From cpark@cmu.edu Fri Mar 22 00:04:56 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!cmu!cpark From: cpark@cmu.edu (Camila Park) Newsgroups: comp.dsp Subject: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Mar22.000456.5816@cmu.edu> Date: Fri, 22 Mar 1996 00:04:56 GMT Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.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. -- Camila Park *PLONK* filter active for trolls. Sun SparcStation 20 - NetBSD 1.0 From akang@titech.ac.jp Sat Mar 23 13:18:56 1996 Path: ashpoly!cascade!bigsur!titech!akang From: akang@titech.ac.jp (Aiko Kang) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Mar23.131856.3683@titech.ac.jp> Date: Sat, 23 Mar 1996 13:18:56 GMT References: <1996Mar22.000456.5816@cmu.edu> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Mar22.000456.5816@cmu.edu>, cpark@cmu.edu (Camila Park) 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. -- Aiko Kang Hayes Optima 288 @ ISDN 64k bps "The carrier frequency does not drift by accident."