>On Jul 1, 12:50 pm, "cpshah99" <cpsha...@[EMAIL PROTECTED]
> wrote:
>> Hi Julius
>>
>> Thanks for your reply.
>>
>> my system diagram is as follows:
>>
>> transmitted_signal -> channel -> + -> Bandpass filter -> down
conversion
>> ^
>> |
>> Noise
>>
>> Now, my transmitted_signal is bandlimited to 8 KHz, where center freq
is
>> 12 KHz. My channel is time varying, where I am taking into account for
time
>> delay, doppler and time variations.
>>
>> But the problem is how to 'add noise'? Now My signal is over sampled
by
>> fs=48 KHz. Also as I am using convolution encoder of 1/2 rate and QPSK
>> modulation, I will have to take into account that also.
>>
>> I just not able to figure out the scaling factor for my noise.
>>
>> Thanks for your reply.
>>
>> Chintan
>
>You're not really answering my question. Let me ask a different way:
>are
>you trying to reproduce some sort of plot from a published paper or
>textbook?
>Which is it, where is it?
>
>It's strange to be asking "how to add noise" without telling what kind
>of noise
>you are trying to add in the first place. The most common is to add
>gaussian
>white noise, and the snippet of code you had will do exactly that.
>Are you
>asking how to compute the correct sigma? Are you trying to reproduce
>a plot
>from somewhere?
>
%%%%%
Hi Julius
Thanks a lot for your reply. I am really stuck.
I want to add white noise and most im****tantly I want to find correct
sigma.
I know that the above code will add white noise, but I can not figure out
how to control variance of this white noise.
I would be really thankkful if you could also explain me as I have been
trying this for so many days.
Thanks again Julius.
Chintan
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