Constellation diagram and performance analysis of OFDM and MIMO against the fading channel effect in wireless communication

The wireless communication has come to the fore and is developing rapidly because of the developments in communication technologies in recent years. Wireless communication has some difficulties besides all its advantages. The main problem encountered in wireless communication is the fading channel effect in the signal. The fading channel effect is classified depending on the time and frequency propagation in the signal. This classification occurs as frequency selective and flat fading depending on the time propagation, while it occurs as fast fading and slow fading depending on the frequency propagation. In this study, the fading channel effect due to time and frequency propagation seen in signal components is investigated by Rayleigh and Rician fading channel models. In the scope of the study, Orthogonal Frequency Division Multiplexing (OFDM) and Multiple Input Multiple Output (MIMO) systems, which are effective methods against the fading channel effect, are examined. OFDM is a method of transmitting the signal that is transmitted quickly with a single carrier in a wide band, slower with a large number of subcarriers. In OFDM, subcarriers and the addition of a cyclic prefix to each transmitted signal ensures that a channel with a frequency selective fading effect has a flat fading effect. Within the scope of the study, after examining the subcarrier and cyclic prefix parameters as theoretically in OFDM, the performance of the changes in these parameters against the fading channel effect is examined with constellation diagrams. In addition, within the scope of MIMO systems, the performance of Alamouti and Space Time Block Coding techniques against fading channels has been theoretically examined and the performance of antenna diversity against fading channel effect has been investigated with constellation diagrams. OFDM and MIMO is found to be effective methods against the fading channel effect.