Performance of Multiple Satellite Systems with Common Downlink Frequency Hopping Patterns

摘要

This report considers a situation in which more than one satellite transmitting frequency-hopped signal is in view of a given terminal. If it is desired that the satellites use the same frequency hopping pattern for ease of acquisition and handover, then a receiver which is in range of more than one satellite may encounter interference. This interference is analyzed for a generalized system of two satellites modelled after the LES-8/9 system. Upperbounds for the probability of error are derived for receivers using a square-law combining rule. This expression is evaluated for the LES-8/9 system, using two different downlink codes. It is seen that the choice of code makes a significant difference in system performance, and that with a suitably chosen code, two satellites may use the same frequency hopping pattern without significant performance degradation. (Author)