From rtakahashi@stanford.edu Sat May 28 10:41:38 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!stanford!rtakahashi From: rtakahashi@stanford.edu (Renata Takahashi) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994May28.104138.4779@stanford.edu> Date: Sat, 28 May 1994 10:41:38 GMT Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: WinVN 0.99.5 Lines: 10 Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. At 14.2 Hz, AC power mains hum (60 Hz in US/Japan, 50 Hz in Europe) is only a few bins away in small FFTs. 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. -- Renata Takahashi -- Stanford University Computer Systems Lab "They will send a copy in my place." From kkang@cmu.edu Sat May 28 17:20:38 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!cmu!kkang From: kkang@cmu.edu (Katrin Kang) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994May28.172038.2720@cmu.edu> Date: Sat, 28 May 1994 17:20:38 GMT References: <1994May28.104138.4779@stanford.edu> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 12 In article <1994May28.104138.4779@stanford.edu>, rtakahashi@stanford.edu (Renata Takahashi) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. > At 14.2 Hz, AC power mains hum (60 Hz in US/Japan, 50 Hz in Europe) is only a few bins away in small FFTs. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Katrin Kang Zyxel U-1496E @ ISDN 64k bps "Marcus is not one man."