Algorithms for MUOS Capacity Analysis

The Mobile User Objective System (MUOS) for satellite communications (SATCOM) is being developed to provide important beyond line-of-sight (BLOS) communications for tactical military users. There is a keen interest in the MUOS data rate capacity as it relates to the available system bandwidth. A set of wide-band code-division multiple access (WCDMA) waveforms will be used to share bandwidth among users and so multiple access interference (MAI) must be considered in evaluating system capacity. In addition, frequency reuse is accomplished based on the employment of multiple satellite beams. While this improves the system capacity, it complicates the supportability analysis because adjacent beam interference can increase the MAI and, as a result, can impact system capacity. The purpose of this paper is to develop algorithms that determine supportability for a given set of links in the MUOS system. These algorithms will be useful in determining system capacity for heterogeneous sets of links. The algorithms take into account the MAI impact of other beams using the same carrier from the same and adjacent satellites. Furthermore, these algorithms have been designed to significantly reduce the dimensionality of the problem and, hence, ease the computational burden required for link supportability calculations. An example capacity calculation is shown for a homogeneous set of users.