Design of a Multi-device Backscatter Communication System with a Multi-Antenna Reader

Abstract

This paper considers a mono-static backscatter communication system with a multi-antenna reader and multiple devices for ultra-low power intemet-of-things. For the system, we present some practical issues to support multiple devices in space division multiple access via coherent detection. We design a frame structure with channel estimation and multiple access phases. The linear channel estimates of the backscatter channels with orthogonal pilots are derived and the effect of the channel estimation errors on the coherent detection are investigated through simulation. The results show that the minimum mean square error estimates improve the detection performance slightly compared to the least square estimate due to a structure of the backscatter channels.