Multiple-input multiple-output (MIMO) target simulation system and method for testing millimeter-wave radar sensors

Abstract

The present application relates to a multiple-input multiple-output (MIMO) target simulation system and method for testing a millimeter-wave radar sensor having multiple radar transmitters and multiple radar receivers.

Description

Background Art

[0001] Millimeter wave (mmWave) automotive radar is a key technology for advanced driver assistance systems (ADAS) and planned autonomous driving systems. Millimeter waves are generated by oscillations at frequencies in the spectrum between 30 gigahertz (GHz) and 300 GHz. For example, millimeter wave automotive radar is used in ADAS to warn of frontal and rear collisions, implement adaptive cruise control and autonomous parking, and ultimately perform autonomous driving on streets and highways. The advantage of millimeter wave automotive radar over other sensor systems is that it can operate in most types of weather and can operate in both light and darkness. The adaptability of millimeter wave automotive radar reduces costs, making it possible to deploy millimeter wave automotive radar in large quantities. Therefore, millimeter wave automotive radar is now widely used for long-range, medium-range, and short-range environmental sensing in ADAS. In addition, millimeter wave automotive radar systems may be widely used in autonomous driving systems currently under development.

[0002] Conventional automotive millimeter-wave radar systems typically have multiple radio frequency (RF) transmitters and multiple RF receivers, where the RF transmitters can be used to improve the radar's spatial resolution or enable transmitter beam scanning. The actual driving environments in which automotive radars can be deployed can be diverse, and many of these driving environments can be complex. For example, actual driving environments can contain numerous objects, and some objects encountered in actual driving environments have complex reflection, diffraction, and multiple reflection characteristics that affect the return signal. The direct consequence of not correctly sensing and / or decoding the return signal may be the triggering of erroneous warnings or inappropriate reactions, or the failure to trigger warnings or reactions that should have been triggered, which in turn may cause a collision.

[0003] In recent years, developers testing autonomous vehicles in real-world driving environments have reported a series of accidents, highlighting the importance of comprehensive testing of automotive radars and onboard drive controllers. To avoid such accidents, automotive radars can be tested in various driving scenarios. The test environment for automotive radars can include a scenario simulator that simulates echo signals from multiple objects or targets to different radar sensors on the vehicle (multi-target echo signals) in a driving scenario. Different radar sensors are tested using these simulated echo signals. However, the use of scenario simulators presents challenges in designing test solutions. For example, to simulate different scenarios (including those where the vehicle is moving), software capable of simulating echo signals from multiple targets is required. Furthermore, the hardware setup must be capable of replaying the echo signals. Given the need to dynamically simulate the echo signals for each radar sensor in various domains, including power, time, Doppler frequency, and spatial domains, designing a test environment with the required flexibility and scalability is challenging. Furthermore, data from multiple radar sensors (for example, to cover long-range, mid-range, and short-range sensing, and different sides of the vehicle) is fused to aid in environmental sensing. Therefore, the scenario simulator needs to simulate the echo signals of multiple radar sensors simultaneously and synchronously.

[0004] One conventional approach is a single-input single-output (SISO) / single-input multiple-output (SIMO) automotive radar target simulator based on analog technology. Analog techniques such as delay lines are used to simulate target return signals with, for example, different delays, frequency shifts, and amplitudes. Due to the cost of analog technology, the ability of SISO / SIMO radar target simulators to simulate multiple targets is generally limited. To simulate the spatial characteristics of target return signals, physical space simulation is used, and a target return signal from a single direction typically requires a single channel radar target simulator output. Therefore, multi-target simulation using this approach does not scale well when the number of targets is large, as is often the case in driving scenarios.

[0005] Another conventional approach is the digital-based SISO / SIMO automotive radar target simulator. This approach allows the simulator to simulate a greater number of targets; however, it uses physical space simulation to emulate target spatial characteristics. Therefore, different targets with different arrival angles require different output channels from the channel simulator. Furthermore, with a digital radar target simulator, a single target echo signal from one direction typically requires one channel of the radar target simulator output. Consequently, this solution does not scale well when there are many targets with many different arrival angles.

[0006] These conventional solutions cannot fully meet the requirements of the highly dynamic scenarios of modern test environments. For example, SISO / SIMO radar target simulators cannot effectively simulate scenarios where radar or sensor transmitters use beamforming or multiple-input, multiple-output (MIMO) technology. For example, when a radar transmitter performs beam scanning, different parts of the driving scene are dynamically illuminated, resulting in significant changes in the target return signal. For a single input, it is unknown which part of the driving scene is illuminated, so the target return signal cannot be accurately simulated. Moreover, when multiple radar signals are involved, a single input to a SISO / SIMO radar target simulator combines multiple signals from different radar transmitters. These combined signals cannot be separated, so the corresponding target return signal cannot be correctly simulated. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The exemplary embodiments are best understood from the following detailed description when read in conjunction with the accompanying drawings. It is emphasized that the various features are not necessarily drawn to scale. In fact, for the sake of clarity of discussion, dimensions may be arbitrarily increased or decreased. Where applicable and feasible, the same reference numerals represent the same elements.

