A hardware emulator testbed for a software-defined radio.

Abstract

Contemporary software-defined radio (SDR) is continuously changing and challenging the way traditional RF systems operate. Having more of a radio system’s operation in software enables further flexibility through the use of software manipulation. Due to practical limitations, however, it is not always feasible to have the entire radio system’s operations performed using software. Practical limitations, therefore, require that a SDR employs some form of RF front-end in order to interface the antenna signals and the signals prior to the data converters. As technology grows in support of SDR development, this hardware interface is becoming increasingly smaller. The problem with the rapid rate at which SDR developments are occurring is that RF hardware needs to change accordingly. Therefore, the RF hardware front-end can be seen as a non-standardised piece of equipment. To the designer, this means having to prototype in hardware in order to experiment with various types of SDR hardware front-ends. One of a SDR’s main attractions is the inherent property of software testability. Taking this fact into account, this thesis investigates the design and operation of a basic softwaredriven RF front-end emulator for a SDR. Basic prototype software models are identified and developed in order to test their performance within the emulator. The focus of the thesis, however, is geared toward the development of a software architecture that enables a high degree of interchangeability amongst the underlying modelled components. In the case of a SDR, the advantage of prototyping in software is in predicting the behaviour of a system prior to having to perform any physical developments. This property of software testability in the emulator can only fully be appreciated if a bench-mark system is used to evaluate the overall performance of the emulator. Therefore, a physical hardware setup is performed in order to test the basic aspects of the emulators operation. This evaluation is not meant as an exhaustive analysis of the emulator, but aims to highlight the overall performance of the emulated system against a typical physical system setup.