In this thesis, we consider maximized power allocation of non-orthogonal multiple ac- cess (NOMA) schemes since it outperforms than orthogonal multiple access (OMA) for the high altitude platform networks (HAPNETs) both in the back- haul and access links. Secondly, we propose a cluster formation (CF) algorithm and power-bandwidth resource allocation (PB-RA) for solving the resource management of HAPNETs. We adopt the particle swarm optimization (PSO) algorithm to explore the optimal de- ployment of high altitude platforms (HAPs) and unmanned aerial vehicles (UAVs) iteratively by a given swarm size. By PSO, we provide the best deployment under a given iteration number. Besides that, numerical results show that the NOMA schemes have better performance than OMA ones concerning different network control factors like the number of BSs, HAPs, and UAVs.

Submitted to the Information Technology (IT) Department in conformity with the requirements for the degree of Doctor of Philosophy in Information Technology, Durban University of Technology. Durban, South Africa, 2016. / This doctoral research introduces an integration of satellite systems and new stratospheric platforms for weather observation, imaging and transfer of meteorological data to the ground infrastructures. Terrestrial configuration and satellite communication subsystems represent well-established technologies that have been involved in global satellite sensing and weather observation area for years. However, in recent times, a new alternative has emerged based on quasi-stationary aerial platforms located in the Stratosphere called High Altitude Platform (HAP) or Stratospheric Communication Platforms (SCP). The SCP systems seem to represent a dream come true for communication engineers since they preserve most of the advantages of both terrestrial and satellite communication systems. Today, SCP systems are able to help, in a more cost effective way, developments of space Earth sensing and weather observation and weather sensing and observation. This new system can provide a number of forms ranging from a low altitude tethered balloon to a high altitude (18 – 25 km) fuel-powered piloted aircraft, solar-powered unmanned airplanes and solar-powered airship.

Submitted to the Information Technology (IT) Department in conformity with the requirements for the degree of Doctor of Philosophy in Information Technology, Durban University of Technology. Durban, South Africa, 2016. / This doctoral research introduces an integration of satellite systems and new stratospheric platforms for weather observation, imaging and transfer of meteorological data to the ground infrastructures. Terrestrial configuration and satellite communication subsystems represent well-established technologies that have been involved in global satellite sensing and weather observation area for years. However, in recent times, a new alternative has emerged based on quasi-stationary aerial platforms located in the Stratosphere called High Altitude Platform (HAP) or Stratospheric Communication Platforms (SCP). The SCP systems seem to represent a dream come true for communication engineers since they preserve most of the advantages of both terrestrial and satellite communication systems. Today, SCP systems are able to help, in a more cost effective way, developments of space Earth sensing and weather observation and weather sensing and observation. This new system can provide a number of forms ranging from a low altitude tethered balloon to a high altitude (18 – 25 km) fuel-powered piloted aircraft, solar-powered unmanned airplanes and solar-powered airship.

New and future telecommunication networks are and will be broadband type. The existing terrestrial and space radio communication infrastructures might be supplemented by new wireless networks that make and will make use of aeronautics-technology. Our study/contribution is referring to radio communications based on radio stations aboard a stratospheric platform named, by ITU-R, HAPS (High Altitude Platform Station). These new networks have been proposed as an alternative technology within the ITU framework to provide various narrow/broadband communication services. With the possibility of having a payload for Telecommunications in an aircraft or a balloon (HAPS), it can be carried out radio communications to provide backbone connections on ground and to access to broadband points for ground terminals. The latest implies a complex radio network planning. Therefore, the radio coverage analysis at outdoors and indoors becomes an important issue on the design of new radio systems. In this doctoral thesis, the contribution is related to the HAPS application for terrestrial fixed broadband communications. HAPS was hypothesised as a quasi-static platform with height above ground at the so-called stratospheric layer. Latter contribution was fulfilled by approaching via simulations the outdoor-indoor coverage with a simple efficient computational model at downlink mode. This work was assessing the ITU-R recommendations at bands recognised for the HAPS-based networks. It was contemplated the possibility of operating around 2 GHz (1820 MHz, specifically) because this band is recognised as an alternative for HAPS networks that can provide IMT-2000 and IMT-Advanced services. The global broadband radio communication model was composed of three parts: transmitter, channel, and receiver. The transmitter and receiver parts were based on the specifications of the IEEE Std 802.16TM-2009 (with its respective digital transmission techniques for a robust-reliable link), and the channel was subjected to the analysis of radio modelling at the level of HAPS and terrestrial (outdoors plus indoors) parts. For the channel modelling was used the two-state characterisation (physical situations associated with the transmitted/received signals), the state-oriented channel modelling. One of the channel-state contemplated the environmental transmission situation defined by a direct path between transmitter and receiver, and the remaining one regarded the conditions of shadowing. These states were dependent on the elevation angle related to the ray-tracing analysis: within the propagation environment, it was considered that a representative portion of the total energy of the signal was received by a direct or diffracted wave, and the remaining power signal was coming by a specular wave, to last-mentioned waves (rays) were added the scattered and random rays that constituted the diffuse wave. At indoors case, the variations of the transmitted signal were also considering the following matters additionally: the building penetration, construction material, angle of incidence, floor height, position of terminal in the room, and indoor fading; also, these indoors radiocommunications presented different type of paths to reach the receiver: obscured LOS, no LOS (NLOS), and hard NLOS. The evaluation of the feasible performance for the HAPS-to-ground terminal was accomplished by means of thorough simulations. The outcomes of the experiment were presented in terms of BER vs. Eb/N0 plotting, getting significant positive conclusions for these kind of system as access network technology based on HAPS.

