Design and Analysis of Network Behaviors for Optimizing Network Energy Efficiency in 5G mmWave Systems

Network behaviors such as power control and transmission duration allocation significantly affect network performance. The existing related works explored network performance improvement by balancing radio resources between backhaul and access links of each millimeter wave (mmWave) small cell in the fifth generation (5G) cellular systems, but they only focused on network throughput instead of network energy efficiency. We address the design and analysis of network behaviors for optimizing network energy efficiency, where each small cell is allowed to adjust not only its individual transmission duration but also its backhaul transmission power, and also each access user is allowed to select an out-band Device-to-Device (D2D) relay if its mmWave access link is blocked. Unlike the existing related works, our scheme allows both backhaul and access powers to be adjusted, which makes the being addressed problem more challenging. Therefore, we formulate it as the Stackelberg game model, which makes the large solution space problem be decomposed into the several interrelated small solution space sub-problems. Thus, the solving difficulty of the challenging problem is reduced. The simulation results demonstrate that the proposed scheme outperforms the comparison algorithms in terms of network energy efficiency while keeping network throughput and convergence speed at acceptable levels.