Soft decoding of recorded HF data

In the search for good error control codes with known decoding algorithms, for the frequency hopping HF channel, the authors have studied how channel measurement information can improve the error-correcting capability of the code. They show the performance of some well-known error-correcting codes when used on the HF channel together with channel measurement information. A frequency hopping system working at HF has been built and tested. The system is built as an experimental system to investigate the various problems one has to deal with when using spread-spectrum coding. The intention is to demonstrate the efficiency with this kind of system compared to other systems in a hostile jamming environment. Based on data recorded from the HF system they have implemented two types of soft decoding algorithms in software and simulated their performances. The two decoding algorithms are the Blokh-Zyablov algorithm and the Chase algorithm.<>