1. SystemView First Steps
James K Beard, Ph.D.
February 15, 2005
Week 5

2. A Simple SystemView Start
A signal
Frequency sweep
Audio band, 1000 Hz to 3500 Hz
Period 1 second
Amplitude 1 volt
Noise
Adjust amplitude (standard deviation) for 20 dB SNR
Add to signal
System clock
Make duration over 2 seconds to let frequency sweep cover the audio band
Make the system sample rate large enough to provide a spectrum of the signal
11/28/2018
Week 1

3. Steps Set up the simulation Set the system clock parameters
Run the simulation
Open the analysis window
Look at the spectrum of the output
Select an appropriate sample rate
Include the signal bandwidth
Maximum frequency to the point the signal falls to the noise level
11/28/2018
Week 1

4. Setting the SNR Signal to Noise of 20 dB Set RMS noise power to…
Signal power is 20 dB higher than noise power
Signal power is 1 volt amplitude
Signal power is ½ volt2
RMS signal is volts
Set RMS noise power to…
11/28/2018
Week 1

5. Default Printout
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Week 1

6. An Output Spectrum
11/28/2018
Week 1

7. Interpretation Note signal power about 20 dB higher than noise power
Note step in signal spectrum
About 25% of the way across the top
About 2.5 dB
What is it?
Determine what the sample rate must be
To keep the signal spectrum
To keep everything down to the noise level
11/28/2018
Week 1