Search

The motivations for deploying energy and spectral-efficient network architectures are the high energy consumption and the need for more spectral resources in modern cellular networks. The key method to solve the energy efficiency EE maximization problem of the downlink non-orthogonal multiple access (NOMA)-based massive MIMO system is to decouple it into user pairing and efficient power allocation problems. This work studies the performance of three main pairing methods in NOMA-based networks: Hungarian, Gale–Shapley, and correlation-based approaches. Firstly, we provide a mathematical analysis for EE of downlink NOMA in a massive MIMO system for the non-line of sight (NLoS) channel model with perfect successive interference cancellation (SIC). Finally, the sequential convex programming (SCP) approach is used to tackle the power allocation problem. Simulation results show that the Hungarian algorithm for pairing plus SCP for power allocation (Hungarian algorithm-SCP) achieves the highest energy efficiency among all the three pairing algorithms with an identical performance to joint user and resource block association with power allocation (joint user-RB PA) algorithm but with much lower computational complexity and outperforms the NOMA SCP greedy algorithm (NOMA-SCP-GA).

Pretensioned extended, bolted end-plate moment connections are very popular due to ease of fabrication and erection. In order to identify the effect of different parameters on the behavior of the connection, a three-dimensional finite element model that accounts for both geometrical and material non-linearities is developed using the multi-purpose software package ANSYS. A parametric study is conducted using this model on two end-plate configurations: four bolts and multiple row extended end plates. The studied parameters were as follows: beam depth, end-plate thickness, bolts diameter, bolts pitch, bolts gage, and end-plate stiffener. Then, yield line analysis is used to propose equations for the end-plate bending capacity. A design model is assumed for bolt forces analysis, and design equations are proposed. The proposed equations are compared to the finite element results and the current design codes.