Angle of arrival estimation method, device, radar sensor and electronic equipment

Abstract

The present application discloses a method, device, radar sensor, and electronic device for estimating angle of arrival. The method is applied to a sensor comprising a physical antenna array, wherein the physical antenna array includes at least one transmitting antenna and multiple receiving antennas. The method comprises: receiving a signal frame; the signal frame is obtained based on a detection signal wave and its echo signal wave emitted by the physical antenna array; using a preset first steering vector and a first receiving signal, the signal frame is estimated to determine the angle information of the detected object; the first steering vector and the first receiving signal are both set based on the aperture information of multiple receiving channels and the wavelength of the detection signal wave; the multiple receiving channels include a first receiving channel constructed based on the receiving antenna and a second receiving channel obtained by mirroring any of the first receiving channels. The mirrored second receiving channel increases the aperture of the physical antenna array, improves the angular resolution of the sensor, and enhances the accuracy of the angle of arrival estimation.

Description

Technical Field

[0001] The embodiments of the present application relate to signal processing technology, and in particular to a method and device for estimating angle of arrival (AoA), a radar sensor, and an electronic device. Background Art

[0002] In the information age, where wireless communication technology is rapidly evolving, short-range wireless communication has gained widespread application in many fields due to its strong anti-interference capabilities, high reliability, and simple and flexible installation and construction. With the increasing popularity of automobiles, intelligent driving technology has begun to emerge, and millimeter-wave automotive radar is a key enabler of intelligent driving technology. However, the complexities of urban traffic place high demands on radar's new capabilities.

[0003] Radar sensors use antenna arrays to find and locate the direction of radiation sources. Angle of Arrival (AoA) estimation leverages this characteristic of antenna arrays to estimate direction. Signals from different directions in space are received and quickly and accurately calculated using estimation methods.

[0004] However, in the prior art, the accuracy of radar angle of arrival estimation is limited by the aperture information between physical antennas, resulting in low resolution of the radar sensor. Summary of the Invention

[0005] The present application provides a method and device for estimating an angle of arrival (AoA) of a radar sensor and electronic equipment to accurately determine the angle information of a detected object.

[0006] In a first aspect, an embodiment of the present application provides an angle of arrival estimation method, which is applied to a sensor including a physical antenna array, wherein the physical antenna array is composed of at least one transmitting antenna and multiple receiving antennas, and the method includes: receiving a signal frame; wherein the signal frame is obtained based on multiple detection signal waves and their respective echo signal waves emitted by the physical antenna array; using a preset first steering vector and a first receiving signal, performing an angle of arrival estimation on the signal frame to determine the angle information of the detected object; wherein the first steering vector and the first receiving signal are both set based on the aperture information of multiple receiving channels and the wavelength of the detection signal wave; the multiple receiving channels include a first receiving channel constructed based on the receiving antenna and a second receiving channel obtained by mirroring any one of the first receiving channels.

[0007] Furthermore, the method further includes: obtaining a selection instruction; and determining the first steering vector and the first receiving signal according to the first receiving channel and the second receiving channel indicated by the selection instruction.

[0008] Furthermore, it also includes: when multiple angle information is detected, detecting the angular interval between multiple objects measured by the sensor; if the angular interval is not less than the true angular resolution, using the second steering vector and the second receiving signal to estimate the wave arrival angle of the signal frame to determine the angle information of each object; wherein the second steering vector and the second receiving signal are both set according to the aperture information of multiple first receiving channels.

[0009] Furthermore, the second receiving channel is obtained by taking one of the first receiving channels as a mirror reference and mirroring the aperture information of the other first receiving channel relative to the mirror reference.

[0010] Further, the plurality of receiving channels include all of the first receiving channels; or at least one of the first receiving channels and at least one of the second receiving channels selected based on the total number of the first receiving channels.

[0011] Furthermore, the amplitude parameter corresponding to the second receiving channel in the first received signal is the same as the amplitude parameter corresponding to the first receiving channel mirrored by the second receiving channel.

[0012] Furthermore, a phase parameter corresponding to the second receiving channel in the first steering vector is inverted based on a mirror reference to a phase parameter corresponding to the first receiving channel mirrored by the second receiving channel.

[0013] In a second aspect, an embodiment of the present application further provides an angle of arrival estimation device, comprising: a memory storing at least one program and aperture information between each antenna in a physical antenna array of a sensor; and a processor connected to the memory, configured to execute the at least one program to perform an angle of arrival estimation method as described in any one of the first aspects using the aperture information to determine angle information of objects around the sensor.

[0014] In a third aspect, an embodiment of the present application further provides a radar sensor, comprising: an antenna array, including a transmitting antenna and multiple receiving antennas; a signal transceiver connected to the antenna array, for transmitting a detection signal wave through the transmitting antenna, and receiving an echo signal wave through the receiving antenna, and outputting a signal frame, wherein the echo signal wave is obtained by reflecting the detection signal wave from an object; and an angle of arrival estimation device as described in the second aspect, connected to the signal transceiver.

[0015] In a fourth aspect, an embodiment of the present application further provides an electronic device, characterized in that it includes: a radar sensor as described in the third application; a processor coupled to the radar sensor; and a memory coupled to the processor; wherein the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can perform the angle of arrival estimation method described in any one of the first aspects.

