MIMO array layout structure and method for improving millimeter wave radar elevation angle finding

Abstract

The application discloses an MIMO array layout structure and method for improving millimeter wave radar elevation angle measurement, belongs to the technical field of millimeter wave radars, and comprises an MIMO antenna array; the MIMO antenna array comprises a transmitting antenna array and a receiving antenna array; the transmitting antenna array and the receiving antenna array are located on the same XY plane, the transmitting antenna array and the receiving antenna array are respectively formed by arranging a plurality of channel antenna arrays, and the phase centers of each antenna in the transmitting antenna array and the receiving antenna array are offset in the XY plane, thereby forming a surface array. In the above manner, the application can improve the number of layers of the elevation angle measurement under the limitation of the effective channel number, improve the performance of the elevation angle measurement, and maintain the horizontal angle measurement performance of the millimeter wave radar.

Description

Technical Field

[0001] This invention relates to the field of millimeter-wave radar technology, and more specifically to a MIMO array layout structure and method for improving the elevation angle measurement of millimeter-wave radar. Background Technology

[0002] As a key sensor in automotive driver assistance systems, millimeter-wave radar provides safety functions such as collision warning and lane keeping assist. At the perception level, it places higher demands on the perception dimension and accuracy of millimeter-wave radar. For example, when dealing with a target with height, the perception system may have different weights for multiple source sensors, leading to a probability of false detection. One reason for this is that the target data provided by millimeter-wave radar lacks confidence and also lacks pitch height information.

[0003] A millimeter-wave radar system with reliable altitude sensing capability must basically have the ability to sample electromagnetic wave signals reflected in space. This sampling capability is provided by the array antenna. Multiple-input multiple-output (MIMO) antennas can provide a virtual aperture larger than the physical aperture of the antenna to achieve better angular resolution. However, due to the limitation of the number of radio frequency channels, the array antenna layout needs to balance angular ambiguity and angular resolution. At the same time, it is also necessary to consider how to allocate channels to achieve horizontal and pitch angle measurement capabilities.

[0004] Thanks to the development of radio frequency integrated circuit technology, more channels for transmission and reception have been achieved through monolithic integration or multi-chip cascading. However, further design of the antenna array layout is still needed to improve the pitch angle measurement capability without sacrificing horizontal angle measurement performance.

[0005] Based on this, the present invention designs a MIMO array layout structure and method to improve the elevation angle measurement of millimeter-wave radar in order to solve the above problems. Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the existing technology, the present invention provides a MIMO array layout structure and method for improving the elevation angle measurement of millimeter-wave radar.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] Improve the MIMO array layout structure for millimeter-wave radar elevation angle measurement, including MIMO antenna arrays;

[0009] The MIMO antenna array includes a transmitting antenna array and a receiving antenna array;

[0010] The transmitting antenna array and the receiving antenna array are located on the same XY plane. The transmitting antenna array and the receiving antenna array are each formed by arranging multi-channel antenna arrays. The phase center (201, 301) of each antenna in the transmitting antenna array and the receiving antenna array has an offset in the XY plane, forming a planar array.

[0011] Furthermore, the phase centers (201, 301) of each antenna in the transmitting antenna array and the receiving antenna array have a lateral spacing in the X-axis direction, and the lateral spacing is an integer multiple of half the wavelength.

[0012] Furthermore, in the transmitting antenna array and the receiving antenna array, at least two channels of the phase center (201, 301) of the antenna have positional offsets in the Y-axis direction, with the offset spacing being an integer multiple of half a wavelength.

[0013] Furthermore, the channels with positional offset in the Y-axis direction are antenna channels in the transmitting antenna array and / or antenna channels in the receiving antenna array.

[0014] Furthermore, the transmitting antenna array has four channels TX1, TX2, TX3 and TX4; the receiving antenna array has four channels RX1, RX2, RX3 and RX4.

[0015] A method for improving the elevation angle measurement of millimeter-wave radar using a MIMO array layout includes the following steps:

[0016] Step 1: Arrange the transmitting antenna array and the receiving antenna array on the same XY plane;

[0017] Step 2: Control the spacing of the four channels TX1, TX2, TX3 and TX4 of the transmitting antenna array in the X-axis direction to T12, T23 and T34 respectively, which are integer multiples of half the wavelength of the radar center operating frequency band; T12, T23 and T34 can be unequal or equal;

[0018] Step 3: Control the spacing of the four channels RX1, RX2, RX3 and RX4 of the receiving antenna array in the X-axis direction to R12, R23 and R34 respectively, which are integer multiples of half the wavelength of the radar center operating frequency band.

