Radar leakage cancellation based on the spatiotemporal relationship between transmitting and receiving antenna pairs

Abstract

A method and electronic device for leakage cancellation. The electronic device includes a first antenna pair, a memory, and a processor. The first antenna pair includes a first transmitter antenna configured to transmit a signal and a first receiver antenna configured to receive a signal. The memory is configured to store data. The processor is configured to: identify a first leakage factor associated with at least the first antenna pair from the data stored in the memory, control the first transmitter antenna to transmit a first signal, generate a first CIR based on reflections of the first signal received by the first receiver antenna, determine leakage in the first CIR based on at least the identified first leakage factor, and cancel the determined leakage from the first CIR.

Description

Technical Field

[0001] The present disclosure generally relates to removing leakage in radar applications. More specifically, the present disclosure relates to removing leakage for radar applications based on the spatiotemporal relationship of transmit and receive antennas. Background Art

[0002] Radar operates to locate targets in the radar field of view in terms of ranging distance and / or angle (azimuth and / or elevation) and / or speed. For certain types of radar, the transmitter and receiver may be mounted closely together, causing the signal emitted by the transmitter to be received directly by the receiver or to bounce off some components or assemblies of the device to reach the receiver. This signal is called a leakage signal. Leakage signals interfere with radar detection and ranging. Due to the presence of strong leakage signals sometimes, detection or ranging distance estimation is challenging. Specifically, because leakage obscures the actual target object, detection or ranging distance estimation is challenging for close ranging distances with values ​​comparable to the spacing between the transmitter and receiver. Due to strong leakage that may obscure the target, detection at close ranging distances may fall short of the standard. Even assuming that detection is successful, ranging distance estimation may also be inaccurate due to leakage distorting the target response. Summary of the Invention

[0003] Technical issues

[0004] One way to overcome this challenge is to compensate for or eliminate leakage signals. Eliminating leakage signals helps achieve reliable detection of target objects and accurately estimate the ranging distance of targets within the radar's close ranging range. Close ranging distance typically refers to distances below 20 cm, such as below 10 cm. The radar described herein can operate in various frequency bands, including but not limited to 6 GHz-8 GHz, 28 GHz, 39 GHz, 60 GHz, and 77 GHz.

[0005] Current methods for separating the leakage contribution from the target contribution assume that either the target contribution or the leakage contribution can be suppressed in some way. For example, current methods utilize a known target position, control the change of the target position, or control the suppression of the target contribution to the received signal.

[0006] Technical Solution

[0007] Embodiments of the present disclosure include a method, an electronic device, and a non-transitory computer-readable medium for leakage cancellation. In one embodiment, the electronic device includes a first antenna pair, a memory, and a processor. The first antenna pair includes a first transmitter antenna configured to transmit a signal and a first receiver antenna configured to receive a signal. The memory is configured to store data. The processor is configured to: identify a first leakage factor associated with at least the first antenna pair from the data stored in the memory, control the first transmitter antenna to transmit a first signal, generate a first CIR based on a reflection of the first signal received by the first receiver antenna, determine leakage in the first CIR based on at least the identified first leakage factor, and cancel the determined leakage from the first CIR.

[0008] In another embodiment, a method for eliminating leakage includes: identifying a first leakage factor associated with at least a first antenna pair of the electronic device from data stored in a memory of the electronic device, wherein the first antenna pair includes a first transmitter antenna and a first receiver antenna; transmitting a first signal via the first transmitter antenna; generating a first CIR based on a reflection of the first signal received by the first receiver antenna, determining leakage in the first CIR based on at least the identified first leakage factor; and eliminating the determined leakage from the first CIR.

[0009] In another embodiment, an electronic device includes a non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to: identify a first leakage factor associated with at least a first antenna pair of the electronic device from data stored in a memory of the electronic device, wherein the first antenna pair includes a first transmitter antenna and a first receiver antenna; control the first transmitter antenna to transmit a first signal via the first transmitter antenna; generate a first CIR based on reflections of the first signal received by the first receiver antenna; determine leakage in the first CIR based on at least the identified first leakage factor, and eliminate the determined leakage from the first CIR.

[0010] Other technical features may be apparent to those skilled in the art from the following drawings, descriptions, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, wherein like reference numerals represent like parts:

[0012] Figure 1 An electronic device according to various embodiments of the present disclosure is shown;

[0013] Figure 2 A monostatic radar according to various embodiments of the present disclosure is shown;

[0014] Figure 3 shows examples of channel impulse responses (CIRs) according to various embodiments of the present disclosure;

[0015] Figure 4 shows a timing diagram for radar transmission according to various embodiments of the present disclosure;

[0016] Figure 5 A method for target detection and ranging according to various embodiments of the present disclosure is shown;

[0017] Figure 6 shows a transmit antenna array and a receive antenna array according to various embodiments of the present disclosure;

[0018] Figure 7 A method of combining multiple CIRs with leakage eliminated according to various embodiments of the present disclosure is shown;

[0019] Figure 8 A method of combining multiple CIRs with leakage eliminated according to various embodiments of the present disclosure is shown;

[0020] Figure 9 illustrates an example of spatial leakage elimination according to various embodiments of the present disclosure; and

[0021] Figure 10 A method of leakage elimination according to various embodiments of the present disclosure is illustrated. Specific embodiments

[0022] Before proceeding with the detailed description below, it may be advantageous to set forth the definitions of specific words and phrases used throughout this disclosure. The term "coupling" and its derivatives refer to any direct or indirect communication between two or more elements, whether or not these elements are in physical contact with each other. The terms "emit," "receive," and "communication" and their derivatives encompass both direct and indirect communication. The terms "include" and "comprises" and their derivatives mean to include but are not limited to. The term "or" is inclusive, meaning and / or. The phrase "associated with..." and its derivatives mean to include, be included within, interconnect with, include, be included within, be connected to or with, be coupled to or with, can communicate with, collaborate with, interlace, juxtapose, be close to, be bound to or with, have, have the property of, have a relationship with, etc. When used with a list of items, the phrase "at least one of..." means that different combinations of one or more of the listed items can be used, and only one item in the list may be needed. For example, "at least one of A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A, B, and C.

[0023] In addition, the various functions described below can be implemented or supported by one or more computer programs, wherein each computer program is formed by computer-readable program code and is implemented in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, processes, functions, objects, classes, instances, related data or a part thereof adapted to be implemented in a suitable computer-readable program code. The phrase "computer-readable program code" includes any type of computer code (including source code, object code and executable code). The phrase "computer-readable medium" includes any type of medium that can be accessed by a computer, such as a read-only memory (ROM), random access memory (RAM), hard drive, compact disc (CD), digital video disc (DVD) or any other type of memory. "Non-transitory" computer-readable medium does not include wired, wireless, optical or other communication links that transmit temporary electrical signals or other signals. Non-transitory computer-readable medium includes a medium that can permanently store data and a medium that can store data and rewrite data later, such as a rewritable optical disc or an erasable memory device.

[0024] Definitions for other specific words and phrases are provided throughout this disclosure. Those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior and future uses of such defined words and phrases.

