An OTA test system supporting full vehicle 5G MIMO measurement
Intelligent Connected Vehicles (ICVs) integrate various wireless communication devices (V2X, mobile communication, Bluetooth, satellite navigation, etc.). The universal test vehicle wireless OTA test system solves two major challenges from theoretical methods and engineering practice. Among them, the spherical near-field and near-far field transformation algorithms solve the serious eccentricity problem of the antenna; the improved RTS method solves the external field environment simulation and MIMO performance testing problems.
The spherical near-field test system of the vehicle wireless OTA test system is set in the center of the microwave anechoic chamber, and consists of a car turntable, an arc-shaped slide rail (with a test probe installed on the slide rail), a test instrument and a test software. The MIMO test system consists of four six-axis manipulators (with a measuring probe installed at the end of the manipulator), test instruments and test software.
Test Technology – New
- Spherical near field scan + near and far field transformation
Test speed – fast
- 8 sets of passive antenna parallel test duration: 5 hours
- Active Antenna SISO Test Duration: 10 minutes
Test Accuracy – High
- System mechanical accuracy: ±0.1°
- Antenna test accuracy: ±0.5dB (typ.)
- SISO test accuracy: ±0.8dB (typ.)
- MIMO test accuracy: ±1dB (typ.)
Test items – All
- Passive Antenna Testing: 3D Pattern, Efficiency, Phase Center, ECC and Custom Metrics
- ICV SISO testing: EIRP, TRP, EIS, TIS, sensitivity and custom metrics
- ICV 2×2/4×4 MIMO testing: urban, rural, high-speed, rain and fog and custom 3D channel environment modeling
- Desense test: self-interference test, motion test
Innovative patented technology to achieve high-precision testing
In order to ensure the accuracy of the measurement results, the main lobe of the test probe must effectively irradiate (that is, full coverage) the radiation position of the antenna under test (often the entire vehicle), as shown in the figure:
In order to achieve high-precision testing, Universal Test has designed a special measurement probe for automobiles. The indicators are as shown in the figure below:
According to the characteristics of the vehicle test, a special MIMO test scheme is designed, and the two-step radiation method is used to achieve accurate and efficient vehicle multi-antenna wireless performance test under complex electromagnetic environment. This solution supports 2×2/4×4 MIMO performance evaluation and is suitable for LTE and 5G sub6G (NSA/SA) communication systems. With the wireless channel emulator, dynamic MIMO tests under standard channel models can be performed, and even environmental simulations of rain, fog, terrain, dynamics, etc., as well as scenario road conditions can be simulated.
The near-far field conversion algorithm is the core of the spherical near-field test system. The general test optimizes the traditional near-far field conversion process, and with the unique probe design, creatively solves the three major challenges of vehicle OTA testing:
- Eccentricity near and far field of large DUT
- Probe Effective Illumination, Cross Polarization, Symmetry Issues
- Probe factor calibration problem in near and far field restoration
When the car is driving, various internal subsystems will affect each other, and the receiving sensitivity of the wireless communication system will be interfered by various noises, and all sensitivity-related tests can use the Desense interference test method. In order to accurately analyze the influence of each module in the car and improve the wireless communication performance of the car, Desense test has become a key indicator of the whole vehicle test.
- Influence of vehicle status on various communication performance
- Influence of in-vehicle equipment on various communication performance
- Influence of vehicle power supply on various communication performance
- Dynamic influence
GTS’s full range of products use high-performance, environmentally friendly fourth-generation absorbing materials based on the world’s leading technology – Universal Testing’s patented polypropylene foam (EPP) absorbing material, which is unmatched by traditional polyurethane sponge (PU) materials. Advantages: moisture-proof, flame-retardant, stable and environmentally friendly.
In order to meet the sampling requirements of high precision (≥ 0.1°) for vehicle measurement, GTS has designed a set of high-efficiency persistent data models to ensure the accuracy and stability of the measurement process and provide users with the most reliable measurement. At the same time, in order to improve the system test speed and reduce the test cost, the system uses a fast measurement algorithm, which can complete the test in the shortest time on the basis of ensuring the reliability of the results.
Rui test automotive measurement software also provides dedicated automotive testing, data analysis and comparison software packages, which support the analysis and comparison of various test data on common configuration computers, including:
- Comparison of near-field test and far-field calculated data
- Comparison of test data of different vehicles
- Comparison of simulation data and measured data
- 2D and 3D comparison from different angles
- Multi-angle and multi-frequency data comparison
- User-defined comparison