Receiver design for dynamic range enhancement in radar systems

Abstract

Embodiments of radar apparatus and methods include receiver circuits configured to receive reflected radio frequency (RF) signals reflected by one or more objects in an observation region. Each receiver circuit (128) is configured to: for a first reflected RF signal, quantize the first reflected RF signal using an analog-to-digital converter (ADC) (130) having a first resolution to produce a digital signal; and for a subsequent reflected RF signal, cancel object information corresponding to one or more stationary or moving objects in the observation region having known Doppler information from the subsequent RF signal based on the digital signal and a priori Doppler information to produce a filtered RF signal including moving object information; adjust the ADC to have a second resolution less than the first resolution; and determine radar cross section data for one or more other moving objects within the observation region using ADC measurements at the second resolution.

Description

Technical Field

[0001] This disclosure generally relates to radar systems, such as automotive radar systems, and more specifically, to receiver methods and designs for dynamic range enhancement. Background Technology

[0002] Using high-resolution analog-to-digital converters (ADCs) in automotive radar receiver circuits can lead to significant power consumption at high sampling rates. To reduce this power consumption, low-resolution ADCs can be employed at the radar receiver. However, automotive radar receiver circuits using low-resolution ADCs may suffer from low dynamic range (LDR) issues, at least in part, because the quantized signal is primarily determined by a high-intensity analog signal, making low-power analog signals more difficult to detect. Consequently, in low-resolution radar receiver circuits, objects with high radar cross-sections (RCS) may obscure objects with low RCS. Furthermore, in the extreme case of one-bit quantization, the RCS of an object can only be estimated to the global scaling factor. Due to these two issues, the overall performance and reliability of low-resolution radar may pose safety risks in automotive applications. Summary of the Invention

[0003] Embodiments of the radar apparatus and method include receiver circuitry configured to receive reflected radio frequency (RF) signals reflected by one or more objects in an observation area. Each receiver circuitry is configured to: for a first reflected RF signal, quantize the first reflected RF signal using an analog-to-digital converter (ADC) with a first resolution to generate a digital signal; and for subsequent reflected RF signals, based on the digital signal and prior Doppler information, eliminate object information corresponding to one or more stationary or moving objects with known Doppler information in the observation area from the subsequent RF signals to generate a filtered RF signal including moving object information; adjust the ADC to have a second resolution less than the first resolution; and use ADC measurements at the second resolution to determine radar cross-section data of one or more other moving objects in the observation area. Attached Figure Description

[0004] A detailed description is illustrated with reference to the accompanying drawings. In the drawings, the leftmost numeral of the reference numeral indicates the drawing in which that numeral first appears. The same reference numerals are used in different drawings and detailed descriptions to indicate similar or identical items or features.

[0005] Figure 1 A diagram is depicted of a system including a radar system according to certain embodiments, the radar system being configured to generate an analog cancellation signal using prior Doppler information, the analog cancellation signal being applied prior to quantization to enhance dynamic range.

[0006] Figure 2A diagram depicts a system including a radar device according to certain embodiments, the radar device being configured to use transmit beamforming such that the radar system illuminates a selected direction with a pulse sequence.

[0007] Figure 3 Depicting according to certain embodiments Figure 1 A simplified view of a portion of the receiver module of a radar system configured to generate an analog cancellation signal that can be applied prior to quantization to enhance dynamic range.

[0008] Figure 4 A diagram depicts a method for processing received radar signals according to certain embodiments, the received radar signals including analog-to-digital converter (ADC) resolution configured to enhance the dynamic range of a receiver module.

[0009] Figure 5A A true distance system according to certain embodiments and a system with Doppler cancellation are depicted. Figure 1-4 The curves of the distance range versus the Doppler range of the receiver module.

[0010] Figure 5B The graphs depict the range interval versus Doppler interval for a real-world range system and a conventional low-dynamic range receiver module.

[0011] Figure 6A Depicting low dynamic range systems and systems for which certain embodiments are described Figure 1-4 The graph shows the detection probability versus signal-to-noise ratio of a moving object using a receiver module with Doppler cancellation.

[0012] Figure 6B Depicting low dynamic range systems and systems for which certain embodiments are described Figure 1-4 The graph shows the detection probability of a static object versus the absolute radar cross-section (RCS) for a receiver module with Doppler cancellation.

[0013] Figure 7A Depicting low dynamic range systems and systems for which certain embodiments are described Figure 1-4 The graph shows the detection probability versus object velocity of a receiver module with Doppler cancellation.

[0014] Figure 7B Depicting low dynamic range systems and systems for which certain embodiments are described Figure 1-4 A graph showing the normalized mean square error (NMSE) of a receiver module with Doppler cancellation versus the object velocity.

[0015] Figure 8A Depicting low dynamic range systems and systems for which certain embodiments are described Figure 1-4A graph showing the normalized mean square error (NMSE) versus the signal-to-noise ratio (SNR) in decibels for a receiver module with Doppler cancellation.

[0016] Figure 8B Depicting low dynamic range systems and systems for which certain embodiments are described Figure 1-4 A graph showing the normalized mean square error (NMSE) of a receiver module with Doppler cancellation versus the absolute RCS of a static object.

[0017] Figure 9 A flowchart is depicted illustrating a method for determining objects within the observation area of ​​a radar system according to certain embodiments.

[0018] Figure 10 A flowchart is depicted illustrating a method for eliminating the dynamic range of a signal enhancement receiver based on prior Doppler information according to certain embodiments.

[0019] While embodiments have been described by way of example in this disclosure, those skilled in the art will recognize that embodiments are not limited to the described examples or drawings. Rather, the drawings and their detailed description are not intended to limit embodiments to the disclosed form, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope defined by the appended claims. The headings used in this disclosure are for organizational purposes only and are not intended to limit the scope of the specification or claims. As used throughout this application, the word “may” is used in a permissible sense (in other words, the term “may” is intended to mean “possibly”) rather than in a mandatory sense (such as “must”). Similarly, the terms “include,” “including,” and “includes” mean including but not limited to. Detailed Implementation

[0020] Embodiments of the radar apparatus and method may include one or more receiver circuits configured to receive reflected radio frequency (RF) signals reflected by one or more objects in an observation area. Each receiver circuit is configured to: for a first RF signal in the reflected RF signal, downconvert and quantize the first RF signal using an analog-to-digital converter (ADC) with a first resolution to generate a digital signal; and for subsequent RF signals in the reflected RF signal, remove object information corresponding to one or more stationary objects in the observation area from the subsequent RF signals based on the digital signal and prior Doppler information to generate a filtered RF signal including moving object information; adjust the ADC to have a second resolution less than the first resolution; and use the ADC to quantize the filtered RF signal to determine range, Doppler, and radar cross-section (RCS) data of one or more moving objects.

[0021] In one or more embodiments, a radar system is described, comprising one or more transmitter modules 118 configured to transmit radar signals toward an observation area, and one or more receiver modules 128 configured to receive reflected signals indicating objects within the observation area. To eliminate ambiguity between stationary objects (e.g., traffic signs, traffic signals, fire hydrants, buildings, etc.) that may have a large radar cross-section relative to one or more moving objects (e.g., pedestrians, vehicles, etc.), receiver module 128 can generate a Doppler-cancelled signal using prior Doppler information of the observation area. This Doppler-cancelled signal can be used to remove (eliminate) stationary object information from the received reflected signal to generate a filtered signal. Receiver module 128 can determine the range Doppler information of one or more moving objects within the observation area from the filtered signal, and then determine the range Doppler information of stationary objects. In one or more embodiments, the Doppler-cancelled signal can be applied prior to quantization to enhance the dynamic range of the radar system. In one or more embodiments, the radar system can be used to enhance the dynamic range of the radar even when the high RCS object may be moving, provided that the Doppler information of the high RCS object is known. The radar system can adjust the resolution of the ADC 130 in slow time and enable the system to resolve scale factor ambiguity in RCS estimation using a one-bit radar.

