Optimal loading of satellite systems with subchannel gain-state control

This paper presents satellite loading methodologies for the wideband global system (WGS) satellites in which the gains of the subchannels are set differently to optimize the aggregate transponder and terminal powers. The methodologies employ classical optimization techniques to iteratively determine both the transponder gain of each subchannel and the transmit powers of the participating terminals. Given the transponder behavior with nonhomogeneous gain state, interference, and intermodulation (IM), efficient loading algorithms are devised to solve the optimal subchannel gains and link transmission powers based on the developed analytical methods. The optimal satellite loading can be achieved in a finite number of iterations to minimize the combined satellite and terminals powers simultaneously and to close involved links. A practical example in computing the optimum gains and transmission powers is also presented.