[0025] Discussed below Figures 1 to 10 The various embodiments used to describe the principles of the present disclosure are illustrative only and should not be construed in any way to limit the scope of the present disclosure. Those skilled in the art will understand that the principles of the present disclosure can be implemented in any suitably arranged wireless communication system.

[0026] Figure 1 An electronic device according to various embodiments of the present disclosure is shown. Figure 1 The embodiment of the electronic device 100 shown in FIGURE 1 is for illustration only. Other embodiments may be used without departing from the scope of this disclosure.

[0027] like Figure 1 As shown in FIG, electronic device 100 includes a radio frequency (RF) transceiver 110, a transmit (TX) processing circuit 115, a microphone 120, a receive (RX) processing circuit 125, a speaker 130, a processor 140, an input / output (I / O) interface (IF) 145, a memory 160, a display 165, an input 170, and a sensor 175. The memory 160 includes an operating system (OS) 162 and one or more applications 164.

[0028] The transceiver 110 transmits signals to other components in the system and receives incoming signals transmitted by other components in the system. For example, the transceiver 110 transmits RF signals (such as Bluetooth or Wi-Fi signals) to an access point (such as a base station, Wi-Fi router, or Bluetooth device) of a network (such as Wi-Fi, Bluetooth, cellular, 5G, LTE, LTE-A, WiMAX, or any other type of wireless network) and receives RF signals (such as Bluetooth or Wi-Fi signals) from an access point (such as a base station, Wi-Fi router, or Bluetooth device) of a network (such as Wi-Fi, Bluetooth, cellular, 5G, LTE, LTE-A, WiMAX, or any other type of wireless network). The received signals are processed by the RX processing circuit 125. The RX processing circuit 125 may transmit the processed signals to the speaker 130 (such as for voice data) or to the processor 140 for further processing (such as for web browsing data). The TX processing circuit 115 receives voice data from the microphone 120 or other outgoing data from the processor 140. The outgoing data may include web data, email, or interactive video game data. TX processing circuit 115 processes outgoing data to generate a processed signal. Transceiver 110 receives the outgoing processed signal from TX processing circuit 115 and converts the received signal into an RF signal for transmission via an antenna. In other embodiments, transceiver 110 may transmit and receive radar signals to detect potential objects in the surrounding environment of electronic device 100.

[0029] In this embodiment, one of the one or more transceivers in the transceiver 110 includes a radar transceiver 150 configured to transmit and receive signals for detection and ranging purposes. For example, the radar transceiver 150 can be any type of transceiver (including but not limited to a WiFi transceiver), such as an 802.11ay transceiver. The radar transceiver 150 includes an antenna array 155, wherein the antenna array 155 includes a transmitter 157 antenna array and a receiver 159 antenna array. The transmitter 157 can transmit signals at frequencies including but not limited to 6 GHz-8 GHz, 28 GHz, 39 GHz, 60 GHz, and 77 GHz. In some embodiments, the signals transmitted by the radar transceiver 150 may include but are not limited to millimeter wave (mmWave) signals. The radar transceiver 150 can receive the signal originally transmitted from the radar transceiver 150 after the signal bounces or reflects from a target object in the surrounding environment of the electronic device 100. The processor 140 may analyze the time difference between when a signal is transmitted by the radar transceiver 150 and when the signal is received by the radar transceiver 150 to measure the distance of the target object from the electronic device 100 .

[0030] The transmitter 157 and the receiver 159 may be positioned in close proximity to one another so that the separation distance between them is small. For example, the transmitter 157 and the receiver 159 may be located within a few centimeters of one another. In some embodiments, the transmitter 157 and the receiver 159 may be co-located such that the separation distance is indistinguishable. Based on the fixed, constant spatiotemporal relationship of the transmitter 157 and the receiver 159, the processor 140 may use information about the spatiotemporal relationship of the transmitter 157 and the receiver 159 to eliminate leakage in the response signal caused by leakage of the transmitted radar signal into the receiver 159, such as radar leakage. For example, the response signal may be as described herein. Figure 3 The channel impulse response (CIR) is further described in .

[0031] The TX processing circuit 115 receives analog or digital voice data from the microphone 120, or receives other outgoing baseband data (such as network data, email, or interactive video game data) from the processor 140. The TX processing circuit 115 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The transceiver 110 receives the outgoing processed baseband or IF signal from the TX processing circuit 115 and up-converts the baseband or IF signal into an RF signal that is transmitted via the antenna.

[0032] The processor 140 is also capable of executing an operating system 162 in the memory 160 to control the overall operation of the electronic device 100. For example, the processor 140 may move data into or out of the memory 160 as needed for the execution process. In some embodiments, the processor 140 is configured to execute an application 164 based on the OS program 162 or in response to a signal received from an external device or operator. In some embodiments, the memory 160 is further configured to store data such as one or more leakage factors, which the processor 140 may utilize to perform leakage cancellation as described herein. In some embodiments, the processor 140 may control the transceiver 110, the RX processing circuit 125, and the TX processing circuit 115 to receive forward channel signals and transmit reverse channel signals according to well-known principles. In some embodiments, the processor 140 includes at least one microprocessor or microcontroller.

[0033] Processor 140 is also connected to I / O interface 145, display 165, input 170, and sensor 175. I / O interface 145 provides electronic device 100 with the ability to connect to other devices such as laptop computers and handheld computers. I / O interface 145 is the communication path between these accessories and processor 140. Display 165 can be a liquid crystal display (LCD), a light emitting diode (LED) display, an organic LED (OLED), an active matrix OLED (AMOLED), or other display capable of presenting text and / or graphics, such as from a website, video, game, image, etc.

[0034] The processor 140 may be connected to an input device 170. An operator of the electronic device 100 may use the input device 170 to input input or data into the electronic device 100. The input device 170 may be a keyboard, a touch screen, a mouse, a trackball, a voice input, or any other device capable of serving as a user interface to allow the user to interact with the electronic device 100. For example, the input device 170 may include voice recognition processing, thereby allowing the user to input voice commands via the microphone 120. For another example, the input device 170 may include a touch panel, a (digital) pen sensor, a key, or an ultrasonic input device. The touch panel may recognize touch input in at least one of a capacitive scheme, a pressure-sensitive scheme, an infrared scheme, or an ultrasonic scheme, for example.

[0035] The electronic device 100 may further include one or more sensors 175, wherein the sensor 175 measures a physical quantity or detects the activation state of the electronic device 100 and converts the measured or detected information into an electrical signal. For example, the sensor 175 may include one or more buttons for touch input, one or more cameras, a gesture sensor, an eye tracking sensor, a gyroscope or gyro sensor, an air pressure sensor, a magnetic sensor or magnetometer, an acceleration sensor or accelerometer, a grip sensor, a proximity sensor, a color sensor, a biophysical sensor, a temperature / humidity sensor, an illumination sensor, an ultraviolet (UV) sensor, an electromyography (EMG) sensor, an electroencephalography (EEG) sensor, an electrocardiography (ECG) sensor, an infrared (IR) sensor, an ultrasonic sensor, a fingerprint sensor, etc. The sensor 175 may further include a control circuit for controlling at least one of the sensors included therein.

