by the receiving portion when the reflecting portion does not reflect the signal. The reflecting portion may have a metasurface. The reflecting portion may include at least one material selected from gold, silver, copper, and aluminum. When the signal is a radar signal, the reflecting portion may be a corner reflector. When the signal is a wireless communication signal, the reflecting portion may be planar. The signal processing device may measure human biometric information. The signal processing device may measure at least one of a human heart rate and a human pulse.The present technology also provides a measurement device including: a transmitting unit that transmits a signal toward an object; a receiving unit that receives the signal from the object; a reflecting unit that reflects the signal toward the object or the receiving unit; and a calculating unit that calculates position information related to the object, wherein the calculating unit calculates the position information based on the signal received by the receiving unit and a positional relationship between the receiving unit and the reflecting unit. The present technology also provides a signal processing method including: receiving a signal from an object; reflecting the signal toward the object or a position where the signal was received; and calculating the position information related to the object based on the received signal and the positional relationship between the position where the signal was received and the position where the signal was reflected.

[0010] According to the present technology, it is possible to improve spatial resolution with a simple configuration. Note that the effects described herein are not necessarily limited to those described herein, and may be any of the effects described in the present disclosure.

[0011] 2A is a block diagram showing an example configuration of a signal processing device 100 according to an embodiment of the present technology. FIG. 2B is a graph showing an example of a change in a signal processed by the signal processing device. FIG. 2B is a schematic diagram showing a processing flow of the signal processing device. FIG. 2A is a schematic diagram showing an example configuration of a signal processing device. FIG. 2B is a graph showing an example of a change in a signal processed by the signal processing device. FIG. 2B is a schematic diagram showing a processing flow of the signal processing device. FIG. 2A is a schematic diagram showing an example configuration of a signal processing device 100 according to an embodiment of the present technology. FIG. 2B is a graph showing an example of a change in a signal processed by the signal processing device. FIG. 2B is a schematic diagram showing a processing flow of the signal processing device. FIG. 2A is a schematic diagram showing an example configuration of a signal processing device 100 according to an embodiment of the present technology. FIG. 2B is a graph showing an example of a processing flow of the signal processing device 100 according to an embodiment of the present technology. FIG. 1 is a flowchart showing an example of a processing flow of a signal processing device 100 according to an embodiment of the present technology. FIG. 2 is a graph showing a processing result of the signal processing device 100 according to an embodiment of the present technology. FIG. 3 is a schematic diagram for describing an operation of the signal processing device 100 according to an embodiment of the present technology. FIG. 4 is a flowchart showing an example of a processing flow of the signal processing device 100 according to an embodiment of the present technology. FIG. 5 is a block diagram showing an example configuration of the signal processing device 100 according to the present technology. FIG. 6 is a flowchart showing an example of a processing flow of the signal processing device 100 according to an embodiment of the present technology. FIG. 7 is a schematic diagram for describing an operation of the signal processing device 100 according to an embodiment of the present technology.1 is a graph showing a processing result of a signal processing device 100 according to an embodiment of the present technology. FIG. 2 is a schematic diagram for explaining an operation of a signal processing device 100 according to an embodiment of the present technology. FIG. 3 is a graph showing a processing result of a signal processing device 100 according to an embodiment of the present technology. FIG. 4 is a graph showing a processing result of a signal processing device 1000 according to an embodiment of the present technology. FIG. 5 is a flowchart showing an example of a processing flow of a signal processing device 100 according to an embodiment of the present technology. FIG. 6 is a block diagram showing an example configuration of a measurement device 1000 according to an embodiment of the present technology. FIG. 7 is a schematic diagram showing an example arrangement position of a measurement device 1000 according to an embodiment of the present technology. FIG. 8 is a flowchart showing an example of a signal processing method according to an embodiment of the present technology.

[0012] Hereinafter, preferred embodiments for implementing the present technology will be described with reference to the drawings. Note that the embodiment described below shows an example of a typical embodiment of the present technology, and does not limit the scope of the present technology. In addition, the present technology can be combined with any of the following examples and their modifications.

[0013] In the following description of the embodiments, configurations may be described using terms including "approximately," such as "approximately parallel" and "approximately perpendicular." For example, "approximately parallel" does not only mean completely parallel, but also means substantially parallel, i.e., including a state where the orientation is deviated from the completely parallel state by, for example, a few percent. The same applies to other terms including "approximately." Furthermore, each figure is a schematic diagram and is not necessarily an accurate depiction. The scale of the drawings has been exaggerated to make the features of the technology easier to understand. Therefore, it should be noted that the scale of the drawings and the scale of the actual device are not necessarily the same.

[0014] Unless otherwise specified, in the drawings, "top" means the top or upper side in the drawing, "bottom" means the bottom or lower side in the drawing, "left" means the left or left side in the drawing, and "right" means the right or right side in the drawing. Furthermore, in the drawings, the same or equivalent elements or members are given the same reference numerals, and redundant explanations will be omitted.

[0015] The description will be given in the following order: 1. First embodiment of the present technology (example of signal processing device) 2. Second embodiment of the present technology (example 1 of signal processing device using radar signals) (1) Signal processing device using radar signals (2) This embodiment (2-1) Range resolution (2-2) Angular resolution (2-3) Specific example of calculation 1 (2-4) Specific example of calculation 2 3. Third embodiment of the present technology (example 2 of signal processing device using radar signals) 4. Fourth embodiment of the present technology (example 3 of signal processing device using radar signals) 5. Fifth embodiment of the present technology (example 4 of signal processing device using radar signals) 6. Sixth embodiment of the present technology (example 5 of signal processing device using radar signals) 7. Seventh embodiment of the present technology (example 1 of signal processing device using wireless communication signals) (1) Signal processing device using wireless communication signals (2) This embodiment 8. Eighth embodiment of the present technology (example 2 of signal processing device using wireless communication signals) 9. Ninth embodiment of the present technology (example 3 of signal processing device using wireless communication signals) 10. 10. Tenth embodiment of the present technology (example 4 of signal processing device using wireless communication signal) 11. Eleventh embodiment of the present technology (example of measurement device) 12. Twelfth embodiment of the present technology (example of signal processing method)

[0016] [1. First embodiment of the present technology (example of signal processing device)] The present technology provides a signal processing device including: a receiving unit that receives a signal from an object; a reflecting unit that reflects the signal toward the object or the receiving unit; and a calculating unit that calculates position information related to the object, wherein the calculating unit calculates the position information based on the signal received by the receiving unit and a positional relationship between the receiving unit and the reflecting unit.

[0017] An example configuration of a signal processing device according to an embodiment of the present technology will be described with reference to Fig. 1. Fig. 1 is a block diagram showing an example configuration of a signal processing device 100 according to an embodiment of the present technology.

[0018] 1, the signal processing device 100 includes a receiving unit 1, a reflecting unit 3, and a calculating unit 4. The reflecting unit 3 is disposed at a position farther from the object 2 than the receiving unit 1.

[0019] The receiving unit 1 receives a signal from an object 2. The reflecting unit 3 reflects the signal from the object 2 toward the object 2 or the receiving unit 1.

[0020] For example, when signals are sent from two positions on the object 2, the reflector 3 reflects each signal, further increasing the path length difference (difference in signal arrival time) between the signals. This makes it easier to observe each of the two positions on the object 2. In other words, spatial resolution is improved.

[0021] The calculation unit 4 calculates position information regarding the object 2 based on the signal received by the receiving unit 1 and the positional relationship between the receiving unit 1 and the reflecting unit 3. This position information includes, for example, information about the distance from the receiving unit 1 to the object 2, and information about the direction (angle) in which the object 2 is located.

[0022] What is important here is that the positional relationship between the receiving unit 1 and the reflecting unit 3 is known. For example, paragraph

[0032] of Patent Document 1 (JP 2018-72171 A) explains that a reflector on a wall surface reflects radio waves, thereby causing a distance difference. However, in this configuration, the reflector is placed in the environment, and the distance between the reflector and the receiving antenna may fluctuate. Therefore, there is room for improvement in terms of improving spatial resolution.

[0023] According to the present technology, since the positional relationship between the receiving unit 1 and the reflecting unit 3 is known, spatial resolution can be improved by performing calculations using the path length difference between the signal from the object 2 and the signal reflected by the reflecting unit 3. This effect also occurs in the same way in other embodiments described later. Therefore, repeated description may be omitted in the descriptions of other embodiments.

[0024] In the signal processing device 100 according to an embodiment of the present technology, it is only necessary that the positional relationship between the receiving unit 1 and the reflecting unit 3 is known, and there is no limitation on the arrangement position of the reflecting unit 3. The reflecting unit 3 may be built into the signal processing device 100 or may be arranged outside the signal processing device 100.

[0025] The above description of the signal processing device according to the first embodiment of the present technology can be applied to other embodiments of the present technology unless there is a particular technical contradiction.

[0026] [2. Second Embodiment of the Present Technology (Example 1 of Signal Processing Device Using Radar Signal)] [(1) Signal Processing Device Using Radar Signal] A signal processing device according to the present technology can transmit and receive, for example, a radar signal. For example, the signal processing device can transmit and receive a radar signal in the millimeter wave band whose frequency changes over time.

[0027] The processing of the signal processing device that transmits and receives radar signals will be described with reference to Fig. 2. Fig. 2A is a schematic diagram showing an example of the configuration of the signal processing device.

[0028] 2A , the transmitting antenna 11 transmits a first signal W1, which is a chirp signal, to the target. The receiving antenna 12 receives a second signal W2, which is a chirp signal reflected by the subject. The chirp signal is a millimeter-wave band signal whose frequency changes over time. That is, each of the first and second signals is a millimeter-wave band signal whose frequency changes over time.

[0029] The mixer 22 combines the first and second signals to generate an IF signal W3, which is then converted into a digital signal by the AD converter 5 and then transformed into the frequency domain by a Fast Fourier Transform (FFT).