[0008] Figure 1 is a simplified block diagram illustrating a multiple-input multiple-output (MIMO) radar target simulation system for testing millimeter-wave radar sensors using dynamic return signal simulation, according to a representative embodiment.

[0009] Figure 2 is a simplified flow chart of a method for testing a millimeter-wave radar sensor using a MIMO radar target simulation system for dynamic return signal simulation, according to a representative embodiment. DETAILED DESCRIPTION

[0010] In the following detailed description, for the purpose of explanation rather than limitation, representative embodiments of the disclosure details are set forth to provide a thorough understanding of the embodiments according to the present teachings. Descriptions of known systems, devices, materials, operating methods, and manufacturing methods may be omitted to avoid making the description of the representative embodiments difficult to understand. However, such systems, devices, materials, and methods known to those of ordinary skill in the art are within the scope of the present teachings and can be used according to the representative embodiments. It should be understood that the terms used herein are only used to describe specific embodiments and are not intended to be limiting. The defined terms are not only the technical and scientific meanings of the defined terms that are generally understood and accepted in the technical field of the present teachings.

[0011] It should be understood that although the terms first, second, third, etc. may be used herein to describe various elements or components, these elements or components should not be limited by these terms. These terms are only used to distinguish one element or component from another element or component. Therefore, the first element or component discussed below can be referred to as the second element or component without departing from the teachings of this disclosure.

[0012] The terms used herein are only used for the purpose of describing specific embodiments and are not intended to be limiting. As used in the specification and the appended claims, the singular forms of the terms "a", "an" and "the" include both the singular and the plural forms, unless the context clearly dictates otherwise. In addition, when used in this specification, the terms "include" and / or "comprise" and / or similar terms clarify the presence of the features, elements and / or parts, but do not exclude the presence or addition of one or more other features, elements, parts and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0013] Unless otherwise specified, when an element or component is referred to as being “connected to,” “coupled to,” or “adjacent to” another element or component, it should be understood that the element or component may be directly connected or coupled to the other element or component, or that intervening elements or components may be present. In other words, these and similar terms include situations where one or more intervening elements or components may be used to connect two elements or components. However, when an element or component is described as being “directly connected” to another element or component, this only includes situations where the two elements or components are connected to each other without any intervening or intervening elements or components.

[0014] In view of the foregoing, the present disclosure is intended to exhibit one or more of the advantages specifically noted below, through one or more of its various aspects, embodiments, and / or specific features or subcomponents. For purposes of explanation and not limitation, exemplary embodiments disclosing specific details are set forth to provide a thorough understanding of the embodiments according to the present teachings. However, other embodiments consistent with the present disclosure that deviate from the specific details disclosed herein are still within the scope of the appended claims. In addition, descriptions of well-known devices and methods may be omitted so as not to obscure the description of the exemplary embodiments. Such methods and devices are within the scope of the present disclosure.

[0015] According to various embodiments, a cost-effective, scalable multi-target dynamic echo signal simulation system and method for testing and evaluating automotive radars with multiple radar transmitters using simulated radar targets provided by a MIMO radar target simulator is provided. Multiple dynamic radar echo signals can be simulated using different angles of arrival without using physical space simulation. Different radar signals are emitted from different radar transmitters of an automotive radar or radar sensor (DUT). The embodiment is scalable to a large number of target echo signals with no restrictions on the parameters of the target echo signals, thus supporting the simulation of relatively complex driving scenarios. The embodiment is also cost-effective. For example, the number of simulator transmitters of the MIMO radar target simulation system being used is the same as the number of radar transmitters of the radar sensor, but is independent of the number of target echo signals to be simulated, thereby allowing the number of simulated radar targets to exceed the number of simulator transmitters (and radar transmitters). Similarly, the number of simulator receivers of the MIMO radar target simulation system is equal to the number of radar transmitters of the radar sensor, and the number of simulator transmitters of the MIMO radar target simulation system is equal to the number of radar receivers of the radar sensor, while the number of radar targets that can be simulated is independent of the hardware configuration. Furthermore, a standard interface enables the simulation of target echo signals in different driving scenarios. Thus, various embodiments address simulating dynamic multiple radar targets with different angles of arrival and cost scalability of radar sensors, such as with beamforming or MIMO radars.

