Single channel radio transmitter and receiver for combined telecommunications and computer engineering educational classes

Abstract

Various methods exist regarding the teaching of key signal processing concepts used in the design of modern communication systems. Such methods range from those being purely theoretical to those that are more software supported through to methods using real-time hardware systems. Design of a radio on a reconfigurable platform would make it more flexible in adapting to the various communication standards. In this project the design and implementation of the modulation and demodulation systems of a simple but operational transceiver on an FPGA is explored. The intention of this artifact is to support students by bringing together topics in telecommunications, computer engineering, signal processing and related areas through the design and implementation of an embedded system. In turn, students’ interaction with such system would help to assist in the understanding of key theoretical concepts. Implementation in this project involved simulations of the systems to be designed through the use of MATLAB. Upon testing of the digital-to-analog converter to be used in conjunction with the FPGA, work was started on the respective systems. This consisted of VHDL code generation together with programming of various IP blocks. Following this, testing was performed to confirm correct operation. The final result included a working prototype model for a DSB-SC modulation to be used in an SDR transmitter system, together with two model systems (coherent and non-coherent) for DSB-SC demodulation in a receiver. The coherent system in fact makes use of a digital Costas Loop for carrier recovery. The final system includes various control blocks for the student user to manage in order to demonstrate theoretical aspects.