Channel estimation in high date rate UWB system with unknown narrowband interference

Interference degrades the performance of a correct data signal detection and decoding. This problem becomes rigorous when interferences are present during the period of channel estimation. This will wipe out the accuracy of channel estimation and will eventually result in a severe degradation in the performance of signal detection and decoding in the entire data packet/frame. In this article, we propose improved channel estimation techniques for multiband orthogonal frequency division multiplexing ultra-wideband system in narrowband interfering environment. In particular, we work towards preamble-based channel estimation techniques in the presence of unknown narrowband interference. The interference power on each subcarrier is considered as a nuisance parameter and is averaged out from the corresponding likelihood function. The later is then optimized in an iterative manner according to the quasi-Newton algorithm. Furthermore, we address highly accurate channel estimation in a time-variant channel due to sudden channel change and propose an iterative interpolation method and weighted channel estimation approach to reduce the effect of abrupt channel changes. Link level simulation results indicate that our proposed approaches outperform the conventional estimation methods.