System Link Analysis for a Hybrid SATCOM System with Various Terminal Types

Tactical SATCOM communications employing spread spectrum techniques have been widely investigated for the past several decades. It is typical that an advanced hybrid direct-sequence code-division multiple access (DS-CDMA) system has various remote terminals and must coexist with a conventional frequency-division multiple access (FDMA) system. In this paper, the system link design issues for such hybrid system are investigated. We first investigate a pure and hybrid DS-CDMA satellite communication system under the constraints of specific payload power limitations, mutual interference, and then for the case of different types of ground based terminals with specific applications. Schemes of "balanced" inbound and outbound channel numbers for simplex or duplex applications are available. Furthermore, the similar link analysis and results for such hybrid systems with conventional FDMA terminals are also examined. It is concluded that two power ratio schemes of fixed available E_b/N₀ margins or fixed desired channels are available for same receiving performance or symmetric I/B and O/B channel number application purposes