Cylindrical Massive MIMO System for HAPS: Capacity Enhancement and Coverage Extension
Koji Tashiro, Kenji Hoshino, Atsushi Nagate
Abstract
Ultra-wide coverage is one of the important concepts of the 6th generation (6G) mobile communications. High-altitude platform stations (HAPS) have attracted a great deal of attention as a leading candidate for the coverage extension. The service link capacity can be increased significantly by means of multiuser multiple-input multiple-output (MIMO) technologies combined with a conventional large-scale planar array antenna. However, the coverage achieved by the planar array is limited to the circle whose radius is only tens of kilometers. This paper proposes a cylindrical massive MIMO (mMIMO) system for achieving ultra-wide coverage such as 100 km as well as high system capacity in HAPS. Assuming the area radius of 100 km, simulation results show that the proposed system improves signal-to-interference-plus-noise ratio by about 10 dB at the boundary of the area, and moreover it achieves up to about 2.1 times as high capacity as the conventional mMIMO with the planar array.