Antenna array optimisation using semidefinite programming for cellular communications from HAPs

Array pattern optimisation based on semidefinite programming is proposed to improve the coverage performance of cellular communications from High Altitude Platforms (HAPs). This optimisation, when applied to a linear vertical array of N omnidirectional antenna elements, allows a coverage performance better than that of an array of N narrowbeam aperture antennas forming hexagonal cells on the ground. In addition to performance enhancement, the HAP antenna payload can be significantly reduced