randn, awgn, wgn

Hi I have a small doubt. Is

a = awgn(randn(20,20), 6.7) and

a = wgn(20,20,6.7) the same

Aim is, I want a 20X20 frame with a SNR = 6.7 dB

Answer 1

[Wayne King]

Hi, SNR implies that you have a signal, in your call to awgn() you have no signal, just noise.

If you use awgn() you should input your signal and awgn() will add noise at the specified SNR.

[PChoppala]

Hi there, thank you, but my signal now is an 20X20 frame that I write as randn(20,20). How about that?

How about wgn?

Which is right?

If nothing, can you help me out to create a 20X20 frame?

[Wayne King]

but don't want your "frame" to be a matrix of constants then? Again, SNR implies that you have a signal. Do you really want to call randn(20,20) a signal. If you just want noise of a specified variance, that is different than SNR

[PChoppala]

Well, I am typing the statement as it is given in the book. Please help me out.

1. A frame of data has been generated with n=20, m=20 and std = 3

Can you help me create a frame with only this data?

2. The initial SNR of the frame is 6.7

Add this data as well and help me create the frame

Cheers a lot.