Reciprocity OTA test system and method

Abstract

The invention discloses a reciprocity OTA test system and method for non-common-aperture antenna equipment, and aims to solve the problem that the reciprocity test of equipment with large size and physical separation of uplink and downlink antennas is difficult to realize strict consistency of uplink and downlink space angles in a limited darkroom environment. The system core comprises a turntable device, a radiation probe module and a control module. The probe module adopts an innovative design of a fixed probe and a movable probe to respectively process uplink and downlink signals. The control module cooperatively drives the rotary table and the movable probe to move, so that the relative space angles between the uplink and the downlink and the corresponding probe are accurately matched with the same target angle. According to the scheme, an expensive static multi-probe array is replaced by dynamic mechanical cooperation, a completely consistent space wave propagation path is created for separated uplink and downlink antennas in a limited space, strict reciprocity of an angle domain is ensured, and system cost and site requirements are remarkably reduced.

Description

Technical Field

[0001] This application relates to the field of wireless communication testing, and in particular to a reciprocity over-the-air (OTA) testing system and method. Background Technology

[0002] Over-the-Air (OTA) testing technology has become an essential method for evaluating the radio frequency (RF) performance of communication equipment due to its non-destructive nature and good adaptability to high-frequency signals. In fields such as satellite communications, devices under test (e.g., satellite payloads or ground terminals) often employ physically separate uplink and downlink antenna arrays, i.e., non-co-aperture antenna designs, and are relatively large in size. This places stringent requirements on the uplink and downlink reciprocity of OTA test systems. Reciprocity refers to the requirement that the spatial channel characteristics of the uplink and downlink in the test system, especially the signal arrival / departure angles, remain consistent to accurately verify advanced functions based on channel reciprocity, such as beamforming.

[0003] There are three main existing typical OTA testing solutions, but none of them can effectively meet the low-cost, high-precision reciprocity testing requirements of large-size, non-common aperture devices: First, there is the single downlink OTA testing system. This architecture can only build a downlink testing environment; the uplink is handled through simple loopback processing, and it inherently does not support uplink and downlink reciprocity testing.

[0004] Secondly, there is the uplink and downlink bidirectional test system using a two-dimensional multi-probe array. This method relies on synthesizing the target field in the test area and using an algorithm to configure a channel simulator to achieve uplink and downlink channel reciprocity. However, for large-sized devices under test with high spatial resolution requirements, extremely dense arraying of probe antennas is necessary to achieve strict field consistency. This leads to a dramatic increase in the number of probes, high system costs, and the two-dimensional planar array struggles to support complex three-dimensional radiation characteristic tests, resulting in poor engineering feasibility and economic efficiency.

[0005] Finally, there is the satellite communication test system using an integrated transceiver probe. While this system can support bidirectional reciprocity testing of common-aperture antenna equipment, for non-common-aperture equipment, due to the asymmetry of geometric positions within a limited anechoic chamber, a single probe cannot simultaneously maintain the same spatial angular relationship with the physically separated uplink and downlink antenna arrays on the equipment, thus inherently violating the uplink and downlink reciprocity condition.

[0006] In summary, existing mainstream OTA testing solutions either cannot achieve reciprocity testing due to architectural limitations, lack practicality due to excessively high implementation costs, or cannot guarantee angle consistency due to physical geometric constraints, all exhibiting significant shortcomings. Therefore, there is an urgent need in this field for an innovative testing system capable of achieving high-precision uplink and downlink reciprocity OTA testing for large-size, non-common-aperture devices at a reasonable cost. Summary of the Invention

[0007] This application proposes a reciprocity OTA testing system and method to solve the problem of how to achieve reciprocity OTA testing with strictly consistent uplink and downlink spatial angles for physically separated large-size antenna devices in a limited environment.

[0008] In a first aspect, embodiments of this application provide a reciprocity OTA testing system, comprising: a turntable device, a radiation probe module, and a control module. The turntable device is used to support and fix the device under test (DUT) and adjust the spatial attitude of the DUT. The radiation probe module includes at least one downlink probe and at least one uplink probe; one of the downlink probe and the uplink probe is configured as a fixed probe, and the other as a movable probe. The control module is used to control the movement of the turntable and the movable probe, such that the relative spatial angles of the downlink probe and the uplink probe with the downlink antenna array and the uplink antenna array of the DUT, respectively, match a common target relative spatial angle. In one embodiment, the turntable device is a three-axis turntable, including an azimuth axis, a pitch axis, and a polarization axis.

