In this paper, an efficient broadcasting technique for digital-video and audio broadcasting (DVB/DAB) is proposed using High-Altitude Platforms (HAP) and a new adaptive beamforming technique. The proposed beamforming technique uses two cascaded weighting functions to generate uniform flat footprint with improved link performance compared to terrestrial systems. These two weighting functions include flattening and smoothing coefficients to generate flat power distribution with lower sidelobe levels. Simulation results show that the generated coverage beam pattern has low sidelobe levels that is more than 40 dB below the main coverage level with less than 1 dB variation over the main coverage lobe level. Also, an almost uniform bit-energy to noise power spectral density can be achieved over the coverage area with minor variations due to the changing slant distance over the coverage area of broadcasting HAP.
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