Optimizing Backscattering Coefficient Design for Minimizing BER at Monostatic MIMO reader

We present a novel monostatic backscatter communication (BSC) protocol for multiple-input-multiple-output (MIMO) reader to detect signals from a single-antenna tag. Understanding tags resource constraints, it involves new preamble designing that neither requires pilot transmission from tag nor channel estimation at reader. So, considering the maximum likelihood detector, we derive closed-form expressions for the optimal detection threshold and bit error rate (BER) by exploiting practically-motivated approximations for short-range BSC channels. Thereafter, analytical insights on the globally-optimal backscattering coefficients (BC) at tag for minimizing BER are provided. Lastly, the analysis is validated via simulations, while shedding key insights on impact of the reader’s array-size, rice factor, and BSC channel gains on optimal BC and achievable BER.