[0016] Therefore, according to one aspect of the present disclosure, a MIMO target simulation system for testing a millimeter-wave radar sensor having multiple radar transmitters and multiple radar receivers is provided, wherein the multiple radar transmitters are used to transmit radar signals, and the multiple radar receivers are used to receive target echo signals in response to the transmitted radar signals reflected from the radar target. The MIMO target simulation system includes an antenna array, multiple simulator receivers, multiple simulator transmitters, and a processing unit. The antenna array includes multiple coupled detection antenna elements to receive radar signals transmitted by the radar transmitters and to transmit simulated target echo signals to the radar receivers. The simulator receiver includes a down-converter and an analog-to-digital converter, wherein the down-converter is used to down-convert the carrier frequency of the radar signal received by the antenna array, and the analog-to-digital converter is used to digitize the down-converted radar signals to provide digital radar signals. The processing unit includes a processor and a memory for storing computer-readable code, which, when executed by the processor, causes the processor to: decouple the digital radar signal; retrieve target parameters generated by a scenario simulator, the target parameters corresponding to the simulated radar targets used to reflect the radar signal transmitted by the radar transmitter; generate simulated target return signals corresponding to the simulated radar targets based at least in part on the target parameters of each of the simulated radar targets in response to the decoupled digitized radar signal; and pre-decouple the simulated target return signals. The simulator transmitter includes a digital-to-analog converter and an up-converter, the digital-to-analog converter performing digital-to-analog conversion on the simulated target return signals to provide simulated simulated target return signals, and the up-converter up-converting the frequencies of the simulated simulated target return signals. The simulator transmitter simultaneously transmits the simulated simulated return target signals to the millimeter-wave radar sensor via an antenna array to simulate returns from multiple simulated targets that respectively respond to the multiple radar signals. The performance of the millimeter-wave radar sensor is determined at least in part based on the simulated return target signals from the simulated targets.

[0017] The number of simulator receivers may be equal to the number of radar transmitters of the millimeter-wave radar sensor, and the number of simulator transmitters may be equal to the number of radar receivers of the millimeter-wave radar sensor. Furthermore, the computer-executable code may cause the processing unit to retrieve the transmit antenna patterns and spacings corresponding to the radar transmitters of the millimeter-wave radar sensor, and to retrieve the receive antenna patterns and spacings corresponding to the radar receivers of the millimeter-wave radar sensor. Providing a simulated target return signal corresponding to the simulated target may also be based on the transmit antenna pattern and spacing and the receive antenna pattern and spacing.

[0018] Figure 1 is a simplified block diagram illustrating a MIMO radar target simulation system for testing millimeter-wave radar sensors using dynamic return signal simulation according to a representative embodiment.

[0019] refer to Figure 1 The radar target simulation system 100 includes an antenna system 110, a digital MIMO target simulator 130, and a memory 150. The antenna system 110 includes a coupled detection antenna array 115 and a multiplexer 125. The coupled detection antenna array 115 includes detection antenna array elements 115. 11 to 115 xy The coupled detection antenna array 115 receives the radar signal from the transmit antenna (not shown) of the DUT 101 and forms a transmit coupling matrix H together with the transmit antenna. Tx The coupled probing antenna array 115 also receives the simulated target echo signal from the MIMO target simulator 130 and, together with the receiving antenna (not shown) of the DUT 101, transmits the simulated target echo signal to the receiving coupling matrix H. Rx , which is transmitted to the receiving antenna of the DUT 101 in the form of. More specifically, the DUT 101 includes a millimeter wave radar sensor, for example, for automotive radar, which transmits radar signals from a plurality of radar transmitters 105 (indicated by a single representative radar transmitter for ease of illustration) and receives simulated target return signals in response to the transmitted radar signals from a MIMO target simulator 130 at a plurality of radar receivers 106 (indicated by a single representative radar receiver for ease of illustration). In an embodiment, the coupled probe antenna array 115 is reconfigurable, meaning that the probe antenna array elements 115 11 to 115 xy The probe antenna array 115 can be placed at different locations on the coupling probe antenna array 115 or on the probe antenna array element 115. 11 to 115 xy It may be fixed, and a switch (not shown) is provided to selectively connect the MIMO target emulator 130 to the coupled probing antenna array 115, wherein the connection may be dynamically reconfigured, for example, by operating the switch.

