Error correction of low rate speech in jammed frequency hop HF

The authors describe the application of error detection and correction (EDAC) coding to LPC (linear predictive coding)-based voice coders at 600, 800, and 1200 bps. In all cases, the transmitted information rate is 2400 bps, which means that rate 1/4, 1/3, and 1/2 codes are employed. The authors first describe the candidate baseline voice coding schemes. They then address the system simulation assumptions, including channel conditions and interleaving. Several candidate EDAC codes, both block and convolutional, are discussed. Comparative results from the simulations are presented. Complexity issues unique to the individual EDAC methods are addressed along with possible enhancements. Conclusions concerning the potential for transmission of error-protected low rate speech over jammed hopped HF channels are presented