Sammenlign metoder

	Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA)	Multiple-Input Multiple-Output (MIMO)	Ortogonal FrekvensdelingsMultiplex (OFDM)
Fagområde	Telekommunikation	Telekommunikation	Telekommunikation
Familie	Process / pipeline	Process / pipeline	Process / pipeline
Oprindelsesår	1990	1995	1971
Ophavsperson	Phil Karn	Telatar, Foschini, and Gans	Weinstein and Ebert
Type	random access protocol	spatial multiplexing technique	multicarrier modulation scheme
Oprindelig kilde	Karn, P. (1990). MACA—a new channel access method for packet radio. In Proceedings of the ARRL/CRRL Amateur Radio 9th Computer Networking Conference, 134-140.	Telatar, I. (1999). Capacity of multi-antenna Gaussian channels. European Transactions on Telecommunications, 10(6), 585-595.	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.
Aliasser	medium access control, WiFi MAC	spatial multiplexing, antenna diversity	multicarrier modulation
Relaterede	3	5	5
Resumé	CSMA/CA is a random access protocol for wireless medium access control, designed to enable multiple devices to share a wireless channel while minimizing collisions. Introduced by Phil Karn in 1990, it is the foundation of WiFi (IEEE 802.11) and is now the de facto standard for unlicensed spectrum access. CSMA/CA combines carrier sensing (listen before transmit) with collision avoidance (RTS/CTS handshake) to improve channel efficiency and fairness, avoiding the efficiency loss of pure random access (Aloha).	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.