Relay-Aided Energy and Information Transmission in mmWave Massive MIMO Systems.

This paper analyzes the performance of a relay-aided millimeter wave (mmWave) massive multiple-input multiple-output (MIMO) system, where the source node needs to harvest energy from the hybrid relay before transmitting its data. A comprehensive MIMO channel model is first developed, where rainfall effects, path loss and small-scale fading are all considered; which properly models the signal propagation on all links of the system. The expression of the asymptotic harvested energy is derived, and then used to assess the asymptotic spectral efficiency and system throughput for various important scenarios. Further, the optimal value of the harvesting time that maximizes throughput is investigated. In particular, it is shown that in operating conditions with light rain, the asymptotic spectral efficiency and throughput increase logarithmically with the number of relay antennas, and that both metrics decrease exponentially with the rain parameters.