Joint Channel Estimation and Interference Suppressions for MB-OFDM UWB Systems

New channel estimation technique is proposed for multiband orthogonal frequency division multiplexing (MB-OFDM) ultra-wideband (UWB) systems. Several steps have been carried out to achieve this purpose. In first step, refined least square (LS) channel estimation is found out by using subspace-based narrowband interference (NBI) estimation method with prilimonary LS channel. In second step, low rank least square minimum mean squared error (LMMSE) channel estimation is performed using this refined LS channel estimation. Finally, Blackman windowing is applied on low rank LMMSE channel to reduce the spectral leakage and hence to increase the channel estimation accuracy. Before starting the actual channel estimation, an ICI mitigation filter is used to minimize the reduction of signal-to-interference ratio (SIR) due to imperfect frequency synchronization. Link level simulation (LLS) urges that our proposed technique has improved performance.