[0022] Figure 1A diagram depicts a radar system 100 according to certain embodiments, configured to generate an analog cancellation signal using prior Doppler information, which can be applied prior to quantization to enhance dynamic range. A radar device 102 (sometimes referred to herein as "radar communication circuitry system 102" or "radar front-end circuitry system 102") can be coupled to a radar microcontroller and processing unit (MCPU) 104, which can be configured to control the operation of various components of the radar system 100. In one or more embodiments, the radar system 100 can be a multiple-input multiple-output (MIMO) radar system, such as a linear frequency modulation (LFM) MIMO radar system (e.g., an LFM automotive MIMO radar system). In one or more embodiments, the radar device 102 can include radar front-end hardware. In one or more embodiments, the radar device 102 can be embodied as a line-replaceable unit (LRU) or modular component designed for rapid replacement at an operating location. Similarly, the radar MCPU 104 can be embodied as a line-replaceable unit (LRU) or modular component. Although a single or monostatic radar device is shown, it should be understood that additional distributed radar devices can be used to form a distributed or multistatic radar. Furthermore, the depicted radar system 100 can be implemented as an integrated circuit, wherein, depending on the application, the radar device 102 and the radar MCPU 104 are formed on separate integrated circuits (chips) or on a single chip.

[0023] According to one or more embodiments, radar system 100 may be implemented as part of an advanced driver assistance system (ADAS) of a vehicle (e.g., vehicle 150). Vehicle 150 may include a circuit system 101, which may include radar device 102 and MCPU 104, one or more I / O interfaces 106, and memory 112. It should be understood that the components of radar system 100 may be distributed at various locations on or within vehicle 150 (e.g., antennas located at one or more front, rear, or side panels of vehicle 150, at the front or rear bumper of vehicle 150, or at other suitable locations on vehicle 150, or at a combination of these locations; processing circuitry, transmitter module 118, and receiver module 128 are disposed at one or more locations within vehicle 150). It should be understood that each of transmitter module 118 and receiver module 128 may be implemented as one or more circuits.

[0024] The radar device 102 may include one or more transmit antenna elements 126 (sometimes referred to herein as “transmit antenna 126”) and receive antenna elements 142 (sometimes referred to herein as “receive antenna 142”) connected to a radio frequency (RF) transmitter (TX) module 118 and a receiver (RX) module 128, respectively. Each transmit antenna 126 and TX module 118 may be designated herein as TX1, TX2, TX3, ... TX m The corresponding transmit channel in the transmit channel group is associated with "m", where "m" is the total number of transmit (TX) channels. Each receive antenna 142 and RX module 128 may be associated with a channel designated herein as RX1, RX2, RX3, ... RX n The corresponding receive channels in the receive channel group are associated, where "n" is the number of receive (RX) channels. As a non-limiting example, a radar device (e.g., radar device 102) may include individual antenna elements (e.g., antenna element 126) respectively connected to four transmitter modules (e.g., transmitter module 118) and sixteen receiver modules (e.g., receiver module 128). These numbers of transmitter and receiver antenna elements and modules are intended to be illustrative and not limiting; other numbers of these elements are possible in one or more other embodiments. In one or more embodiments, radar device 102 may include a first number of antenna elements 126 and transmitter modules 118 and a second number of antenna elements 142 and receiver modules 128. In an illustrative, non-limiting example, the radar system may include four transmitter modules 118 and six receiver modules 128, a single transmitter module 118 and a single receiver module 128, etc.

[0025] Radar device 102 includes a chirp generator 116 configured to supply a chirp input signal to transmitter module 118. For this purpose, chirp generator 116 is configured to receive input program and control signals from MCPU 104 via digital-to-analog converter (DAC) 114, including, as a non-limiting example, a reference local oscillator (LO) signal, a chirp start trigger signal, and program control signals. Chirp generator 116 is configured to generate a chirp signal and transmit it to transmitter module 118 for transmission via transmit antenna element 126.

[0026] In one or more embodiments, each transmitter module 118 may include an RF conditioning module 122 configured to filter the chirped signal. In one or more embodiments, the RF conditioning module 122 may include one or more frequency multipliers configured to increase the frequency of the chirped signal output by the chirped generator 116. Each transmitter module 118 may include a power amplifier 124 configured to amplify the filtered chirped signal before it is provided to and transmitted via one or more corresponding transmit antenna elements 126. Here, the radar device 102 may periodically transmit a digital sequence of pulses s[n] within a coherent processing interval (CPI) comprising L pulses. Each pulse may include N chirps, and each pulse may be separated from the next pulse in the pulse sequence by a guard interval T. G This refers to the brief period during which no pulse is emitted. The digital sequence of pulses can be called a "radar signal" or a "transmitted signal." The RF conditioning module 122 and power amplifier 124 of each transmitter module 118 can provide transmit beamforming functionality, so that the radar signal or transmitted signal is illuminated in a specific direction.

[0027] Radar signals transmitted by transmitter module 118 and transmitting antenna 126 can be reflected by objects in the environment of radar device 102, and a portion of the reflected radar signal (sometimes referred to herein as a “return signal” or “reflection”) is received by receiving antenna element 142 at radar device 102. In one or more embodiments, the reflected radar signal received via one of the receiving antenna elements 142 and a corresponding one of the receiver modules 128 corresponds to a chirp signal transmitted via one of the transmitting antennas 126 and a corresponding transmitter module 118, and such received radar signal may be referred to herein as a “chirp,” a “chirp signal,” or a “received chirp signal.” Such received chirp signal may include interference components attributable to one or more interference signals in the environment of radar system 100.

[0028] At each receiver module 128, the received (RF) antenna signal is amplified by a low-noise amplifier (LNA) 140 and then fed to a mixer 138, where the antenna signal is mixed with a transmit chirp signal generated by an RF conditioning module 122 to down-convert the received signal. The resulting intermediate frequency signal (down-converted RF signal) is fed to a high-pass filter (HPF) 136. The resulting filtered signal is fed to a variable gain amplifier 134, which amplifies the resulting filtered signal before feeding it to a low-pass filter (LPF) 132. This re-filtered signal is fed to an analog-to-digital converter (ADC) 130, which produces a digital output. Each receiver module 128 provides this digital output as a digital signal to a signal processor 110 of an MCPU 104. In this way, the receiver module 128 compresses object echoes with various delays into multiple sinusoidal tones, the frequencies of which correspond to the round-trip delay of the echoes.

[0029] Receiver module 128 may include a Doppler plane cancellation module 144, which may be configured to generate an analog signal to be cancelled before quantization by ADC 130 using known Doppler information of one or more objects in the radar environment. Doppler plane cancellation module 144 may include a signal generator 146, which is configured to receive prior Doppler information from MCPU 104 or from the output of ADC 130. The prior Doppler information may be determined from prior observations by receiver module 128, alternative sensor modes (e.g., cameras), probabilistic models for determining the prior Doppler information, map data including stationary objects (e.g., fire hydrants, traffic lights, traffic signs, building structures, trees, and other permanent structures), other sources, or any combination thereof. Signal generator 146 may include: a memory 149 for storing the prior Doppler information; and a Doppler estimator 148 configured to generate a cancelled signal corresponding to certain objects in the radar environment. The cancellation signal can be provided to a digital-to-analog converter (DAC) 152, which can provide the analog cancellation signal to a summing node 154, which can subtract the analog cancellation signal from the filtered output signal of a low-pass filter 132. The difference signal can be provided to an ADC 130, which can generate a digital output signal that is provided to a signal processor 110 of an MCPU 104.

[0030] In one or more embodiments, the Doppler plane cancellation module 144 is a circuit that can be configured to use prior Doppler information to cancel signal data from received reflected signals (echoes) corresponding to objects with known Doppler data. The signal data is then converted using the ADC 130. In one or more embodiments, the Doppler plane cancellation module 144 can remove high radar cross-section (RCS) objects from the received echoes, which might otherwise obscure low RCS objects, thereby enhancing the dynamic range of the radar device 102.