[0009] In one embodiment, the common target relative spatial angle is the relative spatial angle between the communication peer and the device under test, defined with the position of the fixed probe as the observation point in the simulation scenario.

[0010] In one embodiment, the movement of the movable probe includes a circular motion centered on the fixed probe, used to change the angle between the movable probe and the fixed probe.

[0011] In one embodiment, the movement of the movable probe includes movement toward or away from the fixed probe.

[0012] In one embodiment, the system further includes a peripheral device module, which includes one or more of a satellite payload simulator, a channel simulator, a power amplifier, and a low-noise amplifier.

[0013] Secondly, embodiments of this application also provide a reciprocity OTA testing method, using the reciprocity OTA testing system described in any embodiment of the first aspect, comprising the following steps: The turntable device is controlled to move in coordination with the movable probe so that the relative spatial angle between the downlink probe and the downlink antenna array of the device under test, and the relative spatial angle between the uplink probe and the uplink antenna array of the device under test, are matched with a common target relative spatial angle. Perform uplink and downlink performance tests on the device under test.

[0014] In one embodiment, prior to the coordinated motion step, the following step is included: The phase center of the uplink and downlink antenna arrays of the device under test is calibrated, and their physical coordinates in the coordinate system of the device under test are determined.

[0015] In one embodiment, the steps of controlling the movement of the turntable device include: Based on the physical coordinates of the phase center, the motion parameters required for the turntable device are calculated using a coordinate system transformation algorithm.

[0016] In one embodiment, different relative spatial angles of the target are continuously set, and the movement of the turntable device and the movable probe is controlled synchronously to simulate a continuous test scenario under dynamic communication conditions.

[0017] The above-described technical solutions adopted in the embodiments of this application can achieve the following beneficial effects: This application fundamentally ensures the accuracy and authenticity of the test: through the dynamic coordinated control of the three-axis turntable and the movable probe, this application can create completely consistent spatial wave propagation paths for the physically separated uplink and downlink antenna arrays on the device under test, ensuring strict reciprocity of the uplink and downlink in the angular domain. This allows the test environment to highly simulate the relative motion of the satellite and the terminal in real-world scenarios, thereby greatly improving the accuracy and reliability of the test results and significantly enhancing the consistency between the test results and the actual operating performance of the device. Simultaneously, this application abandons the traditional approach of relying on a large number of densely packed probe arrays to synthesize a test field, innovatively adopting a scheme of combining a small number of probes (one moving and one stationary) with precision mechanical motion. This fundamentally avoids the dependence on hundreds or thousands of probes and related channel simulator channels, significantly reducing the system hardware complexity and cost. Furthermore, because the requirements for the quiet zone size of the anechoic chamber are relaxed, the stringent requirements for the test anechoic chamber space are also reduced, saving valuable site resources. Furthermore, this application addresses the specific type of equipment—large-size, non-common aperture devices—that existing solutions cannot effectively handle. By dynamically adjusting the probe position and device attitude, it cleverly circumvents the geometric asymmetry issues caused by device size and antenna layout, filling a gap in high-precision reciprocity testing methods in this field. Finally, this application uses software to control the turntable angle and probe position. This system can flexibly and accurately simulate any set satellite motion trajectory or communication scenario, achieving dynamic continuous testing. It possesses high flexibility and good scalability, and can meet various complex testing needs. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the single downlink structure of a test system for existing MIMO OTA terminals; Figure 2 This is a schematic diagram of the uplink and downlink bidirectional structure of an existing MIMO OTA terminal testing system. Figure 3 This is a schematic diagram of the uplink and downlink bidirectional structure of an existing satellite communication test system. Figure 4 This is a structural diagram of a reciprocity OTA testing system according to an embodiment of this application; Figure 5 This is a schematic diagram of the three-axis rotary table structure according to an embodiment of this application; Figure 6 This is a schematic diagram of the device under test in an embodiment of this application; Figure 7 This is a schematic diagram of the movement of the radiation probe module in an embodiment of this application; Figure 8 This is a schematic diagram of the turntable rotation and the movement of the up and down probes in an embodiment of this application; Figure 9 This is a flowchart of a reciprocity OTA testing method according to an embodiment of this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] Over-the-Air (OTA) testing technology has become a common method for testing the radio frequency performance of communication equipment due to its non-destructive nature and good adaptability to the millimeter-wave band. Figure 1 - Figure 3 Three typical air interface testing system architectures were presented. Figure 1 The system shown constructs a complete end-to-end downlink test environment. The satellite payload simulator generates a downlink signal, which, after processing by the channel simulator, is amplified and driven by an amplifier to power a multi-probe antenna array within the anechoic chamber. This array synthesizes a target multipath channel environment within the test area (quiet zone) to evaluate the downlink communication performance of the terminal equipment. The uplink signal is then looped back directly to the satellite payload simulator through the link antenna within the anechoic chamber, forming a communication loop. Figure 2 Architecture and Figure 1Similarly, the core difference lies in the fact that both uplink and downlink are processed through a channel simulator. Although different probe antennas may be used for uplink and downlink, the reciprocity of uplink and downlink channel characteristics can be ensured by configuring the channel simulator parameters through specific algorithms. Current satellite communication payload testing commonly employs... Figure 3 The architecture shown is characterized by the use of a channel simulator with bidirectional processing capabilities, eliminating the need for additional power amplifiers provided the input signal power meets requirements. Each probe antenna supports bidirectional links (integrated transceiver), thus enabling simultaneous testing of uplink and downlink.

