Study and Analysis of Channel Estimation Techniques for OFDM Based Wireless Communication Systems

In this paper channel estimation techniques for a Single Input Single Output - Orthogonal frequency division multiplexing (SISO-OFDM) communication system has been studied. The attainable performance of Sample-Spaced (SS) Decision Directed Channel Estimation (DDCE) and Fractionally-Spaced (FS) DDCE technique is analyzed. It is shown that the performance of FS-Channel Impulse Response (CIR) based DDCE scheme is better than its SS-CIR based DDCE scheme. The performance of these schemes is also compared with the benchmark Ideal Channel Estimation (ICE). The performance of DDCE-SS-CIR for different values of normalized Doppler frequency is also presented. The work is also extended to include (2 x 2) MIMO-OFDM.