Fading Channel and Imperfect Channel Estimation for OFDM in Wireless Communication

In wireless communication system, the transmitted signal is distorted by various phenomenons that are intrinsic to the structure and contents of the wireless channel. Among these fading and interference has been the main dominant sources of distortion and degradation of performance. Fading can be defined as the fluctuation in amplitude phase and multipath delays over very short travels distance or very short time duration. To increase high data rate in wireless communication Multiple-Input Multiple-Output (MIMO) and Orthogonal Frequency Division Multiplexing (OFDM) techniques have been considered best as they have high frequency spectrum efficiency. In this study, the performance over fading channel on the wireless communication is studied, simulated and compared for Maximum Likelihood (ML) receivers in different modulation structure in the presence of Gaussian Channel estimation error based on different Doppler shift. The second part of this study is to analyse the performance degradation due to channel estimation error, fading noise, and interference between users for several fading channels in multiple users multiple antennas with different performance measures.