[0016] The present application provides an angle-of-arrival estimation method for a sensor (e.g., a radar sensor), wherein the sensor includes a physical antenna array, wherein the physical antenna array is composed of at least one transmitting antenna and multiple receiving antennas. The method comprises: receiving a signal frame; wherein the signal frame is obtained based on multiple detection signal waves and their respective echo signal waves emitted by the physical antenna array; using a preset first steering vector and a first received signal, performing an angle-of-arrival estimation on the signal frame to determine the angle information of the detected object; wherein the first steering vector and the first received signal are both set based on aperture information of multiple receiving channels and the wavelength of the detection signal wave; the multiple receiving channels include a first receiving channel constructed based on the receiving antenna and a second receiving channel obtained by mirroring any of the first receiving channels. In the above technical solution, the transmitting antenna in the physical antenna array included in the radar sensor can transmit a detection signal wave, and the detection signal wave generates an echo signal wave after detecting an object. The receiving antenna can receive the echo signal wave in the form of a signal frame. Furthermore, the radar sensor can use the first steering vector and the first received signal set according to the aperture information of multiple receiving channels and the wavelength of the detection signal wave to perform virtual aperture arrival angle estimation on the signal frame, thereby determining the angle information of the detected object and estimating the arrival angle of the detected object. Since the multiple receiving channels can include a first receiving channel constructed based on the receiving antenna and a second receiving channel obtained by mirroring any first receiving channel, the introduction of the mirrored second receiving channel increases the aperture of the physical antenna array included in the radar sensor, improves the angular resolution of the radar sensor, and further improves the accuracy of the arrival angle estimation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of a physical antenna array provided in an embodiment of the present application;

[0018] Figure 2 Schematic diagram of the principle of angle of arrival estimation calculation using one transmitting antenna and two receiving antennas;

[0019] Figure 3 To utilize Figure 1 A graph showing a phase difference versus target detection angle, represented by the physical antenna array shown;

[0020] Figure 4 Another graph showing the change of phase difference with the detection target angle provided in an embodiment of the present application;

[0021] Figure 5 A schematic diagram of another physical antenna array provided in an embodiment of the present application;

[0022] Figure 6 A flowchart of a method for estimating angle of arrival provided in Example 1 of the present application;

[0023] Figure 7 A graph showing the angle-energy relationship of an object detected in an angle-of-arrival estimation method provided in Example 1 of the present application;

[0024] Figure 8 A schematic diagram of a physical antenna array in a method for estimating angle of arrival provided in an embodiment of the present application;

[0025] Figure 9 A flowchart of a method for estimating angle of arrival provided in Example 2 of the present application;

[0026] Figure 10 A schematic diagram of the structure of an angle of arrival estimation device provided in Example 3 of the present application;

[0027] Figure 11 A schematic structural diagram of a radar sensor provided in Example 4 of the present application;

[0028] Figure 12 This is a structural diagram of an electronic device provided in Example 5 of the present application. DETAILED DESCRIPTION

[0029] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present application and are not intended to limit the present application. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions of the present application, not all of the structures.

[0030] What should be mentioned before discussing exemplary embodiments in more detail is that some exemplary embodiments are described as processing or the method that flow chart describes.Although flow chart describes each operation (or step) as the processing of sequence, many operations therein can be implemented in parallel, concurrently or simultaneously.In addition, the order of each operation can be rearranged.Described processing can be terminated when its operation is completed, but can also have the additional step that is not included in the accompanying drawings.Described processing can correspond to method, function, procedure, subroutine, subprogram etc.In addition, when not conflicting, the embodiment in the application and the feature in the embodiment can be combined with each other.

[0031] The radar sensor may include a physical antenna array, which may include at least one transmitting antenna and multiple receiving antennas. The multiple receiving antennas are arranged at intervals, and the adjacent intervals are related to the phase of the detection signal wave emitted by the transmitting antenna. The interval d between adjacent receiving antennas may be equal or unequal. For example, the interval between adjacent receiving antennas is not greater than the distance corresponding to half a phase cycle. The spacing d' between adjacent transmitting antennas and receiving antennas can be set according to the leakage signal strength of the isolated adjacent transmitting antennas and receiving antennas, the feeder arrangement, etc. For example, the spacing d' is determined based on at least one of the RF transceiver power of the sensor, the isolation structure between the transmitting antenna and the receiving antenna, and the shape of the feeder. Figure 1 A schematic diagram of a physical antenna array provided in an embodiment of the present application is shown as follows: Figure 1 As shown, the physical antenna array may include a transmitting antenna TX and four receiving antennas RXi placed along the Y direction, for example, RX1, RX2, RX3 and RX4, the distance between each receiving antenna may be d, and the distance between the receiving antenna RX1 and the transmitting antenna TX may be d'.

[0032] Radar sensors typically use the phase difference corresponding to the spacing between multiple receiving antennas (also known as aperture distance or aperture information) to determine the angle information between the radar sensor and the detected object. Figure 2 The schematic diagram of the principle of using one transmitting antenna and two receiving antennas to estimate the angle of arrival is shown in the figure. Figure 2 For example, the following diagram shows the principle of using one transmitting antenna TX and two receiving antennas RX1 and RX2 to estimate the angle of arrival. When the target is in the far field of the radar sensor, the different receiving antennas RX1 and RX2 are approximately parallel light. At this time, the phase difference between RX1 and RX2 is expressed as:

[0033]

[0034] Among them, f c represents the frequency of the detection signal wave emitted by the transmitting antenna TX, c represents the transmission speed of the wave, R represents the distance between the transmitting antenna TX and the object target, R1 and R2 represent the distances between the two receiving antennas RX1 and RX2 and the same object, d represents the aperture information, and θ represents the wave arrival angle. It represents the phase difference between the echo signals formed by the detection signal wave reflected by the object and reaching RX1 and RX2 respectively. c In the case of the aperture information d, the angle information between the radar sensor and the object can be obtained by estimating the angle of arrival.

