Design and field trial measurement results for a portable and low cost VHF / UHF channel sounder platform for IoT propagation research

Propagation research is vital for informing the design of reliable VHF and UHF communications systems for the Internet of Things (IoT). In this paper , a cost - effective and highly portable system is proposed and then used to obtain propagation measur ements in city and sub urban scenarios at 71 MHz and 869.525 MHz. The system calculates the received power, power delay profile and channel frequency response. The portable sounding receiver uses readily available parts: an RTL - SDR (covering 27 MHz – 1.7 GH z) and a Raspberry Pi with touchscreen. The Pi implements all the channel sounding signal processing algorithms in Python , in near real - time . Extracted propagation data and models are presented, from example city and suburban field trials incorporating pedestrian and car use .