Ultra-wideband-based systems and methods for detecting characteristics related to movable objects in an environment

Abstract

A system and method for detecting a characteristic associated with a movable object in an environment, such as an indoor environment, based on ultra-wideband. The method includes transmitting, using an ultra-wideband transmitter, an ultra-wideband radar signal to the environment, and receiving, using an ultra-wideband receiver, a plurality of signals reflected from the environment as a result of the transmission of the first ultra-wideband radar signal. The method further includes processing, using a processor, the plurality of reflected signals and determining, based on the processed reflected signals, a characteristic associated with a movable object in the environment.

Description

TECHNICAL FIELD

[0001] The present invention relates to systems and methods for detecting characteristics associated with movable objects in an environment using ultra-wideband radar signals. BACKGROUND

[0002] Systems and methods for detecting the position of objects are known. One class of systems and methods uses automated image processing of data captured by a video camera. Such systems and methods typically require large computational power to function properly and in some cases raise privacy concerns. Another class of systems and methods is based on tags and anchors, i.e. wearable devices (tags) carried by the target object and adapted to transmit position information to a base station (anchor) using, for example, RFID or other near field technology. For the tag and anchor type to work, the target object must wear or carry the wearable device at the time of measurement. This seems trivial, but remember that wearing or carrying a device can not be easy for a target object such as an elderly person or a person with Alzheimer's. SUMMARY

[0003] It is an object of the present invention to address the above needs, to overcome or substantially ameliorate the above disadvantages, or to provide, more generally, an alternative or improved system and method for detecting characteristics associated with movable objects in an environment.

[0004] According to a first aspect of the present invention, there is provided an ultra- wideband based method for detecting characteristics associated with movable objects in an environment, comprising: transmitting a plurality of first ultra-wideband radar signals into the environment using a first ultra-wideband transmitter; receiving a plurality of first signals reflected from the environment due to the transmission of the first ultra-wideband radar signals using a first ultra-wideband receiver; processing the reflected first signals using a processor; and determining, using the processor, characteristics associated with movable objects in the environment based on the processed reflected first signals.

[0005] In one embodiment of the first aspect, the determining step comprises determining the presence (or absence) of a movable object in the environment.

[0006] In one embodiment of the first aspect, the processing step comprises removing a reference background signal from each reflected first signal. The reference background signal can be predetermined (fixed). Alternatively, the reference background signal can be adjusted (e.g. based on the reflected first signals) in operation.

[0007] In one embodiment of the first aspect, the processing step comprises determining a respective difference between each two temporally adjacent reflected first signals. This involves identifying signal components that have changed between adjacent frames of the reflected first signals.

[0008] In one embodiment of the first aspect, the determining step comprises determining the distance between the movable object and the first ultra-wideband receiver based on the processed reflected first signal.

[0009] In one embodiment of the first aspect, the determining step further comprises determining a change in the distance between the movable object and the first ultra-wideband receiver. By determining the change in distance, a movement trend of the movable object (towards or away from the receiver) can be tracked.

[0010] In one embodiment of the first aspect, the processing step further comprises analyzing at least one of the signal strength and the frequency of the processed reflected first signal. Various signal processing techniques can be used in the analysis, such as domain transformation, thresholding, filtering, scaling, etc.

[0011] In one embodiment of the first aspect, the method further comprises classifying the movable object as being in an active state or an inactive state based on the analysis.

[0012] In one embodiment of the first aspect, the classifying step comprises comparing the processed reflected first signal to a classification threshold. If it is determined that the processed reflected first signal is above the classification threshold, then the object is considered to be in an active state. If it is determined that the processed reflected first signal is below the classification threshold, then the object is considered to be in an inactive state. When the processed reflected first signal is equal to the classification threshold, the object can be considered to be in an active state or in an inactive state. In some embodiments, for example, multiple classification thresholds can be used to better and more finely classify the activity level of the object.

[0013] In one embodiment of the first aspect, the classification threshold depends on the distance between the movable object and the first ultra-wideband receiver. For example, when it is determined that the distance is within a first predetermined distance range, then a first classification threshold is used, and when it is determined that the distance is within a second predetermined distance range (different from the first predetermined distance range), then a second classification threshold (different from the first classification threshold) is used. In practice, each distance range can refer to a respective region in the environment, each region can have different settings and functions such that the object has different activity levels.

