Hi All,
Does anyone know where we can change the Signal to noise ratio value in
GNU
radio companion. i have made one DQPSK simulation for image transfer and
now
i want to check the transmission and reception of the image at different
SNR
values. I am unable to find any signal block where i can change the SNR
value .?? Please if any one can help i will be very grateful.
Hi All,
Does anyone know where we can change the Signal to noise ratio value in GNU
radio companion. i have made one DQPSK simulation for image transfer and now
i want to check the transmission and reception of the image at different SNR
values. I am unable to find any signal block where i can change the SNR
value .?? Please if any one can help i will be very grateful.
Regards,
Waq
You will want to add a Gaussian noise source and a add block to add
AWGN, or you can use the channel_model block. To set the SNR, you will
first have to calculate the signal power in your simulation and from
their, determine the noise power for your desired SNR. The convert the
noise power to an amplitude, which is what the noise source block
takes. Look in gnuradio-examples/python/digital/benchmark_loopback.py
to see an example of these calculations.
Thanks for your reply. yah i did use noise block and i am changing the
amplitude in the noise block but it does not make any difference in the
output. You said calculate the SNR value i have to check signal power
and
determine the noise power. i dont know how to calculate those values.
iam
simply changing the amplitude in the noise block and try to see if it
makes
any difference. And the link you have provided below is the C++ code
that
does not explain anywhere how to calculate or change the SNR value. Can
you
please explain in detail how it works.
i really appriciate your help and support.