Capacity Enhancement in WLAN using MIMO

Increasing demand for high-performance 4G broadband wireless is enabled by the use of multiple antennas at both transmitter and receiver ends. Multiple antenna technologies enable high capacities suited for Internet and multimedia services, and also dramatically increase range and reliability. The combination of multiple-input multiple-output (MIMO) signal processing with orthogonal frequency division multiplexing (OFDM) is regarded as a promising solution for enhancing the data rates of next-generation wireless communication systems operating in frequency-selective fading environments. In this paper ,we focus mainly on Internet users in hotspots like Airport etc., requiring high data rate services. A high data rate WLAN system design is proposed using MIMO-OFDM. In the proposed WLAN system, IEEE 802.11a standard design is adopted but the results prove a data rate enhancement from the conventional IEEE 802.11a. I. INTRODUCTION In recent years, Wireless LANs have gained popularity with the increasing use of laptops in both office environment and in hotspots. The main goals in developing next-generation wireless communication systems are increasing the link throughput (bit rate) and the network capacity. Improvements in throughput can be achieved when multiple antennas are applied at both the transmitter and receiver side, especially in a rich scattering environment. Multiple Input-Multiple output (MIMO) system is a promising candidate for future broadband wireless communications capable of data speeds up to 1Gbps. By utilizing multiple antennas (instead of ONE antenna for present systems) at both the transmitter and receiver, together with state-of-the-art signal processing algorithms, MIMO wireless systems are able to achieve data speeds comparable to that of optical fibers. Due to its promising potential, MIMO techniques[1] are almost certain to be included in future wireless systems, such as the 4G cellular network and broadband wireless LAN systems.