[0014] In one embodiment of the first aspect, the method further comprises adjusting the classification threshold based on the signal strength of the processed reflected first signal.

[0015] In one embodiment of the first aspect, the analyzing the frequency of the processed reflected first signal comprises segmenting the processed reflected first signal to analyze only the portion of the processed reflected first signal that is determined to be associated with the movable object. This reduces the computational power required for the subsequent signal processing.

[0016] In one embodiment of the first aspect, analyzing the frequency of the processed reflected first signals comprises: analyzing the frequency of the processed reflected first signals can further comprise analyzing a change in the frequency spectrum of a series of the processed reflected first signals.

[0017] In one embodiment of the first aspect, the movable object is a human or an animal, and the determining step further comprises determining a respiration rate of the human or animal based on the frequency analysis.

[0018] In one embodiment of the first aspect, the method further comprises transmitting a plurality of second ultra-wideband radar signals into the environment using a second ultra-wideband transmitter; receiving a plurality of second signals reflected from the environment due to the transmission of the second ultra-wideband radar signals using a second ultra-wideband receiver; and processing the reflected second signals using the processor. The determining of the characteristic related to the movable object in the environment is further based on the processed reflected second signals.

[0019] In one embodiment of the first aspect, the processing of the reflected second signals comprises removing a reference background signal from each of the reflected second signals. The reference background signal can be predetermined (fixed). Alternatively, the reference background signal can be adjusted on the fly, e.g., based on the reflected second signals.

[0020] In one embodiment of the first aspect, the processing of the reflected second signals comprises determining a respective difference between every two time-adjacent reflected second signals. This involves identifying signal components that have changed between adjacent reflected second signal frames.

[0021] In one embodiment of the first aspect, the determining step further comprises determining a distance between the movable object and the second ultra-wideband receiver based on the processed reflected second signals.

[0022] In one embodiment of the first aspect, the determining step further comprises determining a change in the distance between the movable object and the second ultra-wideband receiver. By determining the change in the distance, a movement trend (towards or away from the receiver) of the movable object can be tracked.

[0023] In one embodiment of the first aspect, the determining step further comprises determining a 2D position of the movable object in the environment based on the processed reflected first signals and the processed reflected second signals. For example, the 2D position can be determined based on the determined distance (or change in distance) between the movable object and the first ultra-wideband receiver and the determined distance (or change in distance) between the movable object and the second ultra-wideband receiver (assuming the relative position or distance between the two ultra-wideband receivers is known).

[0024] In one embodiment of the first aspect, the determining step further comprises determining a change in the 2D position of the movable object in the environment. By determining the change in the 2D position, the moving path of the movable object can be tracked.

[0025] In one embodiment of the first aspect, the first UWB transmitter and the first UWB receiver are arranged in a single first UWB transceiver; the second UWB transmitter and the second UWB receiver are arranged in a single second UWB transceiver. The first UWB transceiver and the second UWB transceiver can each be independent units and operatively connected to each other. Alternatively, the first UWB transceiver and the second UWB transceiver can be arranged in the same unit. The first UWB transceiver and the second UWB transceiver can preferably communicate with external electronic devices (computer, phone, tablet, server, etc.) through wired or wireless communication networks.

[0026] In one embodiment of the first aspect, the environment is an indoor environment, for example, in a building; the movable object is a human or an animal. In one example, the environment is a home of an elderly person, and the movable object is the elderly person. In another example, the environment is a hospital ward, and the movable object is a patient.

[0027] According to a second aspect of the present application, there is provided an ultra- wideband based system for detecting a characteristic associated with a movable object in an environment. The ultra-wideband based system can be implemented to perform the method of the first aspect. The ultra-wideband based system comprises: a first UWB transmitter for transmitting a plurality of first UWB radar signals to the environment; a first UWB receiver for receiving a plurality of first signals reflected from the environment due to the transmission of the first UWB radar signals; one or more processors for processing the reflected first signals and for determining at least one of the following characteristics associated with the movable object in the environment: presence of the movable object in the environment based on the processed reflected first signals; distance between the movable object and the first UWB receiver; change in the distance between the movable object and the first UWB receiver; and whether the movable object is in an active state or an inactive state.

