International Journal of Recent Technology and Engineering (IJRTE) ISSN: 2277-3878, Volume-8 Issue-2, July 2019 6527 Published By: Blue Eyes Intelligence Engineering & Sciences Publication Retrieval Number: B3576078219/2019©BEIESP DOI: 10.35940/ijrte.B3576.078219 Abstract: Massive Multi-Input and Multi-Output (MIMO) antenna system potentially provides a promising solution to improve energy efficiency (EE) for 5G wireless systems. The aim of this paper is to enhance EE and its limiting factors are explored. The maximum EE of 48 Mbit/Joule was achieved with 15 user terminal (UT)s. This problem is related to the uplink spectral efficiency with upper bound for future wireless networks. The maximal EE is obtained by optimizing a number of base station (BS) antennas, pilot reuse factor, and BSs density. We presented a power consumption model by deriving Shannon capacity calculations with closed-form expressions. The simulation result highlights the EE maximization with optimizing variables of circuit power consumption, hardware impairments, and path-loss exponent. Small cells achieve high EE and saturate to a constant value with BSs density. The MRC scheme achieves maximum EE of 36 Mbit/Joule with 12 UTs. The simulation results show that peak EE is obtained by deploying massive BS antennas, where the interference and pilot contamination are mitigated by coherent processing. The simulation results were implemented by using MATLAB 2018b. Index Terms: Base station, Channel state information. Energy efficiency, Multi input and multi output, Spectral efficiency,. I. INTRODUCTION Future wireless networks demand high-speed data in a dense urban environment under an interference scenario. Massive multi-input and multi-output (MIMO) is the fundamental solution to achieve high spectral efficiency (SE) and data rate by deploying more antennas at the base station (BS). To meet these requirements, the networks need to be developed with high energy efficient [1-3]. Since power consumption (PC) of the system greatly deals with economic and societal concerns. Massive MIMO has evolved substantially over the past few decades and has seen an accelerating trend of technical advances particularly in multi-user communication. The future information and communication technology (ICT) industry should require low PC to support high data rates. New methods and technologies must be designed to attain high energy efficiency (EE) in the fifth generation (5G) networks. Since a large number of Internet-of-Things (IoT) devices and host of inter-connected networks will co-exist on a single platform. Revised Manuscript Received on July 23, 2019. Prasad Rayi, ECE, ANU/ International School of technology and sciences (for owmen) / Rajamahendravaram, India. M.V.S Prasad, ECE, ANU / Rayapati Venkata Rangarao & Jagarlamudi Chandramouli College of Engineering / Guntur , India. The critical challenge of a cellular network is to improve 1000× area throughput with an annual traffic growth rate of 41%-59% over the next 20 years [4]. The network load grows daily 3-10 times higher than the minimum network load reported in [5]. It is recommended to implement novel methods and technologies to be designed to minimize PC. To meet the requirements of urban high dense networks, small cells and massive MIMO are considered as the most promising technologies to achieve high SE and EE [6]. The first technology deploys hundreds of small dipole antennas and fits on the flat-television screen. In massive MIMO, array gain reduces transmit power by using coherent processing, where the multiplexing gain allows high area throughput. From the last decade, more research has done on EE perspective of a system, which is related to the cost-benefit ratio. The EE of a system is defined as the ratio of area SE to the transmit power plus circuit power as follows, Massive MIMO combines with small cells also improve the area throughput but the combined technology increases hardware cost and complexity. The EE maximization has been achieved with UL EE by minimizing [7] the superimposed pilot signals in the DL. Realistic circuit PC and path loss models were proposed [8] to achieve maximal EE. By operating power amplifiers towards saturation region and reducing the peak to average power ratio also improve the EE. The SE and EE are improved by optimizing cell density and frequency spectrum [9]. Optimization of pilot signals also improves the EE [10] with the predefined quality of service and total power budget. Reference signal power control [11] plays an important role to maximize the EE in the UL massive MIMO systems. Scaling laws of EE is analyzed [12] with large BS antennas, and spatial channel correlation. Reducing interference [13] is more effective to gain maximum EE by using spatially dynamic power control in device-to-device networks. Deploying large BS antennas by using scalable optimal power transfer efficiency model was proposed [14] to improve the EE. The optimization of EE is achieved without knowledge of circuit PC [15] by large BS antennas. The EE is an increasing function of the number of BS antennas and UTs in the DL massive MIMO [16]. Massive MIMO: Achievable Energy Efficiency for 5G systems with Multi-user Environment Prasad Rayi, Makkapati Venkata Siva Prasad