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Εξετάστε τις επιλεγμένες μεθόδους δίπλα-δίπλα· οι γραμμές που διαφέρουν επισημαίνονται.
| Πολλαπλών Εισόδων Πολλαπλών Εξόδων (MIMO)× | Ορθογώνια Διαίρεση Συχνότητας (OFDM)× | Μοντέλο Πρόβλεψης Απωλειών Διαδρομής Okumura-Hata× | |
|---|---|---|---|
| Πεδίο | Τηλεπικοινωνίες | Τηλεπικοινωνίες | Τηλεπικοινωνίες |
| Οικογένεια | Process / pipeline | Process / pipeline | Process / pipeline |
| Έτος προέλευσης≠ | 1995 | 1971 | 1968 |
| Δημιουργός≠ | Telatar, Foschini, and Gans | Weinstein and Ebert | Masahiro Okumura and Masahiro Hata |
| Τύπος≠ | spatial multiplexing technique | multicarrier modulation scheme | empirical path loss model |
| Θεμελιώδης πηγή≠ | Telatar, I. (1999). Capacity of multi-antenna Gaussian channels. European Transactions on Telecommunications, 10(6), 585-595. DOI ↗ | 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. DOI ↗ | 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. link ↗ |
| Εναλλακτικές ονομασίες≠ | spatial multiplexing, antenna diversity | multicarrier modulation | path loss model, propagation prediction |
| Συναφείς≠ | 5 | 5 | 4 |
| Σύνοψη≠ | MIMO is a technique that uses multiple transmit and receive antennas to significantly increase channel capacity and reliability. Pioneered theoretically by Telatar (1999) and Foschini & Gans (1998), MIMO exploits multipath propagation—typically a liability in wireless—as an asset by creating independent spatial channels. It is now fundamental to all modern wireless systems including LTE, WiFi-6, and 5G, where it provides both capacity gains through spatial multiplexing and robustness through diversity. | 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. |
| ScholarGateΣύνολο δεδομένων ↗ |
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