[0028] In one embodiment of the second aspect, the UWB-based system further comprises: a second UWB transmitter configured to transmit a plurality of second UWB radar signals into the environment; a second UWB receiver configured to receive a plurality of second signals reflected from the environment due to the transmission of the second UWB radar signals. The one or more processors are arranged to process the reflected second signals. The one or more processors are further arranged to determine, based on the processing of one or both of the reflected first signals and the reflected second signals, at least one of the following properties associated with a movable object in the environment: presence of the movable object in the environment based on the processed reflected second signals; distance between the movable object and the second UWB receiver; change in distance between the movable object and the second UWB receiver; 2D position of the movable object in the environment; and change in 2D position of the movable object in the environment.

[0029] In one embodiment of the second aspect, the one or more processors operatively connected to each other can be distributed among different devices / units or integrated in the same device / unit.

[0030] In one embodiment of the second aspect, the first UWB transmitter and the first UWB receiver are arranged in a single first UWB transceiver; the second UWB transmitter and the second UWB receiver are arranged in a single second UWB transceiver. The first UWB transceiver and the second UWB transceiver can each be independent units and operatively connected to each other. Alternatively, the first UWB transceiver and the second UWB transceiver can be arranged in the same unit. The first UWB transceiver and the second UWB transceiver can preferably communicate with external electronic devices (computer, phone, tablet, server, etc.) through wired or wireless communication networks. BRIEF DESCRIPTION OF DRAWINGS

[0031] Embodiments of the application will now be described, by way of example only, with reference to the accompanying drawings in which:

[0032] Figure 1 is a diagram of an environment in which an UWB-based detection system is implemented according to one embodiment of the application;

[0033] Figure 2 is a functional block diagram of a UWB unit in the UWB-based detection system according to one embodiment of the application; Figure 1

[0034] Figure 3 is a flowchart of a method of detecting properties related to a movable object in an environment using the UWB-based detection system in Figure 1

[0035] Figure 4A ​​is a plot showing a received signal frame (as a result of transmitting an ultra- wideband radar signal), which also shows removal of background signals;

[0036] Figure 4B is a plot showing a profile of a processed radar frame, which also shows detection of a target (e.g., a movable object);

[0037] Figure 4C is a plot showing a profile of a processed radar frame, which also shows detection of a target (e.g., a movable object); Figure 4B is a plot showing a frequency relationship of the profile in

[0038] Figure 5 is a schematic diagram of a system according to one embodiment of the present application, the system including Figure 1 an ultra-wideband-based detection system of DETAILED DESCRIPTION

[0039] Figure 1 An environment 10 is shown, which is fitted with an ultra- wideband-based detection system according to one embodiment of the present application. In this embodiment, the environment 10 is an indoor environment, in the form of a room in a building. A movable object 20, such as a person, is located in the room 10. The ultra- wideband-based detection system includes two ultra- wideband units 100A, 100B, each having a respective ultra- wideband transmitter for transmitting an ultra- wideband radar signal and a respective receiver for receiving signals reflected from the environment 10. The ultra- wideband-based detection system is operable to determine characteristics of the movable object 20 in the environment 10.