High Altitude Platforms (HAP) has been evolving to make a new history in wireless communications infrastructure. A number of applications and services have been proposed for HAP based communications which advance HAP over terrestrial and satellite infrastructure for future communications. Providing high speed multimedia mobile communications through HAPs to the users of Third Generation (3G) holds strong position using one of the proposed band, 2GHz. In this study we investigated how to improve the performance of 3G serving from HAP over a territory having suburban characteristics. Two proposed channel models, free space loss and shadowing loss, has been used to analyze the performance of HAP systems at 2GHz frequency band for suburban regions. Three different parameters namely antenna bore point, HAP antenna roll off factor and user antenna roll off factor have proposed to improve the performance of HAP systems while considering suburban regions. A scenario has introduced consisting of an ideal suburban and rural region to serve 3G services while emphasizing on suburban region. The number of HAPs required to serve the defined suburban region is restricted to at least three due to elevation dependent losses in the scenario. The three proposed parameters have been used to improve the performance of 3G services over the selected suburban region. Application of the parameters over suburban region gives different performances which can be categorized in different ways. Some of the parameters are more elastic than others for a certain coverage area. We conclude with adaptive application of the parameters for 3G services over suburban area to have improved performance of HAP. / +46720459586

Driven by the surging need for seamless connectivity, research in the wireless communication area has dramatically evolved over the years to meet the increasing demand for data rate and seamless coverage. Such evolvement concurs with a notable increase in data traffic and the widespread of data-hungry devices, thereby inflicting stringent requirements on terrestrial networks. Despite the tremendous advances achieved through the past generations of wireless systems, almost half of the world's population remains unconnected, leading to an accentuated digital divide problem. Therefore, this work invigorates a new connectivity solution that integrates aerial and terrestrial communications with a high-altitude platform station (HAPS) to promote a sustainable connectivity landscape. The connectivity solution adopted in this thesis specifically integrates terrestrial base stations with hot-air balloons under the framework of a cloud-enabled HAPS via a data-sharing fronthauling strategy. The aerial (hot-air balloons) and terrestrial base stations, grouped into disjoint clusters, coordinate their mutual transmission to serve aerial (i.e., drones) and terrestrial users. This work studies the downlink communication from the cloud-enabled HAPS to the aerial and terrestrial users under practical system considerations, namely the limited transmit power and the limited-capacity fronthaul link, per-base station. To this end, the first part of the thesis devises a specific optimization problem that maximizes the network sum-rate while accounting for system design constraints to determine the user association strategy, i.e., user to terrestrial clusters or user to air clusters, and the associated beamforming vectors. The second part of the thesis, then, designs a different resource allocations optimization problem that accounts for the fairness among the users, thus adopting a proportionally fair scheduling scheme to assign users on frequency tones to maximize the log of the long-term average rate. On this account, the work solves a handful of non-convex intricate optimization problems using techniques from optimization theory, namely, fractional programming and $\ell_0$-norm approximation. The work consequently outlines the gains realized by providing on-demand coverage in crowded and unserved areas. Moreover, the thesis illustrates the benefits of coordinating the operations of aerial and terrestrial base stations for interference management, load-balancing, and fairness measures.

This thesis is the result of a collaboration between Ericsson AB and Luleå University of Technology. A feasibility study has been conducted to investigate antenna options for the HIBS access link. The study contains two parts. Firstly, a link budget investigating the gain required from the antenna. The metric of concern in the link budget was SNR. Secondly, a wide area coverage investigation that explored coverage feasibility over an area with a radius of 100 km. The metrics of concern in this investigation were antenna gain and beamwidth. Two types of antennas have been included: parabolic reflector and phased array. Seven frequency bands have been studied: 0.7, 1.9, 2.7, 3.5, 6, 10, and 26 GHz. The first three bands shared a bandwidth of 20 MHz, the next three shared a bandwidth of 80 MHz, and the last band had a bandwidth of 100 MHz. This bandwidth difference was found to have a meaningful effect on SNR. The feasibility condition for the link budget was -6 dB SNR for uplink and 6 dB SNR for downlink. The link budget concluded that the first three bands (0.7, 1.9, and 2.7 GHz) are feasible with reasonably sized antennas. This meant a parabolic reflector dish diameter of 0.6 m for all three bands, or a phased array antenna with 4, 32, and 64 elements, respectively, that all resulted in a roughly equal physical size of the array. The 3.5 GHz frequency band was found to be feasible with a much larger antenna (512 element array). The bands above 3.5 GHz were not deemed feasible. The wide area investigation limited the antenna to a phased array antenna. Two cell layouts were considered for coverage: a 7 cell layout with one nadir cell surrounded by 6 cells and a 19 cell layout which encapsulates the former with another layer of 12 cells. The feasibility condition was that the half power beamwidth is equal to the angular size of a cell from the HIBS for each cell layer while maintaining gain. Beamwidth was controlled through array tapering and altering element configurations. This investigation concluded that coverage is feasible for two bands. In the 0.7 GHz band, the chosen option was a 7 cell layout using a single element antenna for the nadir cell and 3 by 1 arrays for the outer cells. In the 1.9 GHz band, the chosen option was a 19 cell layout with a single element antenna for the nadir cell, 5 by 1 arrays for the cells in the middle layer, and 8 by 5 arrays for the outer layer. Higher frequency bands required higher gain antennas which in turn did not provide adequate beamwidth for coverage.