A statistical link budget approach for predicting MSS L-band link margin performance

Link margin specification based on worst case link conditions is conservative and virtually guarantees increased costs and over-design of satellite hardware just to ensure that the worst case link meets requirements. One approach to optimize performance against cost is to specify link margin, or availability, statistically, i.e. link margin that must be met over a specified percentage of the coverage area instead of toward a single point on the Earth's surface or at a minimum elevation angle. A statistical link budget verifies compliance to statistically levied requirements, and takes into account parameters that vary between different instances of the same link to better estimate and characterize the link margin that may be afforded by a given satellite communication system design. These types of link budgets are especially appropriate for mobile satellite systems (MSS), where users or satellites are moving and link parameters are variable as a function of time, location and other conditions. This paper describes an approach for verifying L-band link margin requirements for an MSS constellation of satellites using statistical link budgets, including identifying parameters to treat statistically, as well as processing and calculating results.