Introduction to coding for HF communications
Abstract
The increasing demand for reliable, low error-rate, high-speed digital data transmission at HF has created the need for the adoption of coding schemes. As it is well appreciated by the practicing communicator, a problem in high-speed data transmission is the occurrence of errors. Codes provide an effective approach for the reduction of the error rate. Linear block codes (of which cyclic codes are a subclass) and convolutional codes are the main categories of codes of interest to HF communications. They are capable of correcting random errors due to white Gaussian noise, as well as burst errors due to impulse noise. In block codes, a block of information bits is followed immediately by a group of check bits. The latter verify the presence of errors in the former. In convolutional codes, check bits are continuously interleaved with information bits, and they check the presence of errors not only in the block immediately preceeding them, but in other blocks as well. For the various coding schemes reviewed in the lecture, several numerical examples are given, to help in the quantitative appraisal of the merits of a code, versus required equipment complexity.
- Publication:
-
In AGARD Modern HF Commun. 13 p (SEE N83-30862 19-32
- Pub Date:
- May 1983
- Bibcode:
- 1983mhfc.agarQ....G
- Keywords:
-
- Computer Programming;
- Data Transmission;
- High Frequencies;
- Bits;
- Computer Programming;
- Error Correcting Codes;
- Random Noise;
- Communications and Radar