[0035] To accurately estimate angle of arrival (AoA), radar sensors utilize more receive antennas, and even more transmit antennas, to construct MIMO channels. A MIMO channel represents a virtual channel constructed using any transmit antenna and any receive antenna in a physical antenna array. Leveraging the aperture information between the receive antennas in each virtual channel, the radar sensor is configured with parameters for AoA estimation, including the steering vector a and the received signal S.

[0036] The steering vector a is the response of the array elements represented by all receiving antennas in the MIMO channel to a narrowband signal source with unit energy. When the signal sinθ is incident on the MIMO channel from the direction θ, the steering vector provides a vector matrix of the corresponding signal sinθ constructed using the spatial phase difference between the MIMO channels.

[0037] by Figure 1 Taking the MIMO channel constructed by the physical antenna array shown as an example, the steering vector a is expressed as:

[0038]

[0039] The steering vector a for the MIMO channel is derived using the virtual channel containing receive antenna RX1 as the reference and the aperture information (d, 2d, 3d) of the other receive antennas (RX2, RX3, and RX4) relative to RX1. As can be seen from the above example, adjusting the reference will result in a different representation of the steering vector a, but the phase differences between the virtual channels within the MIMO channel remain unchanged.

[0040] The received signal S is represented by the signal matrix formed when the signal sinθ is incident on the MIMO channel from the θ direction. Figure 1 Taking the MIMO channel formed by the physical antenna array shown as an example, in order to simplify the analysis, the amplitude of the signal received by RX is assumed to be the same. At this time, the radar received signal S is expressed as:

[0041]

[0042] Where N is the noise, [] T is a matrix.

[0043] After receiving the detection signal wave, the receiving antenna in the physical antenna array included in the radar sensor can estimate the original arrival angle of the signal frame of the detection signal wave. For example, the angle information of objects located in the YOZ plane around the radar sensor can be determined based on the above-mentioned steering vector and the received signal. Among them, y θ =a H (θ)·S(θ).

[0044] Of course, the position of the detection target can be expressed as (r, θ), where θ is the angle information of the detection target and r is the distance information from the radar sensor to the detection target. In order to meet the far-field condition, the distance r from the detection target to the radar sensor needs to meet Where λ = c / f, which is the wavelength of free space, c is the speed of light, f is the operating frequency, and m = d' + 3d.

[0045] The detection signal wave emitted by the transmitting antenna is reflected by the detection target to obtain the echo signal wave. The electromagnetic wave phase of the echo signal wave reaching the receiving antenna RXi can be P i (i=1,2,3,4). Since the detection target meets the far-field condition, the phase difference between the echo signal wave received by each receiving antenna and the detection signal wave emitted by the transmitting antenna can be determined. θ∈(-90°,90°). Among them, Figure 3 To utilize Figure 1 The physical antenna array shown is a graph showing the change of phase difference with the detection target angle. Figure 3 Here, d=0.5λ, and the slope of the curve is 360(i-1)d, which is proportional to the distance from RXi to RX1.

[0046] The radar sensor uses the echo signal waves corresponding to each of the multiple transmitted detection signal waves to form a signal frame s(n); and uses the above parameters and the signal frame to estimate the angle of arrival. This provides information about the angle between the detected object and the radar sensor. Here, n>1, for example, n=128 or 256. Examples of methods for estimating the angle of arrival of the signal frame using the steering vector and the received signal include at least one of the following: 1) using a search algorithm to traverse the range of θ values ​​to calculate the angles of arrival corresponding to energy peaks, thereby estimating the angle information of at least one object; 2) using a MUSIC algorithm or a machine learning algorithm to estimate the angle of arrival.

[0047] As can be seen from the formulas for these parameters, the number of MIMO channels, or the aperture information (d, 2d, 3d, etc.) between each virtual channel within a MIMO channel, is crucial for accurately estimating the angle of arrival. For example, increasing aperture information can improve the angular resolution of a radar sensor.

[0048] However, the physical size of a radar sensor's antenna array, particularly one that utilizes packaging technology to secure antennas to a chip package, limits the layout and number of antennas. To improve the angular resolution of a radar sensor and enable it to distinguish multiple objects within its detection range, even those positioned closely together, this application provides a method for estimating the angle of arrival (AoA).

[0049] This application uses the first steering vector and the first receiving signal as parameters. Different from the above example, the first steering vector and the first receiving signal are both set according to the aperture information of multiple receiving channels and the wavelength of the detection signal wave; the multiple receiving channels include a first receiving channel constructed based on the receiving antenna and a second receiving channel obtained by mirroring any of the first receiving channels. In other words, without adding a physical antenna array, this application uses mirroring to virtualize a virtual receiving antenna with a larger aperture, and forms a second receiving channel based on the virtual receiving antenna and the transmitting antenna in the physical antenna array, so that the MIMO channel contains at least one first receiving channel and at least one second receiving channel.

[0050] by Figure 1 Taking the physical antenna array shown as an example, taking one of the receiving antennas RX1 as the mirror reference, the receiving antenna RX4 is mirrored to obtain a virtual receiving antenna RX4'. Figure 4 Another phase difference curve diagram provided in an embodiment of the present application as a function of the detection target angle is shown. Figure 5 A schematic diagram of an antenna array including a mirrored virtual receiving antenna RX4' and physical receiving antennas RX1-RX4 is provided in an embodiment of the present application. Figure 4 As shown, ΔP′4 = -ΔP4, and the slope of ΔP4′ is negative. Due to the introduction of the virtual receiving antenna, the aperture information of the receiving channel formed by receiving antenna RX4 in the antenna array is 3d, and the aperture information of the receiving channel formed by virtual receiving antenna RX4' is -3d. After the introduction of the virtual channel, the radar aperture increases to 6d, thereby improving the angular resolution of the radar sensor.

