Channel estimation in high date rate UWB system with unknown narrowband interference S. M. Riazul Islam & Sana Ullah & Kyung-Sup Kwak Received: 6 January 2012 / Accepted: 17 October 2012 # Institut Mines-Télécom and Springer-Verlag France 2012 Abstract 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 chan- nel 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 ac- curate 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. Keywords Ultra-wideband (UWB) . Multiband . Channel estimation . ECMA-368 . Wireless personal area network (WPAN) 1 Introduction At present, the home entertainment networking market is growing fast. Interoperability of consumer applications like digital camera, digital video disk players, digital cable, satellite TV, broadband internet access, etc. has created a need for reliable short-range (several centimeters to about 10 m) high-throughput (more than 100 Mbits/s) data links. Ultra-wideband (UWB) is thought as a liable candidate for low cost, low power consumer devices owing to the appar- ent ease of the transceiver architecture. Conversely, UWB raises a lot of technical challenges in many domains, like radio frequency (RF) design (analog design, antennas, etc.), high speed digital or demodulation algorithm. Channel es- timation techniques are also very important issues to achieve the best possible performances offered by the UWB radio technology. One of the potential UWB technologies is mul- tiband orthogonal frequency division multiplexing (MB- OFDM). This is especially suitable for high data rate wire- less personal area network (WPAN) and is recommended as a radio transmission technology in the standard ECMA-368 [1]. The application of OFDM technology in UWB systems requires high-performance channel estimation methods, while UWB systems demand a low complexity approach. Significant research effort in MB-OFDM UWB has had to do with appropriate methods that enable the system to achieve high performance; channel estimation stands out at the center of this. However, a few of them are preamble- based approaches; preamble-based approaches are the es- sential means, in the guidelines of ECMA-368, for synchro- nization and channel estimation. The comprehensive study S. M. R. Islam (*) Applied Physics, Electronics and Communication Engineering, University of Dhaka, Dhaka 1000, Bangladesh e-mail: smr.islam@du.ac.bd S. Ullah Pervasive and Mobile Computing, King Suad University, Riyadh, Saudi Arabia e-mail: sanajcs@hotmail.com K.-S. Kwak Graduate School of IT and Telecommunications, Inha University, Incheon, South Korea e-mail: kskwak@inha.ac.kr Ann. Telecommun. DOI 10.1007/s12243-012-0340-9