Technical Paper

Beyond Simulation: Real-world Multi-Channel GPS Signal Record & Playback for Navigation System Tests

With multi-frequency capabilities added to the Averna’s RF Record & Playback (R&P) system, the range of Global Navigation Satellites System (GNSS) applications has drastically increased. Now, the R&P system can be applied to multi-frequency GNSS receivers for testing and validation purposes. Even more, enforced by new fixtures, the R&P can be used for design and development of hybrid GNSS receivers. In fact, the new signals in space, transmitted by a few GNSS satellites (e.g.: Galileo’ GIOVEA/ B or Block IIR-M satellites for GPS) can be recorded during the best satellites visibility and replayed later in the lab environment, reproducing the exact same signal pattern. The ability to record large-band multi-frequency real-world signals for hours on end has substantial implications for today’s GNSS RF testing. By simultaneously recording signals on multiple frequencies with a 16-bit resolution, it becomes possible to capture a wide range of impairments, such as ionospheric amplitude and phase scintillations, carrier/code multipaths and interferences in high dynamic ranges. The use of recorded waveforms for GNSS receiver testing has many advantages over traditional test methods. When compared to GNSS simulators, this method enables more natural impairments as opposed to simulations. Thus, receivers can be tested with a rich and realistic set of data and produce test results that are perfectly repeatable.