Combat durable spread spectrum data link for national military aviation

A foundation to a well-executed military flight operation is a situation awareness. Pilots have to have a real time air picture in their use, i.e., exact information of the own and enemy’s fighters, and instructions of the mission command. The later has to have information for example about the remaining flight time of the fighters. To keep up the situation awareness the fighters participating the flight operation and the mission command on the ground are connected via real time robust communications system. In this thesis, a system development of the experimental SIHTI (Suomen ilmavoimien hajaspektritietovuo) spread spectrum data link fulfilling the national requirements is considered from the requirement specification to the performance measurements of the airproof prototype. Key factors in the system development have been a resistance to heavy jamming and inter-network interference, good LPD/LPI properties, robustness and technical restrictions of the fighters.

The experimental SIHTI data link, which utilize FH/DS-CDMA and TDMA multiple access techniques, was verified by laboratory measurements and flight tests. These verifications showed that in the peacetime circumstances the experimental SIHTI data link operates according to requirements. Instead, in the most demanding wartime circumstances it has some functional faults. In the thesis, it is discussed how these faults can be solved.