[0030] An example of the changes in the first signal and the second signal will be described with reference to Fig. 2B. Fig. 2B is a graph showing an example of changes in the signal processed by the signal processing device. In the left diagram of Fig. 2B, the horizontal axis represents time and the vertical axis represents the frequency of the signal.

[0031] First, the first signal W1 to be transmitted to the target has an initial frequency f ０ to the target frequency f １ The frequency f ０ to frequency f １ The time required for the value to change to ｃ The frequency f ０ and frequency f１ The difference between these is the sweep bandwidth BW.

[0032] Next, the frequency of the second signal W2 reflected by the object also changes over time, similar to the first signal W1. The delay time T is the time from when the signal is transmitted from the millimeter-wave radar device to when it is reflected by the object and returns to the signal processing device.

[0033] The frequency f of the IF signal W3 obtained by mixing the first signal W1 and the second signal W2 is ＩＦ There is a correlation between the distance d from the signal processing device 100 to the object and the distance c to the object. Specifically, the distance d from the signal processing device 100 to the object can be calculated based on the following equation (1), where c represents the speed of light.

[0034]

[0035] Next, the processing flow of the signal processing device will be described with reference to Fig. 3. Fig. 3 is a schematic diagram showing the processing flow of the signal processing device.

[0036] Fig. 3A shows an example of an IF signal, which is an analog signal. In Fig. 3A, the horizontal axis represents time. By AD converting this analog signal, the IF signal, which is a digital signal, shown in Fig. 3B is obtained. By analyzing this IF signal using, for example, a frequency analysis algorithm such as Range FFT (Fast Fourier Transform), frequency components, with frequency represented on the horizontal axis, can be obtained as shown in Fig. 3C.

[0037] The change over time of the first signal transmitted to the target is shown in FIG. 3D. In the graph shown in FIG. 3D, the horizontal axis represents time and the vertical axis represents frequency. As shown in FIG. 3D, the first signal transmitted to the target has an initial frequency f ０ to the target frequency f １ After changing over time to the initial frequency f ０ Then, the first signal returns to the initial frequency f ０ to the target frequency f １The frequency of the first signal changes repeatedly in this manner, and therefore, as shown in Fig. 3C, frequency components corresponding to unit changes in the first signal are obtained.

[0038] In the frequency components shown in Figure 3C, the darker the color, the higher the observation level. A second signal reflected by various objects in space is received, and it can be assumed that frequency components with high observation levels are frequency components based on signals reflected by the object being measured. As described above, there is a correlation between the distance to the object and the frequency of the IF signal, so the distance to the object can be estimated by extracting frequency components with high observation levels.

[0039] Furthermore, it is preferable to be able to estimate the direction in which the object is located in addition to the distance to the object. To achieve this, the receiver 1 preferably has multiple receiving antennas that receive the second signal. As a result, as shown in FIG. 3E, the direction in which the object is located can be estimated based on the phase difference between multiple second signals received during the same chirp time. In FIG. 3E, the vertical axis represents frequency. From the front to the back, frequency components based on the signals received by the receiving antennas are arranged. For each unit change (C1 to C3), four frequency components based on the second signals received by the four receiving antennas are shown. Based on these four frequency components, the direction in which the subject is located can be estimated. Note that the number of receiving antennas is not limited to four; two or more is sufficient.

[0040] The diagram shown in Figure 3E can be converted to the diagram shown in Figure 3F. In Figure 3F, the vertical axis represents frequency and the horizontal axis represents direction. Frequency components corresponding to the chirp time are arranged from the front to the back. In other words, the frequency components change over time as they move from the front to the back. In this way, it is possible to estimate the distance and direction to the target object and observe changes over time, making it possible to observe movements of the body surface caused by, for example, lung expansion.

[0041] However, the means for analyzing the IF signal is not limited to this. For example, the distance to the target may be measured using pulse compression technology. Pulse compression technology is a technology for measuring distance with high resolution using a pulse signal with a short pulse width. The short pulse width can be obtained by cross-correlating the transmitted pulse signal and the received reflected signal. This allows distance to be measured with high accuracy.

[0042] Alternatively, the distance to the subject may be measured using biometric information analysis technology. Biometric information analysis technology is a technology that analyzes weak electromagnetic waves reflected by biological tissue to observe the structure and function of the body. By transmitting electromagnetic waves to biological tissue and analyzing the reflected signals, the structure and function of the tissue can be observed.

[0043] A specific processing flow of the calculation unit included in the signal processing device will be described with further reference to Fig. 4. Fig. 4 is a block diagram showing an example configuration of a signal processing device 100 according to an embodiment of the present technology. As shown in Fig. 4, the signal processing device 100 includes a receiving unit 1 and a calculation unit 4. The signal processing device 100 may further include a transmitting unit 6. The receiving unit 1 and the transmitting unit 6 are preferably included in the same device, but may also be included in separate devices.

[0044] After acquiring raw data from the receiving unit 1, the calculation unit 4 analyzes the raw data using Range FFT and Angle FFT. FFT (Fast Fourier Transform) is a process that converts a signal into the frequency domain. In the time domain, a signal is a value that changes over time, but in the frequency domain, the amplitude and phase of each frequency component can be expressed.

[0045] Next, the calculation unit 4 performs a process (object detection) to detect an object from the signal. The object is detected based on, for example, the signal intensity.

[0046] Next, the calculation unit 4 combines the signals from the multiple receiving units and performs processing to emphasize the signal from a specific direction (beam forming). This processing enables more accurate detection of the signal from the specific direction.

[0047] Next, the calculation unit 4 performs a process to remove the direct current component of the signal (DC compensation). The DC component is the average value of the signal and may affect the frequency component of the signal. By performing this process, the frequency component of the signal can be accurately analyzed.

[0048] Next, the calculation unit 4 performs a process to extract the phase of the signal (phase extraction). The phase can be obtained by arctangent demodulation of the complex signal. By performing this process, minute displacements of the target can be analyzed.

[0049] Next, the calculation unit 4 performs a phase unwrapping process, which makes it possible to interpret the phase change as a continuous change.

[0050] Next, the calculation unit 4 performs a process to convert the phase into a displacement (phase to displacement). The displacement represents the position and movement of an object. By performing this process, the position and movement of the object can be estimated from the phase of the signal.

[0051] Next, the calculation unit 4 performs a process (HR / BR separation) to separate the heart rate (HR) from the pulse rate (BR) using, for example, a band-pass filter.

[0052] Finally, the calculation unit 4 performs a process (HR / BR estimation) to estimate the heart rate (HR) and pulse rate (BR) from the obtained waveform. By performing this process, the heart rate and respiratory rate can be determined.

[0053] In this way, the signal processing device 100 according to an embodiment of the present technology can measure human biological information. In particular, the signal processing device 100 can measure at least one of a human heart rate and a human pulse. Note that the biological information measured by the signal processing device 100 is not limited to the heart rate and the pulse, and the signal processing device 100 can also measure respiratory rate, etc.

[0054] [(2) This Embodiment] [(2-1) Axial Resolution] The operation of the signal processing device according to the present technology will be described with reference to Fig. 5. Fig. 5 is a schematic diagram for explaining the operation of the signal processing device 100 according to one embodiment of the present technology.

[0055] 5, the reflecting unit 3, the receiving unit 1, the first object 21, and the second object 22 are arranged in a straight line. The distance between the first object 21 and the second object 22 is Δd.

[0056] When the signal from the object is a radar signal, the signal is first transmitted from a transmitter (not shown) to the object 2 (the first object 21 and the second object 22) and reflected by the first object 21 and the second object 22 as a first radar signal S1, which is then received by the receiver 1. Therefore, a distance difference Δd occurs between the first radar signal S1 reflected by the first object 21 and the first radar signal S1 reflected by the second object 22.

[0057] Next, the reflector 3 reflects the first radar signal S1 toward the first object 21 and the second object 22. The first radar signal S1 is reflected by the first object 21 and the second object 22 and becomes a second radar signal S2.

[0058] In this case, because the radar signal makes two round trips, the path length of the radar signal doubles, and a distance difference of 2Δd occurs between the second radar signal S2 reflected by the first object 21 and the second radar signal S2 reflected by the second object 22. In other words, the first imaginary object 21a and the second imaginary object 22a can be defined as being virtually located at positions that are twice the distance from the receiving unit 1 to the first object 21 and the second object 22. The distance between the first imaginary object 21a and the second imaginary object 22a can be defined as 2Δd. Even if the first object 21 and the second object 22 cannot be detected separately when the distance difference is Δd, they can be detected separately when the distance difference is 2Δd.

[0059] A calculation unit (not shown) calculates position information about the object based on the first radar signal S1, the second radar signal S2 that is the result of the first radar signal S1 being reflected by the object 2, and the positional relationship between the receiver 1 and the reflector 3. Because the difference in distance between the first object 21 and the second object 22 is doubled, distance resolution is improved, and the calculation unit 4 can distinguish the respective positions of the first object 21 and the second object 22. The radar signal may make three or more round trips, and the greater the number of round trips, the greater the difference in distance between the objects.

[0060] When the speed of light is c and the bandwidth of the radar signals S1 and S2 is BW, the distance resolution d ｒｅｓ can be calculated using the following equation (1).

[0061] d ｒｅｓ =c / 2BW...(1)

[0062] [(2-2) Angular Resolution] In Fig. 5, the reflecting unit 3, the receiving unit 1, the first object 21, and the second object 22 are arranged side by side on a straight line. On the other hand, the first object 21 and the second object 22 may be arranged side by side in the left-right direction as viewed from the receiving unit 1. This will be described with reference to Fig. 6. Fig. 6 is a schematic diagram for explaining the operation of the signal processing device 100 according to an embodiment of the present technology.

