  Quantum illumination (QI) is a revolutionary photonic quantum sensing
paradigm that enhances the sensitivity of photodetection in noisy and lossy
environments. The QI concept has been recently used to propose a quantum
backscatter communication (QBC), with the aim of increasing the receiver
sensitivity beyond the limits of its classical counterpart. One of the
practical challenges in microwave QI is the slow rate at which the entangled
microwave modes can be generated. Here, we propose to mitigate this problem by
using a multiple-input multiple-output antenna system to synthetically increase
the number of efficiently-distinguishable modes in the QBC context.
