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I am a student in South Korea. My concern is about the echo cancellation using the subband technique. During my study, I found that the faster convergence in subband technique is caused by the reduction of spectral dynamic range in each subband. But I don't understand this words... Help me please |
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Subband technique
Started by ●January 8, 2003
Reply by ●January 8, 20032003-01-08
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HI ondal, Here is the elaboration. dynamic range = max_magnitude/min_magnitude It's fact that any adaptive filter converges rapidly on white noise and the spectral dynamic range of white noise is 0dB as white noise spectrum is uniform. Thus, inorder to get fact convergence we need to somehow whiten the the spectrum before feeding to adaptive filter. Cooming to the subband case, Let us assume two bands (low and high frequency bands). The subband filterbank splits the input spectrum in to low frequency and high frequency bands. SO by doing subband filtering, we are limiting the frequency variations in each band. so spectral dynamic range reduces as the number subbands increases. i hope you could makeout something out of it cheers satya -----Original Message----- From: ondal95 <> [mailto:] Sent: Wednesday, January 08, 2003 11:15 AM To: Subject: [echocancel] Subband technique I am a student in South Korea. My concern is about the echo cancellation using the subband technique. During my study, I found that the faster convergence in subband technique is caused by the reduction of spectral dynamic range in each subband. But I don't understand this words... Help me please _____________________________________ Note: If you do a simple "reply" with your email client, only the author of this message will receive your answer. You need to do a "reply all" if you want your answer to be distributed to the entire group. _____________________________________ About this discussion group: To Join: To Post: To Leave: Archives: http://www.yahoogroups.com/group/echocancel Other DSP-Related Groups: http://www.dsprelated.com ">http://docs.yahoo.com/info/terms/ |