[0063] As shown in Figure 6, a first object 21 and a second object 22 are arranged side by side in the left-right direction as viewed from the receiving unit 1. A first line segment L1 is defined connecting the receiving unit 1 and the second object 22. In this case, the distance between the receiving unit 1 and the second object 22 is longer by Δd than the distance between the receiving unit 1 and the first object 21. When the radar signal makes two round trips, this difference in distance doubles.

[0064] In other words, the first fictitious object 21a and the second fictitious object 22a can be defined as being virtually located at a position twice the distance from the receiving unit 1 to the first object 21 and the second object 22. The distance difference can be defined as 2Δd. Because the distance difference is longer, the calculation unit 4 can use the above formula (1) to calculate the position information of the first object 21 and the second object 22 separately.

[0065] (2-3) Specific Example 1 of Calculation A specific example of calculation will be described with reference to Fig. 7. Fig. 7 is a schematic diagram for explaining the operation of the signal processing device 100 according to an embodiment of the present technology.

[0066] 7, the first object 21 and the second object 22 are arranged side by side in the left-right direction as viewed from the receiving unit 1. The reflecting unit 3 is arranged at a position farther away from the first object 21 and the second object 22 than the receiving unit 1.

[0067] The distance resolution for separating and detecting the position information of the first object 21 and the second object 22 will be described. Suppose the bandwidth BW of the radar signal is, for example, 4 GHz, and the speed of light c is 3×10 ８ [m / s], the distance resolution d ｒｅｓ In other words, if the difference in distance between two objects is within 3.75 cm, the signal processing device 100 cannot detect the position information of each of the two objects.

[0068] The distance between the receiving unit 1 and the first object 21 is defined as d. The distance between the first object 21 and the second object 22 is defined as w (w1). The distance difference Δd between the distance from the receiving unit 1 to the second object 22 and the distance from the receiving unit 1 to the first object 21 can be calculated using the following equation (2).

[0069]

[0070] Distance resolution d ｒｅｓ When the distance d is 3.75 cm, Δd must be greater than 3.75 cm. For example, when the distance d is 1 m, using the above formula (1), it can be seen that w1 must be greater than 27.6 cm. In other words, when the distance w1 between the first object 21 and the second object 22 is 27.6 cm or less, the signal processing device cannot detect the position information of each of the two objects.

[0071] However, according to the present technology, because the radar signal makes two round trips, when the distance d between the receiver 1 and the first object 21 is 1 m, the distance between the receiver 1 and the first imaginary object 21a is 2 m. When Δd is 3.75 cm and the distance d is 2 m, calculation using the above formula (1) reveals that w(w2) must be greater than 38.9 cm. The distance w2 between the first imaginary object 21a and the second imaginary object 22a is twice the distance w1 between the first object 21 and the second object 22. Therefore, if the first object 21 and the second object 22 are separated by 19.45 cm, which is half of 38.9 cm, the position information of the first object 21 and the second object 22 can be calculated separately. In this way, the present technology improves spatial resolution.

[0072] This will be further described with reference to Fig. 8. Fig. 8 is a graph showing the processing results of the signal processing device 100 according to an embodiment of the present technology. In Fig. 8, the horizontal axis represents elapsed time t, and the vertical axis represents the strength s of the signal received by the receiving unit 1.

[0073] First, a single signal with a large intensity is detected at point P1. Point P2 indicates that signals reflected by the first object 21 and the second object 22 have been detected. At this point, the first object 21 and the second object 22 have not been detected separately, so only a single signal with a large intensity is displayed.

[0074] Next, the reflecting unit 3 reflects the signal toward the first object 21 and the second object 22, and the first object 21 and the second object 22 reflect this signal toward the receiving unit 1. Then, signals are detected at points P2 and P3, respectively. At point P2, position information of the first object 21 can be detected, and at point P3, position information of the second object 22 can be detected. The first object 21 and the second object 22 can be detected separately.

[0075] The configuration and shape of the reflector 3 are not particularly limited. In the schematic diagram shown in Fig. 5, the reflector 3 is flat, but the shape is not limited to this. The reflector 3 may be, for example, a corner reflector or a curved plate-like shape.

[0076] The material of the reflector 3 is not particularly limited as long as it can reflect a signal. The reflector 3 may be, for example, a metal plate, a copper-clad laminate, a metasurface (metamaterial), or the like. Alternatively, a material that reflects signals and transmits visible light may be used for the reflector 3. As will be described in detail later, the reflector 3 having a metasurface allows the reflector 3 to selectively reflect signals. In other words, the reflector 3 can have an on / off function for reflection.

[0077] However, it is preferable that the material of the reflective portion 3 is one that is less likely to attenuate signal strength due to reflection. Therefore, it is preferable that the reflective portion 3 contains at least one material selected from gold, silver, copper, and aluminum. In particular, it is more preferable that the reflective portion 3 contains aluminum, which is less likely to attenuate signal strength and can reduce manufacturing costs.

[0078] Furthermore, when the signal is a radar signal, it is preferable that the reflecting portion 3 is a corner reflector, as shown in Figure 7. A corner reflector has a structure in which three triangular metal plates are joined at right angles, and is capable of reflecting the signal in the incident direction. Because the corner reflector reflects the signal in the incident direction, it can measure the position information of an object with high accuracy. Furthermore, because the corner reflector has a high reflectivity, it can obtain a strong reflection even from a small object. Furthermore, the corner reflector has a simple structure and is inexpensive to manufacture.

[0079] (2-4) Specific Example 2 of Calculation A further specific example of calculation will be described with reference to FIG. 9. FIG. 9 is a schematic diagram for explaining the operation of a signal processing device 100 according to an embodiment of the present technology. In FIG. 9, a receiving unit 1 and a reflecting unit 3 provided in the signal processing device 100 are shown. Specifically, the receiving unit 1 is configured by arranging a receiving antenna 11, electronic components 12, etc. on a substrate 13. Furthermore, a reference point Pa of the receiving antenna 11 and a reference point Pr of the reflecting unit 3 are shown. The coordinates of the reference point Pa of the receiving antenna 11 are (x ａ , y ａ , z ａ ), and the coordinates of the reference point Pr of the reflecting portion 3 are (x ｒ , y ｒ , z ｒ )

[0080] The signal processing device 100 detects the position information of the human chest 24 and the arm 25 separately. The coordinates of the reference point Pt1 of the human chest 24 are (x ｔ１ , y ｔ１ , z ｔ１ ), and the coordinates of the reference point Pt2 are (x ｔ２ , y ｔ２ , z ｔ２ ) In this case, the distance R between the reference point Pa of the receiving antenna 11 and the reference point Pt1 of the human chest 24 is Ｐａ－Ｐｔ１ can be calculated using the following equation (3).

[0081]

[0082] The distance R between the reference point Pr of the reflecting part 3 and the reference point Pt1 of the human chest 24 is Ｐｒ－Ｐｔ１ can be calculated using the following equation (4).

[0083]

[0084] The distance R' between the reference point Pa of the receiving antenna 11 and the reference point Pt1 of the human chest 24 is observed by receiving the signal reflected by the reflector 3 and then reflected by the human chest 24. Ｐａ－Ｐｔ１ can be calculated using the following equation (5).

[0085] R' Ｐａ－Ｐｔ１ =RＰａ－Ｐｔ１ +R Ｐｒ－Ｐｔ１ ...(5)

[0086] From the above, if the positional relationship (for example, distance, direction, etc.) between the receiving unit 1 and the reflecting unit 3 is known, positional information regarding the target object can be calculated based on this positional relationship and the received signal.

[0087] This will be further described with reference to Fig. 10. Fig. 10 is a graph showing the processing results of the signal processing device 100 according to an embodiment of the present technology. In Fig. 10, the horizontal axis represents elapsed time t, and the vertical axis represents the strength s of the signal received by the receiving unit 1.

[0088] 10, first, one large signal is detected at point P1. This signal is detected at the distance R between the reference point Pa of the receiving antenna 11 and the reference point Pt1 on the human chest 24. Ｐａ－Ｐｔ１ Since the signal was detected in the vicinity of the chest 24 and arm 25, it can be assumed that the signal is from the chest 24 and arm 25 of a person.

[0089] Next, signals are detected at points P2 and P3. The signal detected at point P2 is reflected by reflector 3 and further reflected by human chest 24, and is observed by receiving the signal. This signal is the distance R' between reference point Pa of receiving antenna 11 and reference point Pt1 on human chest 24. Ｐａ－Ｐｔ１ That is, the signal detected at point P2 is a signal from the human chest 24, and the signal detected at point P3 is a signal from the human arm 25. The position information of the chest 24 and the arm 25 can be detected separately.

[0090] In this way, the first round trip of the signal Ｐａ－Ｐｔ１ The second round trip of the signal can detect the distance R' Ｐａ－Ｐｔ１ By detecting the position of the chest 24, the position of the chest 24 becomes clearer, that is, the spatial resolution is improved.

[0091] The signal processing flow by the calculation unit 4 will be described with reference to Fig. 11. Fig. 11 is a flowchart showing an example of a processing flow of the signal processing device 100 according to an embodiment of the present technology.

[0092] 11, first, in step S11, the received signal is divided into two-dimensional coordinates of distance and angle, and analyzed using, for example, a Range FFT (Fast Fourier Transform) and an Angle FFT.

[0093] Next, in step S12, the distance R to the object and the angle θ at which the object is positioned are calculated based on the intensity and phase of the analyzed signal.

[0094] Next, in step S13, the coordinates Pt1 of the object are calculated based on the distance R and the angle θ.

[0095] Next, in step S14, the distance R' is calculated based on the coordinates Pt1 of the object and the coordinates Pr of the reflecting portion 3.

[0096] Finally, in step S15, the signals of the multiple targets are separated based on the peak values ​​of the signals received in the time period around the distance R'. Since the distance R to the target is calculated in step S12, it becomes easier to separate the signals of the multiple targets in step S14.

