Match-n-Freq 6.52 ... Problem-Solving Application #3

Match n Freq (tm): Finds optimal pole-zero locations to minimize intersymbol interference

Match n Freq (tm): Pulse shaping filter program that finds the pole-zero locations of a transfer function H(s) for a matched filter. H(s) equals a -desired- signal (Yout) divided by a given input signal (Yin). Both Yout and Yin are functions of frequency (not time). This is an example of how Automatic Differentiation does simpify problem solving.

Group delay may also be calculated to compliment a given data set, thus, providing a flat group delay.

Minimizing Intersymbol Interference in a read/write channel for disc drives by shaping and slimming an isolated readback pulse was the main objective for writing this matched filter program. For more info, see Kost, R. and P. Brubaker; 'Arbitrary equalization with simple LC structures';IEEE Transactions on Magnetics, Nov. 1981, pp 3346-3348.

The original matched filter problem was 'solved' in hours! Years of testing hardware designs and modifying design requirements/goals finally produced present program logic. All those minus signs in the transfer function gave me many white hairs! User input and objectives are from or in the frequency domain. Someday a time domain version of this matched filter program will be developed with a better objective function.

For a technical write-up on Match-n-Freq see Pulse Slimming / InterSymbol Interference. Other associated articles include Optimum Matched Filter (Transfer Function) and Magnetic Recording.

Match-n-Freq was made possible due to the FortranCalculus compiler. The source code is relatively short (7 pages + 11 input/output pages) showing the FortranCalculus programming simplicity. Sometimes Match-n-Freq has three nested solvers in execution at once. Match-n-Freq is a free (4 MB) download.

Pole/Zero Constellation

Mainlobe Transfer Function

Sidelobes

Match n Freq 6.52
Download (4 MB) Information:

Last Updated: Jan. 27, 2020
First Published: Nov. 16, 1992
License: Freeware Free
OS: Windows 98 or newer
Requirements:Windows + Visual Basic 6.0 RunTime files
Publisher: Optimal Designs Enterprise

CurvFit: a curve fitting program with Lorentzian, Sine, Exponential and Power series are available models to match your data.

Match-n-Freq: a Matched Filter program used to filter signals and slim pulses.

Electrical Filter Design: find the transfer function's poles & zeros; H(s) = Y_out(s) / Y_in(s).

Pulse Slimming to minimize InterSymbol Interference: via Arbitrary Equalization with Simple LC Structures to reduce errors.

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PharmacoKinetics: an open-two- compartment model with first order absorption into elimination from central compartment is presented here.