Research Of WLAN Based On OFDM

As a very convenient data transmission system, Wireless Local Area Networks (WLAN) is combination of wireless communication technology and internet. WLAN experience a growing popularity recently with development of communication. IEEE802.1la has chosen the Orthogonal Frequency Division Multiplexing (OFDM) as the basic technology. This technology will separate a wireless channel to many sub-channels and transmit data at the same time; every speed of sub-carrier is lower than total speed. Then it can overcome the ISI, improve signal quality and raises the speed of entire network. The great merit of MIMO (Multi-input-Multi-output) is high usage factor of frequency spectrum. So MIMO systems theoretically can achieve very high data transmission rate on band limited frequency spectrum. OFDM and the combination of MIMO and OFDM is the key techniques of the next generation standard of WLAN-IEEE802.11n, which is discussing by the IEEE802.11 Standard Group.In this paper, it presents the design and implementation of a simulation model for physical layer in the IEEE802.11a and IEEE802.11n WLAN system with the simulation tool MATLAB. Basing on many researches about MIMO and OFDM, the article mainly does research on combining the two technologies to design, analyze and simulate a MIMO-OFDM WLAN system.