Rohde & Schwarz Signal Generators Simulate Dynamic Fading Scenarios for Testing Military Radiocommunications Equipment

Rohde & Schwarz has added new functionality to its R&S®SMU200A vector signal generator: Equipped with the R&S®SMU-K77 option, the R&S®SMU200A simulates dynamic fading scenarios for testing military radiocommunications equipment. This makes it possible to verify the performance of military radios and optimize their hardware to enable smooth operation under harsh receiving conditions such as dynamic fading and multipath signal propagation. Fading simulation enables precise and repeatable tests in the lab and eliminates the need for expensive field or flight tests.

The state-of-the-art R&S®SMU200A vector signal generator offers – in a single box – all the necessary tools to generate the desired test signals and interferers, and to simulate a radio channel. Together with theR&S®SMU-K77 option, the R&S®SMU200A supports high Doppler speeds and dynamic scenarios including:

• Tower-to-aircraft mode, simulating radiocommunications during aircraft take-off, fly-by and landing
• Ship-to-ship mode, simulating radiocommunications between two ships traveling on straight paths
• User-defined mode, providing ultimate flexibility in transmitter and receiver trajectory simulation

Dynamic scenario simulation is the most appropriate approach for carrying out precise and repeatable tests in a controlled environment at a cost significantly lower than that of conventional live tests. Plus, this approach accelerates time to market for military communications equipment.

The R&S®SMU200A vector signal generator provides flexible signal generation. Users can select from a wide range of predefined communications standards and define custom modulation modes. In addition, they can create, load and play any arbitrary waveform generated with MATLAB®, for example.

Military communications systems (such as on-board radio or tactical radio) mainly operate in the VHF/UHF range. In the past, small bandwidths of only a few kHz and typically analog modulation modes were used. This has gradually changed to include digital modulation techniques such as higher-order phase shift keying (PSK) or quadrature amplitude modulation (QAM), which employ higher bandwidths (several hundred kHz). Channel simulation and fading were minor issues, since the narrowband analog signals were rather resistant to these types of interference. Modern military communications systems, by contrast, are no longer immune to multipath and fading effects.

In modern military radiocommunications, it is beneficial to verify the performance of radio equipment using channel and fading simulators during the development and qualification stages. The communications standards must be selected and the communications hardware designed to optimally match the environmental conditions encountered in operational use. In contrast to mobile radio, there are no fixed standards to test such military communications equipment. Manufacturers either perform expensive drive or flight tests or rely on past design experience. The risks associated with these approaches can prove very costly in the long run.

The R&S®SMU200A vector signal generator has a frequency range from 100 kHz to 2.2/3/4/6 GHz for its first RF path, with an optional second RF path operating in the range up to 2.2 GHz or 3 GHz. The dynamic scenario simulation option is also available for the (R&S®AMU-K77).

The R&S®SMU200A and the R&S®AMU200A support all modern standards such as EUTRA/LTE, 3GPP FDD/HSPA/HSPA+ and WiMAX™, and include a baseband generator with a realtime coder and an arbitrary waveform generator.