German IAV automotive engineering company uses NI RF instruments to implement automotive radio and navigation system test platform

"Now, the high-throughput RF data streaming capability of NI PXI technology allows us to record and playback all common analog and wireless signals and various signal losses that are common in use."

challenge

Develop a radio frequency (RF) signal test solution for car radios and global positioning system (GPS) receivers to reduce time-consuming and expensive field tests while further improving the quality of the equipment.

solution:

Averna ’s engineers took advantage of the high bandwidth of NI PXI products to implement a complete solution that records real-world RF signals, signal losses, and environmental data for easy playback in the laboratory; and, for long-term From the perspective of improving test efficiency, Averna and users have created a common user reference library.

Provide quality products to car manufacturers

The global headquartered German IAV Automotive Engineering Company is one of the world's top engineering and design service providers in the automotive industry, serving the world's most famous auto manufacturers and parts suppliers, including Audi, Bentley, BMW, Chrysler, Daimler, Ford, General Motors, Porsche and Volkswagen.

The company recently tested and validated car radios and navigation systems for one of Germany ’s top car manufacturers. IAV must perform comprehensive RF signal testing on these devices, including AM / FM, RDS, TMC, DAB / DMB, GPS, and HD Radio (IBOC), and meet all common analog and digital wireless standards in Europe. They use a variety of functions to test various device models, covering various types of radio programs, such as rock, jazz, classical and dialogue programs. In addition, from the sunny day in central London to the snowy night on the French Alps winding road, these devices must be tested in all environmental and driving conditions throughout Europe. To meet the strict technical specifications of customers, IAV must guarantee first-class product quality in thousands of possible test cases.

Find reproducible and repeatable test methods

As part of the evaluation, first in the laboratory, IAV uses a typical signal generator for static testing and verification to measure indicators such as critical values, sensitivity, and signal-to-noise ratio. However, many problematic RF signal phenomena can only occur in dynamic environments, such as moving vehicles. These signal losses include multipath interference when the signal bounces off the city ’s skyscrapers, or weather-related attenuation and distortion caused by fog and rain. Mathematical models and test file libraries have deficiencies in simulating these attenuations.

Therefore, IVA sends dozens of professional listeners every year to detect signal glitches on the highway for all possible test cases. However, because this method is not repeatable-test engineers need to run for each specific radio model and signal each time, which is both time-consuming and expensive.

IAV needs to gather signal databases of different control points, under different conditions of the same signal, different signals of the same condition and other combinations to assist in evaluating different devices. They need test methods to be reproducible, as much as possible to improve the efficiency of testing and verification.

Take advantage of NI PXI's record playback function

To help solve these challenges, IAV works with engineers from Averna, a NaTIonal Instruments system alliance partner. IAV uses the Averna RF signal recording and playback system-this is a turnkey system that records real-world signals and can be played back at will, used as a laboratory analysis, and as part of a global receiver tester (URT) platform.

We use the NI PXIe-1065 chassis, NI PXIe-8106 embedded controller, NI PXIe-5672 vector signal generator and NI PXI-5661 vector signal analyzer to create a record playback system. These key technologies can achieve a dedicated bandwidth real-time data streaming of up to 2GB / s per slot from the RF module to the hard drive, as well as high-performance timing and synchronization functions. In addition, we take advantage of the flexibility of NI LabVIEW software to design software components, and at the same time encapsulate the system in a radio-frequency shielded box against noise and interference, which can be used for mobile purposes. The system has a DC / AC converter, a pre-amplifier system with automatic gain control (AGC) to optimize signal acquisition, and multimedia signal recording capabilities. Using NI's commercial off-the-shelf components, we have created a turnkey system that users can use from the beginning of R & D. These components are pre-installed and do not require application software development.

Establish customer RF test signal library

IAV engineers can carry a record-playback system powered by a DC power supply (connected to the car battery) for testing in the back seat of a truck or car. After connecting the antenna to the system, the test engineer accesses the graphical user interface (GUI) through a laptop computer and local area network, records the dynamic signal, and controls the frequency, bandwidth, and gain of the signal. IAV uses this method to record a large number of broadcast and navigation signals to establish a proprietary test file library for easy playback at any time.

To further strengthen the file library, IAV records broadcast and GPS data to analyze the impact of environmental background on the signal. For example, IAV can record the exact location of the vehicle when signal loss occurs, as well as the current weather and road conditions. Because there is not much field testing required, by placing the device under test in a real-world signal and loss environment, IAV engineers can invest more time to further improve the quality of the device.

Simplify troubleshooting

With this record playback system, IAV can now immediately share record data with equipment manufacturers, parts manufacturers and car manufacturers, so that all parties can act as troubleshooters for car radios and navigation equipment under the same signal, loss and environmental background To find the root cause of the problem together. Therefore, those engineers responsible for product quality can remotely diagnose the equipment.

"When you deal with the world's most prestigious car manufacturer, quality is the most concerned." IAV test engineer Hans Joachim Tepper said, "NI PXI technology's high-throughput RF signal streaming capability allows us to record playback All common analog and wireless signals and various signal losses in use are very effective. Averna's URT record playback system helps to integrate these performances and provide the repeatability we need to meet customers' strict Standards. We believe that this solution will significantly improve the efficiency of long-term testing. "

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