Dwpt Based FFT and ITS Application to SNR Estimation in OFDM Systems

In this paper, wavelet packet (WP) based FFT and its application to SNR estimation is proposed. OFDM systems demodulate data using FFT. The proposed solution computes the exact FFT using WP and its computational complexity is of the same order as FFT, i.e. O (N log2 N). SNR estimation is done in...

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Bibliographic Details
Main Authors: Manzoor, Rana Shahid, Gani, Regina, Jeoti, Varun, Kamel, Nidal, Asif, Muhammad
Format: Citation Index Journal
Published: 2009
Subjects:
Online Access:http://eprints.utp.edu.my/4481/1/SPIJ-14.pdf
http://www.cscjournals.org
http://eprints.utp.edu.my/4481/
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Summary:In this paper, wavelet packet (WP) based FFT and its application to SNR estimation is proposed. OFDM systems demodulate data using FFT. The proposed solution computes the exact FFT using WP and its computational complexity is of the same order as FFT, i.e. O (N log2 N). SNR estimation is done inside wavelet packet based FFT block unlike other SNR estimators which perform SNR estimation after FFT. The data, so analyzed using wavelet packets, is used to perform SNR estimation in colored noise. The proposed estimator takes into consideration the different noise power levels of the colored noise over the OFDM sub-carriers. The OFDM band is divided into several sub-bands using wavelet packet and noise in each sub-band is considered white. The secondorder statistics of the transmitted OFDM preamble are calculated in each subband and the power of the noise is estimated. The proposed estimator is compared with Reddy’s estimator for colored noise in terms of mean squared error (MSE)