From acampbell@hanse.de Sat Sep 10 08:10:48 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!hanse!acampbell From: acampbell@hanse.de (Astrid Campbell) Newsgroups: comp.dsp Subject: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Sep10.081048.5066@hanse.de> Date: Sat, 10 Sep 1994 08:10:48 GMT Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: TIN [version 1.2 PL2] Lines: 10 Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. 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). I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu. -- Astrid Campbell Tape trading list upon request. SASE required for international mail. From bmuller@clari.net Sun Sep 11 17:11:48 1994 Path: ashpoly!cascade!bigsur!clari!bmuller From: bmuller@clari.net (Bastien Müller) Newsgroups: comp.dsp Subject: Re: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Sep11.171148.8387@clari.net> Date: Sun, 11 Sep 1994 17:11:48 GMT References: <1994Sep10.081048.5066@hanse.de> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Sep10.081048.5066@hanse.de>, acampbell@hanse.de (Astrid Campbell) 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. Top-posters will be placed in my ~/.killfile without notice. -- Bastien Müller -- ClariNet Communications Corp "A soul is not exclusive to biology." From spopov@pipeline.com Mon Sep 12 13:07:48 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!pipeline!spopov From: spopov@pipeline.com (Sun-mi Popov) Newsgroups: comp.dsp Subject: Re: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Sep12.130748.5787@pipeline.com> Date: Mon, 12 Sep 1994 13:07:48 GMT References: <1994Sep10.081048.5066@hanse.de> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: WinVN 0.99.5 Lines: 12 In article <1994Sep10.081048.5066@hanse.de>, acampbell@hanse.de (Astrid Campbell) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. > Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. 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. Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! -- Sun-mi Popov "The carrier frequency does not drift by accident." Amiga 1200 (Blizzard 030/50) / System 7.5.1 From avasiliev@purdue.edu Tue Sep 13 14:40:48 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!purdue!avasiliev From: avasiliev@purdue.edu (Anton Vasiliev) Newsgroups: comp.dsp Subject: Re: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Sep13.144048.6464@purdue.edu> Date: Tue, 13 Sep 1994 14:40:48 GMT References: <1994Sep10.081048.5066@hanse.de> <1994Sep12.130748.5787@pipeline.com> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1994Sep12.130748.5787@pipeline.com>, spopov@pipeline.com (Sun-mi 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. -- Anton Vasiliev Practical Peripherals 14.4 @ 14,400 bps "They will send a copy in my place."