[0051] Therefore, introducing a virtual receiving antenna into the antenna array can improve the angular resolution of the radar sensor including the physical antenna array and further improve the accuracy of the angle of arrival estimation.

[0052] The angle of arrival estimation method proposed in this application will be described in detail below with reference to diagrams and various embodiments.

[0053] Example 1

[0054] Figure 6 This is a flow chart of a method for estimating an angle of arrival provided in the first embodiment of the present application. This embodiment is applicable to situations where it is necessary to accurately determine the angle information of objects around the sensor. The method can be performed by an angle of arrival estimation device, such as Figure 6 As shown, the specific steps include:

[0055] Step 610: Receive a signal frame, wherein the signal frame is obtained based on a plurality of detection signal waves transmitted by a physical antenna array and a plurality of corresponding echo signal waves.

[0056] Specifically, the detection signal wave emitted by the transmitting antenna is reflected by the detection target (also known as the object) to produce a corresponding echo signal wave. The receiving antenna mixes the multiple echo signal waves and performs A / D conversion, etc. to produce a frame signal s(n), where n is the number of received echo signal waves. The detection signal wave is, for example, an electromagnetic wave with continuous frequency modulation in the millimeter wave band.

[0057] Step 620: Use the preset first steering vector and the first received signal to perform angle of arrival estimation on the signal frame to determine angle information of the detected object.

[0058] Among them, the first steering vector and the first receiving signal are both set based on the aperture information of multiple receiving channels and the wavelength of the detection signal wave; the multiple receiving channels include a first receiving channel constructed based on the receiving antenna and a second receiving channel obtained by mirroring any first receiving channel.

[0059] like Figure 5 As shown, the physical antenna array may include four receive antennas RX1, RX2, RX3, and RX4, and a virtual receive antenna RX4' obtained by mirroring RX4 about RX1. The four receive antennas RX1, RX2, RX3, and RX4 may constitute four first receive channels, each with an aperture of (0, d, 2d, 3d). RX4' constitutes a second receive channel, with an aperture of -3d.

[0060] The radar sensor is configured to form a MIMO channel by configuring RX4' and any receiving antenna (RX1, RX2, RX3, or RX4). For example, a MIMO channel is configured using four physical receiving antennas RX1, RX2, RX3, RX4 and one virtual receiving antenna RX4', and its first steering vector is The first received signal without normalization can be expressed as Among them, s1~s4 are the amplitudes of the received signals of RX1~RX4 after considering the noise, sp1~s p4 These are the phases of the received signals of RX1 to RX4 after taking noise into account. is the amplitude and phase of RX4'.

[0061] As can be seen from the above example, compared to the steering vector (also called the second steering vector) and received signal (also called the second received signal) obtained using the physical antenna array, the first received signal S' has the same amplitude parameter S4 as the mirrored first and second receiving channels. The first steering vector a' has an additional second receiving channel. Figure 5 As shown by the dashed line, due to the parameter in the second steering vector The corresponding second receiving channel is obtained by mirroring the first receiving channel where RX4 is located relative to the first receiving channel where RX1 is located. This increases the sparsity of the MIMO channel without affecting the amplitude of the first steering vector and the first received signal. That is, while increasing the angular resolution of the radar sensor, there is no need to debug the energy of each receiving channel.

[0062] The first steering vector a′ and the first received signal S′ are used to estimate the angle of arrival of the signal frame to determine the angle information of the detected object. Among them, y θ =a' H (θ)·S'(θ). Here, the signal frame is each signal sinθ obtained from each received echo signal wave. n . Among them, θ n is the angle of arrival of the nth signal.

[0063] Figure 7 This is a curve diagram of the angle-energy of the object detected in the method for estimating the angle of arrival provided in the first embodiment of the present application, such as Figure 7 As shown, the solid line is based on the inclusion Figure 1 The angle-energy amplitude curve determined by the angle of arrival estimation performed by the radar sensor of the physical antenna array shown is shown in FIG. Figure 5 The angle-energy amplitude curve determined by the radar sensor of the antenna array shown in FIG. According to the solid line, it can be seen that the signal frame is incident from 0° and 20° respectively. Figure 1 The physical antenna array shown is Figure 1 The angular resolution of the physical antenna array shown is not sufficient to distinguish multiple objects within this angular range. As can be seen from the dotted line, Figure 5 The antenna array shown clearly shows energy peaks at -0.9° and 19.8°, which indicates that the MIMO channel containing virtual receiving antennas can distinguish multiple objects within the 0-20° angle range, that is, the angular resolution is greater than Figure 1 The corresponding angular resolution. Figure 1 The physical antenna array shown, Figure 5 The maximum aperture of the physical antenna array shown is increased from 3d to 6d, thereby increasing the sparsity of the MIMO channel. This improves the angular resolution of the radar sensor, that is, improves the accuracy of the angle of arrival estimation.

[0064] Figure 8 A schematic diagram of a physical antenna array in a method for estimating angle of arrival provided in an embodiment of the present application is shown in FIG. Figure 8As shown, the receiving antennas include RX1, RX2, RX3, and RX4. Using virtual aperture technology, RX2, RX3, and RX4 are mirrored about RX1 to create virtual receiving antennas RX2', RX3', and RX4'. The same transmitting antenna and the receiving antennas RX1, RX2, RX3, and RX4 form four first receiving channels, where the apertures of the first receiving channels corresponding to RX1, RX2, RX3, and RX4 are 0, d, 2d, and 3.5d, respectively. The same transmitting antenna and the virtual receiving antennas RX2', RX3', and RX4' form three second receiving channels, where the apertures of the second receiving channels are d, 2d, and 3.5d, respectively.