[0036] In various embodiments, the electronic device 100 may be a phone or a tablet. In other embodiments, the electronic device 100 may be a robot or any other electronic device that uses the radar transceiver 150. Figure 1 The present disclosure is not limited to any particular type of electronic device.

[0037] Figure 2 A monostatic radar according to various embodiments of the present disclosure is shown. Figure 2 The embodiment of the monostatic radar 200 shown in FIG is for illustration only. Other embodiments may be used without departing from the scope of this disclosure. Figure 2 The monostatic radar 200 shown in FIG. 1 includes a processor 210, a transmitter 220, and a receiver 230. In some embodiments, the processor 210 may be Figure 1 processor 140.

[0038] In some embodiments, the transmitter 220 and the receiver 230 may be included in Figure 1 15. The transmitter 157 and receiver 159 in the antenna array 155 are shown in FIG. 15. In various embodiments, the transmitter 220 and receiver 230 are co-located using a common antenna, or are nearly co-located in the case of separate but adjacent antennas. It is assumed that the monostatic radar 200 is coherent, such that the transmitter 220 and receiver 230 are synchronized via a common time reference.

[0039] Processor 210 controls transmitter 220 to transmit a radar signal or radar pulse. The radar pulse is generated as an implementation of a desired "radar waveform" modulated onto a radio carrier frequency and transmitted omnidirectionally or focused in a specific direction through a power amplifier and an antenna (shown as a parabolic antenna) such as transmitter 220. After the radar pulse has been transmitted, a target 240 at a distance R from radar 200 and within the field of view of the transmitted pulse will be illuminated by an RF power density P for the duration of the transmission. t (in W / m 2 For the first order, P t It is described by mathematical formula 1 (Equation 1):

[0040] [Mathematical formula 1]

[0041]

[0042] Among them, P T is the transmit power [W], G T is the transmitting antenna gain [dBi], A T is the effective aperture area [m 2 ], λ is the wavelength of the radar signal RF carrier signal [m], and R is the target distance [m].

[0043] The transmit power density incident on the target surface results in reflections depending on the material composition, surface shape, and dielectric behavior at the radar signal frequency. Off-direction scattered signals are generally not strong enough to be received back at receiver 230, so only direct reflections contribute to a detectable received signal. Therefore, the illuminated area of ​​the target with a normal vector pointing back to receiver 230 acts as a transmit antenna aperture with directivity or gain, depending on its effective aperture area. The reflected power P is ref1 It is described by mathematical formula 2 (Equation 2):

[0044] [Mathematical formula 2]

[0045]

[0046] Among them, P ref1 is the effective (isotropic) target reflected power [W], A t is the effective target area perpendicular to the radar direction [m 2 ],r t is the reflectivity and shape of the material [0,...,1], G t is the corresponding aperture gain [dBi], and RCS is the radar cross section [m 2 ]. As shown in Equation 2, the corresponding aperture gain [dBi] (G t ) and the reflectivity and shape of the material [0, ..., 1] (r t ) multiplied by the effective target area normal (A t ) divided by (i) the wavelength squared divided by (ii) four times π gives approximately the same result.

[0047] As described in Equation 2, the radar cross section (RCS) is an equivalent area that scales proportionally with the square of the actual reflecting area, is inversely proportional to the square of the wavelength, and is reduced by various form factors and the reflectivity of the material itself. For example, for area A t The flat total reflection mirror, with λ 2 Compared to amplification, RCS=4πA 2 t Due to material and shape dependencies, it is difficult to infer the actual physical area of ​​the target 240 based on the reflected power even if the distance R from the target to the radar 200 is known.

[0048] The target reflected power at the location of the receiver 230 is based on the reflected power density collected over the receiver antenna aperture area at the reverse distance R. The received target reflected power P R It is described by mathematical formula 3 (Equation 3):

[0049] [Mathematical formula 3]

[0050]

[0051] Among them, P R is the received target reflected power [W], A R is the effective aperture area of ​​the receiver antenna [m 2 In some embodiments, A R Can be used with A T same.

[0052] Such a radar system is usable as long as the receiver signal exhibits a sufficient signal-to-noise ratio (SNR). The specific value of SNR depends on the waveform and detection method used. SNR is described by mathematical formula 4 (Equation 4):

[0053] [Math.4]

[0054]

[0055] where kT is the Boltzmann constant x temperature [W / Hz], B is the radar signal bandwidth [Hz], and F is the receiver noise factor, which refers to the degradation of the received signal SNR due to noise contributions to the receiver circuit itself.

[0056] In some embodiments, the radar signal may be a signal having a value represented by T P denoted by a short pulse of duration or width. In these embodiments, the delay t between the transmission and reception of the corresponding echo will be equal to τ = 2R / c, where c is the speed of light in a medium such as air. In some embodiments, there may be several targets 240 at slightly different distances R. In these embodiments, the individual echoes of each individual target 240 are distinguished in this way only if the delays differ by at least one pulse width, and the ranging resolution of the radar is described as ΔR = cΔτ / 2 = cT p / 2. Duration T P The rectangular pulse shows a power spectrum density P(f)~(sin(πfT P ) / (πfT P )) 2 , where the first zero point is at its bandwidth B = 1 / T P Therefore, the relationship between the radar's ranging resolution and the bandwidth of the radar waveform is described by mathematical formula 5 (Equation 5):

[0057] [Math.5]

[0058] ΔR=c / 2B

[0059] Based on the reflected signals received by receiver 230, processor 210 generates a metric that measures the response of the reflected signals as a function of the distance of target 240 from the radar. In some embodiments, the metric may be a channel impulse response (CIR).

[0060] Figure 3 An example of a CIR depicting a measured leakage response according to various embodiments of the present disclosure is shown. The CIR is a measure of the response based on the signal received by the receiver 230. For example, the CIR is a measure of the amplitude and / or phase of the reflected signal as a function of distance. Figure 3 As shown in , the CIR is plotted with the delay tap index of the measured distance represented on the x-axis and the amplitude [dB] of the radar measurement value represented on the y-axis. In a monostatic radar (e.g., radar 200) having separate transmit antenna modules and receive antenna modules, a strong signal can be radiated directly from transmitter 220 to receiver 230, resulting in a strong response at a delay corresponding to the spacing between transmitter 220 and receiver 230. The strong signal radiated from transmitter 220 to receiver 230 is called a leakage signal. Even though it can be assumed that the direct leakage signal from transmitter 220 corresponds to a single delay, the impact of the direct leakage signal can still affect multiple delay taps adjacent to the direct leakage signal.

[0061] exist Figure 3 In the measured leakage response shown in , the main leakage peak is shown at tap 11. In addition, taps 10 and 12 also have strong responses, noting that the responses are 20 dB above the noise floor. Due to additional responses such as those shown at taps 10 and 12, it is difficult to reliably detect and estimate the target ranging distance within those first few taps from the leakage taps.

[0062] Figure 4 FIG. 1 shows a timing diagram for radar transmission according to various embodiments of the present disclosure. Specifically, Figure 4 The frame structure shows how time is divided into frames. Each frame includes multiple bursts. Each burst includes multiple pulses. Figure 4 The timing diagrams shown in assume a basic pulse compression radar system.