[0021] Satellite communication systems operate in different frequency bands for uplink and downlink. Their ground terminals or communication payloads in the Ka band are typically equipped with independent uplink and downlink phased array antenna elements (i.e., non-common-aperture antenna devices), and these devices are much larger than mobile phones and other terminals. Existing air interface test systems struggle to achieve uplink and downlink reciprocity testing for such large-size, non-common-aperture devices under low-cost constraints. A detailed analysis follows: right Figure 1 The system shown: its architecture does not inherently support uplink and downlink reciprocity testing.

[0022] right Figure 2 The system shown relies on synthesizing spatially consistent uplink and downlink target fields within the test area, achieved through a large number of staggered probe antennas. However, for devices under test with high spatial resolution requirements and large dimensions, achieving strict uplink and downlink reciprocity necessitates a significant reduction in probe spacing and a drastic increase in the number of probes. Furthermore, Figure 2 The system is configured in a two-dimensional plane. If it is expanded to three-dimensional space to support more complex radiation characteristics, the number of probes will increase exponentially, leading to a surge in system costs and a significant reduction in engineering feasibility and economic efficiency.

[0023] right Figure 3 The system shown can support bidirectional reciprocity testing of common-aperture antenna devices (using its bidirectional probe and channel simulator), but for non-common-aperture antenna devices, there is an inherent deviation in the spatial angular relationship between the uplink and downlink antenna arrays and the probe antenna within a finite-size anechoic chamber environment. This geometric asymmetry disrupts the uplink and downlink reciprocity condition.

[0024] In summary, none of the existing mainstream air interface testing solutions can effectively meet the bidirectional reciprocity testing requirements of large-size, non-common-aperture satellite communication equipment under the conditions of low cost and high precision.

[0025] The technical solutions provided by the various embodiments of this application are described in detail below with reference to the accompanying drawings.

[0026] Figure 4 A structural diagram of a reciprocity OTA testing system provided in this application embodiment includes: a turntable device 1, a radiation probe module 2, and a control module 3.

[0027] The turntable device is used to support and fix the device under test, and to adjust the spatial attitude of the device under test so that the relative spatial angle between the communication peer and the device under test is consistent with the relative spatial angle of the target.

[0028] The turntable device is used to support and fix the device under test (DUT), and adjusts the spatial orientation of the DUT in the darkroom space by the precise movement of its multiple rotation axes, thereby simulating the dynamic relative angle change between the DUT and its communication counterpart.

[0029] In one embodiment, the turntable device is a three-axis turntable, including an azimuth axis, a pitch axis, and a polarization axis.

[0030] The three-axis rotary table, such as Figure 5 As shown, it includes an azimuth axis 11, a pitch axis 12, and a polarization axis 13. These three axes work together to achieve precise and flexible control of the three-dimensional attitude of the DUT in space.

