Salīdzināt metodes

	Turbo kodēšana ar iteratīvo dekodēšanu	Zemās blīvuma paritātes pārbaudes kodi (LDPC)	Ortogonālā frekvenču multipleksēšana ar sadalītu nesēju (OFDM)
Nozare	Telekomunikācijas	Telekomunikācijas	Telekomunikācijas
Saime	Process / pipeline	Process / pipeline	Process / pipeline
Izcelsmes gads	1993	1962	1971
Autors	Claude Berrou, Alain Glavieux, and Punya Thitimajshima	Robert Gallager	Weinstein and Ebert
Tips	iterative error-correcting code	linear error-correcting code	multicarrier modulation scheme
Pirmavots	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.	Gallager, R. G. (1962). Low-density parity-check codes. IRE Transactions on Information Theory, 8(1), 21-28.	Weinstein, S. B., & Ebert, P. M. (1971). Data transmission by frequency-division multiplexing using the discrete Fourier transform. IEEE Transactions on Communication Technology, 19(5), 628-634.
Citi nosaukumi	iterative decoding, concatenated codes	sparse codes, belief propagation codes	multicarrier modulation
Saistītās	5	5	5
Kopsavilkums	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.	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.	OFDM is a multicarrier modulation technique that divides a wideband channel into many narrowband orthogonal subcarriers. Introduced by Weinstein and Ebert in 1971, it exploits the duality between time and frequency domains to efficiently use spectrum while mitigating intersymbol interference in frequency-selective channels. OFDM is now the standard for high-speed wireless systems including WiFi, cellular LTE, and digital broadcasting.