قارن الطرق

	رموز فحص التكافؤ منخفضة الكثافة (LDPC)	الترميز التوربيني مع فك التشفير التكراري
المجال	الاتصالات	الاتصالات
العائلة	Process / pipeline	Process / pipeline
سنة النشأة	1962	1993
صاحب الطريقة	Robert Gallager	Claude Berrou, Alain Glavieux, and Punya Thitimajshima
النوع	linear error-correcting code	iterative error-correcting code
المصدر التأسيسي	Gallager, R. G. (1962). Low-density parity-check codes. IRE Transactions on Information Theory, 8(1), 21-28.	Berrou, C., Glavieux, A., & Thitimajshima, P. (1993). Near Shannon limit error-correcting coding and decoding: Turbo-codes. In Proceedings of the IEEE International Conference on Communications (ICC), 1064-1070.
الأسماء البديلة	sparse codes, belief propagation codes	iterative decoding, concatenated codes
ذات صلة	5	5
الملخص	LDPC codes, invented by Robert Gallager in 1962 and rediscovered in the 1990s by MacKay, are linear error-correcting codes defined by sparse parity-check matrices. They achieve performance within 0.4 dB of the Shannon limit with iterative belief-propagation decoding and have become the standard for modern wireless (WiFi-6, 5G NR, Digital Video Broadcasting). Unlike turbo codes, LDPC codes have a more elegant graph-theoretic structure and more mature theoretical analysis.	Turbo codes, introduced by Berrou, Glavieux, and Thitimajshima in 1993, are a landmark in channel coding history. They achieve performance within 0.5 dB of the Shannon limit—the theoretical boundary for reliable communication—a feat previously thought impossible with practical complexity. Turbo codes use concatenated convolutional codes with an interleaver and iterative decoding via belief propagation. They were adopted in 3G (UMTS) and remain important in 4G/5G systems alongside LDPC codes.