Random codes: minimum distances and error exponents

IEEE Transactions on Information Theory - Tập 48 Số 9 - Trang 2568-2573 - 2002
A. Barg1,2, G.D. Forney3
1Bell Labs, Lucent Technologies, Inc., Murray Hill, NJ, USA
2Institute of Information Transmission Problems IPPI, Moscow, Russia
3Massachusetts Institute of Technology, Cambridge, MA, USA

Tóm tắt

Minimum distances, distance distributions, and error exponents on a binary-symmetric channel (BSC) are given for typical codes from Shannon's random code ensemble and for typical codes from a random linear code ensemble. A typical random code of length N and rate R is shown to have minimum distance N/spl delta//sub GV/(2R), where /spl delta//sub GV/(R) is the Gilbert-Varshamov (GV) relative distance at rate R, whereas a typical linear code (TLC) has minimum distance N/spl delta//sub GV/(R). Consequently, a TLC has a better error exponent on a BSC at low rates, namely, the expurgated error exponent.

Từ khóa

#Linear codes #Channel coding

Tài liệu tham khảo

dyachkov, 1980, bounds on the average error probability for a code ensemble with fixed composition, Probl Pered Inform, 16, 3 10.1109/18.720546 gallager, 1968, Information Theory and Reliable Communication gallager, 1963, Low Density Parity-Check Codes, 10.7551/mitpress/4347.001.0001 mézard mezard, 2001, aspects of spin glass theory, Workshop on Statistical Physics and Capacity-Approaching Codes 10.1109/TIT.1973.1054971 berlekamp, 1968, Algebraic Coding Theory viterbi, 1979, Principles of Digital Communication and Coding bassalygo, 1991, simple methods for deriving lower bounds in the theory of codes, Probl Pered Inform, 27, 3