[0040] Figure 2 is a block diagram of the main components of an ultra- wideband-based unit 200 according to one embodiment of the present application. Figure 1 Each of the ultra- wideband units 100A, 100B in Figure 2The unit 200 can have a different configuration. Also, it can be implemented in a single device or distributedly implemented in a plurality of devices operatively connected together. The unit 200 generally includes suitable components necessary to receive, store, and process appropriate computer instructions, commands, or code. In this embodiment, the main components of the unit 200 include a UWB transceiver 201 having a transmitter 201T and a receiver 201R. The transmitter 201T and the receiver 201R can be the same component, or they can be different components. The unit 200 also includes a processor 202 and a memory 204. The processor 202 can be formed of one or more CPUs, MCUs, controllers, logic circuitry, Raspberry Pi chips, and the like. The memory 204 can include one or more volatile memory units such as RAM, DRAM, SRAM, one or more non-volatile memory units such as ROM, PROM, EPROM, EEPROM, FRAM, MRAM, FLASH, SSD, NAND, and NVDIMM, or any combination thereof. The unit 200 can also include one or more input devices 206 such as a keyboard, a mouse, a stylus, an image scanner, a microphone, a tactile input device (e.g., a touch-sensitive screen), and an image / video input device (e.g., a camera). The unit 200 can also include one or more output devices 208 such as one or more displays (e.g., monitors), speakers, disk drives, headphones, earphones, printers, 3D printers, and the like. The display can include an LCD display, an LED / OLED display, or any other suitable display that can or can not be touch-sensitive. The unit 200 can also include one or more disk drives 212, which can include solid state drives, hard disk drives, optical disk drives, flash drives, and / or tape drives. A suitable operating system can be installed in the unit 200, for example, on the disk drive 212 or in the memory 204. The components of the unit 200 can be operated by the processor 202. The unit 200 also includes a communication module 210 for establishing one or more communication links (not shown) with one or more other external computing devices such as servers, personal computers, terminals, tablets, telephones, or other wireless or handheld computing devices. The communication module 210 can also establish communication links between different units 200 to enable communication between the units 200. The communication module 210 can be a modem, a network interface card (NIC), an integrated network interface, a radio frequency transceiver, an optical port, an infrared port, a USB connection, or other wired or wireless communication interfaces. The communication links can be wired or wireless, which are used to transfer commands, instructions, information, and / or data.Transceiver 201, processor 202, memory 204, input device 206, output device 208, communication module 210, and disk drive 212 are interconnected via buses, peripheral component interconnect (PCI) (such as PCI Express), universal serial bus (USB), optical buses, or other similar data and / or power buses. Although not shown, unit 200 may be powered by DC power (e.g., battery cell, battery pack) or AC power (e.g., with a power cord and plug for connecting to an AC power outlet). Unit 200 may also be connected to one or more external data storage devices or servers via communication module 210.

[0041] Those skilled in the art will understand that Figure 2 The unit 200 shown is merely exemplary. For example, the number of transceivers 201 in the unit may be more than one. Transmitters 201T and receivers 201R may be arranged separately, rather than as a single transceiver 201. In one example, when multiple units 200 are operatively connected together (e.g., as...), Figure 1 As shown, one of the units 200 can be a master unit 200, and the other units 200 can be slave units controlled by the master unit. The processor of the master unit can control the operation of the processors of the slave units, while data and signal processing can be performed on any processor. In some embodiments, the transmitter 201T and receiver 201R or transceiver 201 can be arranged separately from the other components of the unit 200.

[0042] Figure 3 An embodiment of the present invention is shown, using Figure 1 Method 300 for detecting properties associated with objects 20 in environment 10 using an ultra-wideband detection system.

[0043] Method 300 begins at step 302, where an ultra-wideband radar signal is transmitted to environment 10. In one embodiment, the transmission may be performed by only one of the ultra-wideband transmitters of units 100A and 100B. In another embodiment, the transmission may be performed by the ultra-wideband transmitters of both units 100A and 100B. The transmissions of the two units 100A and 100B may be performed substantially simultaneously, or they may be performed one after the other (with a known time difference), controlled by the processor of one or both of units 100A and 100B.

[0044] The method 300 then proceeds to step 304, in which signals reflected from the environment 10 due to transmission of the ultra-wideband radar signals are received. In embodiments in which transmission is performed by the ultra-wideband transmitter of only one of the units 100A, 100B, the receiver of the respective unit will receive the reflected signals. In embodiments in which transmission is performed by the ultra-wideband transmitters of both units 100A, 100B, the receivers of both units 100A, 100B will receive the respective reflected signals. The reflected signals contain information about the environment 10, including the objects 20 in the environment 10.

[0045] Subsequently, in step 306, the reflected signals are analyzed. This analysis can be performed by the processor of the unit 100A, 100B that received the reflected signals, or by any other processor operatively connected with the units 100A, 100B. In embodiments in which transmission and reception are performed by only one of the units 100A, 100B, the processor of the respective unit will analyze the received reflected signals. In embodiments in which transmission is performed by the ultra-wideband transmitters of both units 100A, 100B, the processors of both units 100A, 100B will process the respectively received reflected signals. This processing can include removing a reference background signal from each of the reflected signals. The reference background signal can be predetermined (fixed), or can be adjusted in operation based on characteristics (intensity, frequency, phase, etc.) of the reflected signals. Alternatively or additionally, this processing can include identifying signal components that have changed between adjacent frames of reflected signals, to determine respective differences between the first signals of each two temporally adjacent reflections. As more and more reflected signals are processed, a temporal waveform can be built. This processing also involves analyzing the signal intensity or frequency (or both) of the processed (e.g., after removal of the background signal) first signals of the reflections, using methods such as frequency-time domain transformation, thresholding (e.g., based on a variable of noise in the signal), filtering, scaling, time gain compensation, etc. In one example, analyzing the frequency of the processed reflected signals involves segmenting the processed first signals of the reflections to analyze only the portions of the processed first signals of the reflections that are determined to be associated with a movable object.

