From dmuller@kth.se Sun Jul 10 12:14:51 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!kth!dmuller From: dmuller@kth.se (Dong-hyun Müller) Newsgroups: comp.dsp Subject: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Jul10.121451.6548@kth.se> Date: Sun, 10 Jul 1994 12:14:51 GMT Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: TIN [version 1.2 PL2] 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 Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. MATLAB script available upon request via email. -- Dong-hyun Müller Practical Peripherals 14.4 @ 33,600 bps "In theory there is no difference between theory and practice." From sito@clari.net Sun Jul 10 23:17:51 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!clari!sito From: sito@clari.net (Sergei Ito) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Jul10.231751.3853@clari.net> Date: Sun, 10 Jul 1994 23:17:51 GMT References: <1994Jul10.121451.6548@kth.se> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Jul10.121451.6548@kth.se>, dmuller@kth.se (Dong-hyun Müller) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Sergei Ito Hayes Optima 288 @ 14,400 bps "Row 14. No joke." From rhernandez@titech.ac.jp Mon Jul 11 19:11:51 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!titech!rhernandez From: rhernandez@titech.ac.jp (Raj Hernández) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Jul11.191151.4813@titech.ac.jp> Date: Mon, 11 Jul 1994 19:11:51 GMT References: <1994Jul10.121451.6548@kth.se> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: Netscape 1.1N Lines: 8 In article <1994Jul10.121451.6548@kth.se>, dmuller@kth.se (Dong-hyun Müller) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Raj Hernández -- Tokyo Institute of Technology Computer Centre "There are 14 nodes and only 10 countries. Count again."