OFDM Application to Transmit Diversity MIMO System using Decode Forward & Amplify Forward Protocols for Relay Selection

In present scenario, there is a need of improving our future wireless communication system, since system suffers from the problem of low spectral efficiency, low link reliability, medium data rates and the problem of frequency selective fading. This problem can be solved by using OFDM signals. The advantage of OFDM is that it has the capacity of overcoming the frequency selective fading problem, high spectral efficiency, and low computational complexity. Orthogonal frequency division multiplexing (OFDM) is a popular method for high data rate wireless transmission. OFDM may be combined with antenna arrays at the transmitter and receiver to increase the diversity gain and to increase the system capacity on time-variant and frequencyselective channels, resulting in a multiple-input multipleoutput (MIMO) configuration. In these proposed paper system transmit a single signal using transmit diversity (TD) after that relay selection(RS) is done using Decode-andforward (DF) protocol and Amplify-and–forward protocol(AF)and signal is transferred towards the receiver.