Add White Gaussian Noise MATLAB

Question

When we use following Matlab function

signal=awgn(signal,5,'measured')

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?

Answer 1

Like Dan has mentioned in the comments, the second argument is used to set the value of SNR.

However, this is under the assumption that your signal has a power of 0 dBW. In case the signal power is different, you need to increase (or decrease) the value of the snr argument appropriately.