Sammenlign metoder

	Okumura-Hata-modellen for forudsigelse af tab på transmissionsvej	Ortogonal FrekvensdelingsMultiplex (OFDM)	Shannon Kanal Kapacitetsteorem
Fagområde	Telekommunikation	Telekommunikation	Telekommunikation
Familie	Process / pipeline	Process / pipeline	Process / pipeline
Oprindelsesår	1968	1971	1948
Ophavsperson	Masahiro Okumura and Masahiro Hata	Weinstein and Ebert	Claude Shannon
Type	empirical path loss model	multicarrier modulation scheme	fundamental theoretical bound
Oprindelig kilde	Okumura, Y., Ohmori, E., Kawano, T., & Fukuda, K. (1968). Field strength and its variability in VHF and UHF land mobile radio service. Review of the Electrical Communication Laboratory, 16(9-10), 825-873.	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.	Shannon, C. E. (1948). A mathematical theory of communication. Bell System Technical Journal, 27(3), 379-423.
Aliasser	path loss model, propagation prediction	multicarrier modulation	channel capacity, information theory bound
Relaterede	4	5	5
Resumé	The Okumura-Hata model is an empirical propagation model for predicting path loss in mobile radio systems. Developed by Okumura (1968) and mathematically formalized by Hata (1980), it is one of the most widely used models for cellular network planning. The model predicts median path loss as a function of frequency, distance, and antenna heights, with environment-specific correction factors. Despite its age, the Okumura-Hata model remains a standard in 2G/3G planning and is often used as a baseline for more sophisticated models.	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.	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.