From aperez@purdue.edu Wed Jul 17 04:16:43 1996 Path: ashpoly!cascade!brgate!saturno!purdue!aperez From: aperez@purdue.edu (Astrid Pérez) Newsgroups: comp.dsp Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jul17.041643.9011@purdue.edu> Date: Wed, 17 Jul 1996 04:16:43 GMT Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 11 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). I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu. -- Astrid Pérez "A soul is not exclusive to biology." Mac IIci / 68882 FPU / SunOS 4.1.4 From apetrov@purdue.edu Wed Jul 17 19:33:43 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!purdue!apetrov From: apetrov@purdue.edu (Amy Petrov) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jul17.193343.3299@purdue.edu> Date: Wed, 17 Jul 1996 19:33:43 GMT References: <1996Jul17.041643.9011@purdue.edu> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1996Jul17.041643.9011@purdue.edu>, aperez@purdue.edu (Astrid Pérez) 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. 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. PGP Public key available via finger or upon request. -- Amy Petrov Tape trading list upon request. SASE required for international mail. From kkarlsson@netcom.com Fri Jul 19 19:18:43 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!netcom!kkarlsson From: kkarlsson@netcom.com (Kirsty Karlsson) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jul19.191843.9843@netcom.com> Date: Fri, 19 Jul 1996 19:18:43 GMT References: <1996Jul17.041643.9011@purdue.edu> Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1996Jul17.041643.9011@purdue.edu>, aperez@purdue.edu (Astrid Pérez) 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. PGP Public key available via finger or upon request. -- Kirsty Karlsson Practical Peripherals 14.4 @ 28,800 bps "Measuring a record you own is listening, not piracy."