[0063] like Figure 4 As shown in , each frame includes multiple bursts N, such as burst 1, burst 2, burst 3, etc. Each burst also includes multiple pulses. For example, Figure 4 Burst 1 is shown to include a number of pulses labeled Pulse 1, Pulse 2, ... to Pulse M.

[0064] For example, in Burst 1, a radar transceiver such as transmitter 157 may transmit Pulse 1, Pulse 2, and Pulse M, where M represents the final pulse in the burst. For simplicity, this description assumes that Pulse M is the third pulse, but this description should not be construed as limiting. In various embodiments, M can be the third pulse or any number of pulses. In Burst 2, transmitter 157 may transmit a similar plurality of pulses: Pulse 1, Pulse 2, and Pulse M. Each different pulse (Pulse 1, Pulse 2, and Pulse M) and burst (Burst 1, Burst 2, Burst 3, etc.) may utilize a different transmit / receive antenna configuration (i.e., a different set of active antenna elements and corresponding analog / digital beamforming weights) to identify a specific pulse or burst. For example, each pulse or burst may utilize a different set of active antenna elements and corresponding analog / digital beamforming weights to identify a specific pulse or burst.

[0065] After each frame, a processor connected to transmitter 157 (such as processor 140) obtains radar measurements at the end of each frame. For example, the radar measurements can be represented as a three-dimensional complex CIR matrix. The first dimension can correspond to the burst index, the second dimension can correspond to the pulse index, and the third dimension can correspond to the delay tap index. The delay tap index can be converted into a measurement of the ranging distance or flight time of the received signal.

[0066] As described in this disclosure, several types of leakage cancellation methods can be utilized that exploit the relationship between one or more transmit and receive antenna pairs across space and time. The leakage cancellation methods described herein exploit the constant relationship between transmit and receive antenna pairs to reconstruct the leakage signal based on past monitoring of the same antenna pair or current measurements as seen by other transmit and receive antenna pairs. Figure 5 These embodiments are broadly shown in FIG.

[0067] Figure 5 A method for target detection and ranging according to various embodiments of the present disclosure is shown. Figure 5 The embodiment of method 500 shown in FIGURE 5 is for illustration only. Other embodiments including additional or fewer operations may be used without departing from the scope of this disclosure.

[0068] At operation 510, radar measurements are obtained as described in greater detail herein. The radar measurements may include storing data regarding the fixed positions of the transmit and receive antenna pairs in memory 160, and obtaining radar measurements such as Figures 2 to 4 The CIR profile described in .

[0069] In operation 520, the processor 140 performs leakage cancellation. The leakage cancellation may be performed based on the stored relationship between one or more transmit and receive antenna pairs across space and time, previous leakage cancellation operations, and the obtained CIR (such as Figure 3Leakage cancellation is performed using information from the CIR (shown in FIG. 1 ) of the electronic device 100. Leakage cancellation cancels the original radar receive signal corresponding to the leakage, rather than the original radar receive signal corresponding to the target. In some embodiments, operation 520 may include additional steps, such as combining leakage from one or more antenna pairs, utilizing stored leakage factors in a template stored in memory 160, and performing presence detection of potential target objects in the surrounding environment of the electronic device 100. Various embodiments for performing leakage cancellation are further described herein.

[0070] In operation 530, the processor 140 performs target detection and ranging based on the result of the leakage elimination. For example, the processor 140 may detect the target based on the peak value remaining in the CIR after the leakage has been eliminated. The processor 140 may also detect the target based on the peak value remaining in the CIR after the leakage has been eliminated. Figure 2 The tap index shown in the CIR shown in determines the distance of the detected target.

[0071] Figure 5 The object detection and ranging methods described in

[15] are not limited to object detection, but can also be used for non-conventional purposes such as context detection. Figure 5 The method of target detection and ranging described in is also independent of movement of the target or electronic device 100 and is robust to variations in leakage (eg, common phase and amplitude jumps).

[0072] Figure 6 1 shows a transmitting antenna array and a receiving antenna array according to various embodiments of the present disclosure. Specifically, Figure 6 The transmitting antenna array 610 and the receiving antenna array 620 are shown. The transmitting antenna array 610 and the receiving antenna array 620 may be provided in a device such as the electronic device 100 or the radar 200. For example, the transmitting antenna array 610 and the receiving antenna array 620 may be the transmitter 157 and the receiver 159, respectively, included in the antenna array 155. As another example, the transmitting antenna array 610 may be the transmitter 220, and the receiving antenna array 620 may be the receiver 230.

[0073] like Figure 6As shown in , transmit antenna array 610 includes nine transmit elements (e.g., 1-9) arranged in a 3×3 pattern. Although depicted as nine transmit elements arranged in a 3×3 pattern, this embodiment should not be construed as limiting, and other embodiments are possible. Any suitable number of transmit elements may be included, and the transmit elements may be arranged in any suitable configuration. Additionally, receive antenna array 620 includes nine receive elements (e.g., 1-9) arranged in a 3×3 pattern. Although depicted as nine receive elements arranged in a 3×3 pattern, this embodiment should not be construed as limiting, and other embodiments are possible. Any suitable number of receive elements may be included, and the receive elements may be arranged in any suitable configuration.

[0074] like Figure 6 As shown in FIG, the transmit antenna array 610 and the receive antenna array 620 are arranged or mounted at fixed positions on the electronic device 100. Regardless of the specific configuration, due to the fixed positions of the transmit antenna array 610 and the receive antenna array 620, the spacing distance and angle relationship between the transmit antenna array 610 and the receive antenna array 620 are constant and time-invariant. For example, the transmit antenna array 610-3 maintains a constant distance and angle with the receive antenna array 620-1, as shown in FIG. Figure 6 By positioning the transmit antenna array 610 and the receive antenna array 620 at fixed, constant, and time-invariant positions, the transmit antenna array 610 and the receive antenna array 620 may be defined by a constant spatiotemporal relationship, wherein the constant spatiotemporal relationship may be used to eliminate radar leakage from the transmit antenna array 610 and the receive antenna array 620.

[0075] The distance separation determines the propagation attenuation level, and the directional relationship determines the antenna gain (based on the radiation pattern) of the transmit antenna array 610 and the receive antenna array 620. The propagation attenuation level and the antenna gain are some of the transformations that the leakage signal undergoes, starting with a digital transmit symbol until the leakage signal is received and demodulated into a digital baseband receive signal. Another transformation includes the combined response of the transmit filter and the receive filter, where the transmit filter and the receive filter include a pulse shaping filter at the transmitter antenna array 610 and a matched filter at the receive antenna array 620. As long as the sampling timing remains unchanged, the combined response is generally constant. When the transformations are constant, they can be used by the processor 140 to reconstruct the leakage signal from previous measurements or current measurements as seen by other antenna pairs, and can be used to eliminate the leakage contribution in the original radar signal.

