The Improvement of Digital HF Communication Through Coding: II--Tandem Interleaved Cyclic Coding

In previous work the technique of error correction of digital data through the use of interleaved cyclic codes and a set of probability functions for the evaluation of error patterns have been presented. In Part I of this paper [1] the performance of a wide range of Bose-Chaudhuri-Hocquenghem (BCH) codes and PMsymbol codes was evaluated on representative portions of the data. Here a method (identified as tandem interleaved cyclic coding) will be presented which allows for a significant increase in error-rate improvement at a reduction in the delay time introduced into the channel. It is demonstrated that it is possible to get almost I00 percent error correction for delays under three seconds for all channel conditions measured.