[0031] In radar system 100, radar MCPU 104 can be connected and configured to supply input control signals to radar device 102 and receive digital output signals generated by receiver module 128 from radar device 102. In one or more embodiments, radar MCPU 104 includes radar controller 108 and signal processor 110 (sometimes referred to herein as "signal processing circuitry 110"), one or both of which may be embodied as a microcontroller unit or other processing unit. According to various embodiments, MCPU 104, radar controller 108, and signal processor 110 each include or are implemented by a computer processing circuitry system.

[0032] The radar controller 108 can receive data from the radar device 102 (e.g., from the receiver module 128) and can control radar parameters of the radar device 102, such as frequency band, length of each radar frame, beamforming directivity, etc., via the DAC 114. For example, the DAC 114 can be used to adjust the radar chirp signal output from the chirp generator 116 included in the radar device 102.

[0033] Signal processor 110 can be configured and arranged for signal processing tasks, such as, but not limited to, object identification, interference mitigation, calculation of distance or range to an object, calculation of the radial velocity of an object, and calculation of the angle of arrival (AoA) of a signal reflected by an object. In this document, the term "AoA" or "angle of arrival" refers to the angle of a reflected signal (e.g., a radar signal) incident on an antenna array. Signal processor 110 can provide calculated values ​​associated with such calculations to storage device 112 and / or other systems via interface 106.

[0034] As a non-limiting example, interface 106 enables MCPU 104 to communicate with other systems via local area networks and wide area networks, the Internet, automotive communication buses, and / or other types of wired or wireless communication systems. In one or more embodiments, MCPU 104 can provide computed values ​​to other systems via interface 106, such as radar-camera-lidar fusion systems; autonomous driving assistance systems including parking, braking, or lane change assist features; etc. Storage device 112 can be used to store instructions from MCPU 104, received data from radar device 102, computed values ​​from signal processor 110, etc. Memory (storage device) 112 can be any suitable storage medium, such as volatile or non-volatile computer-readable storage devices. In one or more embodiments, memory 112 may include hard disk drives, solid-state storage devices, flash memory devices, or other non-volatile storage devices.

[0035] To control the transmitter module 118, the radar controller 108 can be configured to generate transmitter input signals, such as program signals, control trigger signals, reference local oscillator (LO) signals, calibration signals, spectrum shaping signals (e.g., ramp generation in the case of frequency modulated continuous wave (FMCW) radar), or any combination thereof. The radar controller 108 can also be configured to receive, for example, data signals for RF (radio frequency) circuit enable sequences, sensor signals, register programming signals, or state machine signals, or any combination thereof.

[0036] At each receiver module 128, a digital output signal is generated (as discussed above, by applying a cancellation signal based on prior Doppler information to remove known object data from the object return signal) for digital processing by the signal processor 110 to construct and accumulate a multiple-input multiple-output (MIMO) array vector output forming a MIMO aperture for computing AoA estimates and graphs or mappings of object trajectories. Specifically, the signal processor 110 may perform one or more interference suppression processes on the digital output signal (e.g., processes that may include one or more recursive thresholding processes as described herein) before processing the interference-suppressed samples obtained using one or more Fast Fourier Transform (FFT) or Discrete Fourier Transform (DFT) modules (e.g., Fast Time (Distance) FFT modules).

[0037] The processing performed by these modules of signal processor 110 generates a range-chilled antenna cube (RCAC) and a slow-time (Doppler) FFT module, which generates a range-Doppler antenna cube (RDAC) (e.g., including a range-Doppler response map for each RX antenna). Signal processor 110 can then perform constant false alarm rate (CFAR) detection on the range-Doppler antenna cube to detect peaks in the RDAC. Signal processor 110 can further process the RDAC based on the detected peaks to construct a MIMO array vector, which is then processed to perform AoA estimation and object tracking. MCPU 104 can then output the resulting object trajectory (e.g., via interface 106) to other automotive computing or user interface devices for further processing or display.

[0038] Traditionally, high-resolution ADCs in radar systems result in high power consumption at high sampling rates. To reduce this power consumption, low-resolution ADCs can be used at the radar receiver; however, radar systems with low-resolution ADCs may suffer from low dynamic range (LDR) issues. This problem can arise because the quantized signal is primarily determined by a high-intensity analog signal, making it difficult to detect low-power analog signals. Regarding radar systems with low-resolution ADCs, objects with relatively high radar cross-sections (RCS) may obscure objects with relatively high RCS in the low-resolution receiver, thereby impairing the overall performance and reliability of the radar and posing safety risks in automotive applications.

[0039] Receiver module 128 enables the use of a low-resolution ADC while mitigating the problem of high-RCS objects obscuring low-RCS objects in the received signal. Specifically, receiver module 128 can use Doppler plane cancellation module 144 to generate an analog signal corresponding to one or more Doppler intervals using available Doppler information of some objects. This analog signal can be used to cancel the received signal corresponding to one or more objects known from the Doppler information before quantization, thereby enhancing the dynamic range of the radar system, as will be referred to below. Figure 2-4 The following detailed explanation of the receiver module 128 embodiment allows for adjustment of the ADC 130's resolution during "slow time," enabling the receiver module 128 to resolve scaling factor ambiguities in RCS object estimation using a one-bit quantizer, thereby reducing overall power consumption without sacrificing overall resolution.

[0040] In one or more embodiments, the resolution of the ADC 130 of the receiver module 128 can be dynamically adjusted. In one or more embodiments, digital signals received from past radar measurements of the receiver module 118 can be used to determine a time-varying threshold, an analog cancellation signal, or any combination thereof at the ADC 130 during operation (in real-time or near real-time). In one or more embodiments, the signal generator 146 of the Doppler plane cancellation module 144 can store digital signals that can be Doppler-shifted based on prior Doppler information received at the Doppler plane cancellation module 144, and then the Doppler-shifted digital signal is provided to the DAC 152 to generate an analog signal to be canceled from the current analog radar signal.

[0041] Figure 2 A diagram depicts a system 200 including a radar device 102 according to certain embodiments, the radar device 102 being configured to use transmit beamforming such that the radar device 102 illuminates a selected direction with a pulse sequence. The radar device 102 may be implemented as part of a circuit system 101, which may be housed in a vehicle 150. The speed (v) of the vehicle 150... zvehicle The direction of travel of the vehicle 150 can be known. The radar device 102 can transmit radar signals in the direction of travel of the vehicle 150. Typically, the radar signals can be transmitted toward the "observation area" 202 of the radar device 102, which can be determined based on the direction of travel of the vehicle 150. In the example shown, the vehicle 150 can move in the Z direction, as indicated by the XYZ axes 201.

[0042] The observation area 202 can be divided into multiple directions or directional intervals, such as a first direction 204(1), a second direction 204(2), a third direction 204(3), a fourth direction 204(4), and a fifth direction 204(5). The observation area 202 can be divided into any number of directions 204. The radar device 102 can be configured to perform beamforming to focus power (transmitted radar signal 206) along a direction (e.g., the second direction 204(2)). In the example shown, there may be some objects 220 in the second direction that can reflect the transmitted radar signal 206, which can be received by the antenna element 142 and processed by the receiver module 128.

[0043] In the example shown, there is a stationary object 220(2) in direction 204(2) that can reflect a signal in response to the emitted radar signal 206, such as a traffic light, fire hydrant, sign, structure, or another stationary object. In direction 204(2), there may also be an object 220(1) such as a vehicle and an object 220(3) such as a pedestrian. Each object 220 may have a velocity vector (e.g., V) in the X and Z directions corresponding to the X and Z directions of axis 201. x1 V z1 V x2 V z2 V x3 V z3 wait).

