Research Article A Novel Access Control and Energy-Saving Resource Allocation Scheme for D2D Communication in 5G Networks Ning Du , 1,2 Kaishi Sun, 1 Changqing Zhou, 3 and Xiyuan Ma 4 1 College of Electrical Engineering and Automation, Shandong University of Science and Technology, Qingdao 266590, China 2 Department of Mathematics and Information Engineering, Dongchang College of Liaocheng University, Liaocheng 252000, China 3 Shandong Institute of Space Electronic Technology, Yantai 264000, China 4 Department of Computer Science and Engineering, Korea University, Seoul 02841, Republic of Korea Correspondence should be addressed to Ning Du; lczhlydn@126.com Received 13 July 2019; Revised 29 November 2019; Accepted 12 December 2019; Published 8 January 2020 Academic Editor: Eulalia Mart´ ınez Copyright © 2020 Ning Du et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. is paper investigates access link control and resource allocation for the device-to-device (D2D) communication in the fifth generation (5G) cellular networks. e optimization objective of this problem is to maximize the number of admitted D2D links and minimize the total power consumption of D2D links under the condition of meeting the minimum transmission rate requirements of D2D links and common cellular links. is problem is a two-stage nondeterministic polynomial (NP) problem, the solving process of which is very complex. So, we transform it into a one-stage optimization problem. According to the monotonicity of objective function and constraint conditions, a monotone optimization problem is established, which is solved by reverse polyblock approximation algorithm. In order to reduce the complexity of this algorithm, a solution algorithm based on iterative convex optimization is proposed. Simulation results show that both algorithms can maximize the number of admitted D2D links and minimize the total power consumption of D2D links. e proposed two algorithms are better than the energy efficiency optimization algorithm. 1. Introduction As one of the key technologies for the fifth generation wireless communication networks, D2D communication technology has attracted wide attention in academia and industry [1]. Cellular user equipment in close proximity can communicate with each other directly, which can improve spectral effi- ciency, reduce transmission delay, and offload traffic from the base station (BS) [2]. e implementation of D2D commu- nication can be divided into two categories [3]. One is out-of- band D2D communication, which occurs on an unauthorized frequency band, such as bluetooth and WiFi Direct. e other is in-band D2D communication. For in-band D2D com- munication, D2D users adopt the authorized frequency band and benefit from reasonable resource planning and inter- ference management. Based on whether or not D2D users share resources with cellular users, in-band D2D communication is divided into underlay mode and overlay mode. Overlay D2D communication means that sharing the same frequency bands with cellular users is prohibited [4]. Although overlay D2D communication is simple, it cannot make full use of the advantages of D2D communication to improve spectrum efficiency [5]. Underlay cellular D2D communication can improve the efficiency of local business, but may be subject to interference from cellular and D2D users [6]. Appropriate resource allocation can avoid serious interference, which keep interference below a reasonable level. us, resource allocation is one of the most critical issues for underlay D2D cellular networks [6, 7]. A kind of D2D resource allocation scheme based on energy efficiency was proposed by Xu et al. [8], which aimed to maximize the energy efficiency of D2D links while en- suring the minimum throughput of cellular users. In this scheme, D2D links reused the uplink resources of cellular Hindawi Complexity Volume 2020, Article ID 3696015, 11 pages https://doi.org/10.1155/2020/3696015