[0097] The antenna configuration is not particularly limited. For example, a patch antenna, which is a type of planar antenna, can be used. A patch antenna is an antenna that uses a microstrip line. By adjusting the shape and size of the patch, the frequency, gain, directivity, etc. can be changed. Patch antennas have the advantages of being small, lightweight, mechanically stable, inexpensive to manufacture, and being planar, so they can be installed anywhere.

[0098] Connecting multiple patch antennas in an array can increase gain and directivity, enabling beamforming. In particular, a MIMO (Multiple-Input Multiple-Output) array configuration can be achieved. A MIMO array configuration is a technology that improves spatial resolution by placing multiple antennas on the transmitting and receiving sides and transmitting and receiving signals between each antenna.

[0099] The above description of the signal processing device according to the second embodiment of the present technology can be applied to other embodiments of the present technology unless there is a particular technical contradiction.

[0100] 3. Third embodiment of the present technology (second example of a signal processing device using a radar signal) Another example will be described with reference to Fig. 12. Fig. 12 is a schematic diagram for describing the operation of a signal processing device 100 according to an embodiment of the present technology.

[0101] 12 , a first object 21, a second object 22, and a third object 23 are arranged side by side in the left-right direction as viewed from the signal processing device 100. The second object 22 and the third object 23 are arranged symmetrically with respect to the first object 21. Therefore, the distance between the reflecting unit 3 and the second object 22 is the same as the distance between the reflecting unit 3 and the third object 23. As a result, even if the reflecting unit 3 reflects a signal, a difference in distance between the second imaginary object 22 a and the third imaginary object 23 a is unlikely to occur, making it difficult to separately detect the second imaginary object 22 a and the third imaginary object 23 a.

[0102] Therefore, the signal processing device 100 may include a plurality of reflecting units. The calculation unit may calculate position information based on the signal received by the receiving unit and the positional relationship between the receiving unit and each reflecting unit. This will be described with reference to Fig. 13. Fig. 13 is a schematic diagram for explaining the operation of the signal processing device 100 according to an embodiment of the present technology.

[0103] 13, the signal processing device 100 includes a plurality of reflecting sections. In this configuration example, the signal processing device 100 includes a first reflecting section 31 and a second reflecting section 32. The distance between the first reflecting section 31 and the second reflecting section 32 is d1.

[0104] The distance between the first reflecting unit 31 and the second object 22 is the same as the distance between the first reflecting unit 31 and the third object 23. On the other hand, the distance between the second reflecting unit 32 and the second object 22 is different from the distance between the second reflecting unit 32 and the third object 23. This causes a difference in distance between the second object 22 and the third object 23. This allows the calculation unit 4 to calculate position information based on the signal received by the receiving unit 1 and the positional relationship between the receiving unit 1 and each of the reflecting units (the first reflecting unit 31 and the second reflecting unit 32).

[0105] For example, if multiple reflectors 3 are arranged to the left and right of the receiving unit 1, signal paths of different lengths will be generated for targets in horizontal angular directions other than the front direction. This will result in a difference in distance between the signal paths. This will improve the spatial resolution of the signal processing device 100.

[0106] Furthermore, if multiple reflectors 3 are arranged in the front and rear directions as viewed from the receiving unit 1, signal paths of different lengths will be generated for an object in the front direction. This will result in a difference in distance between the signal paths. This improves the spatial resolution of the signal processing device 100.

[0107] This will be further described with reference to Fig. 14. Fig. 14 is a graph showing the processing results of the signal processing device 100 according to an embodiment of the present technology. In Fig. 14, the horizontal axis represents elapsed time, and the vertical axis represents the strength of the signal received by the receiving unit 1.

[0108] First, a single signal with a large intensity is detected at point P1. This point P1 indicates that signals reflected by the first object 21, the second object 22, and the third object 23 have been detected. At this point, the first object 21, the second object 22, and the third object 23 have not yet been detected separately, so only a single signal with a large intensity is displayed.

[0109] Next, the first reflecting unit 31 and the second reflecting unit 32 reflect the signal toward the first object 21, the second object 22, and the third object 23, and the first object 21, the second object 22, and the third object 23 reflect this signal toward the receiving unit 1. Then, at point P2, position information of the first imaginary object 21a, which is the shortest distance from the first reflecting unit 31, is detected. On the other hand, because the distance between the first reflecting unit 31 and the second imaginary object 22a and the distance between the first reflecting unit 31 and the third imaginary object 23a are the same, the second imaginary object 22a and the third imaginary object 23a cannot be detected separately at point P3.

[0110] Next, at point P4, the position information of the first fictitious object 21a and the third fictitious object 23a is detected. In this example, the distance between the second reflector 32 and the first fictitious object 21a is the same as the distance between the second reflector 32 and the third fictitious object 23a. Therefore, at point P4, the first fictitious object 21a and the third fictitious object 23a cannot be detected separately.

[0111] Finally, at point P5, the position information of the second imaginary object 22a, which is the farthest from the second reflecting portion 32, can be detected. In this way, by providing a plurality of reflecting portions, the spatial resolution is improved and the position information of each object can be detected.

[0112] The above description of the signal processing device according to the third embodiment of the present technology can be applied to other embodiments of the present technology unless there is a particular technical contradiction.

[0113] [4. Fourth Embodiment of the Present Technology (Example 3 of Signal Processing Device Using Radar Signal)] In the present technology, a signal makes at least two round trips to a target by reflecting a signal with a reflecting unit 3. In this case, if an unnecessary reflector is located at a position twice the distance from the signal processing device 100 to the target, it may be difficult to distinguish between a signal that has made two round trips along the path from the signal processing device 100 to the target and a signal that has made one round trip along the path from the signal processing device 100 to the unnecessary reflector.

[0114] Therefore, it is preferable that the reflector 3 selectively reflects the signal. That is, the reflector 3 has a function of reflecting the signal and a function of transmitting the signal without reflecting it (a function of turning reflection on / off), and it is preferable that the reflector 3 can select reflection or transmission depending on the situation.

[0115] This will be described with reference to Fig. 15. Fig. 15 is a schematic diagram for explaining the operation of the signal processing device 100 according to an embodiment of the present technology. As shown in Fig. 15, a reference point Pa of the receiving antenna 11, a reference point Pr of the reflecting unit 3, and a reference point Pt1 of the human chest 24 are shown. Furthermore, a reference point Pt3 of an unnecessary reflector is shown at a position that is twice the distance from the reference point Pr of the reflecting unit 3 to the reference point Pt1 of the human chest 24.

[0116] In this case, it may become difficult to distinguish between a signal that has made two round trips along the path from the signal processing device 100 to the human chest 24 and a signal that has made one round trip along the path from the signal processing device 100 to the unwanted reflector 26.

[0117] Therefore, it is preferable that the reflecting unit 3 selectively reflects the signal. It is preferable that the calculating unit 4 calculates position information regarding the object 2 based on a comparison result between a first signal received by the receiving unit 1 when the reflecting unit 3 reflects the signal and a second signal received by the receiving unit 1 when the reflecting unit 3 does not reflect the signal. This will be described with reference to Fig. 16. Fig. 16 is a flowchart showing an example of a processing flow of the signal processing device 100 according to an embodiment of the present technology.

[0118] As shown in FIG. 16, first, in step S21, the calculation unit 4 acquires the first signal received by the receiving unit 1 when the reflecting unit 3 reflects the signal.

[0119] Next, in step S22, the calculation unit 4 acquires the second signal that the receiving unit 1 received when the reflecting unit 3 did not reflect the signal.

[0120] Next, in step S23, the calculation unit 4 compares the first signal with the second signal. This comparison will be described with reference to Fig. 17 . Fig. 17 is a graph showing a processing result of the signal processing device 100 according to an embodiment of the present technology. In Fig. 17 , the horizontal axis represents elapsed time, and the vertical axis represents the strength of the signal received by the receiving unit 1.

[0121] In FIG. 17A, the elapsed time R′ Ｐａ－Ｐ１１ On the other hand, in FIG. 17B, the signal intensity increases at the time of elapsed time R' Ｐａ－Ｐ１１ At time t, the signal strength increases.

[0122] When the first signal received by the receiving unit 1 when the reflecting unit 3 reflected the signal and the second signal received by the receiving unit 1 when the reflecting unit 3 did not reflect the signal both have the intensities shown in Fig. 17A, it can be inferred that there is an unwanted reflector 26. On the other hand, when the first signal has the intensities shown in Fig. 17A and the second signal has the intensities shown in Fig. 17B, it can be inferred that there is no unwanted reflector 26.

[0123] Returning to the explanation of Fig. 16, in step S23, when the intensities of the first signal and the second signal at the predetermined time are different (step S23: No), there is no unnecessary reflector 26, and therefore in step S24, the calculation unit 4 can calculate the position information of the target object 2 using the signal that has made two round trips.

[0124] When the intensities of the first signal and the second signal at a predetermined time are the same (step S23: Yes), an unnecessary reflector 26 is present, and the calculation unit 4 can calculate the position information of the target object 2 using another method, which will be described later.

[0125] To selectively reflect signals, the reflector 3 may have a reconfigurable metasurface (metamaterial). The reconfigurable metasurface controls the resonant frequency of the resonant element using a switching function of a PIN diode or a variable capacitance, thereby suppressing reflection and controlling the reflection direction. By providing the signal processing device 100 with a reconfigurable metasurface, the function of the reflector 3 can be turned on / off (or the reflection direction can be changed). This makes it possible to detect the presence or absence of an unwanted reflector 26.

[0126] Reconfigurable metasurfaces are periodic arrangements of tiny structures made of materials such as metals or dielectrics. These structures are very small compared to the wavelength of the signal, so metasurfaces can be used to control the propagation of signals.

