Building hardware-in-the-loop communication test channels

The concept of a test channel has long been a way of standardizing radio testing. The typical problem test engineers face is how to translate the final radio operating environment into a test plan. The typical approach would be to interpret the design parameters (assuming they were driven by the end user environment) and somehow derive tests to prove out a particular parameter. This is often accomplished through an assemblage of test equipment, each focusing on a specific operational parameter. This paper will discuss an approach that builds upon modern software-based Radio Frequency (RF) environment simulation tools in combination with a channel simulator in order to build the test channel. The advantages of this approach can be a flexible, reconfigurable test system that has clear traceability to the end user environment. This technique can be particularly advantageous when testing radios such as Software Defined Radios (SDRs) that support multiple modulation formats. Examples will highlight utilizing the same hardware for two different test channels; the first space-based, the second terrestrial.