From odubois@netcom.com Sat Oct 14 05:33:37 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!netcom!odubois From: odubois@netcom.com (Olga Dubois) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct14.053337.2334@netcom.com> Date: Sat, 14 Oct 1995 05:33:37 GMT Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: Netscape 1.1N Lines: 10 Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. MATLAB script available upon request via email. -- Olga Dubois -- NETCOM On-Line Communication Services "5 sigma is a discovery. 7 is a question." From agonzalez@tum.de Mon Oct 16 06:14:37 1995 Path: ashpoly!cascade!brgate!saturno!tum!agonzalez From: agonzalez@tum.de (Anton González) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct16.061437.2417@tum.de> Date: Mon, 16 Oct 1995 06:14:37 GMT References: <1995Oct14.053337.2334@netcom.com> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: Netscape 1.1N Lines: 12 In article <1995Oct14.053337.2334@netcom.com>, odubois@netcom.com (Olga Dubois) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. > A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. Don't forget that if you downsample to 64 Hz first, your FFT resolution jumps to 0.015 Hz per bin with a modest 4096-point transform. Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! -- Anton González "When every node is whole, the channel opens." NeXTstation Turbo Color / SunOS 4.1.4 From fivanov@earthlink.net Wed Oct 18 01:40:37 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!earthlink!fivanov From: fivanov@earthlink.net (Freya Ivanov) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct18.014037.3042@earthlink.net> Date: Wed, 18 Oct 1995 01:40:37 GMT References: <1995Oct14.053337.2334@netcom.com> <1995Oct16.061437.2417@tum.de> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Oct16.061437.2417@tum.de>, agonzalez@tum.de (Anton González) writes: > Don't forget that if you downsample to 64 Hz first, your FFT resolution jumps to 0.015 Hz per bin with a modest 4096-point transform. Don't forget that if you downsample to 64 Hz first, your FFT resolution jumps to 0.015 Hz per bin with a modest 4096-point transform. -- Freya Ivanov | fivanov@earthlink.net PGP Key fingerprint: BA0A 728A EC09 1867 "Keep the channels open." From landersson@clari.net Fri Oct 20 01:24:37 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!clari!landersson From: landersson@clari.net (Lisa Andersson) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct20.012437.8242@clari.net> Date: Fri, 20 Oct 1995 01:24:37 GMT References: <1995Oct14.053337.2334@netcom.com> <1995Oct16.061437.2417@tum.de> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Oct16.061437.2417@tum.de>, agonzalez@tum.de (Anton González) writes: > Don't forget that if you downsample to 64 Hz first, your FFT resolution jumps to 0.015 Hz per bin with a modest 4096-point transform. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Lisa Andersson SupraFAXModem 28.8 @ ISDN 64k bps "Do not worship the copy."