[0127] A PIN diode is a diode that can switch between a conductive state and an insulating state by applying a voltage. A variable capacitor is a capacitor that can change its capacitance by applying a voltage. By turning on the PIN diode, the resonant frequency of the resonant element can be set to a specific value, and the function of the reflector 3 can be turned on. By changing the variable capacitance, the reflection direction of the reflector 3 can be controlled.

[0128] The above description of the signal processing device according to the fourth embodiment of the present technology can be applied to other embodiments of the present technology unless there is a particular technical contradiction.

[0129] 5. Fifth Embodiment of the Present Technology (Example 4 of Signal Processing Device Using Radar Signal) The reflecting unit 3 included in the signal processing device 100 according to an embodiment of the present technology may be configured to be positionally changeable. This will be described with reference to Fig. 18 . Fig. 18 is a schematic diagram for describing the operation of the signal processing device 100 according to an embodiment of the present technology.

[0130] 18, the reflecting section 3 is configured so that its position can be changed. In this example, the reflecting section 3 is configured so that its position can be changed in the vertical direction in the figure. For example, the reflecting section 31 moved downward by a distance d2 becomes the reflecting section 32. Note that the moving direction of the reflecting section 3 is not particularly limited, and the reflecting section 3 may move, for example, in the horizontal direction or diagonally.

[0131] The reflector 3 can selectively reflect a signal. In this case, the calculation unit 4 may change the position of the reflector 3 based on a comparison result between a first signal received by the receiving unit 1 when the reflector 3 has reflected the signal and a second signal received by the receiving unit 1 when the reflector 3 has not reflected the signal. This will be described with reference to Fig. 19 . Fig. 19 is a flowchart showing an example of a processing flow of the signal processing device 100 according to an embodiment of the present technology.

[0132] As shown in FIG. 19, first, in step S31, the calculation unit 4 acquires the first signal received by the receiving unit 1 when the reflecting unit 3 reflects the signal.

[0133] Next, in step S32, the calculation unit 4 acquires the second signal that the receiving unit 1 received when the reflecting unit 3 did not reflect the signal.

[0134] Next, in step S33, the calculation unit 4 compares the first signal with the second signal. If the intensities of the first signal and the second signal at a predetermined time are different (step S33: No), it can be inferred that there is no unnecessary reflector 26. In this case, in step S34, the calculation unit 4 can calculate position information of the target object 2 using the signal that has made two round trips.

[0135] When the intensities of the first signal and the second signal at a predetermined time are the same (step S33: Yes), it can be inferred that an unwanted reflector 26 is present. Therefore, in step S35, the calculation unit 4 can change the position of the reflector 3. In this case, the path length of the signal that has made two round trips from the signal processing device 100 to the target object is different from the path length of the signal that has made one round trip from the signal processing device 100 to the unwanted reflector.

[0136] As a result, when the calculation unit acquires the first signal (step S31), acquires the second signal (step S32), and compares the first signal with the second signal (step S33), the intensities of the first signal and the second signal at a predetermined time may differ (step S33: No). In this case, in step S34, the calculation unit 4 can calculate the position information of the target object 2 using the signal that has made two round trips. The loop of steps S31, S32, S33, and S35 can be repeated until the intensities of the first signal and the second signal differ.

[0137] The above description of the signal processing device according to the fifth embodiment of the present technology can be applied to other embodiments of the present technology unless there is a particular technical contradiction.

[0138] 6. Sixth Embodiment of the Present Technology (Fifth Example of Signal Processing Device Using Radar Signal) A signal processing device 100 according to an embodiment of the present technology includes a plurality of reflecting portions 3, and each of the reflecting portions 3 may be selected to be reflective or non-reflective. This will be described again with reference to FIG. 18 .

[0139] The signal processing device 100 may include a plurality of reflecting sections 3. Each reflecting section 3 may selectively reflect a signal. For example, of the two reflecting sections 3 shown in the figure, one reflecting section 32 may be configured to reflect a signal, and the other reflecting section 31 may be configured not to reflect a signal.

[0140] At this time, the calculation unit 4 may select reflection or non-reflection of each reflector 3 based on a comparison result between a first signal received by the receiving unit 1 when the reflector 3 reflected a signal and a second signal received by the receiving unit 1 when the reflector 3 did not reflect a signal. This will be described with reference to Fig. 20 . Fig. 20 is a flowchart showing an example of a processing flow of the signal processing device 100 according to an embodiment of the present technology.

[0141] As shown in FIG. 20, first, in step S41, the calculation unit 4 acquires the first signal received by the receiving unit 1 when the reflecting unit 3 reflects the signal.

[0142] Next, in step S42, the calculation unit 4 acquires the second signal that the receiving unit 1 received when the reflecting unit 3 did not reflect the signal.

[0143] Next, in step S43, the calculation unit 4 compares the first signal with the second signal. If the intensities of the first signal and the second signal at a predetermined time are different (step S43: No), it can be assumed that there is no unnecessary reflector 26. In this case, in step S44, the calculation unit 4 can calculate position information of the target object 2 using the signal that has made two round trips.

[0144] When the intensities of the first signal and the second signal at a predetermined time are the same (step S43: Yes), it can be inferred that an unnecessary reflector 26 is present. Therefore, in step S45, the calculation unit 4 can change the reflector 3 that reflects the signal. In this case, the path length of the signal that has made two round trips from the signal processing device 100 to the target object is different from the path length of the signal that has made one round trip from the signal processing device 100 to the unnecessary reflector.

[0145] As a result, when the calculation unit acquires the first signal (step S41), acquires the second signal (step S42), and compares the first signal with the second signal (step S43), the intensities of the first signal and the second signal at a predetermined time may differ (step S43: No). In this case, in step S44, the calculation unit 4 can calculate the position information of the target object 2 using the signal that has made two round trips. The loop of steps S41, S42, S43, and S45 can be repeated until the intensities of the first signal and the second signal differ.

[0146] The above description of the signal processing device according to the sixth embodiment of the present technology can be applied to other embodiments of the present technology unless there is a particular technical contradiction.

[0147] [7. Seventh embodiment of the present technology (first example of a signal processing device using a wireless communication signal)] [(1) Signal processing device using a wireless communication signal] A signal processing device according to the present technology can transmit and receive, for example, a wireless communication signal. The above content when the signal is a radar signal can also be applied when the signal is a wireless communication signal.

[0148] One example of wireless communication is UWB (Ultra-Wide Band). UWB is a communication technology that uses radio waves with a wide bandwidth. By using radio waves with a bandwidth of 100 MHz or more, UWB can transmit extremely short pulse signals on the order of nanoseconds.

[0149] Distance measurement technology using UWB measures the distance to an object by measuring the propagation time of this short pulse signal. This technology is called the Time of Flight (ToF) method.

[0150] An example of the configuration of a signal processing device 100 when measuring distance using UWB will be described with reference to Fig. 21. Fig. 21 is a block diagram showing an example of the configuration of a signal processing device 100 according to this embodiment. As shown in Fig. 21, the signal processing device 100 includes a receiving unit 1 that receives a signal from an object 2, and a calculating unit 4 that calculates position information related to the object 2. When the signal is a wireless communication signal, the receiving unit 1 is a first transmitting / receiving unit, and the object 2 is a second transmitting / receiving unit.

[0151] The first transceiver 1 includes a first antenna 101, a low-noise amplifier 102, a downconverter 103, a local signal generator 104, a correlator 105, and a pulse waveform generator 106. The second transceiver 2 includes a pulse waveform generator 201, an upconverter 202, a local signal generator 203, a power amplifier 204, and a second antenna 205.

[0152] A processing flow of the signal processing device 100 will be described with reference to Fig. 22. Fig. 22 is a flowchart showing an example of a processing flow of the signal processing device 100 according to an embodiment of the present technology.

[0153] 22, first, in step S51, the second transceiver 2 transmits a short pulse wave on the order of nanoseconds. This pulse wave has high time resolution on the time axis, enabling accurate distance measurement even in a multipath environment.

[0154] Next, in step S52, the first transceiver 1 receives the pulse wave sent from the first transceiver 1 and converts it into a baseband signal (low frequency signal). The received signal is an RF signal (high frequency signal), so it needs to be converted into a baseband signal. This process is called down-conversion.

[0155] Next, in step S53, the received signal and the pulse generated by the pulse generator are input to a correlator with a timing shift. The correlator is a device that measures the similarity between two signals. This process produces a correlation value (CIR: Correlation Intensity Response) that indicates the arrival time of the received signal. The peak position of the CIR is proportional to the distance from the second transceiver 2 to the first transceiver 1.

[0156] Finally, in step S54, the arrival time is calculated from the peak position of the CIR, and the distance to the target is measured by multiplying it by the speed of light.

[0157] (2) This Embodiment The operation of the signal processing device 100 according to this embodiment will be described with reference to Fig. 23. Fig. 23 is a schematic diagram for describing the operation of the signal processing device 100 according to an embodiment of the present technology.

[0158] As shown in FIG. 23, the signal processing device 100 includes a receiving unit 1 that receives a signal from an object 2, a reflecting unit 3 that reflects the signal toward the receiving unit 1, and a calculating unit (not shown) that calculates position information regarding the object 2.

[0159] When the signal is a wireless communication signal, the receiver 1 is the first transceiver and the object 2 is the second transceiver.

[0160] The first transceiver 1 transmits a wireless communication signal toward the second transceiver 2. The second transceiver 2 receives the wireless communication signal from the first transceiver 1 and transmits a first wireless communication signal S1 toward the first transceiver 1 and the reflector 3. The reflector 3 reflects the wireless communication signal from the second transceiver 2 toward the first transceiver 1.

[0161] A calculation unit (not shown) calculates position information regarding the second transceiver 2 based on the first wireless communication signal S1, the second wireless communication signal S2 obtained by reflecting the first wireless communication signal S1 by the reflector 3, and the positional relationship between the receiver (first transceiver) 1 and the reflector 3. The calculation unit 4 can calculate the distance between the first transceiver 1 and the second transceiver 2, for example, by the ToF method.