[0031] The azimuth axis refers to a rotation axis perpendicular to the ground plane, driving the DUT to rotate in the horizontal plane. This axis is mainly used to change the pointing azimuth angle of the DUT. By controlling the rotation of the azimuth axis, the azimuth change of the communication peer (such as a satellite) relative to the DUT can be simulated.

[0032] For example, simulating a geostationary satellite moving from the east to the west side of the ground terminal being measured, this horizontal trajectory change is mainly achieved through the rotation of the azimuth axis. Conversely, this scheme also applies to the ground terminal's movement relative to the satellite.

[0033] The pitch axis is a rotation axis perpendicular to the azimuth axis, driving the DUT to tilt up or down in the vertical plane. This axis is mainly used to change the pitch angle of the DUT. By controlling the rotation of the pitch axis, the change in the elevation angle of the communication peer relative to the DUT can be simulated.

[0034] For example, to simulate a low-orbit satellite rising from the horizon, traversing the sky, and then falling back to the horizon at the other end, this vertical trajectory change is mainly achieved by rotating the pitch axis.

[0035] The polarization axis refers to a rotational axis that coincides with or is parallel to the normal direction of the DUT's radiating aperture, driving the DUT to rotate around its own central axis. This axis is mainly used to adjust the polarization attitude of the DUT antenna, that is, to change the spatial angle of its electromagnetic wave polarization. This is crucial for accurately testing polarization-related performance indicators such as the antenna's cross-polarization isolation.

[0036] For example, when the test requires the antenna polarization direction of the DUT to be adjusted from vertical polarization to a 45-degree angle with the horizontal plane, this can be achieved by controlling the specific angle rotation of the polarization axis.

[0037] In this embodiment, the core function of the three-axis turntable is to compensate for the spatial angle deviation caused by the physical separation (non-common aperture) of the uplink and downlink antenna arrays of the DUT. Specifically, by adjusting the attitude of the DUT, the spatial angle between the downlink antenna of the DUT and the fixed probe is made consistent with the relative spatial angle of the target. Through precise calculations by the control and processing module, the three-axis turntable rotates the DUT to a specific attitude, so that the beam center of its downlink antenna array is precisely aligned with the fixed downlink probe. This attitude (determined by azimuth, elevation, and polarization angles) ensures the accuracy of the downlink spatial angle. Subsequently, the system calculates the actual spatial position of the uplink antenna array based on this attitude and guides the movable uplink probe to the corresponding position, thereby ultimately achieving strict reciprocity of the uplink and downlink in terms of spatial angle. Therefore, the three-axis turntable is a key actuator for achieving high-precision reciprocity testing.

[0038] The device under test consists of uplink and downlink antenna arrays of different apertures, mounted on the turntable. The downlink and uplink antenna arrays are spatially offset, and their structures are as follows: Figure 6 As shown.

[0039] The radiation probe module includes at least one downlink probe and at least one uplink probe. One of the downlink and uplink probes is configured as a fixed probe, while the other is configured as a movable probe. This coordinated design of "one fixed and one movable" aims to ensure the spatial angular consistency of the electromagnetic wave propagation path in the uplink and downlink tests through dynamic adjustment of the physical positions.

[0040] For example, the radiation probe module adopts an independent design of uplink and downlink probes, where the downlink probe is used to transmit signals and the uplink probe is used to receive signals. Together, the two probes enable the entire system to have a complete uplink and downlink link.

[0041] In one embodiment, the movement of the movable probe includes circular motion centered on the fixed probe and movement toward or away from the fixed probe. By finely adjusting the distance and relative angle between the movable and fixed probes, the spatial angle difference between the same probe and the uplink / downlink antennas of the device under test under non-far-field conditions can be compensated.

[0042] Circular motion is used to precisely adjust the orientation of the movable probe on a horizontal plane.

[0043] In one embodiment, the movement of the movable probe includes movement toward or away from the fixed probe.

[0044] The movement of moving closer or further away can be viewed as radial stretching motion.

[0045] Radial telescopic motion is mainly used to finely adjust the distance between the movable probe and the device under test, thereby changing the pitch angle and compensating for far-field conditions.