[0020] The MIMO target emulator 130 includes a plurality of emulator receivers 1311, 1312, ..., 131 p (where p is a positive integer) and a plurality of emulator transmitters 1321, 1322...132 r (where r is a positive integer and can be different from or the same as p). Emulator receivers 1311, 1312...131 pEach of the emulator receivers 1311, 1312, ... 131 includes a down-converter for down-converting the millimeter-wave carrier frequency of the radar signal provided by the coupled detection antenna array 115 via the multiplexer 125 to an intermediate frequency (IF), and an analog-to-digital converter (ADC) for digitizing the down-converted radar signal to provide a digital radar signal. p The number of (or down converters) may be equal to the number of radar transmitters 105 in the DUT 101. Simulator receivers 1311, 1312, ... 131 p Tuned to receive different millimeter wave carrier frequencies corresponding to the radar transmitter 105. Simulator transmitters 1321, 1322...132 r The MIMO target emulator 130 may include a digital-to-analog converter (DAC) for performing digital-to-analog conversion on the simulated target echo signal output by the MIMO target emulator 130 to provide an analog simulated target echo signal, and an up-converter for up-converting the IF frequency of the analog simulated target echo signal to a millimeter wave carrier frequency. r The number of (or up-converters) may be equal to the number of radar receivers 106 in the DUT 101. Simulator transmitters 1321, 1322, ... 132 r The radar receiver 106 is tuned to transmit simulated target return signals of different millimeter wave carrier frequencies respectively corresponding to the radar receiver 106 .

[0021] Thus, the coupled probe antenna array 115 couples the radar signal from the radar transmitter 105 in the DUT 101 to the simulator receivers 1311, 1312, ... 131 p , and the transmitters 1321, 1322...132 from the simulator r The simulated target return signal is coupled to the radar receiver 106 in the DUT 101. By controlling the detection antenna array element 115 for selectively connecting the MIMO target simulator 130 11 to 115 xy and switches (not shown) of RF connectors (not shown), the transmit coupling matrix H can be realized with the lowest number of conditions. Tx 115 detection antenna array elements 11 to 115 xy The set of can be chosen to ensure that the transmit coupling matrix H Tx is fully conditioned and can be decoupled by the decoupling module 133 discussed below. In an embodiment, all or part of the coupled probing antenna array 115 can be coupled to the simulator receivers 1311, 1312, ... 131 pand / or simulator transmitters 1321, 1322...132 r integrated.

[0022] The memory 150 of the radar target simulation system 100 includes an antenna pattern and spacing database 152, a real-time target list database 154, and a target list file database 156. Although each of the antenna pattern and spacing database 152, the real-time target list database 154, and the target list file database 156 is shown as a single illustrative block, it should be understood that each can be implemented by one or more memories and / or databases, or all can be implemented by a single memory / database without departing from the scope of the present teachings. For example, the memory 150 can be implemented using one or more non-transitory computer-readable media. The memory 150 can be implemented by, for example, any number, type, and combination of random access memory (RAM) and read-only memory (ROM) and can, for example, store various types of information, such as computer programs and software algorithms that can be executed by the MIMO target simulator 130 discussed below, as well as data on the antenna pattern / spacing and driving scenarios for the DUT 101. The various types of ROM and RAM may include any number, type, and combination of computer-readable storage media, such as disk drives, electrically programmable read-only memory (EPROM), electrically erasable and programmable read-only memory (EEPROM), registers, hard disks, removable disks, magnetic tape, compact disk read-only memory (CD-ROM), digital versatile disks (DVD), floppy disks, Blu-ray disks, universal serial bus (USB) drives, or any other form of storage media known in the art that are tangible and non-transitory (e.g., as compared to a transient propagating signal).

[0023] The antenna pattern and spacing database 152 stores the antenna patterns and antenna spacings of the transmit antenna (not shown) connected to the radar transmitter 105, and the antenna patterns and antenna spacings of the receive antenna (not shown) connected to the radar receiver 106. The transmit and receive antennas can be the same antennas used for the DUT 101 or different sets of antennas. When the transmit and receive antennas are the same, the antenna spacing will be the same, although the antenna patterns may be different. Before performing target return signal simulation, for example, using a scenario simulator, the antenna pattern and spacing database 152 is populated using measured data and / or simulated data sent to and from the DUT 101. For example, the antenna pattern can be determined by measuring the DUT 101 inside a test chamber (e.g., an anechoic chamber), or can be based on simulated antenna patterns.

[0024] The real-time target list database 154 and the target list file database 156 store data on parameters of simulated radar targets that simulate reflections of radar signals from the DUT 101 to provide simulated target return signals. The target parameters can be generated by a scenario simulator (not shown) that provides a driving simulation scenario and can include information such as the position and size of the simulated radar target. The scenario simulator itself can be implemented using a scenario simulator processing unit that can include one or more computer processors, digital signal processors (DSPs), field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), or combinations thereof using any combination of hardware, software, firmware, hard-wired logic circuits, or combinations thereof. The scenario simulator can include its own memory (e.g., non-volatile and volatile memory) to store computer-readable code that, when executed by the processing unit, models the driving simulation scenario and generates the required data to interface with the MIMO target simulator 130. An example of scenario simulation software is CarMaker available from IPG Automotive, although any compatible scenario simulation software or code can be incorporated without departing from the scope of the present teachings.

