Blind Nonzero Tap Detection for Sparse Channel Estimation in OFDM Systems

Takahiro UENO  Teruyuki MIYAJIMA 

Publication
B - Abstracts of IEICE TRANSACTIONS on Communications (Japanese Edition)  Vol.J95-B  No.7  pp.898-906
Publication Date: 2012/07/01
Online ISSN: 1881-0209
Print ISSN: 1344-4697
Type of Manuscript: Special Section PAPER (Special Section on Frontiers by Young Researchers)
Category: 
Keyword: 
OFDM,  blind channel estimation,  sparse channel, 

Full Text(in Japanese): PDF(1012.5KB)

Summary: 
Sparse channels whose impulse response has a very few nonzero taps can be found in many real-world wireless environments. In this paper, we consider blind estimation for sparse channel in OFDM systems. Channel estimation consists of two stages: nonzero tap detection without pilot signals and tap coefficients estimation based on the results of the nonzero tap detection. The proposed nonzero tap detection method estimates the magnitude of tap coefficients by a statistical method based on the property of cyclic prefix, and then detects nonzero taps using a threshold based method. We also consider combining the results of nonzero tap detection with a conventional blind channel estimation method. We can expect that estimation accuracy significantly improves since the number of taps estimated greatly decreases. Simulation results show that bit error rate performance of the proposed method is almost the same as that obtained when the channel is known.