[0044] Given a vehicle speed, radar device 102 can calculate Doppler data corresponding to a stationary object 220(2) and can calculate a cancellation signal corresponding to the Doppler data, which can be shifted based on the vehicle speed to remove known data corresponding to the stationary object 220(2) from the incoming radar signal at ADC 130. Subsequently, radar device 102 can have a higher dynamic range relative to other objects 220(1) and 220(3) in the same direction of the radar beam.

[0045] The transmitted radar signal 206 may comprise the periodic transmission of an n-length digital sequence s[n] within a coherent processing interval (CPI) comprising L pulses 210, as shown in timing diagram 208. Each pulse 210 comprises N chimes 212. Each chime 212 has a chime duration T. C And each pulse 210 has a time period T P =NT C Pulse 210 is separated by protection interval 214, with protection interval T. G The durations of chirps 212 can be equal and can be selected to provide a chosen chirp duration T. C You can select N digital chirps 2^12 to provide a pulse 2^10 for a time period T. P Alternatively, a protection interval of 214 can be selected. The time period T of pulse 210 is also available. P The number of pulses L and the protection interval T G 214 can define a CPI consisting of L pulses 210, such that the CPI has a duration defined as follows:

[0046] (1)

[0047] The radar device 102 of the circuit system 101 can generate a sequence including pulse 210. The radar device 102 can transmit radar signals in a selected direction 204(2). The radar device 102 can transmit the same waveform (pulse 210) multiple times (L times) within a CPI. The radar device 102 can receive reflected signals from various objects 220 in direction 204(2). The radar device 102 can divide the area (direction 204(2)) into a two-dimensional grid of R range intervals and D Doppler intervals. Each range-Doppler interval has an effective radar cross-section (RCS) to be estimated. If there is no object in the range-Doppler interval, the effective RCS is zero.

[0048] Figure 3 Depicting according to certain embodiments Figure 1 A simplified view of a portion 300 of the receiver module 128 of a radar device 102, which is configured to generate an analog cancellation signal that can be applied prior to quantization to enhance dynamic range. In this example, the transmitter module 118 can cause the antenna element 126 to transmit radar signals toward the observation area 202. The receiver module 128 can receive reflected signals (echoes) from the antenna element 142 and can process the received signals, such as regarding... Figure 1 As described.

[0049] In the example shown, receiver architecture 302 can be part of receiver module 128 and can be derived from low-pass filter 132 ( Figure 1 The analog signal from the low-pass filter 132 is received and processed. The analog signal from the low-pass filter 132 can be provided to a summing element 154, which can subtract the analog cancellation signal from the DAC 152 from the analog signal and provide the resulting signal to the ADC 130. The ADC 130 can generate a digital signal based on the signal provided by the summing element 154, the digital signal including radar measurements that were not removed or cancelled by the analog cancellation signal.

[0050] As previously discussed, the Doppler plane cancellation module 144 may include a signal generation block 146 that can receive digital radar measurements, the Doppler plane to be cancelled or prior Doppler information (PDI), and optionally stored information from memory 149. The Doppler plane cancellation module 144 may use a Doppler estimator 148 to generate a digital cancellation signal corresponding to object 220 based on known Doppler information and the incoming signal. The digital cancellation signal may be provided to a DAC 152, which generates an analog cancellation signal, which may be provided to a summing element 154 to be subtracted from the input signal from low-pass filter 132.

[0051] In the example shown, the ADC 130 can have Bit resolution, where This is a slow time slot index. Slow time slots can be used to dynamically adjust the resolution of the ADC 130 at receiver module 128. Signal generation block 146 can use past measurement data and prior Doppler data to determine a time-varying threshold or analog cancellation signal, which can be used at summing node 154 at the input of ADC 130 to remove known Doppler information, and this known Doppler information can be Doppler shifted based on the Doppler information before providing data to DAC 152 to generate the analog cancellation signal.

[0052] In conventional low dynamic range (LDR) systems, q-bit quantization is used to determine the quantized measurement. The quantized measurement of an LDR system can be determined as follows:

[0053] (2)

[0054] in Represents quantized bits to of Bit quantization, and This indicates that without quantification, from to Receiver measurement data within the range. In this LDR system, distance Doppler data can be determined as follows:

[0055] (3)

[0056] in This represents a predefined matrix known to receiver device 102, and also represents the sequence transmitted by transmitter module 118 and the Doppler drift of the system. Variables This represents a matrix defined on a range-Doppler grid, where the values ​​are the radar cross-sections (RCS) of objects within a specific range-Doppler cell. The LDR system already knows this predefined matrix. Furthermore, any sparse data recovery or matched filtering algorithm can be used to determine the distance to the Doppler grid matrix. This represents an estimate of the RCS values ​​of various objects on the selected direction 204 of the transmitted radar beam 206. Variables Represents a complex circular Gaussian Noise, of which This represents the noise variance.

[0057] Radar device 102 can be configured in the second quantization bit Before quantization, quantization is performed on the adjusted range-Doppler interval values, which have had prior Doppler information removed or subtracted from the range-Doppler values. Radar device 102 starts from the first slow time slot. Measurement data is obtained from the reflected signal in the image, and the measurement data is used to calculate the cancellation signal for subsequent slow time slots, so that the quantized measurement value can be determined as follows. :

[0058] (4)

[0059] in Indicated in pulse sequence The prior Doppler information is applied to the receiver measurement data after signal cancellation, so that for CPI, the sequence... The distance to the Doppler grid for each pulse 210 after the first pulse 210(1) Represented as The quantized distance-Doppler grid estimate can be determined as follows:

[0060] (5)

[0061] As mentioned earlier, variables This represents a matrix defined on a range-Doppler grid, where the values ​​are the radar cross-sections (RCS) of objects within a specific range-Doppler cell. However, the matrix... Unlike the matrix in Equation 3 above, the predefined matrix known to the receiver device 102 is adjusted according to the transmitted signal sequence, as shown in Equation 7 below. Variables This can be understood as representing the RCS measurement data for each Doppler range as follows:

[0062] (6)

[0063] in This represents the distance-Doppler interval of a two-dimensional grid or matrix, and This represents a time interval within pulse 210. The estimated scalar can be determined as follows:

[0064] (7)

[0065] Among the variables The following is determined:

[0066] (8)

[0067] in This represents the time slot for each pulse (2^10). The adjusted matrix. This can be determined as follows:

[0068] (9)

[0069] in ,and Here, variables It can represent the analog (Doppler) cancellation signal, thereby producing an adjusted matrix.

[0070] Radar device 102 can be configured to use measurements from the mixed resolution of the radar channel, excluding those from the Doppler plane used for cancellation. Slow slot 2 to the corresponding slow slot All measurements, estimated distance The first Doppler channel can be estimated using measurements from slow slot 1.

[0071] Figure 4 A diagram depicts a method 400 for processing received radar signals according to certain embodiments, the received radar signals including analog-to-digital converter (ADC) resolution configured to enhance the dynamic range of a receiver module. It should be understood that method 400 can... Figure 1 Each of the receiver modules 128 in the radar device 102 performs this function.

[0072] In the example shown, the ADC 130 can generate a sequence corresponding to L pulses. Multiple bits of each pulse 210 in For each pulse 210(1), 210(2), ..., 210(L-1), 210(L), the ADC 130 generates q1 bits 401(1), q2 bits 401(2), ..., q... L-1 Bit 401(L-1) and q L Bit 401(L). The ADC 130 generates bit q for each pulse 210 according to the slow time index, and because the sampling rate may be in the gigahertz range, multiple samples can be captured for each reflected signal.