[0025] Thus, the real-time target list database 154 includes one or more dynamic target parameters for a simulated radar target that simulate the movement of the simulated target during testing. The target list file database 156 includes target parameters for simulated radar targets pre-generated in batch mode, for example, for different scenarios. The target list file database 156 can be partially populated with parameters from the real-time target list database 154. For example, the real-time target list database 154 can provide real-time updates of the target parameters of the target list file database 156. The target list file database 156 can also be used to provide simulated target parameters in playback mode.

[0026] MIMO target simulator 130 may be implemented as a processing unit. In various embodiments, the processing unit may include one or more computer processors, DSPs, FPGAs, ASICs, or combinations thereof using any combination of hardware, software, firmware, hard-wired logic circuits, or combinations thereof. MIMO target simulator 130 may include its own processing memory (e.g., non-volatile memory) to store computer-readable code (e.g., software, software modules) capable of performing the various functions described herein. For example, the processing memory may store code that can be executed by a processing unit (e.g., a computer processor) to perform some or all aspects of the methods described herein (including those described below with reference to Figure 2That is, execution of the instructions / computer readable code generally causes the processing unit of the MIMO target simulator 130 to respond to the signals from the simulator receivers 1311, 1312, ..., 131 p The received digital radar signal is used to generate a simulated target return signal and send the simulated target return signal to the DUT 101. The memory (and database) as described herein can be RAM, ROM, flash memory, EPROM, EEPROM, registers, hard disk, removable disk, tape, compact disk read only memory (CD-ROM), digital versatile disk (DVD), floppy disk, Blu-ray disc or USB drive, or any other form of storage medium known in the art, which is tangible and non-transitory storage medium (for example, compared to temporary propagation signals). Without departing from the scope of the present teachings, the memory can be volatile or non-volatile, secure and / or encrypted, unsecure and / or unencrypted.

[0027] For illustrative purposes, the MIMO target simulator 130 is indicated by blocks or modules representing instructions / computer readable codes for performing various discrete functions. Figure 1 As shown in , the MIMO target simulator 130 includes a decoupling module 133 , a pre-decoupling module 134 , a file storage parser 135 , a real-time interface 136 , a target simulation parameter preprocessing module 137 and a MIMO target simulation module 138 .

[0028] The decoupling module 133 receives and decouples the signals from the simulator receivers 1311, 1312, ... 131 p The digital radar signal of one or more of them (given by the reverse transmission matrix H Tx -1 The transmit coupling matrix H Tx That is, the transmit coupling matrix H Tx All emulator receivers 1311, 1312...131 p and the transmit antenna of the DUT 101. Decoupling the digital radar signal involves multiplying the digitized signal at the ADC of the MIMO target simulator 130 by the inverse transmit matrix H Tx -1 .

[0029] The pre-decoupling module 134 receives and pre-decouples the simulated target echo signal from the target simulation module 138 (by the reverse receiving matrix H Rx -1 The receiving coupling matrix H Rx , the simulated target echo signal is generated in response to the decoupled digital radar signal. Pre-decoupling refers to the reverse receiving matrix H Rx -1The simulated target echo signal is multiplied by the simulated target echo signal, so that the simulated target echo signal obtained passes through the receiving coupling matrix H formed by the coupled detection antenna array 115 and the radar receiving antenna. Rx After that, the final result is that the simulated target echo signals are not coupled together. In other words, without receiving the coupling matrix H Rx In the absence of coupling effects, the DUT 101 receives an accurate simulated target echo signal for each of the radar receivers. Therefore, the pre-decoupling makes the receiving coupling matrix H output by the coupled detection antenna array 115 Rx can be decoupled by the radar receiver 106. Decoupling and pre-decoupling are performed in the digital domain.

[0030] The file storage parser 135 is configured to parse the parameter data retrieved from the target list file database 156 and provide the parsed parameter data to the real-time interface 136. The parsing is mainly based on the time parameter data of the simulated radar target. The simulated radar targets sharing the same time will be sent to the MIMO target simulator 130 at the same time. When the target parameters are sent to the MIMO target simulator 130, the time difference between the simulated radar targets is maintained. For the real-time target list database 154, the time when the target parameter data is sent to the MIMO target simulator 130 is the time when the target parameter data is generated, and the time can be updated in real time. Therefore, the real-time target list database 154 does not need to be parsed.

