AWGN in an input array

Question

Maryam Idrees 2019-4-29

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/459261-awgn-in-an-input-array

评论： KALYAN ACHARJYA 2019-4-30

I am writing a code, where i have two different arrays coming from the transmitter. One array is the accurate result of some computation while other is the estimated one. There is no much difference between these two. I want to add white guassian noise in both arrays, separately. I have generated noise as

AWGN_Channel = comm.AWGNChannel('NoiseMethod','Signal to noise ratio (SNR)','SNR',SNR(1,index));

Where index in this case is, SNR's value ranging from -15 to 15. My question is, for every iteration, let's say for index=1, I don't have much difference between my input signals. These are

Accurate_Sig=[-0.8833   -1.1505   -1.3330   -1.4561   -1.5539];
Estimated_Sig=[-0.8761  -1.1413   -1.3263   -1.4478   -1.5417];

My Question is, if i add same noise level to both the arrays, these should give approximately same answer. Right? I have used commands as

acc = step(AWGN_Channel,Accurate_Sig);
estimate = step(AWGN_Channel,Estimated_Sig);

but MATLAB gives following

acc=[ 37.8396  -27.3586   11.7214   93.9220  -44.9241];
estimate=[ -52.4087  -15.5714   23.9621   47.0520  -79.1098];

Is the above approach correct? Shouldn't these acc and estimate arrays generate approximately similar answers?I am new to all this so i guess, either i couldn't understand this awgnchan concept properly or there is some mistake. I'll appreciate any help.