[0073] The analog signal y(t) 402(1) is received and provided to a high-resolution (q1-bit) ADC 404(1), which generates a signal that can be stored in a memory, for example... Figure 1The q1-bit quantized signal y1[n] 406(1) is stored in memory 149. In one or more embodiments, the high-resolution ADC 404(1) may have a sixteen-bit resolution (16-bit resolution). In other embodiments, the high-resolution ADC 404(1) may have an eight-bit resolution (8-bit resolution). In yet another embodiment, the high-resolution ADC 404(1) may have a sixteen-bit or higher resolution. The q1-bit quantized signal y1[n] 406(1) may be phase-shifted at mixer 408 based on prior Doppler information 410 to predict the signal to be canceled from the Doppler plane, which may be provided to DAC 412 to generate an analog cancellation signal. In one or more embodiments, the velocity of radar device 102 is accurately known, and therefore the Doppler data of the stationary object is also known, and the prior Doppler information corresponds to the Doppler data of the stationary object relative to radar device 102.

[0074] The analog cancellation signal can be provided to summing node 414, which can receive the signal from each subsequent slow time slot y2, ... y L The cancellation signal is subtracted from the incoming signal 402. The difference from each summing node 414 (the subtracted analog signal) can be quantized by a one-bit ADC 416, which can generate fast-time quantized measurements. 418(2) to 418(L). One-bit quantization can be performed on the remaining slow-time high dynamic range (HDR) signal.

[0075] The Doppler plane v used for elimination is estimated by using measurements from slow-time measurements (quantized measurements from time slots 2 to L). D After obtaining RCS measurements for each range-Doppler interval outside the first slow-time measurement, the estimated value is used to eliminate the signal received in the first slow-time measurement. Then, RCS measurements can be estimated for the range-Doppler intervals corresponding to the Doppler plane.

[0076] In the first stage, radar device 102 can estimate the movement of objects. RCS measurement data for each associated distance Doppler interval This includes log-likelihood maximization with logarithm and penalty according to the following formula:

[0077] (10)

[0078] in It is the negative log-likelihood of the quantized measurement vector, and the sparse regularization parameter. Greater than zero. Radar device 102 knows the Doppler information associated with stationary object 220(2), and therefore uses the optimization of Equation 10 to estimate the moving object information. Equation 10 is an example of an algorithm that can be used to estimate moving object data, but other algorithms can be used to estimate moving object data without departing from the scope of this disclosure.

[0079] Once the estimated moving object value is determined, radar device 102 can detect the estimated moving object using a cell average constant false alarm rate (CA-CFAR) detector. The peak value in the value is used to determine the position of the object in the selected direction, such that for the radar channel, Excluding the Doppler plane v used for elimination D .

[0080] According to the following formula, the scaling factor α can be calculated as follows: And the 16-bit quantization y1[n] is determined:

[0081] (11)

[0082] In Equation 10, the algorithm minimizes the prediction The scaling factor is estimated by the squared error between the measurement and the measurement from the first slow time slot y1 (high resolution).

[0083] Then, the position of the stationary object can be determined using the least mean square method, as shown below:

[0084] (12)

[0085] and The peak value can be detected using any peak detector, such as CA-CFAR or other peak detectors. It should be understood that the least mean square method represents one possible technique for power scaling. In one or more embodiments, a selected power scaling algorithm may or may not include the least mean square method.

[0086] The position of the object in the direction of the radar beam can be determined as follows:

[0087] (13)

[0088] The positions of stationary objects and moving objects are included together. Therefore, in Equation 10, the position of the moving object is determined. In Equations 11-12, one or more positions of one or more stationary objects are determined, and in Equation 13, the positions of both the stationary and moving objects are estimated.

[0089] exist Figure 5A-8B In the following discussion, low dynamic range (LDR) systems will be compared with those using Doppler cancellation. Figure 1-4 The systems are compared. For both systems, the carrier frequency is 80 GHz and the bandwidth is 75 MHz. Chirp duration T C The timeout is 0.13 nanoseconds (ns), the CPI is 0.2 milliseconds (ms), and the protection interval T is... G The signal-to-noise ratio (SNR) is 10 dB, the absolute RCS of a stationary object is 10 dB, the absolute RCS of a moving object is 1 dB, and the false alarm probability is 0.0001 (10^10). -4 The sequence length N is 120, the number of pulses L is 120, the number of distance intervals is 11, and the number of Doppler intervals is 21.

[0090] Figure 5A A true distance system according to certain embodiments and a system with Doppler cancellation are depicted. Figure 1-4 The receiver module's range interval versus Doppler interval curve 500. In the example shown, curve 500 may represent a range-Doppler interval in which an object may be represented. In this example, curve 500 includes the true range-Doppler position indicated by a solid ellipse, and shading may indicate the absolute value of the RCS determination. In curve 500, the detected range-Doppler position may be indicated by a dashed rectangle. In this example, radar system 100 may determine a first detected object 502(1) that may be a stationary object and a second detected object 502(2) that may be a moving object. As described above, radar system 100 may be configured to use prior Doppler information to remove signal information associated with stationary objects from received radar reflections to determine one or more moving objects, and then add the RCS data of the stationary object to determine the range-Doppler data for each interval. Thus, radar system 100 may be configured to determine high RCS objects and low RCS objects, even when the low RCS object and the high RCS object are in the same direction.

[0091] In the presence of objects with a high RCS (Radar Cross Section), an LDR (Low-Radar Detection) radar system may be unable to detect objects with a low RCS. (See below for reference.) Figure 5B An example is described for distance-Doppler interval data of the same object determined by an LDR system that can use a 1-bit quantizer without performing Doppler cancellation.

[0092] Figure 5BA graph 520 depicts the distance interval versus Doppler interval for a true distance system and a conventional low dynamic range (LDR) receiver module. In this example, the LDR system can identify a detected object 522, which can be a stationary object. However, the LDR system may not be able to identify other (moving) objects, which can be represented by undetected objects 524. Undetected objects 524 can be moving objects, such as pedestrians, cyclists, or other moving objects, and the LDR system may not be able to eliminate the ambiguity of undetected objects 524 from received reflections that include stationary objects (e.g., detected object 522).

[0093] Figure 6A Depicting low dynamic range systems and systems for which certain embodiments are described Figure 1-4 The graph 600 shows the probability of moving object detection versus signal-to-noise ratio for a receiver module with Doppler cancellation. As shown in graph 600, for a radar system 100 using Doppler cancellation, the detection probability of two objects rapidly approaches one (100%). Conversely, the detection probability of an LDR system may increase rapidly and then decrease again. The decrease in the detection probability of an LDR system may be due to a stochastic resonance effect, where at high SNR, the LDR cannot use a one-bit quantizer to determine a good estimate of the scale-unquantized signal. If more noise is added to the received signal, there may be enough variation in the signal value (sign flipping in the quantized value) that allows the LDR to identify a second object. However, if the noise is low, the LDR may fail to detect the moving object.

[0094] Figure 6B Depicting low dynamic range systems and systems for which certain embodiments are described Figure 1-4 The graph 620 shows the detection probability of a static object versus absolute radar cross-section (RCS) for a receiver module with Doppler cancellation. For a static object, the detection probability of the radar system 100 can be approximately one (100%). The radar system 100 uses Doppler cancellation to remove the signal data corresponding to the stationary object, thereby allowing a one-bit quantizer to identify the moving object from the subtracted signal. In some cases, Doppler cancellation may be imperfect, so any defects in analog cancellation can be significant when the signal amplitude is strong.

[0095] For static objects with significant RCS values, the detection probability of the LDR system may decrease because the static object masks the low RCS of the moving object. This masking effect can be significant when the RCS of the static object is large.

[0096] Figure 7A Depicting low dynamic range systems and systems for which certain embodiments are described Figure 1-4The graph 700 shows the detection probability versus object velocity for a receiver module with Doppler cancellation. In this graph 700, the radar system 100 can have a high detection probability for moving objects, but may not estimate stationary objects in the first stage because stationary objects are eliminated by the Doppler cancellation signal. Regarding the LDR system, graph 700 shows a relatively low detection probability relative to moving objects, but a high detection probability relative to stationary objects.

[0097] As mentioned earlier, the RCS of a stationary object can make it difficult for an LDR system to detect a moving object. In contrast, radar system 100 can use Doppler cancellation to remove signal data indicating a stationary object in the first processing stage, thus identifying the moving object first.

