Soft-decision threshold decoders
Coding system designers are interested in threshold decoding for convolu-tional codes because of the hardware simplicity of the decoder. Unfortunately, majority-decision threshold decodable codes are sub-optimum, and this involves a loss in coding gain. In this paper a new method for implementing soft-decision threshold decoding is introduced, enabling some of the loss in coding gain to be recovered without too great a sacrifice in hardware simplicity. Decoders for constraint length 2 and 12 segments are described, and their performance in Gaussian noise evaluated. The soft-decision technique used can also be applied to block codes with similar improvements in coding gain, and methods of implementing this are discussed.
KeywordsConvolutional Code Information Digit Hard Decision Constraint Length Error Correction Capability
Unable to display preview. Download preview PDF.
- 1.Massey, J.L.:Threshold Decoding, M.I.T. Press, Cambridge Mass., 1963.Google Scholar
- 2.Goodman, R.M.F., and Ng, W.H.: ‘Soft-decision threshold decoding of convolutional codes’, I.E.R.E. Conf. Proc. No. 37, 1977.Google Scholar
- 3.Wozencraft, J.M., and Jacobs, I.B.: Principles of Communication Engineering, Wiley, New York, 1965.Google Scholar