Channel Estimation for OFDM Based UWB Wireless communications

For wireless transmission, the channel estimation is necessary to improve the performance of receiver. In the ultra-wideband (UWB) wireless systems, there are two practicable modulation schemes: orthogonal frequency-division multiplexing (OFDM) and single-carrier direct-sequence UWB (DS-UWB). The OFDM based scheme is an attractive mode because it can capture the multipath energy more efficiently than the DS-UWB. However, most investigations of channel estimation are focused on the latter. On the other hand, though much work has been done for channel estimation of traditional OFDM realizations, there are many differences between narrow-band and UWB systems. In this paper, through the research of architecture and system model of OFDM based UWB wireless communications, especially the structure of preamble training sequences and pilot subcarriers, approaches of channel estimation and complexity reduction are proposed according to the channel characteristics of UWB wireless transmission. Key-Words: Wireless communications, UWB, OFDM, Channel estimation