[0046] In processing the received signals, in step 308, characteristics associated with the movable objects 20 in the environment 10 are determined. This determination can be performed by the processor of the unit 100A, 100B that performed the processing steps in step 306, or by any other processor operatively connected with the units 100A, 100B.

[0047] A property associated with a movable object 20 in the environment 10 can be the presence (or absence) of the movable object 20 in the environment 10. This can be determined based on the processed signal. If the processed signal does not contain a signal component that varies in time, it is assumed that the object 20 is not present in the environment 10. In one embodiment, even if the processed signal contains a signal component that varies in time, the processed signal is compared to a predetermined reference signal to determine whether the object 20 is present or absent in the environment 10. The determination of the presence (or absence) of the movable object 20 can be performed using only one unit 100A, 100B.

[0048] A property associated with a movable object 20 in the environment 10 can be the distance between the movable object 20 and one of the units 100A, 100B. This can be determined based on the processed signal, based on time-difference-of-arrival ranging or similar techniques. The determination of the distance can be performed by only one unit 100A, 100B (thus determining only one distance) or using both units 100A, 100B (determining respective distances). By monitoring the processed signal over time, it is also possible to determine a change in the distance between the movable object 20 and any of the units 100A, 100B.

[0049] In one embodiment in which both units 100A, 100B determine a respective distance (or a change in the respective distance), a property associated with a movable object 20 in the environment 10 can be a 2D position of the object 20 in the environment 10. The 2D position can be determined based on the determined distance (or change in the distance) between the movable object 20 and the unit 100A and the determined distance (or change in the distance) between the movable object 20 and the unit 100B, assuming that the relative position or distance between the two ultra-wideband receivers of the units 100A, 100B is known. By monitoring the processed signal over time, it is possible to determine a change in the 2D position of the movable object 20 in the environment 10, thus it is possible to track the movement path of the object 20.

[0050] In one embodiment in which the movable object is a human or an animal, a property associated with a movable object 20 in the environment 10 can be the respiration rate of the human or animal. The respiration rate can be determined based on a frequency analysis of the processed received signal.

[0051] The method 300 with steps 306 and 308 can be used to classify whether the object 20 is in an active state (e.g., doing exercise) or in an inactive state (e.g., sleeping). The classification can include comparing the processed reflection signal with a classification threshold. If it is determined that the processed reflection first signal is above the classification threshold, the object 20 is considered to be in an active state. If it is determined that the processed reflection first signal is below the classification threshold, the object 20 is considered to be in an inactive state. In some embodiments, multiple classification thresholds can be used to better and more finely classify the activity level of the object. In one embodiment, the classification threshold is different for different distance ranges between the movable object and the cell 100A, 100B. For example, a first classification threshold is used when the distance is determined to be 0m to 80m (e.g., in region A of Figure 1 , and a second classification threshold different from the first classification threshold is used when the distance is determined to be 80m to 100m (e.g., in region B of Figure 1 . The different regions can represent different regions (e.g., bedroom, bathroom, kitchen, etc.) in which the object 20 will perform different types of activities. The determination of active and inactive states can also take into account the breathing rate of the object (based on the strength of the breathing frequency signal).

[0052] Figure 4A is a plot showing a signal frame received as a result of transmitting an ultra-wideband radar signal and the removal of background signals according to one embodiment of the present application. As shown in Figure 4A , the signal frame contains background signals and signals indicative of conditions of the environment 10 or conditions in the environment 10. The signal frame is processed by removing the background signals therefrom, and optionally applying other signal processing or reconstruction techniques. By doing so, the resulting processed signal will be a “motion signal” indicative of changes in conditions of the environment 10 or changes in conditions in the environment 10 (e.g., characteristics of the object 20).

[0053] Figure 4B is a plot showing a waveform of a processed radar frame and target (e.g., movable object) detection based on the waveform. Figure 4B may be obtained by collecting radar frames similar to Figure 4A and plotting them all in a single chart. In Figure 4B , the thick line circled by the dashed line shows the identified distance variation between the object 20 and the cell 100A or 100B.

