Σύγκριση μεθόδων

	Ορθογώνια Διαίρεση Συχνότητας (OFDM)	Μοντέλο Πρόβλεψης Απωλειών Διαδρομής Okumura-Hata	ZF/MMSE Equalization
Πεδίο	Τηλεπικοινωνίες	Τηλεπικοινωνίες	Τηλεπικοινωνίες
Οικογένεια	Process / pipeline	Process / pipeline	Process / pipeline
Έτος προέλευσης	1971	1968	1974
Δημιουργός	Weinstein and Ebert	Masahiro Okumura and Masahiro Hata	Saleh Mansour and Paul Zervos
Τύπος	multicarrier modulation scheme	empirical path loss model	linear equalization algorithm
Θεμελιώδης πηγή	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.	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.	Proakis, J. G. (2001). Digital Communications (4th ed.). McGraw-Hill.
Εναλλακτικές ονομασίες	multicarrier modulation	path loss model, propagation prediction	channel equalization, interference cancellation
Συναφείς	5	4	5
Σύνοψη	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.	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.	Zero-Forcing (ZF) and Minimum Mean-Square Error (MMSE) equalization are fundamental linear receiver algorithms for combating intersymbol interference in dispersive channels. Developed in the context of data transmission theory, these methods form the basis of modern channel equalization in wireless and wired systems. While ZF aggressively cancels interference, MMSE balances interference suppression with noise enhancement, making it the optimal linear solution under Gaussian noise.