Investigation into network architecture and modulation scheme for IL-STD-1773 optical fiber data buses

摘要

The design issues on network architecture and modulation scheme that can be used to implement reliable MIL-STD-1773 avionics optical fiber data buses are discussed. Both single-star and multi-star architectures are presented to such optical fiber data buses. Several network configurations based on passive and/or active coupling components are also considered, and they are compared in terms of system complexity and reliability. Moreover, three modulation schemes are presented, i.e. partial trilevel Manchester II bi-phase coding, extended Manchester II phase coding with beginning-stopping flags, and pseudofour-ary pulse width modulation, respectively. Their use can feasible sovle the problem associated with fast identification of correct operation states of an active transmitter at the output of optical receivers.