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Data rate and energy efficiency performance of mmWave wireless communication systems consisting of a new lens antenna subarray (LAS) based hybrid multiple input multiple output (MIMO) architecture is investigated. The LAS architecture degenerates into traditional hybrid MIMO architecture (TA) or single lens antenna array architecture (SLA) when the lens diameter of the subarray is reduced or enlarged, respectively. It is shown that under mmWave channel scattering conditions, LAS architecture operates with a data rate approaching that of TA while significantly exceeding the data rate of the SLA. Due to the reduced hardware complexity and power consumption, LAS architectures operate with a significantly improved energy efficiency. In an example system consisting of 64 and 16 transmitter and receiver antennas with 2 RF chains, it is shown that the LAS architecture operates with 2× energy efficiency and 98% spectrum efficiency. In a larger hybrid MIMO antenna systems, LAS architecture is expected to benefit even more. INDEX TERMS MIMO, beamforming, lens antenna, large antenna array, subarray, mmWave.

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In this study, the energy management and switching control of plug-in hybrid electric vehicles (PHEVs) in a hybrid smart micro-grid system was designed. The charging station in this research consists of real market PHEVs of different companies with different sizes. The rate of charging of PHEVs is managed via switching control to receive maximum benefits from renewable energy sources and reduce the consumption of electricity from the grid. To support the optimum utilization of sustainable power, charging time and network stability, seven scenarios were developed for different interaction among the proposed micro-grid system and PHEVs. The proposed hybrid smart micro-grid system consists of three renewable energy sources: photovoltaic (PV) array controlled via an intelligent fuzzy control maximum power point subsystem, a fuel cell stack and a microturbine set controlled by proportional integral differential/proportional integral subsystems. A hybrid energy storage system (super-capacitor, battery storage bank and hydrogen) and residential load are also included in the proposed architecture. The hybrid smart micro-grid system is checked in terms of voltage regulation, frequency deviation and total harmonic distortion (THD). It was found that these are in limits according to the international standards. The simulations verify the feasibility of the proposed system and fulfill the requirement of vehicle-to-grid and grid-to-vehicle operations in a smart grid environment.

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