[0076] In various embodiments, a transmit and receive antenna pair may be referred to as k. For example, element 1 of transmit antenna array 610 and element 1 of receive antenna array 620 may form an antenna pair and be referred to as k. Another transmit and receive antenna pair may be referred to as l. For example, element 9 of transmit antenna array 610 and element 9 of receive antenna array 620 may form an antenna pair and be referred to as l. Although k and l are described herein as describing elements 1 and 9 of two antenna arrays 610 and 620, respectively, each of k and l may refer to any pair of transmit and receive antenna arrays.

[0077] When the antenna pairs transmit orthogonally, the leakage L for each antenna pair (e.g., antenna pair k) can be defined by multiplying the antenna gain of the receive antenna, the antenna gain of the transmit antenna, the propagation loss between the antenna pair, and the filter response seen by the antenna pair. k For example, when the CIR of the leakage at delay tap n is defined as L k [n], then L k [n] can be determined by mathematical formula 6 (Equation 6):

[0078] [Math.6]

[0079] L k [n]=G R，k α k G T，k p k [n]

[0080] Where n is the delay tap received via transmit and receive antenna pair k, G R，k is the antenna gain of the receiving antenna, G T，k is the antenna gain of the transmitting antenna, α k is the propagation loss between the antenna pair, and p k [n] is the combined filter response seen through the pair. Furthermore, the leakage for antenna pair l can be defined as L l [n]=G R，l α l G T，l p l [n] In some embodiments, when there is no target near the radar, the radar can be detected by measuring CIR k [n] to obtain the leakage measurement value L k [n].

[0081] When the sampling timing between two antenna pairs k and l is the same, a constant factor between k and l can be determined to more accurately cancel leakage. Because of the constant spatial relationship between the two pairs, the filter response of each pair can be the same. For all n, the same filter response is denoted as p k[n] = P1[n]. Therefore, the leakage signal determined by k and l differs by a constant factor β determined by mathematical formula 7 (Equation 7), assuming that the index n = 0 corresponds to the leakage peak:

[0082] [Math.7]

[0083]

[0084] The constant factor β may also be referred to as a compensation factor β, a scaling factor β, a leakage factor, or a leakage scaling factor β. The leakage factor β may be stored in a template in memory 160 for future determinations. For example, the stored β of the CIR received by pair l with the target contribution may be used to reconstruct the leakage as monitored by pair k and, accordingly, eliminate the leakage signal from the received CIR of pair k. For example, if the CIR k [n] and CIR1[n] represent the CIRs with target contributions received by pair k and pair l, respectively. Then, the CIR with leakage eliminated received by pair k can be obtained by Mathematical Formula 8 (Equation 8), which is expressed as CIR can，k [n]:

[0085] [Math.8]

[0086] CIR can，k [n] = CIR k [n]-β CIR l [n]

[0087] Because the leakage factor β is calculated and stored to match the leakage, the cancellation of Mathematical Formula 8 (Equation 8) cancels the leakage. The CIR canceled by the leakage received for l can be calculated in a similar manner by using l instead of k and using the inverse of β as the scaling factor. For the contribution of the target, this factor does not compensate for the different scaling, and the target signal is not cancelled. In these embodiments, the cancelled CIR can then be calculated as can，k [n] is input to the detection and ranging system for further processing. In some embodiments, the eliminated CIR may also be stored can，k [n] for further processing later.

[0088] In some embodiments, cancellation (i.e., subtraction) may be performed for each antenna pair in the ranging distance of the index. For example, cancellation may be performed between element 1 of the transmitter antenna array 610 and the receive antenna array 620, between element 2 of the transmitter antenna array 610 and the receive antenna array 620, between element 1 of the transmitter antenna array 610 and the receive antenna array 620, between element 3 of the transmitter antenna array 610 and the receive antenna array 620, and so on. In other embodiments, cancellation may be performed only for ranging distances of delay tap indices (denoted by N) that are expected to be affected by leakage, rather than for all indices. For indices that are not expected to be affected by leakage, the original CIR received by pair k may be retained. For all By CIR can，k [n] = CIR k [n] is used to describe this embodiment. Because the leakage factor β is time-invariant, the leakage factor β can be measured or pre-calculated and then stored in memory 160 for use in eliminating leakage at a later time. For example, as part of a manufacturing process, the leakage factor β can be measured and stored in a template in memory 160 to accurately measure the device-specific leakage factor β.

[0089] In some embodiments, the combined filter response is different for each antenna pair. For example, the difference in filter response may be due to a difference in the sampling timing of the leakage signal. The sampling timing may be a portion of the symbol period of the baseband signal. The difference in the sampling timing of the leakage signal may be due to the link distance between the two pairs k and l being large enough, resulting in different precise fractional sampling times for the leakage of the two pairs k and l. This may result in different combined filter responses. When the combined filter response is different, the leakage monitored by one antenna pair cannot be converted to leakage monitored via another antenna pair by a single leakage factor β, and a separate leakage factor β is used for each index. Because the leakage will be eliminated, a scaling factor around the leakage peak index is determined. For a set of indexes N, the leakage factor β[n] for the set of indexes N within the ranging distance can be determined by mathematical formula 9 (Equation 9):

[0090] [Math.9]

[0091] Where n∈N

[0092] As shown in Mathematical Formula 9 (Equation 9), the leakage scaling factor β[n] can be determined by dividing the first CIR for [k] by the second CIR for [1]. Specifically, the receiver antenna gain G of the first antenna pair can be obtained by R，k , the propagation coefficient α of the first antenna pair k , the transmitter antenna gain G of the first antenna pair T，1and the combined transmitter and receiver filter response p for the first antenna pair k [n] generates the first CIR for [k]. Similarly, the receiver antenna gain G of the second antenna pair can be R，1 , the propagation coefficient α of the second antenna pair l , the transmitter antenna gain G of the second antenna pair T，1 and the combined transmitter and receiver filter response p for the second antenna pair. l [n] generates a second CIR for [l].

[0093] Once the leakage scaling factor β[n] is obtained, it can be used to cancel the leakage using Mathematical Formula 10 (Equation 10):

[0094] [Math.10]

[0095]

[0096] Because of the fixed spatial relationship between antenna pair k and l, the leakage factor β[n] is time-invariant. Therefore, the leakage factor β[n] can be measured and stored in memory 160. For example, as part of a manufacturing process, the leakage factor β[n] can be measured and stored in memory 160 to accurately measure the device-specific leakage factor β[n]. The processor 140 can then identify the leakage factor β[n] associated with the antenna pair k and l.

[0097] As mentioned above, the leakage CIR is a signal that is transformed by the antenna gain, propagation attenuation, and combined filter response to reach the receiver. A scaling factor θ can be determined for a single antenna pair and used to measure the cancellation of the leakage CIR. The scaling factor θ can also be referred to as the leakage factor θ. The leakage factor θ can be determined using Mathematical Formula 11 (Equation 11):

[0098] [Mathematical formula 11]

[0099]

[0100] Among them, L k [n] is the leakage CIR previously measured and stored on the device, and N is the ranging distance of the index expected to be affected by leakage. Although depicted herein as using the absolute difference between the eliminated leakage and the scaling factor multiplied by the leakage CIR previously measured and stored on the device, other numerical methods can be used to determine the leakage factor θ. For example, the squared absolute difference or any other type of distance measurement can also be used.

