Applications of multirate optical fibre code-division-multiplexing systemsto high-speed data communications for air traffic control

Future air traffic control will be based on the distributed processing envi ronment. This leads to the use of high-speed optical fibre networks and sys tems to connect many processors (for both general and specific purposes) an d workstations in the air traffic control centres. To efficiently support s uch applications, communication systems should be capable of multirate oper ations. To achieve this aim, we propose an efficient optical fibre code-div ision multiplexing (OF-CDM) technique that can support multirate data commu nications without any increase of system complexity when compared with the equal-rate operation cast. Unlike conventional optical orthogonal codes (OO Cs), the use of our proposed unequal-length OOCs can eliminate any possible violation of the minimum cross-and auto-correlation constraint (i.e. '1') in multirate OF-CDM systems. Thus, using unequal-length OOCs can achieve a better bandwidth efficiency and a lower bit error rate for multirate transm issions than employing conventional OOCs. Moreover. we present the design o f cost-effective OF-CDM transmitters for multirate data transmissions. The proposed systems can be also employed to support future airborne real-time data distributions and computer interconnects.