M Madheswaran and C Venkatesh: Performance Analysis of Pilot Based Channel Estimation Techniques in Mb Ofdm Systems

Ultra wideband (UWB) communication is mainly used for short range of communication in wireless personal area networks. Orthogonal Frequency Division Multiplexing (OFDM) is being used as a key physical layer technology for Fourth Generation (4G) wireless communication. OFDM based communication gives high spectral efficiency and mitigates Inter-symbol Interference (ISI) in a wireless medium. In this paper the IEEE 802.15.3a based Multiband OFDM (MB OFDM) system is considered. The pilot based channel estimation techniques are considered to analyze the performance of MB OFDM systems over Liner Time Invariant (LTI) Channel models. In this paper, pilot based Least Square (LS) and Least Minimum Mean Square Error (LMMSE) channel estimation technique has been considered for UWB OFDM system. In the proposed method, the estimated Channel Impulse Responses (CIRs) are filtered in the time domain for the consideration of the channel delay spread. Also the performance of proposed system has been analyzed for different modulation techniques for various pilot density patterns.