[0162] In the present embodiment as well, the spatial resolution of the signal processing device 100 is improved because the positional relationship between the first transceiver 1 and the reflector 3 is known. This will be described with reference to Fig. 24. Fig. 24 is a schematic diagram for describing the operation of the signal processing device 100 according to an embodiment of the present technology.

[0163] 24 , a first wireless communication signal from a second transceiver (not shown) is transmitted to the first transceiver 1 and the reflector 3. The first transceiver 1 receives the first wireless communication signal. The reflector 3 reflects the first wireless communication signal toward the first transceiver 1. The first transceiver 1 receives the reflected second wireless communication signal.

[0164] At this time, the second wireless communication signal has a longer path length than the first wireless communication signal, and is therefore received later than the first wireless communication signal. ｄｅｌａｙ can be calculated using the following equation (6) based on the distance dy between the first transceiver 1 and the reflector 3.

[0165] d ｄｅｌａｙ = 2 × dy ... (6)

[0166] This path difference d ｄｅｌａｙ is the minimum distance resolution that the calculation unit can resolve. ｄｅｌａｙ The distance between the first transceiver 1 and the second transceiver 2 is corrected using the above equation, thereby improving the accuracy of distance measurement. Note that the distance dy is set to a value that satisfies the following equation (7).

[0167]

[0168] When the signal is a wireless communication signal, it is preferable that the reflecting portion 3 is planar. Unlike a corner reflector that reflects a radar signal in the incident direction, the reflecting portion 3 that reflects a wireless communication signal does not need to reflect in the incident direction. By having the reflecting portion 3 planar, the signal can be reflected over a wide area and the manufacturing cost is lower than that of a corner reflector.

[0169] 24 shows an example in which the second transceiver (not shown), the first transceiver 1, and the reflector 3 are arranged in a straight line, and a wireless communication signal is transmitted in a direction perpendicular to the surface of the reflector 3. On the other hand, if the direction in which the second transceiver 2 is arranged is known, the calculation unit 4 can calculate the distance with high accuracy even when a wireless communication signal is transmitted in a direction oblique to the surface of the reflector 3. In this regard, FIG. 25 is a schematic diagram for explaining the operation of the signal processing device 100 according to an embodiment of the present technology.

[0170] 25 , the first wireless communication signal is transmitted from a direction oblique to the surface of the reflector 3. Specifically, the first wireless communication signal is transmitted from a direction at an angle θ with respect to the direction perpendicular to the surface of the reflector 3. Since the distance between the first transceiver 1 and the reflector 3 is dy, the distance between the mirror image 1a of the first transceiver 1 and the reflector 3 is also dy.

[0171] A first wireless communication signal S1 from a second transceiver (not shown) is transmitted to the first transceiver 1 and the reflector 3. The first transceiver 1 receives the first wireless communication signal S1. The reflector 3 reflects the first wireless communication signal S1 toward the first transceiver 1. The first transceiver 1 receives the reflected second wireless communication signal S2.

[0172] At this time, the second wireless communication signal S2 has a longer path length than the first wireless communication signal S1, and is therefore received later than the first wireless communication signal S1. ｄｅｌａｙ can be calculated using the following equation (8) based on the distance dy between the first transceiver 1 and the reflector 3 and the angle θ at which the second transceiver 2 is arranged.

[0173] d ｄｅｌａｙ= 2 × dy × cos θ (8)

[0174] This path difference d ｄｅｌａｙ is the minimum spatial resolution that the calculation unit can resolve. ｄｅｌａｙ The distance between the first transceiver 1 and the second transceiver 2 is corrected using the distance d ｄｅｌａｙ is a value that satisfies the following equation (9): where c is the speed of light and BW is the bandwidth of the wireless communication signal.

[0175] d ｄｅｌａｙ =c / BW...(9)

[0176] The calculation of the calculation unit at this time will be described with reference to Fig. 26. Fig. 26 is a graph showing the processing results of the signal processing device 100 according to an embodiment of the present technology. In Fig. 26, the horizontal axis represents elapsed time. The vertical axis represents the strength of the signal received by the receiving unit 1. First, at point P1, one signal with a large strength is detected. This point P1 indicates that the first wireless communication signal S1 transmitted from the second wireless communication signal S2 has been detected.

[0177] Next, a signal with a large intensity is detected at point P2, which indicates that the second wireless communication signal S2 reflected by the reflector 3 has been detected.

[0178] The time difference t between the time when the first wireless communication signal S1 is detected and the time when the second wireless communication signal S2 is detected ｄｅｌａｙ can be calculated using the following equation (10).

[0179] t ｄｅｌａｙ =2×dy×cosθ / c (10)

[0180] As mentioned above, the path difference d ｄｅｌａｙ is the minimum spatial resolution that the calculation unit can resolve. ｄｅｌａｙ When the value of satisfies the following equation (11), the calculation unit can separately detect the first wireless communication signal S1 and the second wireless communication signal S2.

[0181] t ｄｅｌａｙ >1 / BW...(11)

[0182] It should be noted that this technology is not limited to UWB, but can also be applied to wireless communication technologies such as Bluetooth (registered trademark), Bluetooth (registered trademark) Low Energy, Wi-Fi, and millimeter waves.

[0183] Distance measurement methods can be widely used without any restrictions, such as an impulse method (UWB: Ultra-Wide Band), wideband frequency scanning (Channel Sounder), frequency spreading using a spreading code, and OFDM (Orthogonal Frequency Division Multiplexing).

[0184] The above description of the signal processing device according to the seventh embodiment of the present technology can be applied to other embodiments of the present technology unless there is a particular technical contradiction.

[0185] [8. Eighth Embodiment of the Present Technology (Example 2 of Signal Processing Device Using Wireless Communication Signals)] The seventh embodiment is an example of a case where the direction in which the second transceiver 2 is arranged is known. On the other hand, an example of a case where the direction in which the second transceiver 2 is arranged is unknown will be described with reference to Fig. 27. Fig. 27 is a schematic diagram for explaining the operation of a signal processing device 100 according to an embodiment of the present technology.

[0186] 27, the signal processing device 100 includes a plurality of first transceivers 11 and 12. The distance between the first transceivers 11 and 12 is dx.

[0187] The first wireless communication signal S1 is transmitted from a direction oblique to the surface of the reflector 3. Specifically, the first wireless communication signal S1 is transmitted from a direction at an angle θ with respect to the direction perpendicular to the surface of the reflector 3. This first wireless communication signal S1 is transmitted to the first transceiver 1 and the reflector 3. The first transceiver 1 receives this first wireless communication signal S1. The reflector 3 reflects this first wireless communication signal S1 toward the first transceiver 1. The first transceiver 1 receives this reflected second wireless communication signal S2.

[0188] The path difference d between the first wireless communication signal S1 and the second wireless communication signal S2 ｄｅｌａｙ＿ａｎｔcan be calculated using the following equation (12) based on the distance dx between the first transceivers 1 and the angle θ at which the second transceiver 2 is arranged.

[0189] d ｄｅｌａｙ＿ａｎｔ = dx × sin θ (12)

[0190] At this time, a calculation unit (not shown) can calculate position information regarding the target (second transceiver unit) based on the positional relationship (for example, distance, angle, etc.) between the first transceivers 11 and 12 and the first wireless communication signal S1 and the second wireless communication signal S2 received by each of the first transceivers 11 and 12. In other words, the first wireless communication signals S1 and the second wireless communication signals S2 received by each of the first transceivers 11 and 12 are used. This improves the measurement accuracy of the angle θ at which the second transceiver unit 2 is disposed.

[0191] This will be described with reference to Fig. 28. Fig. 28 is a graph showing a processing result of the signal processing device 100 according to an embodiment of the present technology. In Fig. 28A, the horizontal axis indicates elapsed time, and the vertical axis indicates the strength of the signal received by the first transceiver 1. In Fig. 28B, the horizontal axis indicates elapsed time, and the vertical axis indicates the strength of the signal received by the first transceiver 1.

[0192] Point P1 indicates that the first wireless communication signal S1 transmitted from the second wireless communication signal S2 has been detected. Point P1 indicates that the second wireless communication signal S2 reflected by the reflector 3 has been detected.

[0193] At this time, the calculation unit 4 can calculate position information about the target (second transceiver unit) based on the first wireless communication signal S1 and the second wireless communication signal S2 received by the first transceivers 11, 12. That is, the calculation unit 4 can calculate position information about the target (second transceiver unit) with high accuracy by comparing the phases of the first wireless communication signals S1 at point P1 and the phases of the second wireless communication signals S2 at point P2.

[0194] This embodiment is not limited to a signal processing device that transmits and receives wireless communication signals, but may also be, for example, a signal processing device that transmits and receives radar signals. That is, a signal processing device that transmits and receives radar signals may include multiple receiving units. The positional relationship between the receiving units is known. For example, as shown in FIG. 27 , assume that the distance between the receiving units is dx.

[0195] In this case, the calculation unit can calculate the position information of the object based on the positional relationship between the receiving units and the first and second radar signals received by the receiving units. By using the above formula (12) or the like, the calculation unit can calculate the position information of the object with high accuracy.

[0196] The above description of the signal processing device according to the eighth embodiment of the present technology can be applied to other embodiments of the present technology unless there is a particular technical contradiction.

[0197] 9. Ninth embodiment of the present technology (third example of a signal processing device using wireless communication signals) Another example of a signal processing device including a plurality of first transceivers will be described with reference to Fig. 27 again. ｄｅｌａｙ can be calculated using the following equation (13) based on the distance dy between the first transceiver 1 and the reflector 3 and the angle θ at which the second transceiver 2 is disposed.

[0198] d ｄｅｌａｙ = 2 × dy × cos θ (13)

[0199] When the speed of light is c and the frequency of the wireless communication signal is f, the wavelength λ of the wireless communication signal can be calculated using the following equation (14).

