On the Cost-Effectiveness of Using Beamforming at the Ground Station for Aeronautical Communications

In recent years, beamforming techniques have become increasingly popular, primarily because of their ability to enhance the performance of communication systems. These techniques might also yield improvements in aeronautical communications systems. However, the deployment of beamforming techniques comes with additional cost. In this paper, we assess the cost-effectiveness of employing beamforming techniques for air-ground communications to determine its feasibility. The study compares the antenna gain-cost ratio of using beamforming techniques to using a single-omnidirectional antenna. The cost function is determined by both the number of antenna elements in a single station and the total number of ground stations needed to cover an area. The cost-effectiveness evaluations are conducted for two use cases: The L-band Digital Aeronautical Communications System (LDACS) and the implementation of beamforming at higher frequencies. According to the cost-effectiveness metric defined in this paper, beamforming is not cost-effective at frequencies below 4 GHz, including LDACS.