On the channel control modem for DAMA applications

We discuss the requirements and performance of a channel control modem (CCM) for use in demand assigned multiple access (DAMA) satellite communication applications. The DAMA net controller manages the network assignments via the forward orderwire bursts (also called packets), and the net members request for services via the returned orderwire. A net member may also communicate with any other net member via an intermittently assigned time slot. Thus, the important feature of the CCM operation is burst mode communication. The burst acquisition and the bit error rate performance of the CCM will directly affect the overall performance of the DAMA network. Depending upon the band (UHF, SHF, C, Ku, or X) in use and the type of users (mobile or stationary), the signal conditions for the modem operation can be quite different. This CCM is designed to operate under all the conditions for military as well as commercial users. The digital signal processing approach provides the modem with maximum flexibility allowing it to work with preamble structures specified in MIL-STD-188-182 and 183 or any other future standards such as for SHF and tri-band (X, C, and Ku) applications.