[0054] Figure 4C is a plot showing the frequency relationship of a portion of the signal waveform in the plot of Figure 4B . For example, Figure 4C may be obtained by performing a short-time fast Fourier transform on the portion of the waveform circled by the dashed line.Figure 4C The graph in the figure shows the change of the extracted movement signal (movement rate) over time. The signal forming the graph can be analyzed and processed to extract the respiratory rate, and the signal intensity can be used to set a threshold for the system's activity level (e.g., as described above).

[0055] Figure 5 This is a schematic diagram of a system according to an embodiment of the present invention, the system including Figure 1 Ultra-wideband-based detection systems. For example... Figure 5 As shown, units 100A and 100B are operatively connected to one or more external electronic devices via a communication network 30. The communication network 30 can be wired or wireless (preferably). The external electronic device 40 can be in the form of a computer server 40A, a smartphone / tablet 40B, or a smartwatch 40C. The basic structure of the external electronic device 40 is known, and it generally includes a processor, memory, I / O devices, a communication module, a disk drive, etc. (e.g., similar to reference...). Figure 2 (Those described). The system allows units 100A and 100B to send data, alarms, and information to external electronic devices 40 for viewing, analysis, storage, etc. In one example, if it is determined that the activity level of object 20 abruptly drops to 0 (which may indicate that object 20 has fainted), units 100A and 100B can send an alarm to external electronic devices 40 to notify the user or administrator of such external electronic devices 40 of this event and take emergency action.

[0056] Although not strictly necessary, the embodiments described with reference to the accompanying drawings can be implemented as an application programming interface (API) or a set of libraries used by developers, or can be included in another software application, such as a terminal or personal computer operating system or a portable computing device operating system. Typically, since program modules include routines, programs, objects, components, and data files that assist in performing specific functions, those skilled in the art will understand that the functionality of a software application can be distributed across multiple routines, objects, or components to achieve the same functionality required here.

[0057] It should also be understood that any suitable computing system architecture can be used where the methods and systems of the present invention are implemented entirely or partially by a computing system. This will include stand-alone computers, network computers, and dedicated or non-dedicated hardware devices. When using the terms "computing system" and "computing device," these terms are intended to include any suitable arrangement of computer or information processing hardware capable of implementing the described functions.

[0058] Those skilled in the art will appreciate that the application described herein is susceptible to variations and / or modifications as can be best suited to a specific individual needs and requirements. For example, the ultra-wideband-based system 100 can be formed from a single unit or more than two units (unlike the units shown in Figure 1 FIG. 1). The system 100 can be formed from multiple ultra-wideband-based transmitter-receiver pairs / transceivers that are operatively connected with a single standalone computing device (laptop, desktop, etc.). The application can be applied to an outdoor environment. The movable object can be an animal. The application can be applied to an environment in which there are multiple objects (not just one as shown in the figures). As such, the described embodiments of this application should be considered in all respects as illustrative and not restrictive.

Claims

1. An ultra-wideband based method for detecting a characteristic associated with a movable object in an environment, comprising: transmitting, using a first ultra-wideband transmitter, a plurality of first ultra- wideband radar signals into the environment; receiving, using a first ultra-wideband receiver, a plurality of first signals reflected from the environment as a result of the transmission of the first ultra-wideband radar signals; processing, using a processor, the reflected first signals; and determining, using the processor, a characteristic associated with a movable object in the environment based on the processed reflected first signals, wherein the processing step comprises: analyzing at least one of a signal strength and a frequency of the processed reflected first signals; and classifying the movable object as being in an active state or an inactive state by comparing the processed reflected first signals to one of classification thresholds, wherein the classification thresholds are different for different distance ranges between the movable object and the ultra-wideband transmitter; wherein the classification thresholds represent different areas in the environment in which the movable object performs different types of activities.

2. The method of claim 1, wherein the determining step comprises determining a presence of the movable object in the environment.

3. The method of claim 1, wherein the processing step comprises removing a reference background signal from each reflected first signal.

4. The method of claim 1, wherein the processing step comprises determining a respective difference between each two time-adjacent reflected first signals.

5. The method of any one of claims 1 to 4, wherein the determining step comprises determining a distance between the movable object and the first ultra-wideband receiver.

