Design of MIMO Systems using Energy Detectors for Sub-TeraHertz Applications

The significant amount of unused spectrum in sub-TeraHertz frequencies is contemplated to realize high rate wireless communications for beyond 5G networks. Yet, the performance of sub-TeraHertz systems is severely degraded by strong oscillator phase noise. Therefore, we investigate in this paper the use of multiple-input multiple-output (MIMO) systems with energy detection receivers to achieve high rate communications robust to phase noise. First, the design of the receiver detection algorithm is addressed. We derive the joint maximum likelihood detector corresponding to the studied nonlinear MIMO channel. Second, the system performance is assessed through numerical simulations. We consider a realistic scenario modeling an indoor wireless link with directive antennas and strongly correlated line-of-sight channels. Our results demonstrate that high rate sub-TeraHertz systems can be implemented on low-complexity and low-power architectures using MIMO systems and energy detection receivers.