Live RF Image Transmission using OFDM with RPi and PlutoSDR

Abstract

Orthogonal frequency-division multiplexing (OFDM) is a multi-carrier digital communication technique which addresses digital communication problems like intersymbol interference (ISI), low data rates, and inter-carrier interference (ICI). It uses multiple low data rate carriers to assemble a high data rate communication system. Each low data rate carrier has enough long symbol periods which then eliminates ISI. Orthogonality allows each carrier frequency to be closely spaced, although overlapped, without ICI. The contribution of this paper is to show that real-time OFDM RF communications is possible and assess its performance. This was achieved by integrating several embedded platforms: a light-weight processor, web camera, and software define radio using the Mathworks MATLAB environment. This is an efficient way to transmit live images or video feeds for monitoring and surveillance purposes. The work focused on transmitting live images at a constant rate from the web camera to the software defined radio, which relayed it to another software defined radio at a remote location.