Sparse-Coded Ambient Backscatter Communication for Massive OFDM-Induced IoT Networks

Ambient backscatter communication (AmBC) is a promising solution for Internet of Things (IoT) network in terms of installation cost and energy efficiency. However, it is challenging to achieve massive connectivity in typical AmBC system due to lack of coordination among RF sources, tags and the reader. Such uncoordinated interferences can seriously degrade the system performance, limiting the data rate and communication range essential for numerous IoT applications. To tackle the challenging issues, we propose a novel sparse-coded AmBC (SC-AmBC) system using sparse codes and utilizing the structure of orthogonal frequency division multiplexing (OFDM) signals. The system utilizes the inherent characteristics in ambient sources and RF tags to enhance connectivity for massive IoT applications including smart city and factory. Numerical results demonstrate the potential of sparse codes for AmBC in terms of energy efficiency and receiver sensitivity at the reader.