[0019] Step 4: Offset the position of some channel antennas in the transmitting antenna array and / or receiving antenna array on the Y-axis;

[0020] Step 5: Perform the Kronecker product on the coordinates of each channel of the transmitting and receiving antenna arrays to obtain the position coordinates of the virtual channel.

[0021] Furthermore, the two channels in the receiving antenna array are offset in the Y-axis direction.

[0022] Furthermore, one channel in the transmitting antenna array and two channels in the receiving antenna array are offset in the Y-axis direction.

[0023] Furthermore, one channel in the transmitting antenna array and two channels in the receiving antenna array are offset in the Y-axis direction.

[0024] Beneficial effects

[0025] This invention can increase the number of elevation angle measurement layers under the limitation of the number of effective channels, improve the elevation angle measurement performance, and maintain the horizontal angle measurement performance of millimeter-wave radar. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0027] Figure 1 This is a schematic diagram of the array antenna layout for improving elevation angle measurement performance according to the present invention;

[0028] Figure 2 This is a schematic diagram of the equivalent virtual aperture arrangement of the present invention. Figure 1 ;

[0029] Figure 3 This is a schematic diagram of the array arrangement of the physical apertures of the present invention. Figure 1 ;

[0030] Figure 4 This is a schematic diagram of the array arrangement of the physical apertures of the present invention. Figure 2 ;

[0031] Figure 5 This is a schematic diagram of the array arrangement of the physical apertures of the present invention. Figure 3 . Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] The present invention will be further described below with reference to embodiments.

[0034] Example 1

[0035] This embodiment provides a MIMO array layout structure for improving the elevation angle measurement of millimeter-wave radar, including a MIMO antenna array 10;

[0036] The MIMO antenna array 10 includes a transmitting antenna array 20 and a receiving antenna array 30;

[0037] The transmitting antenna array 20 and the receiving antenna array 30 are located on the same XY plane. The transmitting antenna array 20 and the receiving antenna array 30 are respectively formed by multi-channel antenna arrays. The phase center (201, 301) of each antenna in the transmitting antenna array 20 and the receiving antenna array 30 has an offset in the XY plane, forming a planar array.

[0038] For example, the transmitting antenna array 20 has four channels TX1, TX2, TX3 and TX4; the receiving antenna array 30 has four channels RX1, RX2, RX3 and RX4.

[0039] Preferably, the phase centers (201, 301) of each antenna in the transmitting antenna array 20 and the receiving antenna array 30 have a lateral spacing in the X-axis direction, and the lateral spacing is an integer multiple of half the wavelength.

[0040] Preferably, in the transmitting antenna array 20 and the receiving antenna array 30, at least two channels of the phase centers (201, 301) of the antennas have positional offsets in the Y-axis direction, with the offset spacing being an integer multiple of half the wavelength; that is, the coordinate positions of the phase centers (201, 301) of the antennas in the Y-axis direction are at least two different from the others, for example... Figure 1 In the process, the coordinate positions of TX1, RX1, and RX4 in the Y-axis direction are different from the others, and the three channels TX1, RX1, and RX4 have position offsets in the Y-axis direction.

[0041] Preferably, there is a channel with a position offset in the Y-axis direction, which can be either an antenna channel in the transmitting antenna array 20 or an antenna channel in the receiving antenna array 30.

[0042] Example 2

[0043] This embodiment provides a MIMO array layout method for improving elevation angle measurement of millimeter-wave radar, including the following steps:

[0044] Step 1: Arrange the transmitting antenna array 20 and the receiving antenna array 30 on the same XY plane;

[0045] Step 2: The spacing of the four channels TX1, TX2, TX3 and TX4 of the transmitting antenna array 20 in the X-axis direction is controlled at T12, T23 and T34 respectively, which are integer multiples of half the wavelength of the radar center operating frequency band; T12, T23 and T34 can be unequal or equal, depending on whether there is any overlap of X-axis coordinates in the channel distribution in the virtual aperture in the X-axis direction;

[0046] Step 3: Control the spacing of the four channels RX1, RX2, RX3 and RX4 of the receiving antenna array 30 in the X-axis direction to R12, R23 and R34 respectively, which are integer multiples of half the wavelength of the radar center operating frequency band;

[0047] Step 4: The position of some channel antennas in the transmitting antenna array 20 and / or receiving antenna array 30 is offset on the Y-axis. The purpose is to simultaneously sample the phase information of the azimuth and elevation incoming wave signals. The antenna array element is equivalent to transmitting or receiving radar waves from a certain position in the aperture. Generally, its position is located at the geometric center of the antenna element aperture, i.e., the phase center (201, 301).