[0065] It should be noted that the above examples construct a MIMO channel using a single transmit antenna, all physical receive antennas, and a mirrored virtual receive antenna. Depending on the radar sensor's computing resources, the MIMO channel can be configured with multiple receive channels, including a first receive channel and a second receive channel, based on the number of receive channels that can be formed by the physical antenna array.

[0066] Embodiment 1 of the present application provides an angle-of-arrival estimation method for a sensor, wherein the sensor includes a physical antenna array, wherein the physical antenna array includes a transmitting antenna and multiple receiving antennas. The method includes: receiving a signal frame; wherein the signal frame is obtained based on multiple detection signal waves and their respective echo signal waves emitted by the physical antenna array; using a preset first steering vector and a first receiving signal, performing an angle-of-arrival estimation on the signal frame to determine the angle information of the detected object; wherein the first steering vector and the first receiving signal are both set based on the aperture information of multiple receiving channels and the wavelength of the detection signal wave; the multiple receiving channels include a first receiving channel constructed based on the receiving antenna and a second receiving channel obtained by mirroring any of the first receiving channels. In the above technical solution, the transmitting antenna in the physical antenna array included in the radar sensor can transmit a detection signal wave, and the detection signal wave generates an echo signal wave after detecting an object. The receiving antenna can receive the echo signal wave in the form of a signal frame. Furthermore, the radar sensor can use the first steering vector and the first received signal set according to the aperture information of multiple receiving channels and the wavelength of the detection signal wave to perform virtual aperture arrival angle estimation on the signal frame, thereby determining the angle information of the detected object and estimating the arrival angle of the detected object. Since the multiple receiving channels can include a first receiving channel constructed based on the receiving antenna and a second receiving channel obtained by mirroring any first receiving channel, the introduction of the mirrored second receiving channel increases the aperture of the physical antenna array included in the radar sensor, improves the angular resolution of the radar sensor, and further improves the accuracy of the arrival angle estimation.

[0067] Example 2

[0068] Figure 9 This is a flow chart of a method for estimating the angle of arrival provided in Example 2 of this application. Figure 9 As shown, unlike the previous embodiment, the MIMO channels of the radar sensor can be configured by selecting instructions. The method also includes:

[0069] Step 910: Obtain a selection instruction; determine the first steering vector and the first received signal according to the first receiving channel and the second receiving channel indicated by the selection instruction.

[0070] The selection instructions are used to enable the radar sensor to select corresponding MIMO channels constructed using each first receiving channel and / or each second receiving channel according to different modes. The mode is related to the electronic device for which the radar sensor is used. For example, the radar sensor is configured in an automated driving system. Based on instructions issued by the automated driving system, the radar sensor selects and provides MIMO channels with different configurations to estimate the angle of arrival. The modes are also used to provide the radar sensor with multiple angular resolutions. For example, the radar sensor may be configured with multiple MIMO channels, each with a different angular resolution, and the angular information between the radar sensor and multiple surrounding objects may be estimated by switching between different modes. The different MIMO channels corresponding to each selection instruction and their corresponding parameters for angle of arrival estimation may be preconfigured or generated based on the information in the selection instruction. For example, the different MIMO channels and their corresponding parameters may be preset in the radar sensor via a configuration file or a configuration table. For another example, the radar sensor may be configured with information about the spacing between antennas in a physical antenna array, and the corresponding parameters may be generated based on the received selection instructions.

[0071] by Figure 8 For example, when receive antennas RX1 and RX2 and virtual receive antennas RX3' and RX4' are determined for angle of arrival estimation according to a selection instruction, the multiple MIMO channels determined for the same transmit antenna TX1 include: TX1-RX1, TX1-RX2, TX1-RX3', and TX1-RX4'. For the same transmit antenna TX1, the first receive channel includes the receive channel determined using receive antennas RX1 and RX2; and for the same transmit antenna TX1, the second receive channel includes the receive channel determined using virtual receive antennas RX3' and RX4'. Aperture information for each of these multiple receive channels is used to configure a first steering vector and a first received signal for angle of arrival estimation.

[0072] In actual applications, the selection instruction may also be generated by a user trigger, for example, in a testing phase, the selection instruction may be generated by user settings.

[0073] In an embodiment of the present application, the first receiving channel and the second receiving channel can be determined according to a selection instruction triggered by the user. The aperture of the first receiving channel and the virtual aperture of the second receiving channel can be used to determine the aperture of the physical antenna array, and then determine the first steering vector and the first receiving signal of the radar sensor including the physical antenna array.

[0074] Step 920: Receive a signal frame.

[0075] The signal frame is obtained based on the detection signal wave and its echo signal wave transmitted by the physical antenna array.

[0076] As previously mentioned, the transmitting antenna in the physical antenna array included in the radar sensor can transmit a detection signal wave to the surrounding area. The detection signal wave is reflected by the detection target to obtain an echo signal wave. The receiving antenna can receive the echo signal wave in the form of a signal frame.

[0077] Step 930: Use the preset first steering vector and the first received signal to perform angle of arrival estimation on the signal frame to determine angle information of the detected object.

[0078] The first steering vector and the first receiving signal are both set based on aperture information of multiple receiving channels and the wavelength of the detection signal wave; the multiple receiving channels include a first receiving channel constructed based on the receiving antenna and a second receiving channel obtained by mirroring any of the first receiving channels. The multiple receiving channels include all of the first receiving channels; or at least one of the first receiving channels and at least one of the second receiving channels selected based on the total number of the first receiving channels.

[0079] The amplitude parameter of the first received signal corresponding to the second receive channel is the same as the amplitude parameter corresponding to the mirrored first receive channel. The phase parameter of the first steering vector corresponding to the second receive channel is inverted based on a mirror reference to the phase parameter corresponding to the mirrored first receive channel.

