OTA testing is a critical process for assessing the performance, reliability, and security of wireless devices and systems. This involves subjecting the device or system to various environmental and usage scenarios, such as different signal strengths, angles of incidence, and interference sources. The test measures the device’s ability to receive, transmit, and process signals accurately and efficiently under these conditions.

When it comes to mmWave 5G NR devices and systems, OTA testing is particularly challenging due to their unique characteristics. Compared to previous wireless technologies, 5G operates at much higher frequencies (24-39 GHz), which presents several practical and technical issues, including:

Higher path loss and attenuation: mmWave signals have shorter wavelengths and are more prone to reflection, diffraction, and absorption by obstacles such as buildings, trees, and even human bodies.

Narrow beamwidth and directional propagation: mmWave signals are highly directional and require beamforming to steer them towards the receiver. This means that the wireless link can be easily broken if the beam alignment is disrupted by movements or misalignments.

Lower penetration through materials: mmWave signals have poorer penetration through walls, windows, and other materials, which affects the coverage and reliability of the wireless network.

All of these factors must be taken into account when designing and performing OTA tests for mmWave 5G NR devices and systems.

Key Elements of an Effective OTA Test for mmWave 5G NR Devices and Systems

1. Test Scenarios and Criteria

The first step in creating an effective OTA test for mmWave 5G NR devices and systems is to define the test scenarios and criteria that accurately represent the real-world usage and performance expectations. This involves identifying the key metrics to measure, such as the received signal strength indicator (RSSI), the signal-to-noise ratio (SNR), the bit error rate (BER), and the throughput. The test setup and conditions should also consider the effects of different signal paths and obstacles, such as multi-path fading, shadowing, and interference.

2. Test Environment

The OTA test environment should replicate the real-world conditions as closely as possible to ensure the test results are relevant and meaningful. This involves setting up a test chamber or anechoic chamber that can shield the signals from external interference and reflections. The chamber should be large enough to accommodate the device or system under test and the required test equipment, such as antennas, amplifiers, and spectrum analyzers.

3. Test Equipment

The OTA test equipment is critical for generating, transmitting, and receiving the test signals accurately and reliably. The equipment should support the required frequency bands, power levels, and modulation formats for mmWave 5G NR devices and systems. This includes high gain antennas and amplifiers that can compensate for the high path loss and attenuation of mmWave signals. The equipment should also provide accurate measurements of the test metrics such as RSSI and SNR.

4. Test Execution and Analysis

The OTA test execution and analysis should follow a rigorous and repeatable process to ensure the validity of the results. This involves calibrating the test equipment, positioning the device or system under test, and configuring the test conditions and parameters. The test signals should be generated and transmitted according to the defined test scenarios and criteria. The received signals should be analyzed and measured using the test equipment to calculate the test metrics. The test results should be recorded and analyzed to identify any issues or discrepancies.

Conclusion

Creating an effective OTA test for mmWave 5G NR devices and systems requires careful consideration of the unique characteristics and challenges posed by this new technology. By defining the test scenarios and criteria, setting up a realistic test environment, selecting the right test equipment, and following a rigorous test execution and analysis process, you can accurately and reliably assess the performance and reliability of mmWave 5G NR devices and systems. This ensures that they meet the demanding requirements of the 5G ecosystem and pave the way for a new era of wireless connectivity.