A Robust Software Radio Testset for Research and Laboratory Instruction

Abstract

Since the mid-1990s, communication technology has advanced dramatically, making it possible to achieve high data rates for both enterprise and individual users. The rapid and widespread deployment of wireless communications systems employing a variety of regional standards has led to the software radio (SWR) concept. The essential idea of SWR is to incorporate the entire functionality of a wireless transceiver into software running on a digital signal processor (DSP) or microprocessor, resulting in devices that are more compact, power-efficient, and readily adaptable to new standards and environments. In reality, the state of current technology is such that this goal can be only partially realized. It is still necessary to implement some of the RF functionality in hardware due to speed limitations of existing DSP's. This intermediate stage of development is referred to as software-defined radio (SDR). This thesis will focus on a robust, flexible SDR design suitable for use in undergraduate laboratory experiments, as well as in graduate research. The design presented here uses a Motorola 68HC11 microcontroller for baseband functions and a Cirronet WIT2410 RF front-end module. The 68HC11 is studied by most students prior to taking a wireless laboratory course at Auburn University, and is therefore a ""known"" quantity with reduced learning curve. The WIT2410 is a well documented, field-proven RF front-end module providing considerable flexibility to the user. Importantly, it is available in a fairly rugged package which provides a large degree of immunity to electrostatic discharge (ESD). The proposed system design obtained by coupling the 68HC11 with the Cirronet WIT2410, is presented, as well as a sample experiment that can be run in an undergraduate laboratory setting.