MmWave massive MIMO small cells for 5G and beyond mobile networks: An overview

Promising technologies are being investigated to integrate them into the fifth generation (5G) and beyond mobile network systems. The main goal of these technologies is to evolve cellular networks that will significantly stress forward the limit of legacy network systems through all dimensions performance metrics. Some of the most potential key enabler technologies are millimeter waves (mmWave), massive multiple-input multiple-output (MIMO) and small cells (SC) systems. These sets of technologies will dramatically increase the network throughput, enhance the spectral and energy efficiency, increase the network capacity and improve the network coverage by using the joint capabilities of the huge available bandwidth in mmWave frequencies while achieving high multiplexing gains through the extreme antenna arrays gains and achieving full coverage network by network densification through small cells. In this paper we present a detailed overview of millimeter wave, massive MIMO, small cells, channel estimation, beamforming technology, signal processing techniques in mmWave, beyond 5G systems, challenges and future research trends.