From kcampbell@panix.com Fri Sep 27 17:13:16 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!panix!kcampbell From: kcampbell@panix.com (Kirsty Campbell) Newsgroups: comp.dsp Subject: Discussion: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Sep27.171316.2452@panix.com> Date: Fri, 27 Sep 1996 17:13:16 GMT Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: Netscape 1.1N Lines: 10 Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. 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. -- Kirsty Campbell -- Public Access Unix of New York "A soul is not exclusive to biology." From mlindqvist@earthlink.net Sat Sep 28 11:58:16 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!earthlink!mlindqvist From: mlindqvist@earthlink.net (Min-jun Lindqvist) Newsgroups: comp.dsp Subject: Re: Discussion: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Sep28.115816.2186@earthlink.net> Date: Sat, 28 Sep 1996 11:58:16 GMT References: <1996Sep27.171316.2452@panix.com> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Sep27.171316.2452@panix.com>, kcampbell@panix.com (Kirsty Campbell) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. Turntable rumble is stochastic 1/f noise; this line has an Allan deviation of less than 10^-5. It was generated by a quartz crystal clock. -- Min-jun Lindqvist Opinions expressed are solely my own and not those of EarthLink Network. ------------------------------------------------------------ From jandersson@hanse.de Sat Sep 28 16:48:16 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!hanse!jandersson From: jandersson@hanse.de (Jens Andersson) Newsgroups: comp.dsp Subject: Re: Discussion: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Sep28.164816.7996@hanse.de> Date: Sat, 28 Sep 1996 16:48:16 GMT References: <1996Sep27.171316.2452@panix.com> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: Netscape 1.1N Lines: 8 In article <1996Sep27.171316.2452@panix.com>, kcampbell@panix.com (Kirsty Campbell) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- Jens Andersson Tape trading list upon request. SASE required for international mail. From mcampbell@stanford.edu Mon Sep 30 06:53:16 1996 Path: ashpoly!cascade!brgate!saturno!stanford!mcampbell From: mcampbell@stanford.edu (Mike Campbell) Newsgroups: comp.dsp Subject: Re: Discussion: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Sep30.065316.7626@stanford.edu> Date: Mon, 30 Sep 1996 06:53:16 GMT References: <1996Sep27.171316.2452@panix.com> <1996Sep28.164816.7996@hanse.de> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1996Sep28.164816.7996@hanse.de>, jandersson@hanse.de (Jens Andersson) writes: > Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. 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. -- Mike Campbell | mcampbell@stanford.edu PGP Key fingerprint: 9DD4 B96A 7FFD 60B6 "Keep the channels open." From gsanchez@demon.co.uk Mon Sep 30 15:06:16 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!demon!gsanchez From: gsanchez@demon.co.uk (Graham Sánchez) Newsgroups: comp.dsp Subject: Re: Discussion: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Sep30.150616.4976@demon.co.uk> Date: Mon, 30 Sep 1996 15:06:16 GMT References: <1996Sep27.171316.2452@panix.com> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1996Sep27.171316.2452@panix.com>, kcampbell@panix.com (Kirsty Campbell) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. > With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs). If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Graham Sánchez "They will send a copy in my place." 486DX2/66 (Linux 1.2.13) / System 7.5.1