Coverage and Performance Evaluation of Multibeam Stratospheric Platforms Wireless Broadband Services

Abstract

In this paper, the radiation pattern of 121 cell aperture antenna for a High-Altitude Platform (HAP) communication network via TV White Space (TVWS) spectrum is investigated. The HAP was placed 17 km above the ground with a coverage radius of 100 km and a cell radius of 10.5 km. For a co-channel cell group of 121 cells served by a payload of aperture antennas on a HAP, the effect of the antenna aperture function on co-channel interference has been explored. For each cell, the required antenna beam widths were derived from the cell’s subtended angles. The proposed system coverage, re-use distance, multibeam antenna pattern, Carrier-to-interference ratio (CIR), Carrier-to-interference-plus-noise-ratio (CINR), and side lobe level values for uniform apertures were investigated. To assess the system’s effectiveness, the CIR at each ground location (x, y) and the cumulative distribution function (CDF) of CINR were investigated for each co-channel cell category. The distribution of CIR levels as contour plots has been presented. The
CIR values are higher at cell centers and lower at cell edges. Furthermore, the importance of minimizing the average side lobe level has been investigated. This paper demonstrated that it is possible to get a good wireless broadband performance by exploiting TVWS spectrums from HAP.