Enhancing energy efficiency for cellular-assisted vehicular networks by online learning-based mmWave beam selection

Millimeter Wave (mmWave) technology has been regarded as a feasible approach for future vehicular communications. Nevertheless, high path loss and penetration loss raise severe questions on mmWave communications. These problems can be mitigated by directional communication, which is not easy to achieve in highly dynamic vehicular communications. The existing works addressed the beam alignment problem by designing online learning-based mmWave beam selection schemes, which can be well adapted to high dynamic vehicular scenarios. However, this kind of work focuses on network throughput rather than network energy efficiency, which ignores the consideration of energy consumption. Therefore, we propose an Energy efficiency-based FML (EFML) scheme to compensate for this shortfall. In EFML, the energy consumption is reduced as far as possible under the premise of meeting the basic data rate requirements of vehicle users, and the users requesting the same content in close proximity can be organized into the same receiving group to share the same mmWave beam. The simulation results demonstrate that, compare with the comparison method with best energy efficiency, the proposed EFML improves energy efficiency by 17–41% in different scenarios.

Regression-Based Beam Training for UAV mmWave Communications

For the unmanned aerial vehicle (UAV) Millimeter-Wave (mmWave) communication systems, an efficient and accurate beam training method is urgently required to overcome the severe path loss. By taking into account the mmWave propagation environment,a three-dimensional (3D) intelligent beam training strategy by leveraging the polynomial regression model and optimized beam patterns is proposed in this paper. We treat the mmWave beam selection as a polynomial regression problem. The regression function is obtained by a machine learning (ML) method based on the dataset and a special beam pattern is achieved to obtain the dataset consisting of measured powers and estimated angles. Furthermore, a noise suppression method involving the use of denoising autoencoder (DAE) is developed to improve the robustness of the proposed regression model.Numerical simulation results demonstrate that our proposed beam training strategy is capable of getting the same precision as the exhaustive search methods with a shorter time.

Optimization Analysis of The Strength Capacity and The Economic Value Comparison of Castellated Steel Beam and Its Equivalent IWF Beam

The research is aimed to figure out the comparison of the strength capacity and economic value comparison of castellated steel beam to its equivalent IWF beam. The profile of the castellated steel beam in this study included all profiles of castellated steel beam on the market based on the products catalog of the castellated steel beam from PT. Gunung Garuda. The finite element method was used in this study with the aid from Abaqus program to get a comparison of the strength capacity of castellated steel beam to its equivalent IWF beam. The next stage next involved the calculation of a comparison of the economic value of the castellated steel beam with hexagonal holes with to its equivalent IWF beam. The results of the study showed that the castellated steel beam experienced an increase in the strength capacity of 1,189 up to 2,330 times compared to its equivalent IWF beam. The comparison of the strength capacity between the castellated steel beam and its equivalent IWF beam is at 1,010 up to 1,539. Based on the combination between the comparison of strength capacity and the economic value, there are 14 (58.33%) profiles of the castellated steel beam which is categorized as efficient in terms of the design of the structure and cost, there are four (16.67%) profiles of the castellated steel beam which is categorized as efficient in terms of the design of the structure but not efficient in terms of cost, and there are 6 (25.00%) profiles of the castellated steel beam which is categorized as inefficient in terms of the design of the structure and cost. The results of this study indicate that the castellated steel beam can replace its equivalent IWF beam. Selection of profile of the castellated steel beam is appropriate to provide efficiency in terms of weight of the structure between 58.5% to 15.1% and can provide efficiency in terms of cost of between 48.4% to 0.9%.