[0048] Step 5: Perform Kronecker product on the coordinates of each channel of the transmitting antenna array 20 and the receiving antenna array 30 to obtain the position coordinates 401 of the sixteen virtual channels;

[0049] like Figure 2 As shown in the equivalent virtual aperture layout diagram 40, although a 3-layer layout is achieved in the physical aperture layout, a 4-layer layout is obtained in the virtual aperture 402. More antenna channels or antenna layers help improve the angular resolution.

[0050] Example 3

[0051] like Figure 3 The physical aperture array layout diagram 500 is shown. The physical aperture array 501 shows that two channels in the receiving antenna array 30 are offset in the Y-axis direction by offsets dy1 and dy2. By giving reasonable offsets, such as dy1≠dy2, a three-layer layout 503 is obtained, resulting in a three-layer virtual aperture 502.

[0052] Example 4

[0053] like Figure 4 The physical aperture array layout diagram 600 is shown. The physical aperture array 601 shows that one channel in the transmitting antenna array 20 and two channels in the receiving antenna array 30 are offset in the Y-axis direction by an offset amount of dy1-3. By giving a reasonable offset amount, a 4-layer layout 603 is obtained, and a 4-layer virtual aperture 602 is obtained.

[0054] Example 5

[0055] like Figure 5 The physical aperture array layout diagram 700 is shown. The physical aperture array 701 shows that one channel in the transmitting antenna array 20 and two channels in the receiving antenna array 30 are offset in the Y-axis direction by an offset amount of dy1-3. By giving a reasonable offset amount, a 5-layer layout 703 is obtained, and a 5-layer virtual aperture 702 is obtained.

[0056] This invention can increase the number of elevation angle measurement layers under the limitation of the number of effective channels, improve the elevation angle measurement performance, and maintain the horizontal angle measurement performance of millimeter-wave radar.

[0057] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A MIMO array layout structure for improving elevation angle measurement in millimeter-wave radar, characterized in that, The array includes a MIMO antenna array (10); the MIMO antenna array (10) includes a transmitting antenna array (20) and a receiving antenna array (30); the transmitting antenna array (20) has four channels TX1, TX2, TX3 and TX4; the receiving antenna array (30) has four channels RX1, RX2, RX3 and RX4; the transmitting antenna array (20) and the receiving antenna array (30) are located on the same XY plane, and the transmitting antenna array (20) and the receiving antenna array (30) are respectively formed by multi-channel antenna arrays. The phase center (201, 301) of each antenna in the transmitting antenna array (20) and the receiving antenna array (30) are offset in the XY plane to form a surface array; wherein, one channel in the transmitting antenna array (20) and two channels in the receiving antenna array (30) are offset in the Y-axis direction, and the offset distance is an integer multiple of half the wavelength.

2. The MIMO array layout structure for improving millimeter-wave radar elevation angle measurement according to claim 1, characterized in that, The phase centers (201, 301) of each antenna in the transmitting antenna array (20) and receiving antenna array (30) have a lateral spacing in the X-axis direction, and the lateral spacing is an integer multiple of half a wavelength.

3. A MIMO array layout method for improving elevation angle measurement in millimeter-wave radar, characterized in that, The layout is based on the layout structure described in claim 1, including the following steps: Step 1: Arrange the transmitting antenna array (20) and the receiving antenna array (30) on the same XY plane; Step 2: The spacing of the four channels TX1, TX2, TX3 and TX4 of the transmitting antenna array (20) in the X-axis direction is controlled at T12, T23 and T34 respectively, which are integer multiples of half the wavelength of the radar center operating frequency band; T12, T23 and T34 can be unequal or equal; Step 3: The spacing of the four channels RX1, RX2, RX3 and RX4 of the receiving antenna array (30) in the X-axis direction is controlled at R12, R23 and R34 respectively, which are integer multiples of half the wavelength of the radar center operating frequency band; Step 4: The position of one channel in the transmitting antenna array (20) and two channels in the receiving antenna array (30) is offset in the Y-axis direction, and the offset spacing is an integer multiple of half the wavelength; Step 5: The coordinates of each channel of the transmitting antenna array (20) and the receiving antenna array (30) are multiplied by Kronecker to obtain the position coordinates (401) of sixteen virtual channels.

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