# Issue with Results from GR-CDMA **URL:** \ **Category:** GNU Radio\ **Created:** [January 29, 2015, 6:10pm UTC](https://www.ruby-forum.com/t/issue-with-results-from-gr-cdma/234005 "2015-01-29T18:10:06Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\ **Post date:** [January 29, 2015, 6:10pm UTC](https://www.ruby-forum.com/t/issue-with-results-from-gr-cdma/234005/1 "2015-01-29T18:10:06Z")
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.[http://imageshack.com/a/img633/757/Yx8B7r.png](http://imageshack.com/a/img633/757/Yx8B7r.png) 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. [http://imageshack.com/a/img631/8451/CDqdTM.png](http://imageshack.com/a/img631/8451/CDqdTM.png) 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. [http://imageshack.com/a/img538/7792/1xXqN4.pngAfter](http://imageshack.com/a/img538/7792/1xXqN4.pngAfter) 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.