Performance Evaluation of mMIMO NOMA as Applied to Aeronautical Communications System

As the number of flights continues to rise daily, finding an optimal solution that can efficiently boost the spectral efficiency of aeronautical communication systems has become imperative. The proposed solution by ICAO is to use the L-band digital aeronautical communication system (LDACS) instead of the VHF band to handle future requirements. However, using the L-band for aeronautical communications is difficult because it affects legal systems. Many onboard systems that operate on L-band already exist, such as the joint tactical information distribution system (JTIDS), the military tactical air navigation (TACAN) system, and the distance measurement equipment (DME). The DME determines the slant distance between the aircraft and the ground station and is one of the most crucial systems. So, we need complex techniques to mitigate the interference with the LDACS system. Our proposed solution is using the NOMA access technique in the VHF digital system to enhance the capacity of the aeronautical communication system without utilizing any other bands to avoid interference, which requires complex techniques to mitigate. In our work, we investigate the maximization of spectral efficiency for NOMA-based massive MIMO for aeronautical communications by using different matching algorithms for aircraft pairing in NOMA, such as the Gale Shapley algorithm, then compare the same algorithm with different beamforming techniques and with different CTGS antennas number. Results demonstrate GS algorithm provides better spectral efficiency than fixed pairing NOMA. Results also show that the achievable spectral efficiency with the MR beamforming technique is lower than that for ZF beamforming. Thus, the optimal solution comprises GS pairing and ZF beamforming.