SRML: Space Radio Machine Learning

Space-based communications systems to be employed by future artificial satellites, or spacecraft during exploration missions, can potentially benefit from software-defined radio adaptation capabilities. Multiple communication requirements could potentially compete for radio resources, whose availability of which may vary during the spacecraft\u27s operational life span. Electronic components are prone to failure, and new instructions will eventually be received through software updates. Consequently, these changes may require a whole new set of near-optimal combination of parameters to be derived on-the-fly without instantaneous human interaction or even without a human in-the-loop. Thus, achieving a sufficiently set of radio parameters can be challenging, especially when the communication channels change dynamically due to orbital dynamics as well as atmospheric and space weather-related impairments. This dissertation presents an analysis and discussion regarding novel algorithms proposed in order to enable a cognition control layer for adaptive communication systems operating in space using an architecture that merges machine learning techniques employing wireless communication principles. The proposed cognitive engine proof-of-concept reasons over time through an efficient accumulated learning process. An implementation of the conceptual design is expected to be delivered to the SDR system located on the International Space Station as part of an experimental program. To support the proposed cognitive engine algorithm development, more realistic satellite-based communications channels are proposed along with rain attenuation synthesizers for LEO orbits, channel state detection algorithms, and multipath coefficients function of the reflector\u27s electrical characteristics. The achieved performance of the proposed solutions are compared with the state-of-the-art, and novel performance benchmarks are provided for future research to reference

Investigation of the effects of cloud attenuation on satellite communication systems

The aim of this project is to investigate the attenuation due to clouds at 20- 50GHz; to develop an accurate long-term prediction model of cloud attenuation applicable to slant-path links and evaluate the impact of cloud attenuation dynamics on the design of future portable EHF earth-space systems. Higher frequencies offer several advantages, for example, greater bandwidth and immunity to ionospheric effects. The EHF band is being targeted for the launch of earth-space communication systems to provide global delivery of bandwidthintensive services (e.g. interactive HDTV, broadband internet access and multimedia services, television receive-only, etc.) to portable terminal units. Since spectrum shortage and terminal bulk currently preclude the realization of these breakthrough-broadband wireless communication services at lower frequencies, a better understanding is needed in order to optimize their usage. One major obstacle in the design of EHF earth-space communication systems is the large and variable signal attenuation in the lower atmosphere, due to a range of mechanisms including attenuation (and scattering) due to clouds and rain, tropospheric scintillation caused by atmospheric turbulence and variable attenuation by atmospheric gasses. In particular, cloud attenuation becomes very significant at EHF. In this thesis, we start with an overview of literature review in the first chapter. Followed next by the theory and description of accepted-up to date- cloud attenuation models in the field (chapter 2). Then followed up by a description of the pre-processing, validations, sources and assumptions made in order to conduct the analysis of the cloud attenuation in this work (chapter 3). Afterwards, a comprehensive analysis of Meteorological and local tropospheric degradation was carried out (chapter 4). That was followed by an overview of cloud fade statistics and suggested methods to counter their effects (chapter 5). And finally the improved cloud attenuation model and the enhancement of the currently accepted cloud attenuation model (ITU-R 840.4) by terms of validating the effective temperature concept and ways of acquiring it (chapter 6)

Proceedings of the Twentieth NASA Propagation Experimenters Meeting (NAPEX XX) and the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop

The NASA Propagation Experimenters (NAPEX) Meeting and associated Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop convene yearly to discuss studies supported by the NASA Propagation Program. Representatives from the satellite communications (satcom)industry, academia, and government with an interest in space-ground radio wave propagation have peer discussion of work in progress, disseminate propagation results, and interact with the satcom industry. NAPEX XX, in Fairbanks, Alaska, June 4-5, 1996, had three sessions: (1) "ACTS Propagation Study: Background, Objectives, and Outcomes," covered results from thirteen station-years of Ka-band experiments; (2) "Propagation Studies for Mobile and Personal Satellite Applications," provided the latest developments in measurement, modeling, and dissemination of propagation phenomena of interest to the mobile, personal, and aeronautical satcom industry; and (3)"Propagation Research Topics," covered a range of topics including space/ground optical propagation experiments, propagation databases, the NASA Propagation Web Site, and revision plans for the NASA propagation effects handbooks. The ACTS Miniworkshop, June 6, 1996, covered ACTS status, engineering support for ACTS propagation terminals, and the ACTS Propagation Data Center. A plenary session made specific recommendations for the future direction of the program

Proceedings of the Twentieth NASA Propagation Experimenters Meeting (NAPEX 20) and the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop

The NASA Propagation Experimenters (NAPEX) Meeting is convened each year to discuss studies supported by the NASA Propagation Program. Representatives from the satellite communications (satcom) industry, academia, and government who have an interest in space-ground radio wave propagation are invited to NAPEX meetings for discussions and exchange of information. The reports delivered at these meetings by program managers and investigators present recent activities and future plans. This forum provides an opportunity for peer discussion of work in progress, timely dissemination of propagation results, and close interaction with the satcom industry

Proceedings of the Seventeenth NASA Propagation Experimenters Meeting (NAPEX 17) and the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop

The NASA Propagation Experimenters Meeting (NAPEX) is convened annually to discuss studies made on radio wave propagation by investors from domestic and international organizations. NAPEX 17 was held on 15 June 1993. The meeting was organized into two technical sessions. The first session was dedicated to slant path propagation studies and experiments. The second session focused on propagation studies for mobile and personal communications. Preceding NAPEX 17, the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop was held on 14 June 1993 to review ACTS propagation activities with emphasis on ACTS experiments status and data collection, processing, and exchange

Proceedings of the 19th NASA Propagation Experimenters Meeting (NAPEX 19) and the 7th Advanced Communications Technology Satellite (ACTS) Propagation Studies Workshop (APSW 7)

The NASA Propagation Experimenters Meeting (NAPEX), supported by the NASA Propagation Program, is convened annually to discuss studies made on radio wave propagation by investigators from domestic and international organizations. NAPEX 19 was held on 14 Jun. 1995, in Fort Collins, Colorado. Participants included representatives from Canada, Japan, and the United States, including researchers from universities, government agencies, and private industry. The meeting focused on mobile personal satellite systems and the use of 20/30-GHz band for fixed and mobile satellite applications. In total, 18 technical papers were presented. Following NAPEX 19, the Advanced Communications Technology Satellite (ACTS) Propagation Studies Workshop 7 (APSW 7) was held on 15-16 Jun. 1995, to review ACTS propagation activities with emphasis on the experimenters' status reports and dissemination of propagation data to industry