Massive MIMO meets decision fusion: Decode-and-fuse vs. decode-then-fuse

We study channel-aware decision fusion over a multiple-input multiple-output (MIMO) channel in the largearray regime at the decision-fusion center (DFC). Inhomogeneous large-scale fading between the sensors and the DFC is consider in addition to the small-scale fading, and pilot-based channel estimation is performed at the DFC. Linear processing techniques are analyzed in order to design low-complexity alternatives to the optimum log-likelihood ratio test (LLRT). Performance evaluation based on Monte Carlo simulations are presented.