see some comments inline.
> Hello
sorry for the last message thought i attached my screenshot results at
first. I am having some problems as to whether the information from the
cdma transmission and reception are accurate. I have posted my
screenshots for clarification hopefully.
The
first screenshot is from executing the "cdma_txrx.grc" which seems to
test well I believe because moving the sliders around and threshold I am
able to notice when it performs tracking and acquisition of the signal
automatically.
A: I do not recall a "noise voltage" block in the cdma_txrx application. The SNR is controlled by the slider aptly called "EsN0dB".
The
second screenshot is me loading two USRP's. This is the execution of
the "cdma_tx.grc file with the UHD:USRP Sink and its WX GUI FFT Plot. My
issue here is the FFT plot doesn't look right to. By the way the
channel model for this is AWGN.
A: You are saying "FFT plot doesn't look right". What is it that you expect to see and you don't ?
Can you please elaborate on what does not look right about this?
BTW, you don't need the cdma_tx to get this FFT plot: the cdma_txrx should give you exactly the same at the output of the tx.
After
running the "cdma_tx.grc" file, I proceed to go to my other laptop and
run the "cdma_rx.grc" file which is connected to that USRP(UHD USRP
SOURCE. The image above is what I get. In the beginning it seems to be
acquiring the packets then a few seconds later a lot of invalid packets
get detected. Overall all are these images close to what I should be
seeing.
A: you have not told us anything about your system, so we cannot help you.
For instance, what is your hardware setup (daughtercards, carrier frequency, sample rate, etc),
what is the expected frequency error,
what are the RX parameters that you have set?
are they compatible with you working environment?
is your laptop handling well the acquisition load (have you checked the load on your CPU cores?)
Achilleas