6. The method of claim 5, wherein the determining step further comprises determining a change in the distance between the movable object and the first ultra-wideband receiver.

7. The method of claim 1, wherein the classification thresholds depend on the distance between the movable object and the first ultra-wideband receiver.

8. The method of claim 7, further comprising adjusting the classification thresholds based on the signal strength of the processed reflected first signals.

9. The method of claim 1, wherein analyzing the frequency of the processed reflected first signals comprises: segmenting the processed reflected first signals to analyze only portions of the processed reflected first signals determined to be associated with the movable object.

10. The method of claim 1, wherein the movable object is a human or an animal, and wherein the determining step further comprises determining a respiration rate of the human or the animal based on the frequency analysis.

11. The method of any one of claims 1 to 4, further comprising: transmitting, using a second ultra-wideband transmitter, a plurality of second ultra- wideband radar signals into the environment; receiving, using a second ultra-wideband receiver, a plurality of second signals reflected from the environment as a result of the transmission of the second ultra- wideband radar signals; and processing, using the processor, the reflected second signals; wherein the determining step is further based on the processed reflected second signals. ​ 12. The method of claim 11, wherein the processing of the reflected second signals comprises removing a reference background signal from each reflected second signal.

13. The method of claim 11, wherein the processing of the reflected second signals comprises determining a respective difference between each two time-adjacent reflected second signals.

14. The method of claim 11, wherein the determining step further comprises determining a distance between the movable object and the second ultra-wideband receiver based on the processed reflected second signals.

15. The method of claim 14, wherein the determining step further comprises determining a change in the distance between the movable object and the second ultra-wideband receiver.

16. The method of claim 14, wherein the determining step further comprises determining a 2D position of the movable object in the environment based on the processed reflected first signals and the processed reflected second signals.

17. The method of claim 16, wherein the determining step further comprises determining a change in the 2D position of the movable object in the environment.

18. The method of any one of claims 1-4, wherein the first ultra-wideband transmitter and the first ultra-wideband receiver are arranged in a single ultra-wideband transceiver.

19. The method of claim 11, wherein the second ultra-wideband transmitter and the second ultra-wideband receiver are arranged in a single ultra-wideband transceiver.

20. The method of any one of claims 1-4, wherein the environment is an indoor environment.

21. The method of any one of claims 1-4, wherein the movable object is a human or an animal.

22. An ultra-wideband-based system for detecting a characteristic associated with a movable object in an environment, comprising: a first ultra-wideband transmitter for transmitting a plurality of first ultra- wideband radar signals to an environment; a first ultra-wideband receiver for receiving a plurality of first signals reflected from the environment as a result of the transmission of the first ultra-wideband radar signals; one or more processors for processing the reflected first signals and for determining a characteristic associated with a movable object in the environment, wherein the characteristic is: a presence of a movable object in the environment based on the processed reflected first signals; a distance between the movable object and the first ultra-wideband receiver; a change in the distance between the movable object and the first ultra-wideband receiver; and whether the movable object is in an active state or an inactive state by comparing the processed reflected first signals to one of classification thresholds, wherein the classification thresholds are different for different distance ranges between the movable object and the ultra-wideband transmitter, wherein the classification thresholds represent different regions in the environment in which the movable object performs different types of activities.

23. The ultra-wideband-based system of claim 22, wherein the first ultra- wideband transmitter and the first ultra-wideband receiver are arranged in a single ultra- wideband transceiver.

24. The ultra-wideband-based system of claim 22 or 23, further comprising: ​ a second ultra-wideband transmitter to transmit a plurality of second ultra-wideband radar signals to an environment; and a second ultra-wideband receiver to receive a plurality of second signals reflected from the environment as a result of the transmission of the second ultra-wideband radar signals; wherein the one or more processors are to process the reflected second signals; wherein the one or more processors are further arranged to determine, based on the processing of one or both of the reflected first signals and the reflected second signals, at least one of the following characteristics associated with the movable object in the environment: presence of the movable object in the environment based on the processed reflected second signals; a distance between the movable object and the second ultra-wideband receiver; a change in the distance between the movable object and the second ultra-wideband receiver; a 2D position of the movable object in the environment; and a change in the 2D position of the movable object in the environment.

25. The ultra-wideband-based system of claim 24, wherein the second ultra-wideband transmitter and the second ultra-wideband receiver are arranged in a single ultra-wideband transceiver.

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