[0080] As described in the first embodiment, after determining the first and second receiving channels, the aperture of the physical antenna array can be determined, and thus the first steering vector a and the first received signal S can be determined. Based on the determined first steering vector and the first received signal, a virtual aperture angle of arrival (AoA) is estimated for the signal frame to determine the angle of objects detected by the radar sensor. Because the virtual receiving antenna increases the aperture of the physical antenna array, the radar's angular resolution is improved.

[0081] In some other examples, in the scheme of obtaining the second receiving channel by mirroring the first receiving channel and estimating the angle of arrival based on the second receiving channel, the signal received by each first receiving channel inevitably contains noise. Therefore, the parameter of the first receiving signal corresponding to the second receiving channel The angle of arrival (AoA) calculated using the second steering vector and the second received signal contains noise from the first receiving channel sp1, which serves as the reference, and the first receiving channel sp4, which is used for mirroring. Therefore, the angular accuracy is inferior to the angle of arrival calculated using the second steering vector and the second received signal. To balance the angular resolution and angular accuracy requirements of the radar sensor, when multiple angles are estimated in a signal frame, steps 940-950 are performed to improve the accuracy of the estimated angles.

[0082] Step 940: When multiple angle information is detected, detect the angle intervals between the multiple objects measured by the sensor.

[0083] Step 950: If the angular interval is not less than the true angular resolution, perform angle of arrival estimation based on the second steering vector and the second received signal set based on the aperture information of the plurality of first receiving channels.

[0084] Here, when multiple angles of information are detected, it indicates that multiple detectable objects exist around the radar sensor. If the angular spacing between the multiple objects is less than the angular resolution of the second MIMO channel constructed using the physical antenna array, it indicates that the second steering vector and second received signal configured by the second MIMO channel cannot estimate a more accurate angle of arrival. Conversely, if the angular spacing between the multiple objects is greater than or equal to the angular resolution of the second MIMO channel, step 950 is executed to obtain more accurate angular information for each object.

[0085] by Figure 7 Taking the energy peak represented by the dotted line in the angle range of -10° to 30° as an example, the angular interval between the angular information of two objects estimated using the virtual aperture (-0.9° and 19.8°) represented by the dotted line is approximately 20°. If the angular interval is greater than the angular resolution of the MIMO channel constructed using the physical antenna array, the angular information of the two objects with higher accuracy is calculated by executing steps 940-950; otherwise, the radar sensor outputs the angular information of the two objects as (-0.9° and 19.8°).

[0086] It should be noted that Figure 9 A flow chart combining selection instructions and angle accuracy is shown. Here, step 950 can be as follows Figure 9 The process is performed as shown. Although not shown in the figure, the mode can also be switched by generating a selection instruction to perform the arrival angle estimation using the second steering vector and the second received signal.

[0087] A second embodiment of the present application provides an angle-of-arrival estimation method, which determines multiple receiving channels for angle-of-arrival estimation based on a first receiving channel and a second receiving channel indicated by an acquisition selection instruction, and uses a first steering vector and a first received signal set based on the aperture information of the multiple receiving channels and the wavelength of the detection signal wave to perform angle-of-arrival estimation on a signal frame, thereby determining the angle information of the detected object and achieving angle-of-arrival estimation of the detected object. Of course, when the radar sensor determines that multiple angle information has been detected, it can detect the angular interval between the multiple objects measured. If the angular interval is not less than the actual angular resolution, a physical antenna array that does not include a virtual receiving antenna can also be used to determine an accurate angle-of-arrival estimation result with higher efficiency. Therefore, a second steering vector and a second received signal are set based on the aperture information of all first receiving channels, and the second steering vector and the second received signal are used to perform angle-of-arrival estimation on the signal frame to determine the angle information of each object. When determining the angle information of an object, the multiple receiving channels may include a first receiving channel constructed based on a receiving antenna and a second receiving channel obtained by mirroring any of the first receiving channels. The introduction of the mirrored second receiving channel increases the aperture of the physical antenna array included in the radar sensor, improves the angular resolution of the radar sensor, and further enhances the accuracy of the angle of arrival estimation.

[0088] Example 3

[0089] Figure 10 This is a structural diagram of a wave angle estimation device provided in Example 3 of the present application, such as Figure 10 As shown, the angle of arrival estimation device includes: a memory 1010 storing at least one program and aperture information between antennas in a physical antenna array of a sensor; and a processor 1020 connected to the memory and configured to execute the at least one program to perform the angle of arrival estimation method described in any one of Embodiments 1 and 2 using the aperture information to determine angle information of objects around the sensor.

[0090] There is a conversion relationship between the aperture information and the phase difference between the antennas. Therefore, the memory 1010 may also store the phase difference between the antennas.

[0091] The number of processors 1020 in the angle of arrival estimation device can be one or more. Figure 10 In the figure, a processor 1020 is used as an example; the processor 1020 and the memory 1010 in the angle of arrival estimation device can be connected via a bus or other means. Figure 10 The bus connection is taken as an example.

[0092] The memory 1010, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to the angle-of-arrival estimation method in the embodiments of the present application. The processor 1020 executes the software programs, instructions, and modules stored in the memory 1010 to execute various functional applications and data processing of the angle-of-arrival estimation device, thereby implementing the aforementioned angle-of-arrival estimation method.

[0093] The memory 1010 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system and applications required for at least one function; the data storage area may store data created based on the use of the terminal, etc. In addition, the memory 1010 may include a high-speed random access memory and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some instances, the memory 1010 may further include a memory remotely located relative to the processor 1020, and these remote memories may be connected to the device / terminal / server via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0094] The angle of arrival estimation device provided in the embodiment of the present application can execute the angle of arrival estimation method provided in the above embodiment, and has corresponding functions and beneficial effects.