[0046] For example, when simulating a communication endpoint moving from near the zenith (pitch angle close to 90 degrees) to near the horizon (pitch angle very small) of the device under test, it is necessary to simultaneously control the movable probe to move significantly away from the fixed probe on a radial track and to perform circular motion. This changes the geometry of the beam coverage, thus accurately matching the continuous changes in pitch angle. The combination of radial and circular motion allows the movable probe to be freely positioned on a two-dimensional plane (usually a vertical or horizontal plane), enabling it to cover any azimuth-pitch angle combination required by the simulation scenario. This is key to achieving full-space angle simulation.

[0047] For example, the downlink probe is fixedly installed, while the uplink probe is designed to perform precise movements within a limited space centered on the downlink probe. This movement includes two key degrees of freedom: circular motion (changing the relative angle between the fixed and movable probes) and radial telescopic motion (changing the distance). Figure 7 As shown.

[0048] It should be noted that there is no direct correspondence between the two movements and angles of the movable probe. If the downlink antenna of the device under test and the fixed probe are used as a reference rotating platform, the corresponding position of the movable probe can be determined based on the position of the uplink antenna of the device under test and the rotation of the platform. In this case, the probe is moved to the corresponding position simply by circular and moving closer to or further away from the platform.

[0049] The three-dimensional angle and the three-dimensional spatial position of the movable probe are corresponding, but a single movement and a single angle (azimuth angle, pitch angle) are not corresponding.

[0050] Specifically, the fixed probe is rigidly mounted at a specific location in the anechoic chamber, serving as a stable spatial angular reference point. For example, it can be configured as a downlink probe to continuously transmit downlink test signals to the device under test. The movable probe, on the other hand, is mounted on a precision displacement mechanism, such as an uplink probe, allowing it to move flexibly in the radial and circumferential directions centered on the fixed probe.

[0051] During operation, once the turntable adjusts the orientation of the device under test (DUT) to align its downlink antenna array with the fixed probe to simulate the downlink angle, the control module drives the movable probe to shift, precisely "catching up" with and aligning it with the uplink antenna array, which has changed position due to the device's rotation. This ensures that the uplink experiences the exact same relative spatial angle as the downlink. This design cleverly overcomes the testing challenges caused by the physical separation of non-co-aperture antennas, replacing the expensive and complex multi-probe array required to construct a consistent beam field across the entire angle with the limited mechanical movement of the movable probe. It efficiently achieves strict uplink-downlink reciprocity within a limited anechoic chamber space.

[0052] In one embodiment, the common target relative spatial angle is the relative spatial angle between the communication peer and the device under test, defined with the position of the fixed probe as the observation point in the simulation scenario.

[0053] This application establishes an absolute reference frame for the angle simulation of the test system. Specifically, it maps the physical position of a fixed probe in the anechoic chamber to the location of the communication peer (such as a low-Earth orbit satellite) in the simulated world.

[0054] For example, when simulating a scenario where a low-orbit satellite passes overhead, the target's relative spatial angle is a series of time-varying azimuth and elevation angle data observed from the ground terminal (corresponding to the device under test) and the satellite (corresponding to the fixed probe).

[0055] After acquiring these preset angle data, the control system (control module) uses them as the final "target" to be achieved, and then reverse-engineers and drives the turntable and movable probe to move in coordination. This precise definition allows the abstract simulation scene parameters to be accurately converted into executable mechanical motion commands in the dark room, ensuring the consistency between the test environment and the real application scenario.

[0056] For example, such as Figure 8 As shown, any relative position between the satellite and the ground terminal corresponds to a specific three-axis turntable rotation angle and uplink probe position. By setting a predefined set of three-axis turntable rotation angles and probe positions, any satellite trajectory can be simulated.

[0057] This embodiment achieves high-fidelity simulation of continuous and smooth satellite trajectories through time synchronization and control parameter interpolation algorithms. This embodiment focuses on solving the trajectory jump problem caused by the approximation of continuous motion from discrete position points, ensuring a seamless transition in the test environment.

[0058] Specifically, the system does not mechanically execute preset position commands point by point, but rather performs real-time interpolation calculations (such as linear interpolation or S-curve interpolation) on the rotation angle of each axis of the turntable and the displacement of the probe between two adjacent target position points, based on a high-precision clock reference.

