Modeling and simulation of a non-coherent frequency shift keying transceiver using a Field Programmable Gate Array (FPGA)

Abstract

In this thesis, the principals of Software Defined Radio are demonstrated by implementing a Binary Frequency Shift Keying (BFSK) receiver-transmitter in a Field Programmable Gate Array (FPGA). After introducing the theory behind the Non-Coherent BFSK demodulation implemented at the receiver, the design of transmitter and receiver is illustrated. The design environment of choice is Mathworks'® Simulink and Xilinx® System Generator, a dedicated library for Mathworks' Simulink. The design is downloaded to a Virtex-4 FPGA. The receiver is Non-Coherent (NC) in the sense that the receiver need not know the phase of the incoming signal. A feedback circuit is responsible for both packet and bit synchronization. Also, the receiver is implemented using non-coherent match filters instead of low pass filters which would be easier, but would degrade the performance. Finally, some interesting experiences that were gained during the learning process are discussed. In Appendix A, we evaluate different technological options in implementing communication modulating techniques and Software Defined Radio. These options include Digital Signal Processors, Field Programmable Gate Arrays, General Purpose Processors and Application Specific Integrated Circuits and a comparison between these choices is made.