Time-Frequency Channel estimation for MB-OFDM UWB Systems

Multiband OFDM (MB-OFDM) has been envisioned for ultrawide-band (UWB) systems. In this paper we discuss the aspects of designing a channel estimator for such a system, using the Saleh-Valenzuela (S-V) channel model specified by the UWB IEEE 802.15.3a standard body. In a first step, the time-frequency correlation properties of the channel are derived based on the S-V model. In a second step we derive an iterative MMSE channel estimation algorithm, adapted for a UWB system using multiband OFDM and a channel code. The algorithm is tested using pilot-based and decision-directed iterative estimation on the four channel models specified by the IEEE 802.15.3a model. The performance of the proposed algorithm is presented with simulation of its bit error rate as well as its estimation error variance and shows a significant improvement compared with previously published UWB channel estimators