[0095] Example 4

[0096] Figure 11 This is a schematic diagram of the structure of a radar sensor provided in Example 4 of the present application, such as Figure 10 As shown, it includes: an antenna array 1110, including a transmitting antenna and multiple receiving antennas; a signal transceiver 1120, connected to the antenna array 1110, for transmitting a detection signal wave through the transmitting antenna, and receiving an echo signal wave through the receiving antenna, and outputting a signal frame, wherein the echo signal wave is obtained by reflecting the detection signal wave from an object; and an angle of arrival estimation device 1130 as described in Example 3, connected to the signal transceiver 1120.

[0097] The radar sensor provided in the embodiment of the present application can output a digital signal by processing the echo electrical signal within a directional range based on the antenna included in the radar sensor, and has the same beneficial effects as the antenna provided in the first and second embodiments.

[0098] Furthermore, the signal transceiver 1120 includes a signal transmitter and a signal receiver. The antenna array 1110 and signal transceiver 1120 each have circuit structures determined based on the radar sensor's requirements for ambient environment detection and signal processing. These circuits transmit detection signal waves and receive echo signal waves at a preset frequency band or fixed frequency, and process the corresponding changing electrical signals.

[0099] The signal transmitter is used to transmit the changing electrical signal corresponding to the detection signal wave to the transmitting antenna in the antenna device. Specifically, the signal transmitter performs frequency and phase modulation on the reference electrical signal provided by the signal source, and modulates it into a current-changing transmitting electrical signal in the radio frequency band for output to the transmitting antenna.

[0100] The signal receiver is used to demodulate and filter the received electrical signals (ie, the changed electrical signals) output by the receiving antennas in the antenna array using the transmitted electrical signals to obtain baseband digital signals for extracting measurement information.

[0101] The signal processor is connected to the signal transceiver and is configured to extract and output measurement information from the received baseband digital signal. The signal frame processed by the signal processor is a frame of multiple baseband digital signals obtained by signal processing based on a probe signal wave transmitted by at least one transmitting antenna. The angle of arrival estimation method described above is used to perform digital signal processing calculations to output the estimated angle information.

[0102] Example 5

[0103] Figure 12 This is a structural diagram of an electronic device provided in Example 5 of the present application. Figure 12 A block diagram of an exemplary electronic device 12 suitable for implementing embodiments of the present application is shown. Figure 12 The electronic device 12 shown is merely an example and should not limit the functions and scope of use of the embodiments of the present application.

[0104] like Figure 12 As shown, electronic device 12 is implemented as a general-purpose computing electronic device. Components of electronic device 12 may include, but are not limited to, a radar sensor 25, one or more processors or processing units 16, a system memory 28, and a bus 18 connecting various system components (including system memory 28 and processing unit 16).

[0105] Bus 18 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processor, or a local bus using any of a variety of bus architectures. Examples of these architectures include, but are not limited to, an Industry Standard Architecture (ISA) bus, a Micro Channel Architecture (MAC) bus, an Enhanced ISA bus, a Video Electronics Standards Association (VESA) local bus, and a Peripheral Component Interconnect (PCI) bus.

[0106] The electronic device 12 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by the electronic device 12, including volatile and non-volatile media, removable and non-removable media.

[0107] The system memory 28 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and / or cache memory 32. The electronic device 12 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, the storage system 34 may be configured to read and write non-removable, non-volatile magnetic media ( Figure 12 Not shown, often called a "hard drive"). Although Figure 12 Not shown, a disk drive for reading and writing to a removable non-volatile disk (e.g., a "floppy disk"), and an optical drive for reading and writing to a removable non-volatile optical disk (e.g., a CD-ROM, DVD-ROM, or other optical media) may be provided. In these cases, each drive may be connected to the bus 18 via one or more data medium interfaces. The system memory 28 may include at least one program product having a set (e.g., at least one) of program modules that are configured to perform the functions of the various embodiments of the present application.

[0108] A program / utility 40 having a set (at least one) of program modules 42 may be stored, for example, in system memory 28. Such program modules 42 include, but are not limited to, an operating system, one or more application programs, other program modules, and program data, each of which, or some combination thereof, may include an implementation of a network environment. Program modules 42 generally implement the functions and / or methods of the embodiments described herein.

[0109] The electronic device 12 may also communicate with one or more external devices 14 (e.g., a keyboard, a pointing device, a display 24, etc.), one or more devices that enable a user to interact with the electronic device 12, and / or any device that enables the electronic device 12 to communicate with one or more other computing devices (e.g., a network card, a modem, etc.). Such communication may be performed through an input / output (I / O) interface 22. Furthermore, the electronic device 12 may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) through a network adapter 20. Figure 12 As shown, the network adapter 20 communicates with other modules of the electronic device 12 via the bus 18. Figure 12 Not shown, other hardware and / or software modules may be used in conjunction with the electronic device 12, including but not limited to microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0110] The processing unit 16 executes various functional applications and page displays by running programs stored in the system memory 28, for example, implementing the angle of arrival estimation method provided in the embodiment of the present invention. The method is applied to a sensor including a physical antenna array, wherein the physical antenna array is composed of at least one transmitting antenna and multiple receiving antennas, including:

[0111] Receive a signal frame; wherein the signal frame is obtained based on multiple detection signal waves and their respective echo signal waves transmitted by the physical antenna array;

[0112] Using a preset first steering vector and a first receiving signal, the signal frame is estimated to estimate the angle of arrival to determine the angle information of the detected object; wherein the first steering vector and the first receiving signal are both set based on the aperture information of multiple receiving channels and the wavelength of the detection signal wave; the multiple receiving channels include a first receiving channel constructed based on the receiving antenna and a second receiving channel obtained by mirroring any of the first receiving channels.