[0098] Figure 7B Depicting low dynamic range systems and systems for which certain embodiments are described Figure 1-4 The graph 720 shows the normalized mean square error (NMSE) versus object velocity for a receiver module with Doppler cancellation. Graph 720 can represent the first stage of signal processing for radar system 100, in which moving objects are ignored and stationary objects are identified. In this example, the NMSE of radar system 100 is significantly lower than the NMSE of an LDR system used for moving objects. In the first stage of signal processing, the NMSE of radar system 100 increases relative to stationary objects because radar system 100 uses a Doppler-cancelled signal to remove stationary object data. The NMSE of radar system 100 versus... Figure 7A The detection probabilities shown are consistent.

[0099] Figure 8A Depicting low dynamic range systems and systems for which certain embodiments are described Figure 1-4 The graph 800 shows the normalized mean square error (NMSE) versus signal-to-noise ratio (SNR) in decibels for the receiver module with Doppler cancellation. As shown in graph 800, radar system 100 outperforms the LDR system. Due to simulated Doppler cancellation, the NMSE of radar system 100 is significantly lower than that of the LDR system as the SNR increases.

[0100] Figure 8B Depicting low dynamic range systems and systems for which certain embodiments are described Figure 1-4 Figure 820 shows the curves of the normalized mean square error (NMSE) versus the absolute RCS of a static object for a receiver module with Doppler cancellation. Due to the normalization relative to the norm of the radar channel, the NMSE of the radar system 100 has a non-monotonic sequence. In this case, as the NMSE decreases, the norm of the static RCS detection increases.

[0101] Figure 9A flowchart depicts a method for determining objects in an observation area of ​​a radar system 100 according to certain embodiments. At 902, method 900 may include receiving reflected signals from one or more objects within the observation area from a selected slow time slot at a receiver module 128 of the radar device 102. In one or more embodiments, the radar device 102 may include one or more transmitter modules 118 and one or more receiver modules 128. The one or more transmitter modules 118 may guide a sequence s[n] of L radar pulses in a selected direction within the observation area of ​​the radar device 102, and the one or more receiver modules 128 may receive reflected signals corresponding to radar pulses reflected by one or more objects (or objects) within the observation area. The one or more receiver modules 128 may be configured to process the first reflected signal using a relatively high-resolution ADC 130. In one or more embodiments, the receiver module 128 may select a first slow time slot and may store a q1-bit quantized signal in memory.

[0102] At 904, in the first stage, method 900 may include removing static object information from the reflected signal at receiver module 128 to determine one or more moving objects. In one or more embodiments, the quantized signal from the first slow time slot may be phase-shifted based on prior Doppler information to predict a signal corresponding to a static object. Receiver module 118 may generate one or more cancellation signals based on the quantized signal data and prior Doppler information to remove the static object information. Receiver module 118 may determine one or more moving objects by processing the resulting (subtracted) signal using a quantizer with a lower resolution.

[0103] In one or more embodiments, the ADC 130 may process the first reflected signal using a first resolution and may process subsequent signals using a second resolution smaller than the first resolution. In one or more embodiments, the first resolution may be 16 bits and the second resolution may be one bit. In one or more embodiments, the first resolution may be 32 bits, 16 bits, or another resolution, and the second resolution may be selected to be smaller than the first resolution.

[0104] In the second phase, at 906, method 900 may include removing moving object information from the reflected signal at receiver module 128 to determine one or more static objects. In one or more embodiments, receiver module 128 may use estimated moving object data and quantized signal data from the first reflected signal to estimate the distance and RCS of the stationary object.

[0105] In method 908, method 900 may include combining data from one or more static objects and data from one or more moving objects to determine objects within an observation area. The determined objects may include both static and moving objects.

[0106] Method 900 can be derived from Figure 1 The radar system 100 performs actions to enhance dynamic range when detecting objects. The radar system 100 can be configured to dynamically adjust the resolution of the ADC across slow time, while providing enhanced dynamic range with reduced overall power consumption. In one or more embodiments, the constellation of digital data samples output by the receiver module 128 can vary over slow time because the resolution of the ADC 130 can vary over slow time. In one or more embodiments, the power consumed by the receiver module 128 can vary over slow time, partly because the resolution of the ADC 130 varies over time.

[0107] Figure 10 A flowchart depicts a method 1000 for dynamic range determination using a signal enhancement receiver based on prior Doppler information, according to certain embodiments. At 1002, method 1000 may include receiving reflected pulse signals from one or more objects within an observation area from a selected slow time slot at a receiver module 128 of a radar device 102. In one or more embodiments, the radar device 102 may include one or more transmitter modules 118 and one or more receiver modules 128. The one or more transmitter modules 118 may guide a sequence s[n] of L radar pulses in a selected direction within the observation area of ​​the radar device 102, and the one or more receiver modules 128 may receive reflected signals corresponding to radar pulses reflected by one or more objects (or objects) within the observation area. The one or more receiver modules 128 may be configured to process the first reflected signal using a relatively high-resolution ADC 130. A first slow time slot, such as y1[n], may be selected, and a q1-bit quantized signal may be stored in memory.

[0108] In 1004, method 1000 may include estimating RCS measurement data for one or more moving objects using a one-bit sparse recovery algorithm. In one or more examples, before estimating the RCS measurement data, radar device 102 may determine prior Doppler information and may generate a Doppler cancellation signal configured to eliminate signal information associated with static objects within the observation area.

[0109] In 1006, method 1000 may include determining one or more peaks based on estimated RCS measurement data. In one or more embodiments, a detector such as a CA-CFAR detector or another peak detector may be used to determine the peaks.

[0110] In 1008, method 1000 may include estimating a scaling factor based on estimated moving object data and high-resolution quantized data y1[n] in a slow time slot. In one or more embodiments, the scaling factor may be estimated as the minimum difference between the estimated magnitude of the quantized high-resolution data and the moving object data.

[0111] In 1010, method 1000 may include estimating distance data and RCS data for one or more static objects within the observation area. As previously described, in the first stage, prior Doppler data is used to eliminate Doppler information corresponding to static objects, leaving only data attributable to moving objects, which is used to estimate the distance Doppler data of the moving objects. Thereafter, the previously excluded static object Doppler information is used to determine the static objects. In one or more embodiments, a peak detector may be used to determine the static object distance Doppler information.

[0112] In step 1012, method 1000 may include determining one or more moving objects and one or more static objects in an observation area based on estimated RCS measurement data. In one or more embodiments, the object information of the determined static and moving objects may be used to determine all objects in selected directions within the observation area. This process may be repeated for each direction or "sub-section" of the observation area to determine stationary and moving objects in the observation area of ​​the radar device.

[0113] In conjunction with the above text about Figure 1-10 The described systems, methods, and apparatus include a radar system comprising one or more transmitter modules 118 configured to transmit radar signals toward an observation area, and one or more receiver modules 128 configured to receive reflected signals indicating objects within the observation area. To eliminate ambiguity between stationary objects (e.g., traffic signs, traffic signals, fire hydrants, buildings, etc.) that may have a large radar cross-section relative to one or more moving objects (e.g., pedestrians, vehicles, etc.), receiver module 128 can generate a Doppler-cancelled signal using prior Doppler information of the observation area. This Doppler-cancelled signal can be used to remove (eliminate) stationary object information from the received reflected signals to generate a filtered signal. Receiver module 128 can determine the range Doppler information of one or more moving objects within the observation area from the filtered signal, and then determine the range Doppler information of stationary objects. In one or more embodiments, the Doppler-cancelled signal can be applied prior to quantization, thereby enhancing the dynamic range of the radar system. The system can adapt the resolution of the ADC 130 in slow time and enable the system to resolve scaling factor ambiguities in RCS estimation using a one-bit radar.

[0114] One or more embodiments can be further understood from the following examples.

