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At least 145 records · Page 8

Simulating Global AeroMACS Airport Ground Station Antenna Power Transmission Limits to Avoid Interference With Mobile Satellite Service Feeder Uplinks

The Aeronautical Mobile Airport Communications System (AeroMACS), which is based upon the IEEE 802.16e mobile wireless standard, is expected to be implemented in the 5091 to 5150 MHz frequency band. As this band is also occupied by Mobile Satellite Service feeder uplinks, AeroMACS must be designed to avoid interference with this incumbent service. The aspects of AeroMACS operation that present potential interference are under analysis in order to enable the definition of standards that assure that such interference will be avoided. In this study, the cumulative interference power distribution at low Earth orbit from transmitters at global airports was simulated with the Visualyse Professional software. The dependence of the interference power on antenna distribution, gain patterns, duty cycle, and antenna tilt was simulated. As a function of these parameters, the simulation results are presented in terms of the limitations on transmitter power from global airports required to maintain the cumulative interference power under the established threshold.

Wilson, Jeffrey D.↗

Optical Array Versus Monolithic Telescope Ground Station Cost Assessment

The purpose of this study is to outline the design of an optimal array of optical telescopes to emulate performance of a monolithic 12 m telescope in support of deep-space communications. In this case, optimal means minimizing the initial capital investment and operational cost while maintaining performance requirements of the deep-space link. The design is approached from a practical, engineering perspective. Pulse position modulation (PPM) signal formatting and photon counting detectors are assumed at each telescope in the array. That is, the telescopes function as so-called light buckets, so direct detection (as opposed to coherent reception) of the received signals is assumed, and there is no intention to consider active compensation for atmospheric turbulence-induced phase fluctuations. A parametric analysis among aperture size, detector size, and primary mirror surface quality, in the context of field-of-view expansion, is presented to minimize the cost function.

Romanofsky, Robert R.↗