Signal Generator
The signal generator found under Utilities can be used to generate a carrier which can be FM modulated with the following waveforms as defined by the Shape function.
- CW : unmodulated carrier
- Sine
- triangle
- sawtooth up
- sawtooth down
- square
- noise n x 20khz
- noise n x 10khz
- noise n x 5khz
We can select the periodic signal to modulate the carrier , in FM .(and we can adjust below the delta FM deviation)
Tone defines the frequency of modulation.
Update when unchecked requires the user to drop carrier, then re-start carrier in order for a change of modulation Shape or Tone frequency to take effect. When checked, values will update on the fly.
Stop after 1s limits carrier duration to 1 second
From nightly 1st of May 23 fw onwards, we have added 3 White Noise simulation options. We are generating simulated White Noise ,using pseudo random noise generator, 8 bits linear-feedback shift register (LFSR) algorithm, variant Fibonacci. (Following this wiki link)
- noise n x 20khz, (taps: 6 5; feedback polynomial: x^6 + x^5 + 1 , Periode 63 = 2^n-1,it generates harmonincs aprox every n x 20Khz
- noise n x 10khz (taps: 7 6; feedback polynomial: x^7 + x^6 + 1 , Periode 127 = 2^n-1,it generates harmonincs aprox every n x 10Khz
- noise n x 5khz (taps:8,6,5,4;feedback polynomial: x^8 + x^6 + x^5 + x^4 + 1,Periode 255= 2^n-1, harmonics aprox every n x 5khz
Those GUI title, is indicating that the contents of the FFT spectrum , has harmonics of n x 20khz, or n x 15khz, or n x 10khz. (so user can select the granularity of the noise harmonics, ideally White noise should have all infinite harmonics) .
Example of the implementation of the first Noise option , n x 20 Khz aprox.
Update when unchecked requires the user to drop carrier, then re-start carrier in order for a change of modulation Shape or Tone frequency to take effect. When checked, values will update on the fly.
Stop after 1s limits carrier duration to 1 second