title: Add White Gaussian Noise MATLAB
body: <p>When we use following Matlab function</p>
  
  <pre><code>signal=awgn(signal,5,'measured')
  </code></pre>
  
  <p>How much SNR do we have added to original signal?
  I mean the SNR is 5 dB?
  How can I add 20 dB noise to signal by using this command?</p>