Experimental results on the application of convolutional coding and Viterbi decoding as a frequency diversity technique in HF data transmission

A method of using coding and soft-decision decoding techniques to replace a conventional diversity combiner is examined. It uses a rate-1/2 convolutional code and Viterbi decoding in a dual diversity configuration at 75 bps, and is easily implemented with an eight-bit microprocessor. The results of comparisons between the coding technique and standard diversity combining on several short-and medium-range HF links are given, and its advantages and limitations in HF data systems applications are discussed.