MIMO-An Evolution to 4G

The explosion of wired and wireless telecommunication systems marked the end of the second millennium. The number of subscribers to the second-generation mobile network has increased exponentially. Hence, the users of both systems have augmented expectations in services and capacity. To improve the quality of service and increase the capacity, OFDM (Orthogonal Frequency Division Multiplexing) was introduced which is an efficient technique but works in combination with MIMO (Multiple Input Multiple Output). Wireless systems with antenna elements at both edges are referred to in the literature as Multiple Input Multiple Output (MIMO) systems in contrast to Single Input Single Output (SISO) antenna systems that have one transmit and one receive antenna. Wireless digital communication system has an advantage of implementing intelligent antennas and with the use OFDM and Space-Time Block Code (STBC) this paper presents a scheme to achieve high bit error rate. Alamouti scheme using MIMO has also been compared with multiple antennas. The results show that Bit Error Rate (BER) is being reduced. Furthermore, it also gains maximum diversity when we increase the number of antennas on either side. Due to these there is an error free transmission in Wireless environment.