Spatial Multiplexing Technique for MIMO Backscatter Communication

In the domain of the Internet of Things (IoT), managing a variety of signals from numerous tags presents a significant challenge in terms of communication efficiency. This paper proposes an innovative approach designed to minimize symbol error rates by utilizing the least-square technique for channel estimation in backscatter communication scenarios. Furthermore, the zero forcing algorithm is applied to segregate individual data streams, thereby enhancing overall communication performance. The proposed approach employs a dual-polarized Vivaldi antenna to differentiate between data streams in an over-the-air setting where two backscattering tags coexist. The Error Vector Magnitude (EVM) for each tag is measured at 3.1 % and 4.9 %, respectively.