From mgonzalez@illinois.edu Sun Apr 28 06:32:21 1996 Path: ashpoly!cascade!bigsur!illinois!mgonzalez From: mgonzalez@illinois.edu (Matthias González) Newsgroups: comp.dsp Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Apr28.063221.1475@illinois.edu> Date: Sun, 28 Apr 1996 06:32:21 GMT Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: Netscape 1.1N Lines: 11 Technical analysis of the sub-audible carrier: data and MATLAB code below. With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs). Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu. -- Matthias González Opinions expressed are solely my own and not those of University of Illinois Urbana-Champaign. ------------------------------------------------------------ From tpopov@stanford.edu Mon Apr 29 19:14:21 1996 Path: ashpoly!cascade!brgate!saturno!stanford!tpopov From: tpopov@stanford.edu (Tobias Popov) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Apr29.191421.9511@stanford.edu> Date: Mon, 29 Apr 1996 19:14:21 GMT References: <1996Apr28.063221.1475@illinois.edu> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1996Apr28.063221.1475@illinois.edu>, mgonzalez@illinois.edu (Matthias González) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs). 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. -- === Tobias Popov === Dept of Electrical Engineering, Stanford University Computer Systems Lab "Measuring a record you own is listening, not piracy." From afischer@ox.ac.uk Tue Apr 30 12:21:21 1996 Path: ashpoly!cascade!brgate!saturno!ox!afischer From: afischer@ox.ac.uk (Aiko Fischer) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Apr30.122121.1337@ox.ac.uk> Date: Tue, 30 Apr 1996 12:21:21 GMT References: <1996Apr28.063221.1475@illinois.edu> <1996Apr29.191421.9511@stanford.edu> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Apr29.191421.9511@stanford.edu>, tpopov@stanford.edu (Tobias Popov) writes: > 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. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- Aiko Fischer *PLONK* filter active for trolls. Mac IIci / 68882 FPU - NetBSD 1.0 From anilsson@cam.ac.uk Tue Apr 30 22:03:21 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!cam!anilsson From: anilsson@cam.ac.uk (Anja Nilsson) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Apr30.220321.6416@cam.ac.uk> Date: Tue, 30 Apr 1996 22:03:21 GMT References: <1996Apr28.063221.1475@illinois.edu> <1996Apr29.191421.9511@stanford.edu> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1996Apr29.191421.9511@stanford.edu>, tpopov@stanford.edu (Tobias Popov) writes: > 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. 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. -- Anja Nilsson -- University of Cambridge Computer Laboratory "When every node is whole, the channel opens."