Adaptive data communication techniques for HF systems

HF communication system parameters and techniques must be optimized and adapted in real time if maximum throughput is to be achieved. Current adaptive HF techniques, such as FED-STD-1045/MIL-STD-188-141A, use channel evaluation and selective call to react to the changing HF propagation conditions. New data link protocols such as those in appendix B of proposed FED-STD-1052 and others take adaptive communications one step further, Proposed FED-STD-1052 appendix B (referred to simply as FED-STD-1052) specifies means by which frame size, modem data rate, and modem interleaver depth can be adapted in real time for changing HF conditions. Transmit power control is an additional system parameter whose adaptation affects throughput. For an HF sytem to be truly adaptive, it must take advantage of all of the techniques mentioned. The authors discuss the adaptation of data communication system parameters to deal with the changing HF environment, and present the tradeoffs for this multidimensional optimization