[0200] λ=c / f...(14)

[0201] The phase difference ΔΦ between the first wireless communication signal S1 and the second wireless communication signal S2 can be calculated using the following equation (15).

[0202] ΔΦ=d ｄｅｌａｙ / λ (15)

[0203] At this time, the calculation unit may calculate position information related to the target (second transceiver unit) based on the phase difference ΔΦ between the first wireless communication signal and the second wireless communication signal received by the first transceiver units 11 and 12, respectively. This will be described with reference to FIG. 29 . FIG. 29 is a graph showing a processing result of the signal processing device 100 according to an embodiment of the present technology. In FIG. 29A , the horizontal axis represents elapsed time, and the vertical axis represents the strength of the signal received by the first transceiver unit 1. In FIG. 29B , the horizontal axis represents elapsed time, and the vertical axis represents the strength of the signal received by the first transceiver unit 1.

[0204] 29 , the calculation unit may calculate position information regarding the target (second transceiver unit) based on the phase difference between the first wireless communication signal and the second wireless communication signal received by the first transceiver units 11 and 12. Instead of the phase difference, the time difference between the time when the first wireless communication signal is received and the time when the second wireless communication signal is received may be used. Alternatively, both the phase difference and the time difference may be used.

[0205] By making the phase intervals for the frequency of the wireless communication signal finer, the time intervals within the wavelength can be made finer, allowing for more accurate angle measurement.

[0206] The above description of the signal processing device according to the ninth embodiment of the present technology can be applied to other embodiments of the present technology unless there is a particular technical contradiction.

[0207] [10. Tenth Embodiment of the Present Technology (Example 4 of Signal Processing Device Using Wireless Communication Signal)] The above-mentioned reflecting unit that selectively reflects a signal can also be provided in a signal processing device that receives a wireless communication signal. By turning on / off the reflection function of the reflecting unit, the calculation unit can distinguish between a wireless communication signal reflected by the reflecting unit and a wireless communication signal from an unnecessary reflector. This will be described with reference to FIG. 30 . FIG. 30 is a flowchart showing an example of a processing flow of a signal processing device 100 according to an embodiment of the present technology.

[0208] As shown in FIG. 30, first, in step S61, the calculation unit 4 observes the propagation characteristics (CIR: Channel Impulse Response) of the first signal received by the first transceiver 1 when the reflector 3 reflects the signal.

[0209] Next, in step S62, the calculation unit 4 observes the propagation characteristic (CIR) of the second signal received by the first transmission / reception unit 1 when the reflector 3 does not reflect the signal.

[0210] Next, in step S63, the calculation unit 4 compares the first signal with the second signal. At this time, the calculation unit 4 calculates the path difference d between the first wireless communication signal S1 and the second wireless communication signal S2. ｄｅｌａｙ Comparison can be made within the range of

[0211] Next, in step S63, if the intensities of the first signal and the second signal at a predetermined time are different (step S63: No), it can be inferred that there is no unnecessary reflector 26. In this case, in step S64, the calculation unit 4 can calculate the position information of the second transceiver 2 using the wireless communication signal reflected by the reflector.

[0212] When the intensities of the first signal and the second signal at a predetermined time are the same (step S63: Yes), it can be inferred that there is an unnecessary reflector 26. Therefore, the calculation unit 4 can calculate the position information of the target object 2 using another method. As described above, for example, in step S65, the calculation unit may change the position of the reflector.

[0213] To selectively reflect signals, the reflector 3 may have a reconfigurable metasurface. The reconfigurable metasurface controls the suppression of reflection and the reflection direction by controlling the resonant frequency of the resonant element using a switching function of a PIN diode or a variable capacitance. By providing the signal processing device 100 with a reconfigurable metasurface, the function of the reflector 3 can be turned on / off (or the reflection direction can be changed). This makes it possible to detect the presence or absence of an unwanted reflector 26.

[0214] The above description of the signal processing device according to the tenth embodiment of the present technology can be applied to other embodiments of the present technology unless there is a particular technical contradiction.

[0215] [11. Eleventh Embodiment of the Present Technology (Example of Measurement Device)] The present technology provides a measurement device including: a transmitter that transmits a signal toward an object; a receiver that receives a signal from the object; a reflector that reflects the signal toward the object or the receiver; and a calculator that calculates position information related to the object, wherein the calculator calculates the position information based on the signal received by the receiver and a positional relationship between the receiver and the reflector.

[0216] A measurement device according to an embodiment of the present technology will be described with reference to Fig. 31 . Fig. 31 is a block diagram showing a configuration example of a measurement device 1000 according to an embodiment of the present technology. As shown in Fig. 31 , the measurement device 1000 includes a transmitter 6, a receiver 1, a reflector 3, and a calculator 4. The receiver 1 and the transmitter 6 are preferably included in the same device, but may be included in separate devices.

[0217] The transmitter 6 transmits a signal toward the object 2. The receiver 1 receives the signal from the object 2. The reflector 3 reflects the signal toward the object 2 or the receiver 1. The calculator 4 calculates position information regarding the object 2 based on the signal received by the receiver 1 and the positional relationship between the receiver 1 and the reflector 3.

[0218] The techniques described in the other embodiments above can be applied to the transmitter 6, receiver 1, reflector 3, and calculator 4.

[0219] An example of the arrangement position of this measuring device 1000 will be described with reference to Fig. 32 and Fig. 33. Fig. 32 and Fig. 33 are schematic diagrams showing an example of the arrangement position of the measuring device 1000 according to an embodiment of the present technology. Fig. 32 is a view of the interior of the automobile as seen from the side. Fig. 33 is a view of the interior of the automobile as seen from above.

[0220] 32 and 33, the measurement devices 1000a and 1000b can be arranged inside an automobile. The first measurement device 1000a is arranged on the ceiling inside the automobile. The second measurement device 1000b is arranged near the seat of the driver 41.

[0221] 32, each of the first measuring device 1000a and the second measuring device 1000b can detect the position of the driver's heart with high accuracy, and therefore each of the first measuring device 1000a and the second measuring device 1000b can detect the driver's heart rate with high accuracy.

[0222] Heart rate is an indicator of stress, fatigue, drowsiness, and other conditions. If heart rate changes suddenly while driving, it could lead to an accident. By monitoring a driver's heart rate, it is possible to detect driver stress, fatigue, drowsiness, and other conditions early on, thereby reducing the risk of an accident.

[0223] An example of the placement positions of the measurement devices 1000a and 1000b will be described with reference to Figure 33. A first imaginary line L3 passing through approximately the center between the driver 41 and the first passenger 42, and a second imaginary line L4 passing through approximately the center between the driver 41 and the second passenger 43 are shown. The first measurement device 1000a, which is placed on the ceiling of the vehicle, is placed near the center of the vehicle.

[0224] When the first measuring device 1000a separately detects the driver 41 and the first passenger 42, it is preferable that the reflecting unit (not shown) is not disposed on the first virtual line L3. By disposing the reflecting unit closer to the driver 41 or the first passenger 42 than the first virtual line L3, a difference in distance occurs in the paths of the respective signals. This improves the spatial resolution of the first measuring device 1000a.

[0225] The same applies to the case where the first measuring device 1000a separately detects the second passenger 43 and the third passenger 44.

[0226] When the first measuring device 1000a separately detects the driver 41 and the second passenger 43, it is preferable that the reflecting unit (not shown) is not located on the second virtual line L4. By locating the reflecting unit closer to the driver 41 or the second passenger 43 than the second virtual line L4, a difference in distance occurs in the paths of the respective signals. This improves the spatial resolution of the first measuring device 1000a.

[0227] The same applies to the case where the first measuring device 1000a detects the first passenger 42 and the third passenger 44 separately.

[0228] Furthermore, when separately detecting the driver 41, the first passenger 42, the second passenger 43, and the third passenger 44, it is preferable that the reflecting portion is not located on the first virtual line L3 or the second virtual line L4. In other words, it is preferable that the distances from the driver 41, the first passenger 42, the second passenger 43, and the third passenger 44 to the reflecting portion are different from each other.

[0229] The placement position of the measuring device 1000 is not limited to this example. Although not shown in the drawings, the measuring device 1000 may be placed, for example, near the front window inside the vehicle. Note that even in this case, it is preferable that the reflecting portion is placed so that a difference in distance occurs in the signal paths to each detection target object.

[0230] The above description of the measurement device according to the eleventh embodiment of the present technology can be applied to other embodiments of the present technology unless there is a particular technical contradiction.

[0231] [12. Twelfth Embodiment of the Present Technology (Example of Signal Processing Method)] The present technology provides a signal processing method that includes receiving a signal from an object, reflecting the signal toward the object or a position where the signal was received, and calculating position information related to the object based on the received signal and a positional relationship between the position where the signal was received and the position where the signal was reflected.

[0232] A signal processing method according to an embodiment of the present technology will be described with reference to Fig. 34. Fig. 34 is a flowchart showing an example of the signal processing method according to an embodiment of the present technology.

[0233] To realize the signal processing method according to this embodiment, for example, the above-mentioned signal processing device can be used. First, in step S1, a receiving unit included in the signal processing device receives a signal from an object.

[0234] Next, in step S2, a reflector included in the signal processing device reflects the signal toward the object or the receiving unit (the position where the signal is received). The angle of the reflector is designed so that the signal can be reflected toward the object or the receiving unit.

[0235] Next, in step S3, the calculation unit provided in the signal processing device calculates position information regarding the object based on the signal received by the receiving unit and the positional relationship between the receiving unit (the position where the signal was received) and the reflecting unit (the position where the signal was reflected).

[0236] The above description of the signal processing device according to the twelfth embodiment of the present technology can be applied to other embodiments of the present technology unless there is a particular technical contradiction.

[0237] It should be noted that the embodiments of the present technology are not limited to the above-described embodiments, and various modifications are possible within the scope of the present technology. The specific numerical values, shapes, materials (including compositions), etc. described in each embodiment are merely examples, and the present technology is not limited to these.

