Application Note: Software-Defined Radio Measurement Solutions

Interoperability concerns and high costs, associated with existing communication systems, are driving the integration of software defi ned radio (SDR) technology into commercial and military wireless systems. On the commercial side, the mobile communications industry has seen the parallel evolution of a wide variety of incompatible radio standards throughout the world and even within specifi c geographies. Consumers want the ability to use the most reliable service in a given location. Developing a truly international handset is nearly impossible. Multi-mode handsets provide some relief, but with increased cost, higher power consumption and limited fl exibility as standards evolve.

In the original context, the term software defi ned radio (SDR) refers to a reconfi gurable radio based solely on software and having the analog-to-digital conversion occurring directly at the antenna [1, 2]. While practical limitations in the current performance of analog-to-digital converters (ADC) prevent sampling wideband waveforms directly at the antenna, the development of a radio system that can change its operating frequency, modulation, operating bandwidth and network protocol without the need to change the system hardware is highly desirable.

This application note introduces the SDR architecture and types of analysis tools that are available when measuring the digital, analog and RF sections of a software radio. This note also shows how vector signal analysis tools can be applied across multiple domains when designing and troubleshooting SDR components and systems. Also discussed are vector signal generation and how software radio design has infl uenced the connection of this predominately RF/ analog hardware into the digital domain. Lastly, this note will introduce how instruments and radio hardware can be directly integrated into advanced software simulation tools.