With increasing growth in the number of satellites and aircraft in the high altitude and low Earth orbit region, and the data rates required for the services they provide needing to also increase, there is a need for research to develop new techniques for improved and efficient allocation and management of RF spectrum in the region in support of higher data rates with lower latency.This thesis contributes a new combined antenna topology and communications architecture supporting satellite and high altitude platform communications, based on a novel cell sector topology and handover methodology, and which allows for spectrum re-use between space, air and ground. By utilising, modifying and combining existing standards, the actions of communications attach, connect, handover, and link tear down are developed to work with the proposed communications architecture in which the cell sectors are in motion relative to platforms and to the ground.To understand the implications of this problem a mathematical model was constructed, and to improve the fidelity of the model the ITU-R P.2041 standard was implemented in software code and used to provide simulation results using constraint data derived from a detailed literature survey.Using this model, three experiments were considered to explore approaches to providing improved communication data rate and spectrum usage. Of these it was concluded, using mathematical modelling in software, and using satellite simulation tools, that a solution with a system architecture using RF gradient optic antennas, Space Division Multiple Access (SDMA), Direct Sequence Spread Spectrum Code Division Multiple Access (DSSS-CDMA), protocols from the Third Generation Partnership Project - Universal Mobile Telephony System (3GPP-UMTS), with a Cooperative Multi-Point Multiple Input Multiple Output (CoMP-MIMO)–like architecture was the most successful of the approaches studied in fulfilling the need for a novel improved communications capability for the high altitude, low Earth orbit region.From this research it was found that there is a way to provide managed spectrum vertical three-dimensional spatial re-use through the creation of communication “moving-cells-in-the-sky”, and that these ‘cells’, analogous in a sense to ground mobile phone cells, can be individually addressed, and data transferred to and from users within each of these three dimensional spatial cells. The methods to achieve this novel capability are described herein.In addition to concluding how to create such three dimensional communication cells in vertical space, it was found that the cells could support vertical RF spectrum re- use, with the useful and novel feature of allowing ground user equipment to operate using the same RF frequencies as air and space craft with insignificant levels of interference, and with considerable increases in data rates and capacity. Finally the research shows that handover between cells can be achieved based on careful re-use of existing standards for ground mobile phone systems.The research concluded with the identification of further work, which includes extending the results to other application areas, both on the ground and in space.
Multiple Satellite Communication System for Low Earth Orbit and High Altitude Platforms
Jones, E. (Author). 4 Oct 2018
Student thesis: Doctoral Thesis › PhD