Lightweight and Cost-Effective Spectrum Analyser Based on Software Defined Radio and Raspberry Pi

Software Defined Radio (SDR) has become an increasingly credible alternative solution to solid state radio problems. The practical application of SDR in building a spectrum analyser can be complex and expensive; however, the use of lightweight, cost-effective, low-cost SDR and low-power microprocessors can significantly reduce the cost. This paper investigates ways to build lightweight, cost-effective spectrum analysers and their most effective design and implementation, utilising the RTL-SDR USB device, a software modelling tool (GNU Radio), and a low-power-microprocessor Raspberry Pi. The RTL-SDR USB device, GNU Radio Software and Raspberry Pi are configured together to produce a lightweight SDR-based spectrum analyser. In this particular implementation, the spectrum analyser is used to examine a small section of the electromagnetic spectrum to test the suitability of the configuration for complex Fast Fourier Transform calculations. For comparison purposes, another spectrum analyser is built using a more powerful microprocessor (AMD Turion), and the results recorded and compared. The experimental results and comparative evaluation of the two spectrum analysers demonstrate that the Raspberry Pi-based design performs equally well despite its limited resources and low cost. This shows the success and potential of this SDR and Raspberry Pi-based spectrum analyser as a credible device for a number of intelligence analyses applications in a secure environment.