[0031] The real-time interface 136 is configured to interface between the target simulation module 138 and each of the real-time target list database 154 and the target list file database 156 to retrieve corresponding parameter data. Sensor transmit antenna pattern and antenna spacing data, as well as sensor receive antenna pattern and antenna spacing data, are retrieved from the antenna pattern and spacing database 152 and provided to the target simulation parameter preprocessing module 137 via a separate radar target simulator configuration interface (not shown), which is configured once at the beginning of the test operation. The target simulation parameter preprocessing module 137 preprocesses the parameter data from the real-time interface 136 and the radar target simulator configuration interface by calculating parameters for configuring the MIMO target simulation. For example, the target parameter data may include echo delay, Doppler frequency, radar cross section, departure angle, and arrival angle data.

[0032] The target simulation module 138 receives target parameters generated by the scenario simulator from the real-time target list database 154 and / or the target list file database 156, as well as sensor transmit and receive antenna patterns and antenna spacing data from the antenna pattern and spacing database 152. The target simulation module 138 generates simulated target return signals corresponding to the simulated radar targets that respectively respond to the digitized radar signals based at least in part on the corresponding target parameters. The target parameters of each of the simulated target return signals may include, for example, the time at which the simulated target return signal is transmitted, the Doppler frequency of the simulated target return signal, the round-trip time delay of the simulated target return signal from the simulated target to one of the radar receivers 106, the radar cross section (RCS) of the corresponding simulated target for a given direction, the angle of arrival of the simulated target return signal relative to one of the radar receivers 106, and the departure angle of the radar signal on the simulated target. The simulated target return signals indicate reflections of the radar signal transmitted by the radar transmitter 105 by the simulated radar target. The target simulation module 138 is capable of simultaneously generating simulated target return signals corresponding to multiple targets in response to multiple radar signals transmitted by multiple radar transmitters 105.

[0033] The target simulation module 138 determines a simulated target return signal T corresponding to each of the simulated radar targets and receives the target return signal T from the simulator transmitters 1321, 1322, ... 132 r The number of simulated radar targets and corresponding simulated target echo signals is the same as the number of simulated radar targets and corresponding simulated target echo signals of the simulator transmitters 1321, 1322, ..., 132 r The number of is irrelevant (can be the same as the number of radar transmitters 105). Each simulated target echo signal T is determined according to the following equation (1):

[0034]

[0035] In equation (1), m is the index number of the radar transmitter, b is the index number of the radar receiver, and k is the index number of the simulated radar target having the input signal from the mth radar transmitter and the output signal from the nth radar receiver. Different simulated radar targets can have the same parameters or different parameter values. By changing the parameter values, different radar targets can be dynamically simulated. For example, the position parameter τ of the simulated radar target can be changed k To simulate the movement of the radar target. In other examples of parameters, the Doppler frequency f k To simulate the movement speed, and can be achieved through AoA k To change the direction of the echo signal.

[0036] In addition, x mis the radar signal transmitted on the mth radar transmitter, G Tx，m is the complex antenna pattern of the mth radar transmitter, f0 is the carrier frequency of the radar signal transmitted at the mth radar transmitter, and f k is the Doppler frequency of the corresponding echo signal from the simulated radar target k in response to the radar signal transmitted on the mth radar transmitter, d Tx is the spacing of the radar transmitter antenna element corresponding to the radar transmitter relative to other radar transmitter antenna elements, AoD k is the departure angle of the radar signal radiated to the simulated radar target k, and α k G is the total gain of the physical channel to the transmitted radar signal due to the simulated radar target k. Rx，n is the complex antenna pattern of the nth radar receiver, d Rx is the distance between the radar receiver antenna unit corresponding to the radar receiver and other radar receiver antenna units, and AQA k is the arrival angle of the simulated target echo signal corresponding to (reflected from) radar target k.

[0037] In equation (1), it is assumed that each of the radar transmit antenna elements and the radar receive antenna elements are in a uniform linear array. Equation (1) can be directly extended to 2D arrays by considering the two-dimensional (2D) spacing of the antenna array and considering the angle of arrival and angle of departure in the azimuth and elevation planes.

[0038] Therefore, for example, the simulated target return signal of the nth radar receiver can be determined according to the following equation (2):

[0039]

[0040] Based on equation (2), it can be seen that for the simulated target echo signal from the mth radar transmitter to the nth radar receiver, each simulated radar target can be implemented by some common functions, including a delay function that simulates the echo delay, a complex gain function that simulates the gain of the entire echo signal, and a Doppler frequency function that simulates the Doppler shift of the simulated target echo signal from radar transmitter 105 to radar receiver 106. Based on the target parameters and the antenna pattern and spacing information of radar transmitter 105 and radar receiver 106, all parameters of these functions can be derived according to equation (2) and all parameters can be simulated accordingly.

[0041] Figure 2 is a simplified flow chart of a method for testing a millimeter-wave radar sensor (eg, a DUT) using a MIMO radar target simulation system for dynamic return signal simulation, according to a representative embodiment.

