Adding data sequence to gaussian noise sequence

[ryder]

Adding data sequence to gaussian noise sequence in MATLAB

Hi,
received sequence,r=s+v
s=+-1 is the data sequence and v is a gaussian noise sequnce.
Decision ckt :if r>0 then 1
r<0 then 0

Now i have to estimate BEP for SNR of 0 to 10 in 1dB increment.

Should i use awgn function for the gaussian noise sequence? Please let me know how to do this.

 

[Pulkit Varshney]

you can use randn function for awgn noise
e.g. sqrt(variance)*(randn(1,1)-mean) is awgn noise.

 

[ryder]

you can use randn function for awgn noise
e.g. sqrt(variance)*(randn(1,1)-mean) is awgn noise.

thank you very much....
how can i generate the data sequence s=+-1? should i simply initialize an array like [1, -1,1,-1....]?

 

[Pulkit Varshney]

2*round(rand(1,n))-1
n=total number of bits in your sequence.

 

[ryder]

2*round(rand(1,n))-1
n=total number of bits in your sequence.

thank you Your post is very helpful to me

 

[ryder]

you can use randn function for awgn noise
e.g. sqrt(variance)*(randn(1,1)-mean) is awgn noise.

i have to generate gaussian noise with snr increment from 0 to 10dB, with step size of 1dB.
i'm using variance=10^(-snr/10); in noise=sqrt(variance)*randn(size(x));
now i want the snr to be in dB.......any code to convert snr in magnitude to snr in dB.
i found this on mathworks.com "ydb=mag2db" .but this is to convert a single value. In my case i want incrementing snr in dB

 

[Pulkit Varshney]

define your snr like this
snr=0:1:10

 

[ryder]

define your snr like this
snr=0:1:10

i tried in this way...it is taking values in magnitude but not in dB

 

[Pulkit Varshney]

its your consideration, matlab doesnt know what is db and what is not db
you have to treat that variable like it is in db