[0101] The leakage factor θ can be used to perform leakage cancellation. For example, the leakage factor θ can perform leakage cancellation when used in Mathematical Formula 12 (Equation 12):

[0102] [Math.12]

[0103]

[0104] In some embodiments, L can be measured or pre-calculated k [n], which is then stored in memory 160 for use at a later time to eliminate the leakage of the CIR of the additional antenna pair. In various embodiments, L k The value of [n] can be described as a leakage factor. In some embodiments, the leakage factor θ can be measured or pre-calculated and then stored in a template stored in memory 160 for use in eliminating leakage of the CIR of additional antenna pairs at a later time. For example, when different transmit powers are used, each leakage factor θ can be stored for different configurations of the electronic device 100. For example, as part of the manufacturing process, the leakage factor θ can be measured and stored in a template to accurately measure the device-specific leakage factor θ. The processor 140 can then identify the leakage factor θ associated with the antenna pair for later use in determining leakage in the CIR. In other embodiments, the leakage factor θ can be calculated at the current time as needed so that the leakage factor θ can be adjusted based on changes in transmit power.

[0105] In some embodiments, the sampling timing may be different when hardware initialization is performed. For more accurate leakage cancellation, rather than storing only one leakage CIR for each fractional sampling timing, the leakage CIR measured using each fractional sampling timing may be stored in a template. The fractional sampling timing is defined at receiver 230, so processor 210 can adjust the sampling timing to maximize signal strength. In these embodiments, the sampling timing selected during the initialization process can be used to select a corresponding leakage CIR stored in the template for use in leakage cancellation as described herein.

[0106] The processor 210 or 140 may identify the L associated with a particular antenna pair in the template stored in the memory 160. k [n] After the processor 210 has controlled the transmitter 220 to transmit the first signal and generated the CIR based on the reception of the reflection of the first signal by the receiver 230, the processor 210 generates the CIR based on the stored L k [n] Determine a leak in the CIR. After the leak of the CIR has been determined, the processor may eliminate the determined leak from the CIR and perform object detection based on the CIR with the leak eliminated.

[0107] In some embodiments, the leakage factor β may be the same as the leakage factor θ. The leakage factor β may also be stored in a template in memory 160, where the template may be the same as or different from the template storing the leakage factor θ. The processor 210 may control the second transmitter 220 of the second antenna pair to transmit an additional signal and generate a second CIR based on a reflection of the first signal received by the second receiver 230 of the second antenna pair. The processor 210 may then determine leakage of the second CIR based on the leakage factor β and eliminate the determined leakage from the second CIR. The processor 210 may then perform object detection based on the second CIR with leakage eliminated.

[0108] Figure 7 In some embodiments, the processor 140 may utilize M antenna pairs instead of M antenna pairs. Figure 6 , where M represents the number of antenna pairs. Using M antenna pairs instead of a single antenna pair provides multiple estimates of the CIR after leakage cancellation. Before processor 140 performs the detection and ranging process, the multiple estimates can be combined to obtain better performance, such as an improvement in the signal-to-noise ratio.

[0109] The number of groups of two pairs can be selected in various ways. For example, if absolute independence between the leakage-cancelled CIRs is desired, M pairs can be used to form M / 2 non-overlapping groups of two pairs. In this embodiment, M is described as an even number. In other embodiments where M is an odd number, a floor function can be used to avoid inaccurate calculations. If the independence criterion is not required, M pairs can be used to form M-1 groups of two pairs. Although described herein as M / 2 or M-1 groups of two pairs, these embodiments should not be construed as limiting. Other embodiments are possible. Method 700 depicts combining the leakage-cancelled CIRs of antenna pair M for more robust target detection and ranging.

[0110] In operation 710, various leakage-canceled CIRs are obtained. For example, leakage-canceled CIR 1 is obtained in operation 710a, leakage-canceled CIR 2 is obtained in operation 710b, and leakage-canceled CIR K is obtained in operation 710n. The leakage-canceled CIR K obtained in operation 710n may be understood to represent leakage-canceled CIRs of any number of antenna pairs M obtained in operation 710. Figure 6 One or more of the methods described in the description of to obtain CIR 1, CIR 2, ..., CIR n with leakage eliminated. Figure 6 The pair of antenna arrays described in obtains the CIR with each leakage cancelled. For example, the CIR with each leakage cancelled can be described as CIRcan [n].

[0111] In operation 720, the processor 140 combines each of the leakage-canceled CIRs 1, 2, ..., and n obtained in operation 710. Each of the leakage-canceled CIRs 1, 2, ..., and n can be combined in various ways. In some embodiments, the processor 140 may combine the leakage-canceled CIRs 1, 2, ..., and n by calculating an average of the leakage-canceled CIRs 1, 2, ..., and n. The calculated average (such as the squared magnitude of a complex number) may be in the complex domain or in the power domain. In other embodiments, the processor 140 may combine the leakage-canceled CIRs 1, 2, ..., and n by performing beamforming on the leakage-canceled CIRs 1, 2, ..., and n. For example, the processor 140 may combine the leakage-canceled CIRs 1, 2, ..., and n using a maximum ratio combining (MRC) scheme.

[0112] In other embodiments, the processor 140 may calculate the leakage-canceled CIR 1, CIR 2, ..., CIR n results obtained in operation 710 by using a weighted average, a maximum value, or a minimum value. The weighted average may be used to establish a higher weight, i.e., a priority, for the leakage-canceled CIR of a specific antenna pair. For example, the processor 140 may use Equation 4 An SNR is determined for each of the antenna pairs M, and corresponding SNR values ​​for each of the antenna pairs M are compared to determine a weighted average of the results of operation 710.

[0113] In operation 730, the processor 140 performs target detection and ranging based on the result of the leakage-eliminated CIR combined in operation 720. For example, the processor 140 may detect a target based on a peak remaining in the CIR after the leakage has been eliminated. The processor 140 may also detect a target based on the peak remaining in the CIR. Figure 2 The tap index shown in the CIR shown in determines the distance of the detected target.

[0114] Figure 8 1 shows a method for combining multiple CIRs with leakage eliminated according to various embodiments of the present disclosure. In some embodiments, the processor 140 may utilize M antenna pairs instead of Figure 6 The single antenna pair k and l described in , where M represents the number of antenna pairs. Using M antenna pairs instead of a single antenna pair provides multiple estimates of the CIR after leakage cancellation.

[0115] The number of groups of two pairs can be selected in various ways. For example, if absolute independence between the leakage-cancelled CIRs is desired, M pairs can be used to form M / 2 non-overlapping groups of two pairs. If the independence criterion is not required, M pairs can be used to form M-1 groups of two pairs. Although depicted herein as M / 2 or M-1 groups of two pairs, these embodiments should not be construed as limiting. Other embodiments are possible. Method 800 depicts performing ranging on each of the leakage-cancelled CIRs obtained for antenna pair M before combining the results of target detection and ranging.

