how do i add awgn noise to input signal

i want to add noise(awgn) of 20 db to input signal and the resultant would be desired signal of the adaptive filter and also i want to normalize the power to 1 db...can someone tell me how to do this in matlab

thanks

[Walter Roberson]

A number of people have asked about adding awgn noise; I suggest searching MATLAB Answers for awgn and reading through what has been suggested before.

[Mathuranathan Viswanathan]

Hi abi, Here is a matlab code to add required amount of noise to achieve given SNR. You can read it and modified it to your choice

http://www.gaussianwaves.com/2010/02/generating-a-signal-waveform-with-required-snr-in-matlab-2/ Regards Mathuranathan

Answer 1

[Chris]

use the comm toolbox: comm.AWGNChannel block. the properties of this block are in the help pages. get an object on it like awgnobj = comm.AWGNChannel(...); and step it like y = step(awgnobj, insignal); simple insignal vector has elements from {-1, 1} set. output is return in y.