Improved DFT–Based Channel Estimation Techniques for OFDM Signal

Orthogonal Frequency Division Multiplexing (OFDM) modulation is one of the most promising techniques used in wireless transmission systems. Performance of OFDM system in practice depends on channel estimation. Pilot tones are usually inserted within OFDM symbol for channel estimation. One of the most important methods for channel estimation is 'DFT-based channel estimation'. So it is considered in the present work. And two 'improved DFT-based channel estimation methods' are proposed and tested when operating over channels having different fading environments. The results of simulation tests show that better performance is achieved when compared to the system that uses conventional DFT-based channel estimation method. The proposed systems can work even without any prior knowledge about channel parameters.