[0116] In operation 810, various leakage-canceled CIRs are obtained. Operation 810 may be performed in the same manner as operation 710. For example, leakage-canceled CIR 1 is obtained in operation 810a, leakage-canceled CIR 2 is obtained in operation 810b, and leakage-canceled CIR K is obtained in operation 810n. The leakage-canceled CIR K obtained in operation 810n may be understood to represent leakage-canceled CIRs of any number of antenna pairs M obtained in operation 810. Figure 6 One or more of the methods described in the description of to obtain CIR 1, CIR 2, ..., CIR n with leakage eliminated. Figure 6 The pair of antenna elements described in obtains the CIR with each leakage cancelled. For example, the CIR with each leakage cancelled can be described as CIR can [n].

[0117] In operation 820, the processor 140 performs target detection and ranging based on each individually obtained leakage-cancelled CIR. For example, in operation 820a, the processor 140 controls target detection and ranging based on the leakage-cancelled CIR 1 obtained in operation 810a. In 820b, the processor 140 controls target detection and ranging based on the leakage-cancelled CIR 2 obtained in operation 810b. In 820n, the processor 140 controls target detection and ranging based on the leakage-cancelled CIR K obtained in operation 810n. The target detection and ranging process in each of operations 820a, 820b, and 820n may include detecting a target based on a peak remaining in each corresponding leakage-cancelled CIR. The processor 140 may also determine the distance of the detected target based on the tap index of the detected target in the CIR.

[0118] In operation 830, processor 140 combines the target detection and ranging results from operation 820 for each corresponding leakage-cancelled CIR to produce a final detection and estimation output. Processor 140 can combine the results in various ways, such as using an average, a weighted average, a maximum, and a minimum. For example, if three antenna pairs are used at operations 820a, 820b, and 820n and a target is detected at 5 cm, 7 cm, and 9 cm from the electronic device 100, respectively, processor 140 can produce different final outputs based on the combination method. If processor 140 averages the results of operation 820 to produce the final output, the final output will show a target at 7 cm from the electronic device 100. If processor 140 uses the maximum value, the final output will show a target at 9 cm from the electronic device 100. If processor 140 uses the minimum value, the final output will show a target at 5 cm from the electronic device 100.

[0119] In some embodiments, when the processor 140 combines the results of operation 820 using weighted averaging, the processor 140 may use the SNR of the detected signal as a weight to establish a higher weight, i.e., a priority, for a specific antenna pair among the antenna pairs M. For example, the processor 140 may use Equation 4 The SNR of each of the antenna pairs M is determined, and the corresponding SNR values ​​of each of the antenna pairs M are compared to determine a weighted average of the results of operation 820. In the above example, in operations 820a, 820b, and 820n using three antenna pairs and detecting a target at 5 cm, 7 cm, and 9 cm from the electronic device 100, respectively, the average value is 7 cm. However, using the weighted average value in which the antenna pair that detected the target at 5 cm has the highest SNR value and is included twice in the weighted average calculation, the weighted average value is 6.5 cm. In this example, the final output of operation 830 may indicate that the target was detected at 6.5 cm.

[0120] In some embodiments, processor 140 may control the output of a binary output. For example, processor 140 may control the output of a result indicating the presence or absence of a target within the ranging distance, or the presence or absence of a target at a specific tap index. In embodiments where processor 140 controls the output of a binary result, processor 140 may combine the target detection and ranging results using a majority vote. For example, if three antenna pairs are used at operations 820a, 820b, and 820n, and a target is detected in operations 820a and 820b but not in operation 820n, because the two antenna pairs that detected the target constitute a majority, the majority vote causes processor 140 to control the output of a result indicating the detection of the target. As another example, the output may be a binary output indicating whether a target was detected at a specific tap index. In the example where three antenna pairs are used at operations 820a, 820b, and 820n and a target is detected at tap index 11 in operations 820a and 820b but no target is detected at tap index 11 in operation 820n, because the two antenna pairs of the three antenna pairs that detect the target at tap index 11 constitute a majority, the majority voting method causes the processor 140 to control the output to indicate a result that a target is detected at tap index 11.

[0121] Figure 9 An example of spatial leakage elimination according to various embodiments of the present disclosure is shown. Specifically, Figure 9 A method 900 of spatial leakage cancellation using M antenna pairs is shown.

[0122] In operation 910, a set of reference pairs R is selected from M antenna pairs. M represents the number of antenna pairs on the electronic device and can be Figure 7 and Figure 8 The set of reference pairs R may be selected based on various criteria. For example, the set of reference pairs R may be selected differently for different delay taps. The set of reference pairs R may be selected from an index that associates the set of reference antenna pairs R with a particular delay tap. In some embodiments, the same set of reference pairs may be used for all delay taps, for which leakage cancellation is performed throughout method 900. For example, one antenna pair in the set of reference pairs R may be element 1 of transmit antenna array 610 and receive antenna array 620, and a second antenna pair may be element 2 of transmit antenna array 610 and element 2 of receive antenna array 620.

[0123] In operation 920, for each of the antenna pairs M on the electronic device, leakage is canceled using a reference pair R. In some embodiments, leakage cancellation can be achieved by subtracting the leakage from the CIR of the reference pair R after scaling by the corresponding leakage scaling factor. Antenna pairs may include element 3 of transmit antenna array 610 and element 3 of receive antenna array 620, element 4 of transmit antenna array 610 and element 4 of receive antenna array 620, and so on. During operation 920, since leakage from each antenna pair on the electronic device 600 is subtracted using the reference pair R, the reference pair R is included in the leakage cancellation. When the antenna pair subtracted using the reference pair R is one of the reference pairs, leakage is subtracted by excluding the reference pair as a reference. Leakage subtraction can be depicted as using R-1 reference pairs. Based on the leakage subtraction for each of the antenna pairs on the electronic device 100, the non-reference antenna pair has R radar signals with leakage subtracted, and the reference antenna pair R has R-1 radar signals with leakage subtracted. The radar signals can be depicted as CIRs as previously described herein.

[0124] At operation 930, the leakage-subtracted CIRs are averaged for each antenna pair. For example, when one antenna includes element 3 of transmit antenna array 610 and element 3 of receive antenna array 620, and the other antenna includes element 4 of transmit antenna array 610 and element 4 of receive antenna array 620, the leakage-subtracted radar signals of the two antennas are averaged to obtain an averaged leakage-canceled radar signal or leakage-subtracted radar signal. At operation 940, the averaged leakage-subtracted CIRs of the antenna pair M are combined. For example, beamforming techniques may be used to average or combine the M leakage-subtracted CIRs. Although operations 930 and 940 are described herein as being performed sequentially, in some embodiments, operations 930 and 940 may be performed as a single, combined step. For example, processor 140 may average each of the R leakage-subtracted radar signals and the R-1 leakage-subtracted radar signals to generate a combined leakage-subtracted radar signal. The combined leakage-subtracted radar signal is the final output of the leakage cancellation.

[0125] At operation 950, the processor 140 performs target detection and ranging based on the combined leakage-canceled radar signal of the antenna pair M. Target detection and ranging may include detecting a target based on a peak remaining in the combined leakage-canceled CIR. The processor 140 may also determine a range of the detected target based on a tap index of the detected target in the CIR.

