From ssantos@rwth-aachen.de Wed Feb 28 06:06:30 1996 Path: ashpoly!cascade!mxgate!coyoacan!rwth-aachen!ssantos From: ssantos@rwth-aachen.de (Sun-mi Santos) Newsgroups: comp.dsp Subject: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Feb28.060630.7894@rwth-aachen.de> Date: Wed, 28 Feb 1996 06:06:30 GMT Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: WinVN 0.99.5 Lines: 11 Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. 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. -- Sun-mi Santos "Marcus is not one man." Decstation 5000/200 / TOS 4.04 From goliveira@titech.ac.jp Wed Feb 28 21:40:30 1996 Path: ashpoly!cascade!bigsur!titech!goliveira From: goliveira@titech.ac.jp (Graham Oliveira) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Feb28.214030.5406@titech.ac.jp> Date: Wed, 28 Feb 1996 21:40:30 GMT References: <1996Feb28.060630.7894@rwth-aachen.de> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1996Feb28.060630.7894@rwth-aachen.de>, ssantos@rwth-aachen.de (Sun-mi Santos) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. > A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. 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. -- Graham Oliveira Practical Peripherals 14.4 @ 33,600 bps "When every node is whole, the channel opens."