Salīdzināt metodes

	Ortogonālā frekvenču multipleksēšana ar sadalītu nesēju (OFDM)	Polārie kodi ar secīgu atcelšanas dekodēšanu	Šenona kanāla ietilpības teorēma
Nozare	Telekomunikācijas	Telekomunikācijas	Telekomunikācijas
Saime	Process / pipeline	Process / pipeline	Process / pipeline
Izcelsmes gads	1971	2009	1948
Autors	Weinstein and Ebert	Erdal Arikan	Claude Shannon
Tips	multicarrier modulation scheme	recursive error-correcting code	fundamental theoretical bound
Pirmavots	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.	Arikan, E. (2009). Channel polarization: A method for constructing capacity-achieving codes for symmetric binary-input memoryless channels. IEEE Transactions on Information Theory, 55(7), 3051-3073.	Shannon, C. E. (1948). A mathematical theory of communication. Bell System Technical Journal, 27(3), 379-423.
Citi nosaukumi	multicarrier modulation	channel polarization, recursive codes	channel capacity, information theory bound
Saistītās	5	5	5
Kopsavilkums	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.	Polar codes, introduced by Erdal Arikan in 2009, are the first constructive family of codes proven to achieve the Shannon capacity of symmetric binary-input memoryless channels. They use recursive construction and successive cancellation decoding, a simple greedy algorithm with theoretical guarantees. Polar codes were adopted in 5G NR for control channel coding and are studied for future 6G systems. Unlike turbo and LDPC codes (which are empirical), polar codes provide rigorous theoretical foundations.	Shannon's channel capacity theorem, published in 1948, establishes the maximum rate at which information can be reliably transmitted over a noisy channel. Expressed as C = B log2(1 + S/N) for additive white Gaussian noise (AWGN), it is a fundamental bound in information theory and communications engineering. Shannon proved that reliable communication is possible at any rate below capacity, and impossible above it. This theorem underpins the design of all modern communication systems and motivates coding theory, modulation, and signal processing techniques.