[0126] Figure 10 An example method of leakage elimination according to various embodiments of the present disclosure is shown. For example, Figure 10 A method 1000 of eliminating leakage for radar applications as described throughout this disclosure is shown.

[0127] In operation 1010 , the processor 140 identifies a first leakage factor. For example, the processor 140 can identify the first leakage factor from leakage factors in an index stored in the memory 160 .

[0128] At operation 1020, the processor 140 controls the transmitting antenna to transmit a first signal. For example, the transmitting antenna may be the transmitter 157 that transmits a radar signal or radar pulse. The radar signal or pulse may then be reflected from a target object and then received by a receiving antenna such as the receiver 230. The transmitting antenna may be included in an antenna pair including a transmitting antenna and a receiving antenna.

[0129] In operation 1030, the processor 140 generates a first CIR based on the reflected radar signal received by the receiving antenna. The first CIR may be, for example, Figure 3 The CIR is depicted in Figure 1. The generated CIR is a measurement of the reflected signal, or echo, from one or more potential targets as a function of distance at the receive antenna. The y-axis measures the amplitude of the radar measurement in dB, and the x-axis measures the delay tap index corresponding to the distance from the receive antenna.

[0130] In operation 1040, the processor 140 determines leakage in the first CIR. The leakage in the first CIR may be determined based on at least the first leakage factor identified in operation 1010. More specifically, the processor 140 may apply the first leakage factor to the first CIR generated in operation 1030 to determine leakage in the first CIR.

[0131] At operation 1050 , the processor 140 cancels the determined leakage from the first CIR. By canceling the determined leakage from the first CIR, the leakage-cancelled CIR more accurately depicts potential target objects in the environment surrounding the electronic device 100.

[0132] In some embodiments, the electronic device 100 may further include a second antenna pair, wherein the second antenna pair includes a second transmitter antenna configured to transmit signals and a second receiver antenna configured to receive signals. The first leakage factor may be a leakage scaling factor used to cancel relative leakage between the first antenna pair and the second antenna pair. In these embodiments, the processor 140 may control the second transmitter antenna to transmit a second signal, generate a second CIR based on reflections of the second signal received by the second receiver antenna, and determine leakage in the first CIR based on the leakage scaling factor and the second CIR.

[0133] In some embodiments, processor 140 may divide the first CIR by the second CIR to determine a leakage scaling factor. The first CIR may be generated based on a receiver antenna gain of the first antenna pair, a propagation coefficient of the first antenna pair, a transmitter antenna gain of the first antenna pair, and a combined transmitter and receiver filter response of the first antenna pair. The second CIR may be generated based on a receiver antenna gain of the second antenna pair, a propagation coefficient of the second antenna pair, a transmitter antenna gain of the second antenna pair, and a combined transmitter and receiver filter response of the second antenna pair.

[0134] In some embodiments, the processor 140 may select a set of reference antenna pairs based on the presence of more than two antenna pairs on the electronic device 100. For each additional antenna pair, the processor 140 may cancel the leakage of the additional antenna pair from the leakage of each reference antenna pair in the set of reference antenna pairs to generate a leakage-canceled CIR. The processor 140 may then average the leakage-canceled CIRs generated for each reference antenna pair in the set of reference antenna pairs.

[0135] In some embodiments, to select the set of reference antenna pairs, the processor 140 is configured to select the set of reference antenna pairs from an index that corresponds the set of reference antenna pairs to a particular delay tap.

[0136] In some embodiments, memory 160 is configured to store the first leakage factor in a template. Processor 140 may select the first leakage factor from the template and remove leakage from the additional CIR obtained by the additional antenna pair based on the first leakage factor selected from the template.

[0137] In some embodiments, the processor 140 may perform object detection using the first CIR with leakage cancelled.

[0138] Nothing in the description herein should be read as implying that any particular element, step, or function is essential to be included in the scope of a claim. Furthermore, unless the specific word "means for" is followed by a participle, no claim is intended to invoke 35 U.S.C. ξ 112(f).

Claims

1. An electronic device comprising: a first antenna pair comprising a first transmitter antenna configured to transmit signals and a first receiver antenna configured to receive signals; a second antenna pair comprising a second transmitter antenna configured to transmit signals and a second receiver antenna configured to receive signals; a memory configured to store data; as well as a processor operatively connected to the first antenna pair, wherein the processor is configured to: identifying, from the data stored in the memory, a leakage scaling factor for relative leakage cancellation between the first antenna pair and the second antenna pair; transmitting a first signal via a first transmitter antenna and transmitting a second signal via a second transmitter antenna; generating a first channel impulse response based on reflections of the first signal received by the first receiver antenna; generating a second channel impulse response based on reflections of the second signal received by the second receiver antenna; determining leakage in the first channel impulse response based on the leakage scaling factor and the second channel impulse response; removing the determined leakage from the first channel impulse response; and Object detection is performed using the leakage-cancelled first channel impulse response.

2. The electronic device according to claim 1, wherein The processor is configured to: The leakage scaling factor is determined by dividing the first channel impulse response by the second channel impulse response, where: The first channel impulse response is generated based on a receiver antenna gain for the first antenna pair, a propagation coefficient for the first antenna pair, a transmitter antenna gain for the first antenna pair, and a transmitter and receiver combined filter response for the first antenna pair, and A second channel impulse response is generated based on a receiver antenna gain for the second antenna pair, a propagation coefficient for the second antenna pair, a transmitter antenna gain for the second antenna pair, and a combined transmitter and receiver filter response for the second antenna pair, and A control memory stores the leakage scaling factor.

3. A method for leak elimination, the method comprising: identifying, from data stored in a memory of an electronic device, a leakage scaling factor for relative leakage cancellation between a first antenna pair of the electronic device and a second antenna pair of the electronic device, wherein the first antenna pair includes a first transmitter antenna and a first receiver antenna and the second antenna pair includes a second transmitter antenna and a second receiver antenna; transmitting a first signal via a first transmitter antenna and transmitting a second signal via a second transmitter antenna; generating a first channel impulse response based on reflections of the first signal received by the first receiver antenna; generating a second channel impulse response based on reflections of the second signal received by the second receiver antenna; determining leakage in the first channel impulse response based on the leakage scaling factor and the second channel impulse response; removing the determined leakage from the first channel impulse response; and Object detection is performed using the leakage-cancelled first channel impulse response.

4. The method of claim 3, further comprising: The leakage scaling factor is determined by dividing the first channel impulse response by the second channel impulse response, where: The first channel impulse response is generated based on a receiver antenna gain for the first antenna pair, a propagation coefficient for the first antenna pair, a transmitter antenna gain for the first antenna pair, and a transmitter and receiver combined filter response for the first antenna pair, and A second channel impulse response is generated based on a receiver antenna gain for the second antenna pair, a propagation coefficient for the second antenna pair, a transmitter antenna gain for the second antenna pair, and a combined transmitter and receiver filter response for the second antenna pair, and The leakage scaling factor is stored in a memory.

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