[0115] Example 1: A radar device may include: one or more receiver circuits 128 configured to receive reflected RF signals reflected by one or more objects in an observation area of ​​the radar device 102, each receiver circuit 128 including: a mixer 138 configured to down-convert the reflected RF signals; and an analog-to-digital converter (ADC) 130. 130 is configured to quantize the reflected RF signal, and for a first RF signal in the reflected RF signal, the ADC is configured to quantize a first down-converted RF signal using a first resolution to generate a digital signal from a first slow time slot of the first RF signal; a Doppler plane cancellation circuit 144 is configured to generate a cancellation signal, the cancellation signal being configured to cancel object information corresponding to one or more stationary or moving objects with known Doppler in the observation area; and a node (154) between the mixer (138) and the ADC (130), the node (154) being used to combine the signals before the down-converted reflected RF signal and the cancellation signal are quantized by the ADC; wherein for subsequent RF signals in the reflected RF signal, the receiver circuit (128) is configured to: adjust the ADC (130) to have a second resolution less than the first resolution, and use ADC measurements at the second resolution to determine radar cross-section (RCS) data of one or more other moving objects in the observation area.

[0116] Example 2: According to the radar device of Example 1, each of the one or more receiver circuits 128 is configured to reduce power consumption by adjusting the ADC 130 to have the second resolution.

[0117] Example 3: A radar device according to any one of Examples 1 or 2, wherein the second resolution is one bit.

[0118] Example 4: According to the radar device of Example 3, each of the one or more receiver circuits 128 is configured to resolve scaling factor ambiguity in the RCS data for the second resolution by scaling the power level between the digital signal from the first time slot and the RCS data of the moving object in the one or more moving objects.

[0119] Example 5: A radar apparatus according to any one of Examples 1 to 4, wherein the Doppler plane cancellation circuit 144 and the node 154 are configured to: eliminate the expected return caused by the one or more other moving objects from the acquired measurement data to determine second RCS data of one or more stationary or moving objects; and combine the RCS data and the second RCS data to determine object data, the object data including data related to moving and stationary objects in the observation area.

[0120] Example 6: A radar device according to any one of Examples 1 to 5, wherein prior Doppler information is determined based on one or more of past radar measurements or predetermined maps corresponding to the geophysical location of the radar device 102.

[0121] Example 7: A radar device according to any one of Examples 1 to 6, further comprising: a microcontroller and processing unit 104 coupled to the output of the ADC 130 of each of the one or more receiver circuits to receive one or more of the digital signal or the RCS data; and wherein each of the one or more receiver circuits 128 comprises: a memory configured to store the digital signal from the first slow time slot; and a Doppler cancellation circuit 144 configured to: receive the prior Doppler information from the memory or the one or more of the microcontroller and processing unit; and phase-shift the digital signal based on the prior Doppler information to generate a Doppler cancellation signal, thereby eliminating the object information corresponding to the one or more stationary objects in the observation area.

[0122] Example 8: According to the radar device of Example 7, wherein the Doppler cancellation circuit includes: a signal generator 146 configured to generate the Doppler cancellation signal; a digital-to-analog converter (DAC) 152 including an input coupled to the signal generator and an output configured to provide the Doppler cancellation signal; a node 154 including a first input for receiving a subsequent down-converted RF signal, a second input coupled to the output of the DAC, and an output for providing an output signal corresponding to the difference between the subsequent RF signal and the cancellation signal; and wherein the ADC 130 includes an input coupled to the output of the node and includes a receiver circuit output coupled to the microcontroller and processing unit.

[0123] Example 9: A method for determining one or more objects in an observation area of ​​a radar system includes: receiving reflected signals reflected by one or more objects in the observation area of ​​a radar device 102 at one or more antennas 142 of a receiver circuit 128; quantizing a first reflected signal using an analog-to-digital converter (ADC) 130 of the receiver circuit 128, the ADC 130 having a first resolution to generate a first digital signal; determining a canceled signal based on prior Doppler information and the first digital signal using a Doppler plane cancellation circuit 144 of the receiver circuit 128; removing reflected signals from subsequent reflected signals caused by one or more stationary or moving objects having known Doppler information from subsequent reflected signals using a node 154 based on the canceled signal; adjusting the resolution of the ADC 130 from the first resolution to a second resolution less than the first resolution; and quantizing subsequent reflected signals using the ADC 130 to determine data corresponding to one or more other moving objects in the observation area.

[0124] Example 10: According to the method of Example 9, it further includes resolving scaling factor ambiguity in radar cross-section (RCS) data for the second resolution by scaling the power level between the first digital signal and the data corresponding to the one or more moving objects.

[0125] Example 11: The method according to any one of Examples 9 or 10 further includes: estimating stationary object data based on the data corresponding to the moving object and the first digital signal; and combining the stationary object data with the data corresponding to the one or more moving objects to determine distance and radar cross-section data of one or more objects in the observation area.

[0126] Example 12: According to the method of Example 11, estimating the stationary object data includes eliminating data corresponding to the one or more moving objects from the subsequent RF signal to determine stationary object data associated with one or more stationary objects in the observation area.

[0127] Example 13: The method according to any one of Examples 9 to 12, wherein before determining the cancellation signal, the method includes determining the prior Doppler information based on one or more of past radar measurements or predetermined maps corresponding to the geophysical location of the radar device.

[0128] Example 14: The method according to any one of Examples 9 to 13, wherein determining the cancellation signal comprises: storing the first digital signal in the memory of the receiver circuit 102; receiving the prior Doppler information from one or more of the memory or microcontroller and processing unit 104 at the Doppler cancellation circuit 144 of the receiver circuit 128; and phase-shifting the digital signal based on the prior Doppler information to generate the cancellation signal, thereby canceling the information of stationary objects corresponding to the one or more stationary objects in the observation area, and canceling the information of moving objects having known Doppler in the observation area.

[0129] Example 15: The method according to any one of Examples 9 to 14, wherein the second resolution is one bit.

[0130] Example 16: The method according to any one of Examples 9 to 15, wherein the first resolution is sixteen bits or greater.

[0131] Example 17: A radar apparatus includes one or more receiver circuits configured to receive reflected signals reflected by one or more objects in an observation area of ​​the radar apparatus. Each receiver circuit is configured to: quantize a first reflected signal using an analog-to-digital converter (ADC) with a first resolution to generate a digital signal from a first slow time slot; determine a cancellation signal based on prior Doppler information and the digital signal corresponding to one or more stationary objects in the observation area; apply the cancellation signal to subsequent reflected signals in the reflected signal at a summing node of the receiver circuit to remove stationary object information from the subsequent reflected signals, thereby generating a filtered signal; adjust the ADC to have a second resolution less than the first resolution; and quantize the filtered signal using the adjusted ADC to determine radar cross-section (RCS) data of one or more moving objects in the observation area.

[0132] Example 18: The radar device according to Example 17, wherein each of the one or more circuits is configured to reduce power consumption by adjusting the ADC to have the second resolution.

[0133] Example 19: A radar apparatus according to any one of Examples 17 or 18, wherein: the second resolution is one bit; and each of the one or more receiver circuits is configured to resolve scale factor ambiguity in the RCS data for the second resolution by squaring the minimum distance between the digital signal from the first time slot and the RCS data of the moving object in the one or more moving objects.

[0134] Example 20: A radar device according to any one of Examples 17 to 19, further comprising a microcontroller and a processing unit coupled to the output of the ADC of each of the one or more receiver circuits to receive one or more of the digital signal or the RCS data; and each of the one or more receiver circuits comprising: a memory configured to store the digital signal from the first slow time slot; and a Doppler cancellation circuit configured to: receive the prior Doppler information from the memory or the one or more of the microcontroller and processing units; and phase-shift the digital signal based on the prior Doppler information to generate a Doppler cancellation signal, thereby canceling the object information corresponding to the one or more stationary objects in the observation area, or canceling the object information corresponding to the one or more moving objects having a known Doppler in the observation area.

