A coded frequency diversity system for HF data transmission

An error control scheme based on convolutionally-coded frequency diversity transmission and soft-decision Viterbi decoding is proposed for HF data transmission. Simulation and experimental results are presented that show that the block error rate performance of the system is much better than that of conventional frequency diversity systems. It is also shown that the new scheme achieves significant throughput under channel conditions where conventional systems fail. A real-time microprocessor implementation of the system is described.