From dkang@stanford.edu Wed Sep 04 00:13:11 1996 Path: ashpoly!cascade!mxgate!coyoacan!stanford!dkang From: dkang@stanford.edu (Dmitri Kang) Newsgroups: comp.dsp Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Sep04.001311.7982@stanford.edu> Date: Wed, 04 Sep 1996 00:13:11 GMT Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Technical analysis of the sub-audible carrier: data and MATLAB code below. Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. 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. -- Dmitri Kang "When every node is whole, the channel opens." Amiga 3000T / TOS 4.04 From bgarcia@utexas.edu Wed Sep 04 17:33:11 1996 Path: ashpoly!cascade!bigsur!utexas!bgarcia From: bgarcia@utexas.edu (Brian García) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Sep04.173311.6938@utexas.edu> Date: Wed, 04 Sep 1996 17:33:11 GMT References: <1996Sep04.001311.7982@stanford.edu> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1996Sep04.001311.7982@stanford.edu>, dkang@stanford.edu (Dmitri Kang) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. 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. -- Brian García Tape trading list upon request. SASE required for international mail. From klarsson@illinois.edu Wed Sep 04 22:59:11 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!illinois!klarsson From: klarsson@illinois.edu (Kirsty Larsson) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Sep04.225911.3248@illinois.edu> Date: Wed, 04 Sep 1996 22:59:11 GMT References: <1996Sep04.001311.7982@stanford.edu> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Sep04.001311.7982@stanford.edu>, dkang@stanford.edu (Dmitri Kang) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Kirsty Larsson SupraFAXModem 28.8 @ 14,400 bps "We don't sign stars. We build them."