A short report discusses a methodology for designing Ka-band Deep-Space-to-Earth radio-communication links. This methodology is oriented toward minimizing the effects of weather on the Ka-band telecommunication link by maximizing the expected data return subject to minimum link availability and a limited number of data rates. This methodology differs from the current standard practices in which a link is designed according to a margin policy for a given link availability at 10° elevation. In this methodology, one chooses a data-rate profile that will maximize the average data return over a pass while satisfying a minimum- availability requirement for the pass, subject to mission operational limititations expressed in terms of the number of data rates used during the pass. The methodology is implemented in an intelligent search algorithm that first finds the allowable data-rate profiles from the mission constraints, spacecraft-to-Earth distance, spacecraft EIRP (effective isotropic radiated power), and the applicable zenith atmospheric noise temperature distribution, and then selects the best data rate in terms of maximum average data return from the set of allowable data-rate profiles.
This work was done by Shervin Shambayati of Caltech for NASA's Jet Propulsion Laboratory. For further information, access the Technical Support Package (TSP) free online at www.techbriefs.com/tsp under the Information Sciences category.
The software used in this innovation is available for commercial licensing. Please contact Karina Edmonds of the California Institute of Technology at (818) 393-2827. Refer to NPO-41073.
This Brief includes a Technical Support Package (TSP).
Generation of Data-Rate Profiles of Ka-Band Deep-Space Links
(reference NPO-41073) is currently available for download from the TSP library.
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Overview
The document titled "Technical Support Package for Generation of Data-Rate Profiles of Ka-Band Deep-Space Links" is a comprehensive resource prepared under the sponsorship of NASA. It focuses on the advancements in communication technology, particularly the transition from X-band to Ka-band for deep-space missions. This shift is driven by the increased availability of spectrum in the Ka-band, which allows for higher data rates and improved communication capabilities.
The document outlines the analytical models and methodologies used for optimizing link performance in Ka-band communications. It emphasizes the importance of various factors such as weather conditions, elevation profiles, and data rate profiles in maximizing the average data return during communication passes. The optimization process relies on statistical forecasting, which can be conducted on yearly, monthly, or other relevant time scales.
Key sections of the document discuss the operational requirements and availability considerations for Ka-band missions. It highlights that the number of data rates used during a pass is primarily limited by mission-specific inputs and the experiment plan. A minimum availability requirement of 90% is suggested for initial analyses, ensuring that the communication link remains reliable throughout the mission.
The document also addresses the Pt/No (power-to-noise) requirements, which are influenced by modulation indices, channel coding types, and receiver bandwidth settings. These parameters are crucial for ensuring effective communication and data transmission in the challenging environment of deep space.
In addition to technical specifications, the document serves as a guide for researchers and engineers involved in the design and implementation of Ka-band communication systems. It provides insights into the challenges and considerations necessary for successful deep-space missions, including the need for robust forecasting and optimization techniques.
Overall, this Technical Support Package is a valuable resource for understanding the complexities of Ka-band deep-space communication, offering guidance on data-rate profile generation and the factors that influence link performance. It aims to facilitate the development of advanced communication systems that can support future space exploration missions, ultimately contributing to the broader goals of scientific discovery and technological innovation in aerospace.
