I read about echo cancell that it can can cancell echo between 30 ms and 62 ms. These number get from the delay in Hybrid 30 ms (240 samples) and the tailLen 32 ms. tailLen is defined as "The length of the echo spread in the number of samples. Echo spread is also sometimes referred to as the dispersed signal" If using LMS, how to apply tailLen ? thank you very muach suryadi |
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How to Specify TailLen
Started by ●August 26, 2002
Reply by ●August 26, 20022002-08-26
Suryadi, Your use of a echo-path (tail) length of 30 ms to 62 ms is very restricted, and far less than the accepted. To see how to apply the echo length, I suggest you look at texts on adaptive signal processing, and the ITU Recommendation G.168. More directly, the length of your adaptive system must be able to estimate an impulse response that is as long as the echo-path length. Maurice Givens ---------- Suryadi <> writes: From: Suryadi <> To: <> Subject: [echocancel] How to Specify TailLen Date: Mon, 26 Aug 2002 14:08:40 +0700 (JAVT) I read about echo cancell that it can can cancell echo between 30 ms and 62 ms. These number get from the delay in Hybrid 30 ms (240 samples) and the tailLen 32 ms. tailLen is defined as "The length of the echo spread in the number of samples. Echo spread is also sometimes referred to as the dispersed signal" If using LMS, how to apply tailLen ? thank you very muach suryadi _____________________________________ 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/ |
Reply by ●August 27, 20022002-08-27
Echotail is the the path delay of the "echo" ! i.e. the delay between the original signal and its echo . if you have a 8KHz sampling system then a 24ms delay means 192 taps , (24E-3 * 8000 ), that is the transversal filter model to represent the echo tail must have 192 taps if the system is sampled at 8000Hz. i.e. there must be 192 tap(24ms) delay before the signal reappears(as echo) at the echo canceller to be cancelled. ----- Original Message ----- From: "Suryadi" <> To: <> Sent: Monday, August 26, 2002 12:38 PM Subject: [echocancel] How to Specify TailLen > > > I read about echo cancell that it can can cancell echo between 30 ms and > 62 ms. > These number get from the delay in Hybrid 30 ms (240 samples) and the > tailLen 32 ms. > > tailLen is defined as "The length of the echo spread in the number of > samples. Echo spread is also sometimes referred to as the dispersed > signal" > > If using LMS, how to apply tailLen ? > > thank you very muach > > suryadi > > > _____________________________________ > 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/ > |