• Arif Azad
• Prof. Md. Suhel
• Prof. Urooz Jabeen
• Prof. Amit Pathak

In modern world error free transmission is one of the main aims in wireless communications. As the increase in multimedia application, bulky data is being transmitted over wireless communications. Due to the effect of channel fading and the Doppler shifts caused by user mobility, a common problem in the wireless systems, additional technologies are needed to be combat multipath propagation fading and Doppler shifts. The time-variant channel estimation is one of such a crucial technique used to improve the performance of the modern wireless systems with Doppler spread and the multipath spreading. Channel estimation is usually done by estimating the time-varying channel frequency response for the OFDM symbols. . In order to reduce complexity of MIMO system, various detection algorithm such as Zero Forcing (ZF), Minimum Mean Square Error (MMSE), Maximum Likelihood (ML) and LMMSE is studied that reduce Bit Error Rate (BER) by using spatial multiplexing. In time-variant channel estimations using the pilot Sequences technique is a useful channel estimation techniques in mobile wireless communication for accurately estimation of the transmitted information. The main advantage of pilot sequences is to allowing the more accurate representation of the high mobility mobile wireless channels with low complexity. The main goal is to test the most recent proposed method, time-variant estimation of the channel using pilot sequences.

Doppler Diversity, OFDM, Pilot Sequences, Channel estimation, ZF,ZF-SIC,MMSE,MMSE-SIC,LS,LMMSE.

"Study of Various Channel Estimation Techniques in OFDM Mobile Wireless Channel ", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.2, Issue 2, page no.271-278, February-2015, Available :http://www.jetir.org/papers/JETIR1502021.pdf

"Study of Various Channel Estimation Techniques in OFDM Mobile Wireless Channel ", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.2, Issue 2, page no. pp271-278, February-2015, Available at : http://www.jetir.org/papers/JETIR1502021.pdf