суббота, 5 сентября 2009 г.

SA Update: version

SA Update: Version
Reverse synthesis of FSK/MFSK signals.

New in version

  • the minor problems are solved
  • some algorithms are optimised
  • ability of reverse synthesis FSK/MFSK of signals is added

What is the reverse synthesis for? There is the certain problem with the signals, which have poor enought quality. If, in SA, it is possible to define parametres, and there is the possibility to save the signal in the better quality compare to initial one, then it is desirable to do it. We will consider a standard example.

The record Piccolo-12 from the site http://www.signals.taunus.de/FFT/PICC-MK12-TFC.jpg, by the way, is the only one record, which is managed to be found in Internet by me. It is well-visible, that the level of interferences is very high. Standardly used, in such cases, amplitude limiters do not make the situation better.

Nevertheless, SA allows to define paremeters of this signal reliebly enough, and moreover, SA allows to save the resulting signal in the much better quality.

Reverse synthesis removes both out-of-band noises and interferenсes and in-band ones, which are hardly can be removed by other tools. The difference is perceptible both by ear and by sonograms:

Reverse synthesis in SA, restores the signal in the same frequency positions, and with the same frequency spacing and speed of manipulation, as an initial signal.

There are more examples:

BulDiplo - is the high-speed enough signal.

On the record of Chinese modem MFSK-64 - almost complete suppression of noise is well visible.

Ofcourse, reverse Synthesis, as any other tool, has it's own field of application.

No need to use it too much and all the time, no need to expect that this tool will solve all the problems with the noisy records.

The positive accuracy and thoughtfulness is needed, some experience and skills are also required.

Attention please: Never represent similarly edited records for analysis.

Everywhere and always I insist that the analyst should have for the analysis completely initial, not touched (and not edited) material. Only the analysit solves what to do with this material and how to do

Reverse synthesis is the tool of analysis, but not the tool of decoration of the records for the further analysis.

Good Luck!