[0042] refer to Figure 2 In block S211, a radar signal transmitted by a radar transmitter in a millimeter-wave radar sensor (e.g., DUT 101) is received via an antenna array coupled with a detection antenna element. The millimeter-wave radar sensor may include a radar transmitter for transmitting the radar signal and a radar receiver for receiving a simulated target echo signal from a MIMO radar target simulation system. The radar signal is transmitted as a transmission coupling matrix H transmitted by the radar transmitter. Tx In block S212, for example, the reverse transmission matrix H is used Tx -1 To decouple the received radar signal.

[0043] In block S213, target parameters are retrieved. For example, the target parameters may be determined by a scenario simulator and stored in one or more databases storing a real-time target list and a file target list (e.g., real-time target list database 154, target list file database 156). The target parameters may then be retrieved from the database. The target parameters correspond to simulated radar targets reflecting radar signals transmitted by the radar transmitter. The target parameters are continuously updated in the real-time target list and pre-stored in a target list file, such as from a dumped target list file. In block S214, the transmit antenna pattern and antenna spacing corresponding to the radar transmitter, as well as the receive antenna pattern and antenna spacing corresponding to the radar receiver, are retrieved from the database. The transmit and receive antenna patterns and spacings may be determined by measuring the antenna pattern of the radar sensor within an anechoic chamber or by, for example, three-dimensional electromagnetic (EM) simulation of the millimeter-wave radar sensor antenna, and stored in one or more databases (e.g., antenna pattern and spacing database 152).

[0044] In block S215, in response to the decoupled radar signal, simulated target return signals corresponding to the simulated targets are generated based at least in part on the target parameters, transmit antenna pattern, and receive antenna pattern of each of the simulated targets. The simulated target return signals can be generated by a DSP or other processing unit, for example, according to a target return signal algorithm (such as the algorithm indicated by equations (1) and (2) above).

[0045] In block S216, pre-decoupling is performed on the simulated target echo signal. That is, the reverse receive coupling matrix H is used. Rx -1 The simulated target echo signal is pre-decoupled. The pre-decoupling may include multiplying the simulated target echo signal by the reverse receiving coupling matrix H Rx -1 So that it is then multiplied by the receive coupling matrix H formed by the coupled detection antenna array and the radar receiving antenna RxThis will result in uncoupled simulated target echo signals in the millimeter-wave radar sensor.

[0046] In block S217, the pre-decoupled simulated target echo signals are transmitted to the radar receiver via the antenna array. The simulated target echo signals simulate simulated target echoes that would respond to the received radar signals, respectively. Furthermore, simulated target echo signals may be received from multiple simulated targets in response to the multiple radar signals. In block S218, the performance of the millimeter-wave radar sensor is determined, for example, using at least a partially identified target list reported by the millimeter-wave radar sensor based on the decoupled simulated target echo signals transmitted to and received by the radar receiver. That is, the simulated target echo signals may be used to compare the identified target list with a simulated target list of simulated targets to determine the number of matches between the two, thereby indicating the number of simulated targets and / or target echo signals. Generally, the smaller the difference between the identified target list and the simulated target list, the better the performance of the millimeter-wave radar sensor. The target parameters may be reconfigurable and may be mapped from different scenarios to a common set of implementation parameters of the same processor function to generate simulated echo signals corresponding to the different scenarios.

[0047] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments.

[0048] Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude the inclusion of other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0049] Aspects of the present invention may be implemented as devices, methods, or computer program products. Thus, aspects of the present invention may take the form of a fully hardware implementation, a fully software implementation (including firmware, resident software, microcode, etc.), or an implementation combining software and hardware aspects, which may generally be referred to herein as a "circuit," "module," or "system." Additionally, aspects of the present invention may take the form of a computer program product implemented in one or more computer-readable media having computer executable code implemented thereon.

[0050] Although representative embodiments are disclosed herein, those skilled in the art will appreciate that many variations are possible in light of the present teachings and still fall within the scope of the appended claims. Accordingly, the present invention is intended to be limited only by the scope of the appended claims.