[0238] The present technology may also be configured as follows. [1] A signal processing device including: a receiving unit that receives a signal from an object; a reflecting unit that reflects the signal toward the object or the receiving unit; and a calculating unit that calculates position information regarding the object, wherein the calculating unit calculates the position information based on the signal received by the receiving unit and a positional relationship between the receiving unit and the reflecting unit. [2] The signal processing device according to [1], wherein the reflecting unit selectively reflects the signal. [3] The signal processing device according to [2], wherein the calculating unit selects reflection or non-reflection from the reflecting unit based on a comparison result between the signal received by the receiving unit when the reflecting unit reflects the signal and the signal received by the receiving unit when the reflecting unit does not reflect the signal. [4] The signal processing device according to any one of [1] to [3], wherein the reflecting unit is arranged at a position farther from the object than the receiving unit. [5] The signal processing device according to any one of [1] to [4], wherein, when the signal is a radar signal, the receiving unit receives a first radar signal transmitted from a transmitting unit to an object and reflected by the object, the reflecting unit reflects the first radar signal toward the object, and the calculating unit calculates position information regarding the object based on the first radar signal, a second radar signal obtained by reflecting the first radar signal by the object, and a positional relationship between the receiving unit and the reflecting unit. [6] The signal processing device according to [5], further comprising a plurality of the receiving units, and the calculating unit calculates position information regarding the object based on the positional relationship between the respective receiving units and the first radar signal and the second radar signal received by the respective receiving units.[7] The signal processing device according to any one of [1] to [6], wherein, when the signal is a wireless communication signal, the receiving unit is a first transceiver unit, and the object is a second transceiver unit, the first transceiver unit transmits the wireless communication signal toward the second transceiver unit, the second transceiver unit receives the wireless communication signal from the first transceiver unit and transmits a first wireless communication signal toward the first transceiver unit and the reflecting unit, the reflecting unit reflects the wireless communication signal from the second transceiver unit toward the first transceiver unit, and the calculating unit calculates position information regarding the second transceiver unit based on the first wireless communication signal, a second wireless communication signal obtained by reflecting the first wireless communication signal by the reflecting unit, and a positional relationship between the receiving unit and the reflecting unit. [8] The signal processing device according to [7], further comprising a plurality of the first transceivers units, and the calculating unit calculates position information regarding the object based on the positional relationship of the respective first transceivers units and the first wireless communication signal and the second wireless communication signal received by the respective first transceivers units. [9] The signal processing device according to [7] or [8], comprising a plurality of the first transceivers, wherein the calculation unit calculates position information regarding the object based on a time difference or a phase difference, or both, between the first wireless communication signal and the second wireless communication signal received by each of the first transceivers.

[10] The signal processing device according to any one of [1] to [9], wherein the reflecting unit is configured to be positionally changeable and selectively reflects the signal, and the calculation unit changes the position of the reflecting unit based on a comparison result between the signal received by the receiving unit when the reflecting unit has reflected the signal and the signal received by the receiving unit when the reflecting unit has not reflected the signal.

[11] The signal processing device according to any one of [1] to

[10] , comprising a plurality of the reflecting units, wherein the calculation unit calculates the position information based on the signal received by the receiving unit and the positional relationship between the receiving unit and each of the reflecting units.

[12] The signal processing device according to any one of [1] to

[11] , wherein each of the reflecting portions selectively reflects the signal, and the calculation portion calculates position information regarding the object based on a comparison result between a first signal received by the receiving portion when the reflecting portion reflects the signal and a second signal received by the receiving portion when the reflecting portion does not reflect the signal.

[13] The signal processing device according to any one of [1] to

[12] , wherein the reflecting portion has a metasurface.

[14] The signal processing device according to any one of [1] to

[13] , wherein the reflecting portion includes at least one material selected from gold, silver, copper, and aluminum.

[15] The signal processing device according to any one of [1] to

[14] , wherein the reflecting portion is a corner reflector when the signal is a radar signal.

[16] The signal processing device according to any one of [1] to

[15] , wherein the reflecting portion is planar when the signal is a wireless communication signal.

[17] A signal processing device according to any one of [1] to

[16] , which measures human biological information.

[18] A signal processing device according to

[17] , which measures at least one of a human heart rate and a pulse rate.

[19] A measurement device comprising: a transmitter that transmits a signal toward an object; a receiver that receives a signal from the object; a reflector that reflects the signal toward the object or the receiver; and a calculator that calculates position information related to the object, wherein the calculator calculates the position information based on the signal received by the receiver and a positional relationship between the receiver and the reflector.

[20] A signal processing method including: receiving a signal from an object; reflecting the signal toward the object or a position where the signal was received; and calculating position information related to the object based on the received signal and the positional relationship between the position where the signal was received and the position where the signal was reflected.

[0239] 100 Signal processing device 1 Receiving unit (first transmitting / receiving unit) 2 Object (second transmitting / receiving unit) 21 First object 22 Second object 23 Second object 21a First virtual object 22a Second virtual object 23a Third virtual object 3 Reflecting unit 31 First reflecting unit 32 Second reflecting unit 4 Calculating unit 6 Transmitting unit 1000 Measuring device S1 Receiving a signal from an object S2 Reflecting the signal towards the object or receiving unit S3 Calculating position information relating to the object

Claims

1. A signal processing device comprising: a receiving unit that receives a signal from an object; a reflecting unit that reflects the signal toward the object or the receiving unit; and a calculating unit that calculates position information regarding the object, wherein the calculating unit calculates the position information based on the signal received by the receiving unit and the positional relationship between the receiving unit and the reflecting unit.

2. The signal processing device according to claim 1, wherein the reflecting section selectively reflects the signal.

3. The signal processing device according to claim 2, wherein the calculation unit selects whether the reflecting unit reflects or does not reflect based on a comparison result between the signal received by the receiving unit when the reflecting unit reflects the signal and the signal received by the receiving unit when the reflecting unit does not reflect the signal.

4. The signal processing device according to claim 1, wherein the reflecting section is disposed at a position farther from the object than the receiving section.

5. The signal processing device of claim 1, wherein when the signal is a radar signal, the receiving unit receives a first radar signal transmitted from a transmitting unit to an object and reflected by the object, the reflecting unit reflects the first radar signal toward the object, and the calculating unit calculates position information regarding the object based on the first radar signal, a second radar signal resulting from the first radar signal being reflected by the object, and a positional relationship between the receiving unit and the reflecting unit.

6. A signal processing device as described in claim 5, comprising a plurality of said receiving units, and wherein said calculation unit calculates position information regarding said object based on the positional relationship between each of said receiving units and said first radar signal and said second radar signal received by each of said receiving units.

7. A signal processing device as described in claim 1, wherein, when the signal is a wireless communication signal, the receiving unit is a first transceiver unit, and the object is a second transceiver unit, the first transceiver unit transmits the wireless communication signal toward the second transceiver unit, the second transceiver unit receives the wireless communication signal from the first transceiver unit and transmits a first wireless communication signal toward the first transceiver unit and the reflecting unit, the reflecting unit reflects the wireless communication signal from the second transceiver unit toward the first transceiver unit, and the calculation unit calculates position information regarding the second transceiver unit based on the first wireless communication signal, a second wireless communication signal resulting from the first wireless communication signal being reflected by the reflecting unit, and a positional relationship between the receiving unit and the reflecting unit.

8. A signal processing device as described in claim 7, comprising a plurality of the first transceivers, and the calculation unit calculates position information regarding the object based on the positional relationship between each of the first transceivers and the first wireless communication signal and the second wireless communication signal received by each of the first transceivers.

9. A signal processing device as described in claim 7, comprising a plurality of the first transceivers, and wherein the calculation unit calculates position information regarding the object based on a time difference or a phase difference, or both, between the first wireless communication signal and the second wireless communication signal received by each of the first transceivers.

10. A signal processing device as described in claim 1, wherein the reflecting unit is configured to be positionable and selectively reflects the signal, and the calculation unit changes the position of the reflecting unit based on a comparison result between the signal received by the receiving unit when the reflecting unit reflects the signal and the signal received by the receiving unit when the reflecting unit does not reflect the signal.

11. The signal processing device according to claim 1, comprising a plurality of the reflecting parts, and the calculation part calculates the position information based on the signal received by the receiving part and the positional relationship between the receiving part and each of the reflecting parts.

12. A signal processing device as described in claim 1, wherein each of the reflecting parts selectively reflects the signal, and the calculation part calculates position information regarding the object based on a comparison result between a first signal received by the receiving part when the reflecting part reflects the signal and a second signal received by the receiving part when the reflecting part does not reflect the signal.

13. The signal processing device according to claim 1, wherein the reflecting portion has a metasurface.

14. The signal processing device according to claim 1, wherein the reflecting portion includes at least one material selected from the group consisting of gold, silver, copper, and aluminum.

15. The signal processing device according to claim 1, wherein when the signal is a radar signal, the reflecting portion is a corner reflector.

16. The signal processing device according to claim 1, wherein when the signal is a wireless communication signal, the reflecting portion is planar.

17. The signal processing device according to claim 1, which measures human biological information.

18. The signal processing device according to claim 17, which measures at least one of a human heart rate and a pulse rate.

19. A measuring device comprising: a transmitting unit that transmits a signal toward an object; a receiving unit that receives a signal from the object; a reflecting unit that reflects the signal toward the object or the receiving unit; and a calculating unit that calculates position information regarding the object, wherein the calculating unit calculates the position information based on the signal received by the receiving unit and the positional relationship between the receiving unit and the reflecting unit.

20. A signal processing method comprising: receiving a signal from an object; reflecting the signal toward the object or a position where the signal was received; and calculating position information regarding the object based on the received signal and a positional relationship between the position where the signal was received and the position where the signal was reflected.

Images