[0135] The foregoing detailed description is illustrative in nature only and is not intended to limit the embodiments of the subject matter or the application and use of such embodiments. As used herein, the word "exemplary" means "serving as an example, instance, or illustration." Any embodiment described herein as exemplary is not necessarily to be construed as preferred or advantageous over other embodiments. Furthermore, there is no intention to be bound by any express or implied theory presented in the foregoing technical field, background art, or specific embodiments.

[0136] The connecting lines shown in the various figures contained herein are intended to illustrate exemplary functional relationships and / or physical couplings between various elements. It should be noted that many alternative or additional functional relationships or physical connections may exist in embodiments of this subject matter. Furthermore, certain terms may be used herein for illustrative purposes only and are therefore not intended to be limiting, and the terms “first,” “second,” and other such numerical terms relating to structures do not imply order or sequence unless the context clearly indicates otherwise.

[0137] The above description refers to elements or features that are “connected” or “coupled” together. As used herein, unless explicitly stated otherwise, “connected” means that one element is directly engaged to (or directly connected to) another element, and not necessarily mechanically engaged to (or directly connected to) another element. Similarly, unless explicitly stated otherwise, “coupled” means that one element is directly or indirectly engaged to (or directly or indirectly electrically connected to, or otherwise connected to) another element, and not necessarily mechanically engaged. Therefore, although the schematic diagrams shown in the accompanying drawings depict an exemplary arrangement of elements, additional intermediate elements, means, features, or components may be present in embodiments of the subjects depicted.

[0138] While at least one exemplary embodiment has been presented in the detailed description above, it should be understood that numerous variations exist. It should also be understood that the one or more exemplary embodiments described herein are not intended to limit the scope, applicability, or configuration of the claimed subject matter in any way. Rather, the detailed description above will provide those skilled in the art with a convenient roadmap for implementing the one or more embodiments described. It should be understood that various changes can be made to the function and arrangement of the elements without departing from the scope defined by the claims.

Claims

1. A radar device, characterized by include: One or more receiver circuits configured to receive reflected radio frequency (RF) signals reflected by one or more objects in the observation area of ​​the radar device, each receiver circuit including: A mixer configured to down-convert the reflected RF signal; An analog-to-digital converter (ADC) is configured to quantize the reflected RF signal, wherein, for a first RF signal in the reflected RF signal, the ADC is configured to quantize a first down-converted RF signal using a first resolution to generate a digital signal from a first slow time slot of the first RF signal; A Doppler plane cancellation circuit, configured to generate a cancellation signal, the cancellation signal being configured to cancel object information corresponding to one or more stationary or moving objects having a known Doppler amplitude in the observation area; and At the node between the mixer and the ADC, the node is used to combine the down-converted reflected RF signal and the cancellation signal before they are quantized by the ADC; For subsequent RF signals in the reflected RF signal, the receiver circuit is configured to: The ADC is adjusted to have a second resolution that is less than the first resolution; and The radar cross-section (RCS) data of one or more other moving objects within the observation area are determined using ADC measurements at the second resolution.

2. The radar device according to claim 1, characterized in that, The Doppler plane cancellation circuit and the node are used for: Eliminate the expected returns caused by the one or more other moving objects from the acquired measurement data to determine the second RCS data of the one or more stationary or moving objects; and The RCS data and the second RCS data are combined to determine object data, which includes data related to moving and stationary objects in the observation area.

3. The radar device according to claim 1, characterized in that, In addition, including: A microcontroller and processing unit, the microcontroller and processing unit being coupled to the output of the ADC of each of the one or more receiver circuits to receive one or more of the digital signal or the RCS data; and Each of the one or more receiver circuits said therein includes: A memory configured to store the digital signal from the first slow time slot; as well as Doppler cancellation circuit, the Doppler cancellation circuit being configured to: The prior Doppler information is received from the memory or one or more of the microcontroller and processing unit; and The digital signal is phase-shifted based on the prior Doppler information to generate a Doppler cancellation signal, thereby eliminating the object information corresponding to the one or more stationary objects within the observation area.

4. The radar device according to claim 3, characterized in that, The Doppler cancellation circuit includes: A signal generator configured to generate the Doppler cancellation signal; A digital-to-analog converter (DAC), the DAC including an input coupled to the signal generator and an output configured to provide the Doppler cancellation signal; The node includes a first input for receiving a subsequent down-converted RF signal, a second input coupled to the output of the DAC, and an output for providing an output signal corresponding to the difference between the subsequent RF signal and the cancellation signal; and The ADC includes an input coupled to the output of the node and an output of a receiver circuit coupled to the microcontroller and processing unit.

5. A method for determining one or more objects in the observation area of ​​a radar system, characterized in that, The method includes: The radar device receives reflected signals from one or more objects in the observation area of ​​the radar device at one or more antennas of the receiver circuit. The first reflected signal is quantized using an analog-to-digital converter (ADC) of the receiver circuit, the ADC having a first resolution to generate a first digital signal; The Doppler plane cancellation circuit of the receiver circuit is used to determine the cancellation signal based on prior Doppler information and the first digital signal; Based on the cancellation signal, nodes are used to remove reflection signals caused by one or more stationary or moving objects with known Doppler information from subsequent reflection signals; Adjust the resolution of the ADC from the first resolution to a second resolution that is smaller than the first resolution; and The ADC is used to quantize subsequent reflected signals to determine data corresponding to one or more other moving objects within the observation area.

6. The method according to claim 5, characterized in that, In addition, including: Estimating stationary object data based on the data corresponding to the moving object and the first digital signal; as well as The stationary object data is combined with the data corresponding to the one or more other moving objects to determine the distance and radar cross-section data of one or more objects in the observation area.

7. The method according to claim 6, characterized in that, Estimating the stationary object data includes eliminating data corresponding to the one or more other moving objects from the subsequent reflected signals to determine stationary object data associated with one or more stationary objects in the observation area.

8. The method according to claim 5, characterized in that, Determining the cancellation signal includes: The first digital signal is stored in the memory of the receiver circuit; The prior Doppler information is received from one or more of the memory or microcontroller and processing unit at the Doppler cancellation circuit of the receiver circuit; and The digital signal is phase-shifted based on the prior Doppler information to generate the cancellation signal, thereby canceling the information of stationary objects corresponding to one or more stationary objects in the observation area, and canceling the information of moving objects with known Doppler values ​​in the observation area.

9. A radar device, characterized in that, include: One or more receiver circuits, configured to receive reflected signals reflected by one or more objects in the observation area of ​​the radar device, each receiver circuit being configured to: For the first reflected signal in the reflected signal, the first reflected signal is quantized using an analog-to-digital converter (ADC) with a first resolution to generate a digital signal from the first slow time slot; The cancellation signal is determined based on prior Doppler information and the digital signal corresponding to one or more stationary objects within the observation area; At the summing node of the receiver circuit, the cancellation signal is applied to subsequent reflected signals in the reflected signal to remove stationary object information from the subsequent reflected signals, thereby generating a filtered signal; The ADC is adjusted to have a second resolution that is less than the first resolution; and The filtered signal is quantized using an adjusted ADC to determine the radar cross-section (RCS) data of one or more moving objects within the observation area.

10. The radar device according to claim 9, characterized in that, In addition, including: A microcontroller and processing unit, the microcontroller and processing unit being coupled to the output of the ADC of each of the one or more receiver circuits to receive one or more of the digital signal or the RCS data; and Each of the one or more receiver circuits said therein includes: A memory configured to store the digital signal from the first slow time slot; Doppler cancellation circuit, the Doppler cancellation circuit being configured to: The prior Doppler information is received from the memory or one or more of the microcontroller and processing unit; and The digital signal is phase-shifted based on the prior Doppler information to generate a Doppler cancellation signal, thereby eliminating the object information corresponding to one or more stationary objects in the observation area, or eliminating the object information corresponding to one or more moving objects with known Doppler in the observation area.

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