I am using
gr-spread module to transmit a signal using FHSS. When I receive the FHSS signal, the received signal has a completely different hopping sequence as from the transmitted one. I am using USRP N210 for transmission and reception. I am not sure why this is happening. The transmitted sequence is (frequencies in Khz)
187.5
-12.5
162.5
-62.5
62.5
137.5
-112.5
-37.5
112.5
-162.5
-137.5
-87.5
12.5
37.5
87.5
and the received sequence is
37.5
62.5
112.5
-187.5
12.5
187.5
-37.5
87.5
162.5
-87.5
0
137.5
-137.5
-112.5
-62.5
37.5
62.5
I have created a movie out of the images which plots the IQ, FFT and WaterFall plot for the transmitted signal and the received signal using the "plot_psd_base.py" file in gr-utils. Please have a look at both of them
here and
here.
Please see the attached files for the flowgraphs, I am using as the transmitter and receiver.
I have stored the received and transmitted signal to a file. Since these are large files I have uploaded them to google drive
here.