[0059] For example, when simulating the overhead trajectory of a high-speed, low-Earth orbit satellite, the control system performs microsecond-level smooth interpolation and synchronization control on thousands of intermediate states within one second, making the movement of the turntable and probe extremely smooth and continuous, rather than step-like jumps. This dynamic interpolation mechanism effectively avoids abrupt changes in radio frequency signal phase and amplitude jitter caused by discontinuous motion, providing the device under test with a stable and continuous dynamic test condition that closely resembles the real environment. This is particularly beneficial for verifying the device's tracking and holding capabilities and communication stability under rapidly changing channels.

[0060] The control module is used to control the movement of the turntable and the movable probe, so that the relative spatial angles of the downlink probe and the uplink probe with the downlink antenna array and the uplink antenna array of the device under test are respectively matched to a common target relative spatial angle.

[0061] The core function of the control module is to execute a dynamic spatial geometric alignment algorithm, which compensates for the spatial viewing angle deviation caused by the physical separation (non-common aperture) of the uplink and downlink antennas of the device under test by coordinating the rotational motion of the turntable with the linear / circular motion of the probe. For example, when simulating a scenario where the satellite's elevation angle relative to the ground terminal is 45 degrees and its azimuth angle is 60 degrees, the control module first calculates the target angle and instructs the turntable to rotate, ensuring that the device's downlink antenna array is precisely aligned with the fixed downlink probe. Subsequently, based on the calibrated uplink and downlink antenna phase center coordinates, the module calculates the actual spatial position of the uplink antenna array after rotation, and then drives the movable uplink probe to a specific point so that the line connecting it to the uplink antenna array also forms a 45-degree elevation angle and a 60-degree azimuth angle. This process essentially decomposes and transforms the abstract vector of "target relative spatial angle" into specific control commands for the turntable's axes and the probe's displacement mechanism through precise coordinate transformation and inverse kinematics. This reconstructs a completely consistent spatial path for two independent RF links in physical space, ultimately achieving rigorous uplink and downlink reciprocity testing that is difficult to achieve with traditional solutions under low-cost conditions.

[0062] In one embodiment, the system further includes a peripheral device module, which includes one or more of a satellite payload simulator, a channel simulator, a power amplifier, and a low-noise amplifier.

[0063] The satellite payload simulator is used to generate baseband signals that conform to specific communication standards (such as 5G NTN or dedicated satellite communication protocols) and to complete baseband processing, encoding, modulation and other processes.

[0064] For example, when testing the downlink receiving sensitivity of a ground terminal, the satellite payload simulator simulates a satellite payload, generating a downlink signal containing specific data packets. Simultaneously, it analyzes the signals sent back by the device under test (ground terminal) via the uplink, demodulating and decoding them, and ultimately providing key performance indicators such as bit error rate and throughput. Its purpose is to reproduce the communication behavior of a real network in a laboratory environment, providing the device under test with a standard and controllable signal source and performance analysis terminal.

[0065] The channel simulator is positioned between the satellite payload simulator and the power amplifier / low-noise amplifier to accurately simulate various impairment effects suffered by wireless signals during space propagation in the digital domain.

[0066] For example, to test the performance of a device under test (DUT) in high-speed mobile satellite channels, a channel simulator can accurately reproduce complex real-world channel conditions such as Doppler shift, signal propagation delay, atmospheric attenuation (e.g., rain attenuation), and multipath effects. Its core value lies in placing the DUT under stress testing in a repeatable and configurable harsh or typical channel environment, thereby evaluating its robustness and reliability in practical applications. This is a crucial step in achieving high-confidence OTA performance verification.

[0067] The power amplifier and the low-noise amplifier are crucial for ensuring that the signal strength meets the test dynamic range.

[0068] For example, the power amplifier is located in the downlink and is used to amplify the weak radio frequency signal output by the channel simulator so that it reaches a signal power level that can drive the downlink probe and simulate long-distance transmission to the device under test.

[0069] The low-noise amplifier is located at the front end of the uplink, immediately after the uplink probe. It is used to amplify the very weak uplink signal emitted by the device under test after spatial path loss, while introducing as little of its own noise as possible, so as to ensure that subsequent devices (such as channel simulators) can perform clear and accurate signal analysis.

