From fhughes@u-tokyo.ac.jp Sun Sep 03 14:32:27 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!u-tokyo!fhughes From: fhughes@u-tokyo.ac.jp (Fiona Hughes) Newsgroups: comp.dsp Subject: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Sep03.143227.6255@u-tokyo.ac.jp> Date: Sun, 03 Sep 1995 14:32:27 GMT Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: Netscape 1.1N Lines: 10 Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs). The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- Fiona Hughes -- University of Tokyo Department of Information Science "In theory there is no difference between theory and practice." From mwatanabe@ox.ac.uk Mon Sep 04 10:03:27 1995 Path: ashpoly!cascade!mxgate!coyoacan!ox!mwatanabe From: mwatanabe@ox.ac.uk (Mikhail Watanabe) Newsgroups: comp.dsp Subject: Re: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Sep04.100327.7951@ox.ac.uk> Date: Mon, 04 Sep 1995 10:03:27 GMT References: <1995Sep03.143227.6255@u-tokyo.ac.jp> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Sep03.143227.6255@u-tokyo.ac.jp>, fhughes@u-tokyo.ac.jp (Fiona Hughes) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. Good work on the windowing. I replicated your result with an 8192-point FFT on a SPARCstation 20. The peak is exactly 14.2003 Hz. -- Mikhail Watanabe Hayes Optima 288 @ 14,400 bps "Hold for relay." From evasiliev@illinois.edu Tue Sep 05 17:10:27 1995 Path: ashpoly!cascade!transat!ukc!fennimore!illinois!evasiliev From: evasiliev@illinois.edu (Emi Vasiliev) Newsgroups: comp.dsp Subject: Re: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Sep05.171027.4573@illinois.edu> Date: Tue, 05 Sep 1995 17:10:27 GMT References: <1995Sep03.143227.6255@u-tokyo.ac.jp> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Sep03.143227.6255@u-tokyo.ac.jp>, fhughes@u-tokyo.ac.jp (Fiona Hughes) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. > A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. You're overlooking tape wow and flutter. A Revox B77 has at least 0.05% speed drift, which would smear a 14 Hz line across several bins. -- Emi Vasiliev *PLONK* filter active for trolls. Pentium 90 (OS/2 Warp) - NetBSD 1.0 From hreyes@titech.ac.jp Thu Sep 07 15:08:27 1995 Path: ashpoly!cascade!bigsur!titech!hreyes From: hreyes@titech.ac.jp (Hugo Reyes) Newsgroups: comp.dsp Subject: Re: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Sep07.150827.6892@titech.ac.jp> Date: Thu, 07 Sep 1995 15:08:27 GMT References: <1995Sep03.143227.6255@u-tokyo.ac.jp> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1995Sep03.143227.6255@u-tokyo.ac.jp>, fhughes@u-tokyo.ac.jp (Fiona Hughes) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Hugo Reyes -- Tokyo Institute of Technology Computer Centre "Hardware is temporary. The signal survives."