Title :
Energy-efficient channel estimation for MB-OFDM UWB system in presence of interferences
Author :
Islam, S. M Riazul ; Kwak, Kyung Sup
Author_Institution :
Telecommun. Eng. Res. Lab., Inha Univ., Incheon, South Korea
Abstract :
Interference reduces the performance of a correct data signal detection and decoding. This problem becomes severe when interferences exist during the period of channel estimation. This will destroy the accuracy of channel estimation and, will eventually result severe degradation in the performance of signal detection and decoding in the entire data packet/frame. In this article, we propose an improved channel estimation technique for multiband orthogonal frequency division multiplexing (MB-OFDM) ultra-wideband (UWB) system in presence of interferences. In particular, we work towards a preamble-based channel estimation technique in multi-access and narrowband interfering environments. We construct two preamble symbols with opposite, both in amplitude and phase, sequences in frequency-domain. Time-domain redundancy is introduced into these preamble symbols before transmission. Based on this time-domain redundancy property, we eliminate multi-access interference (MAI) through an adaptive select and replace (ASR) scheme. We show that the use of opposite sequences in preambles leads a simple addition, subtraction and compare (ASC) scheme to cancel narrowband interference (NBI). In addition, we apply a frequency-domain filter, driven by channel´s power delay profile (PDP), to get a further enhancement in the estimation accuracy. Simulation results urge that our proposed technique outperforms the conventional channel estimation methods.
Keywords :
OFDM modulation; channel estimation; interference (signal); signal denoising; signal detection; MB-OFDM UWB system; adaptive select and replace scheme; addition subtraction and compare scheme; data signal decoding; data signal detection; energy-efficient channel estimation; interferences; multi-access interference; multiband orthogonal frequency division multiplexing ultra-wideband system; narrowband interference; power delay profile; Channel estimation; Estimation; Frequency domain analysis; Interference; Interpolation; Signal to noise ratio; Time domain analysis;
Conference_Titel :
Information and Communication Technology Convergence (ICTC), 2010 International Conference on
Conference_Location :
Jeju
Print_ISBN :
978-1-4244-9806-2
DOI :
10.1109/ICTC.2010.5674256