[0070] The two amplifiers worked together to compensate for the air path loss, creating a complete, closed-loop communication link with a signal-to-noise ratio that met the test requirements.

[0071] Figure 9 This application also provides a flowchart of a reciprocity OTA testing method, using the reciprocity OTA testing system described in any embodiment of the first aspect, including steps 910 and 920.

[0072] Step 910: Control the turntable device and the movable probe to move in coordination, so that the relative spatial angle between the downlink probe and the downlink antenna array of the device under test, and the relative spatial angle between the uplink probe and the uplink antenna array of the device under test, are matched with a common target relative spatial angle.

[0073] This step is the core execution stage of the method described in the embodiments of this application. Its essence is a dynamic spatial geometric closed-loop calibration process, which aims to create completely consistent electromagnetic wave incident / exit angles for physically separated uplink and downlink antenna arrays through precise registration of mechanical motion.

[0074] For example, when the target angle is set to 30 degrees azimuth and 60 degrees elevation, the system does not adjust the turntable and probe independently, but performs collaborative calculations: First, it drives the turntable to make the downlink antenna array of the device under test accurately point to the fixed downlink probe to achieve downlink angle matching; then, the system calculates the latest spatial coordinates of the uplink antenna array based on the current attitude of the turntable, and immediately drives the movable uplink probe to a specific position to ensure that the line of sight from the probe to the uplink antenna array also meets the requirements of 30 degrees azimuth and 60 degrees elevation.

[0075] The successful execution of this step fundamentally solved the key problem of achieving angular domain reciprocity for non-common aperture antennas in a limited test space, transforming the complex beam alignment problem into a precise motion control problem, and laying an accurate physical foundation for subsequent performance testing.

[0076] Step 920: Perform uplink and downlink performance tests on the device under test.

[0077] This step is the measurement phase for formally evaluating the end-to-end communication performance of the device under test under the stable test conditions of angular domain reciprocity established in step 910.

[0078] Specifically, with the uplink and downlink spatial angles strictly aligned, peripheral equipment modules (such as satellite payload simulators and channel simulators) will construct a complete bidirectional communication link and apply standardized test signals and channel conditions to the device under test.

[0079] For example, throughput testing can be performed by measuring the maximum stable data rate that the uplink and downlink of the device under test (DUT) can transmit under specific signal-to-noise ratios and multipath fading channel models, thereby verifying the effectiveness of its beamforming algorithm and link adaptive capabilities. The test results obtained in this step, because they exclude reciprocity errors introduced by the geometric deviations of the test system itself, can reflect the performance limits of the DUT in simulated real-world operating scenarios.

[0080] In one embodiment, prior to the coordinated motion step, the following step is included: Step 900: Calibrate the phase center of the uplink and downlink antenna arrays of the device under test and determine their physical coordinates in the coordinate system of the device under test.

[0081] This step is a fundamental calibration process to ensure the accuracy of all subsequent motion control. Its purpose is to accurately obtain the spatial position of the effective radiation point of the antenna array and unify it into a fixed reference frame.

[0082] For example, on a large ground terminal, its uplink and downlink antenna arrays may be installed at different locations on different antenna surfaces, resulting in significant physical offsets. By using precision measurement systems such as near-field scanning or compact field measurement, the equivalent electromagnetic wave source point (i.e., the phase center) of each antenna array when radiating a signal can be measured and calculated, and its three-dimensional coordinates relative to a specific reference point on the device under test (such as the center of a turntable mounting flange) can be recorded. This calibration process correlates the antenna's electrical characteristics with its mechanical position, providing indispensable initial parameters for subsequent calculations of the different spatial trajectories of non-co-aperture antennas caused by equipment rotation.

[0083] In one embodiment, the steps of controlling the movement of the turntable device include: Based on the physical coordinates of the phase center, the motion parameters required for the turntable device are calculated using a coordinate system transformation algorithm.

[0084] This step utilizes spatial geometry to convert the target angle command into an executable mechanical action.