[0113] Of course, those skilled in the art will appreciate that the processor may also implement the technical solution of the angle of arrival estimation method provided in any embodiment of the present application.

[0114] Example 6

[0115] A sixth embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the method for estimating the angle of arrival provided in the embodiment of the present application is implemented. The method is applied to a sensor including a physical antenna array, wherein the physical antenna array includes at least one transmitting antenna and multiple receiving antennas, including:

[0116] Receive a signal frame; wherein the signal frame is obtained based on multiple detection signal waves and their respective echo signal waves transmitted by the physical antenna array;

[0117] Using a preset first steering vector and a first receiving signal, the signal frame is estimated to estimate the angle of arrival to determine the angle information of the detected object; wherein the first steering vector and the first receiving signal are both set based on the aperture information of multiple receiving channels and the wavelength of the detection signal wave; the multiple receiving channels include a first receiving channel constructed based on the receiving antenna and a second receiving channel obtained by mirroring any of the first receiving channels.

[0118] The computer storage medium of the embodiment of the present application can adopt any combination of one or more computer-readable media.Computer-readable media can be computer-readable signal media or computer-readable storage media.Computer-readable storage media can be, for example, but not limited to: electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or components, or any combination of the above.More specific examples (non-exhaustive list) of computer-readable storage media include: electrical connection with one or more wires, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above.In this document, computer-readable storage media can be any tangible medium containing or storing a program, which can be used by an instruction execution system, device or device or used in combination with it.

[0119] A computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0120] Program code embodied on a computer-readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0121] The computer program code for performing the operations of the present application can be written in one or more programming languages, or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0122] Those skilled in the art will appreciate that the modules or steps of the present application described above can be implemented using a general-purpose computing device. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Alternatively, they can be implemented using program code executable by a computer device, so that they can be stored in a storage device and executed by the computing device. Alternatively, they can be fabricated into separate integrated circuit modules, or multiple modules or steps can be fabricated into a single integrated circuit module for implementation. Thus, the present application is not limited to any specific combination of hardware and software.

[0123] In addition, the acquisition, storage, use, and processing of data in the technical solution of this application comply with the relevant provisions of national laws and regulations.

[0124] Note that the above are only preferred embodiments of the present application and the technical principles employed. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the scope of protection of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments and may include many other equivalent embodiments without departing from the scope of the present application. The scope of the present application is determined by the scope of the appended claims.

Claims

1. A method for estimating angle of arrival, characterized in that: Applied to a sensor comprising a physical antenna array, wherein the physical antenna array comprises at least one transmitting antenna and a plurality of receiving antennas, the method comprises: Receive a signal frame; wherein the signal frame is obtained based on multiple detection signal waves and their respective echo signal waves transmitted by the physical antenna array; performing an angle-of-arrival estimation on the signal frame using a preset first steering vector and a first received signal to determine angle information of the detected object; wherein the first steering vector and the first received signal are both set based on aperture information of a plurality of receiving channels and the wavelength of the detection signal wave; the plurality of receiving channels include a first receiving channel constructed based on the receiving antenna and a second receiving channel obtained by mirroring any of the first receiving channels; Also includes: When multiple angle information is detected, detecting the angular intervals between the multiple objects measured by the sensor; If the angular interval is not less than the true angular resolution, the second steering vector and the second received signal are used to estimate the angle of arrival of the signal frame to determine the angular information of each object; wherein the second steering vector and the second received signal are both set based on the aperture information of the multiple first receiving channels.

2. The method for estimating the angle of arrival according to claim 1, wherein: Also includes: Get the selection instruction; The first steering vector and the first received signal are determined according to the first receiving channel and the second receiving channel indicated by the selection instruction.

3. The method for estimating angle of arrival according to claim 1, wherein: The second receiving channel is obtained by taking one of the first receiving channels as a mirror reference and mirroring the aperture information of the other first receiving channel relative to the mirror reference.

4. The method for estimating angle of arrival according to claim 1, wherein: The plurality of receiving channels include all of the first receiving channels; or at least one of the first receiving channels and at least one of the second receiving channels selected based on the total number of channels of the first receiving channels.

5. The method for estimating angle of arrival according to claim 1, wherein: The amplitude parameter corresponding to the second receiving channel in the first receiving signal is the same as the amplitude parameter corresponding to the first receiving channel mirrored by the second receiving channel.

6. The method for estimating angle of arrival according to claim 1, wherein: The phase parameter corresponding to the second receiving channel in the first steering vector is inverted based on a mirror reference to the phase parameter corresponding to the first receiving channel mirrored by the second receiving channel.

7. A device for estimating an angle of arrival, characterized in that: include: a memory storing at least one program and aperture information between antennas in a physical antenna array of the sensor; A processor is connected to the memory and is configured to execute the at least one program to perform the angle of arrival estimation method according to any one of claims 1 to 6 using each of the aperture information to determine angle information of objects around the sensor.

8. A radar sensor, characterized in that: include: an antenna array, including a transmitting antenna and multiple receiving antennas; a signal transceiver connected to the antenna array, configured to transmit a detection signal wave via a transmitting antenna, receive an echo signal wave via a receiving antenna, and output a signal frame, wherein the echo signal wave is obtained by reflecting the detection signal wave from an object; The angle of arrival estimation device according to claim 7, connected to the signal transceiver.

9. An electronic device, characterized in that: include: The radar sensor of claim 8; a processor coupled to the radar sensor; and a memory coupled to the processor; The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can perform the angle of arrival estimation method according to any one of claims 1 to 6.

Images