Claims

1. A multiple-input multiple-output (MIMO) target simulation system for testing a millimeter-wave radar sensor having multiple radar transmitters and multiple radar receivers, the radar transmitters being configured to transmit multiple radar signals, the multiple radar receivers being configured to receive multiple target return signals in response to the multiple radar signals reflected from radar targets, the system comprising: an antenna array comprising a plurality of coupled detection antenna elements to receive the plurality of radar signals transmitted by the plurality of radar transmitters and to send simulated target return signals to the plurality of radar receivers; a plurality of simulator receivers including a downconverter for downconverting carrier frequencies of the plurality of radar signals received by the antenna array and an analog-to-digital converter for digitizing the downconverted radar signals to provide digital radar signals; A processing unit comprising a processor and a memory for storing computer-readable code, the computer-readable code, when executed by the processor, causing the processor to: decoupling the digital radar signal; retrieving target parameters generated by a scenario simulator, the target parameters corresponding to a plurality of simulated radar targets for reflecting the plurality of radar signals emitted by the plurality of radar emitters; generating, in response to the decoupled digital radar signals, simulated target return signals corresponding to the plurality of simulated radar targets based at least in part on the target parameter of each of the plurality of simulated radar targets; and pre-decoupling the simulated target echo signal; as well as a plurality of simulator transmitters including a digital-to-analog converter for performing digital-to-analog conversion on the simulated target echo signal to provide an analog simulated target echo signal and an up-converter for up-converting the frequency of the analog simulated target echo signal; wherein the plurality of simulator transmitters simultaneously transmit the simulated target echo signals to the millimeter wave radar sensor via the antenna array to simulate echoes from a plurality of simulated targets respectively responding to the plurality of radar signals, and The performance of the millimeter-wave radar sensor is determined at least in part based on the simulated target return signals from the multiple simulated targets.

2. The system according to claim 1, wherein the number of the simulator receivers is equal to the number of radar transmitters of the millimeter wave radar sensor; and The number of the simulator transmitters is equal to the number of the radar receivers of the millimeter-wave radar sensor.

3. The system of claim 1 , wherein the computer readable code further causes the processor to: Retrieving transmit antenna patterns and spacings corresponding to the plurality of radar transmitters of the millimeter wave radar sensor, respectively; and Retrieve the receiving antenna patterns and spacings corresponding to the plurality of radar receivers of the millimeter wave radar sensor respectively, The provision of the simulated target echo signals corresponding to the multiple simulated targets is also based on the transmitting antenna pattern and spacing and the receiving antenna pattern and spacing.

4. The system of claim 1 , wherein the plurality of radar signals transmitted by the plurality of radar transmitters are arranged in a transmit coupling matrix, and wherein decoupling the digital radar signal comprises decoupling the transmit coupling matrix using an inverse transmit coupling matrix.

5. The system according to claim 4, wherein pre-decoupling the simulated target return signal includes multiplying the simulated target return signal by an inverse receive coupling matrix, so that subsequent multiplication by the receive coupling matrix formed by the antenna array and the radar receive antenna results in the uncoupled simulated target return signal in the millimeter wave radar sensor not being interfered with by other simulator transmitters among the multiple simulator transmitters.

6. The system of claim 1, further comprising a real-time target list populated by the scenario simulator, wherein the target parameter is continuously updated in the real-time target list.

7. The system of claim 1, further comprising a target list file populated by the scenario simulator, wherein the target parameters are stored in the target list file from a dumped target list file.

8. The system of claim 1, wherein the number of simulated radar targets and corresponding simulated target return signals is independent of the number of simulator transmitters.

9. A method for testing a millimeter-wave radar sensor including multiple radar transmitters and multiple radar receivers using a multiple-input multiple-output (MIMO) target simulation system, the method comprising: receiving radar signals transmitted by the plurality of radar transmitters via an antenna array comprising a plurality of coupled detection antenna elements; decoupling the received radar signal; retrieving target parameters provided by a scenario simulator, the target parameters corresponding to simulated targets for reflecting the radar signals emitted by the plurality of radar emitters; retrieving transmit antenna patterns corresponding to the plurality of radar transmitters and receive antenna patterns corresponding to the plurality of radar receivers; generating, in response to the decoupled radar signals, simulated target return signals corresponding to each of the simulated targets based at least in part on target parameters of the simulated targets, the transmit antenna pattern, and the receive antenna pattern; pre-decoupling the simulated target echo signal; as well as The pre-decoupled simulated target return signal is transmitted to the plurality of radar receivers via the antenna array to simulate returns from the simulated target that respectively respond to the received radar signals, wherein performance of the millimeter-wave radar sensor is determined at least in part based on comparing a recognized target list of the millimeter-wave radar sensor with a simulated target list of the simulated target using the simulated target return signal to determine a number of matches.

10. The method of claim 9, wherein the radar signals transmitted by the plurality of radar transmitters are arranged in a transmit coupling matrix, and wherein decoupling the received radar signals comprises decoupling the transmit coupling matrix using an inverse transmit coupling matrix, and Pre-decoupling the simulated target echo signal includes multiplying the simulated target echo signal by a reverse coupling matrix, so that subsequent multiplication by a receiving coupling matrix formed by the antenna array and the radar receiving antenna results in an uncoupled simulated target echo signal in the millimeter wave radar sensor.

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