[0085] Specifically, the algorithm deals with a complex spatial geometry problem: the known goal is to align the downlink antenna phase center with a fixed probe, but the entire turntable and equipment are being driven. The algorithm must account for the offset (i.e., a non-zero radius of rotation) of the downlink antenna phase center relative to the turntable's rotation center, and through coordinate rotation and translation transformations, accurately calculate the turntable azimuth, elevation, and polarization angles required to achieve the target angle. This is analogous to driving a long-wheelbase truck around a corner; to ensure the rear of the truck passes a point, the steering trajectory of the front of the truck needs to be compensated for with lead and offset.

[0086] In one embodiment, different relative spatial angles of the target are continuously set, and the movement of the turntable device and the movable probe is controlled synchronously to simulate a continuous test scenario under dynamic communication conditions.

[0087] This application extends the testing from a static single point to a dynamic continuous process, aiming to verify the performance of the device under test in real changing environments.

[0088] For example, to test a user terminal used for low-Earth orbit satellite communication, the system pre-generates a simulated satellite overhead trajectory consisting of hundreds of consecutive time points, each corresponding to a specific set of azimuth and elevation angles. During testing, the system continuously reads these target angles in a time sequence and calls coordinate system transformation algorithms in real time to synchronously drive the turntable and probe to move smoothly and continuously, making the device under test appear to be constantly communicating with a real satellite flying overhead. This method is no longer a "photograph" of the device in a static state, but a "video recording" of its tracking capabilities, switching performance, and link stability throughout the entire communication process, greatly enhancing the realism and value of the test and exposing dynamic problems that cannot be detected in static testing.

[0089] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0090] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when an element is “connected” or “coupled” to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, the terms “connected” or “coupled” as used herein may include wireless connections or wireless coupling.

[0091] In the description of this application, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Furthermore, in the description of this application, unless otherwise stated, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0092] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical, technical, and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0093] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A reciprocity OTA test system characterized by, The system comprises a turntable device, a radiation probe module and a control module. The turntable device is used to carry and fix the device under test and adjust the spatial posture of the device under test. The radiation probe module comprises at least one downlink probe and at least one uplink probe; one of the downlink probe and the uplink probe is set as a fixed probe, and the other is set as a movable probe. The control module is used to control the movement of the turntable and the movable probe, so that the relative spatial angle between the downlink probe and the downlink antenna array of the device under test and the relative spatial angle between the uplink probe and the uplink antenna array of the device under test match a common target relative spatial angle.

2. The reciprocity OTA test system of claim 1, wherein, The turntable device is a three-axis turntable comprising an azimuth axis, an elevation axis and a polarization axis.

3. The reciprocity OTA test system of claim 1, wherein, The common target relative spatial angle is the relative spatial angle between the communication opposite end and the device under test defined by the position of the fixed probe as an observation point in a simulation scenario.

4. The reciprocity OTA test system of claim 1, wherein, The movement of the movable probe comprises a circular motion centered on the fixed probe, which is used to change the angle between the movable probe and the fixed probe.

5. The reciprocity OTA test system of claim 1, wherein, The movement of the movable probe comprises a close or far movement relative to the fixed probe.

6. The reciprocity OTA test system of claim 1, wherein, The system further comprises a peripheral device module comprising one or more of a satellite payload simulator, a channel simulator, a power amplifier and a low noise amplifier.

7. A reciprocity OTA test method using the reciprocity OTA test system of any one of claims 1-6, characterized by, The method comprises the following steps: controlling the movement of the turntable device and the movable probe to match a common target relative spatial angle between the relative spatial angle between the downlink probe and the downlink antenna array of the device under test and the relative spatial angle between the uplink probe and the uplink antenna array of the device under test; performing the performance test of the device under test in uplink and downlink.

8. The reciprocity OTA test method of claim 7, wherein, Before the step of controlling the movement of the turntable device and the movable probe, the method further comprises the following steps: calibrating the phase center of the uplink and downlink antenna arrays of the device under test and determining the physical coordinates of the phase center in the coordinate system of the device under test.

9. The reciprocity OTA test method of claim 7, wherein, The step of controlling the movement of the turntable device comprises: calculating the required movement parameters of the turntable device by a coordinate system conversion algorithm based on the physical coordinates of the phase center.

10. The reciprocity OTA test method of claim 7, wherein, continuously setting different target relative spatial angles and synchronously controlling the movement of the turntable device and the movable probe to simulate a continuous test scenario in a dynamic communication scenario.

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