# Re: gr-cdma **URL:** \ **Category:** GNU Radio\ **Created:** [January 23, 2015, 11:55pm UTC](https://www.ruby-forum.com/t/re-gr-cdma/233943 "2015-01-23T23:55:04Z")\ **Posts on this page:** 7\ **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 23, 2015, 11:55pm UTC](https://www.ruby-forum.com/t/re-gr-cdma/233943/1 "2015-01-23T23:55:04Z")
The beautiful thing about open source is that all the detail are there for you to see! Looking at the cdma\_parameters.py file, you can see: pulse\_training = numpy.array((1,1,1,1,-1,1,1,-1))+0j pulse\_data =numpy.array((-1,1,-1,1,-1,-1,-1,-1))+0j so we are using 8 chips per symbol with two orthogonal codes for training and data. You can change them and put anything you like (they better be orthogonal AND each should have good autocorrelation properties-- or at least the training code should) best, Achilleas ---
**Author:** ![Achilleas\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/74df32/32.png) [@Achilleas\_A](https://www.ruby-forum.com/u/Achilleas_A)\ **Post date:** [January 24, 2015, 12:03am UTC](https://www.ruby-forum.com/t/re-gr-cdma/233943/2 "2015-01-24T00:03:34Z")
* * * Discuss-gnuradio mailing list removed\_email\_address@domain.invalid [https://lists.gnu.org/mailman/listinfo/discuss-gnuradio](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio) ---
**Author:** ![Achilleas\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/74df32/32.png) [@Achilleas\_A](https://www.ruby-forum.com/u/Achilleas_A)\ **Post date:** [January 27, 2015, 6:13pm UTC](https://www.ruby-forum.com/t/re-gr-cdma/233943/3 "2015-01-27T18:13:15Z")
Frank, you can perform simulations and plot BER vs SNR using either of the two apps provided (ie, either the txrx or the separate tx and rx apps that communicate through FIFO). The file vs FIFO is irrelevant here: the FIFOs are just used for “emulating” the communication between the two different tx and rx applications. In both cases you can either dump the rx results to a file and compare with the “known” tx transmission, or you can add BER GRC blocks… All the above are not gr-cdma related, so i am sure you can find plenty of examples of how this is done in this list and in the gnuradio examples. Achilleas On Mon, Jan 26, 2015 at 10:01 PM, Frank P. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![Achilleas\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/74df32/32.png) [@Achilleas\_A](https://www.ruby-forum.com/u/Achilleas_A)\ **Post date:** [January 27, 2015, 4:02am UTC](https://www.ruby-forum.com/t/re-gr-cdma/233943/4 "2015-01-27T04:02:16Z")
Sounds good! I figured this already just wanted to be sure. And will I be able to plot the BER vs. Eb/NO by using the writing and reading to fifo or simply reading and writing to a file and importing the data to matlab for the BER vs Eb/NO plot? ``` On Friday, January 23, 2015 5:59 PM, Frank P. ``` [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: | Sounds good! I figured this already just wanted to be sure. And will I be able to plot the BER vs. Eb/NO by using the writing and reading to fifo or simply reading and writing to a file and importing the data to matlab for the BER vs Eb/NO plot? Sent from Yahoo Mail for iPhone At Jan 23, 2015, 5:53:58 PM, Achilleas A. wrote:The beautiful thing about open source is that all the detail are there for you to see! Looking at the cdma\_parameters.py file, you can see: pulse\_training = numpy.array((1,1,1,1,-1,1,1,-1))+0j pulse\_data =numpy.array((-1,1,-1,1,-1,-1,-1,-1))+0j so we are using 8 chips per symbol with two orthogonal codes for training and data. You can change them and put anything you like (they better be orthogonal AND each should have good autocorrelation properties-- or at least the training code should) best, Achilleas | ---
**Author:** ![Achilleas\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/74df32/32.png) [@Achilleas\_A](https://www.ruby-forum.com/u/Achilleas_A)\ **Post date:** [January 29, 2015, 5:25am UTC](https://www.ruby-forum.com/t/re-gr-cdma/233943/5 "2015-01-29T05:25:26Z")
I don’t know what fft you are talking about… If you have any SPECIFIC questions please write to this list with your SPECIFIC results (and maybe screenshots) and explain why you think what you see is wrong. The culture in this community is that we try things on our own and we ask for help (we generally don’t ask people to do our job…) As far as I am concerned this discussion thread has gone quite long… We are looking forward to your contributions to the gnuradio community. best, Achilleas ---
**Author:** ![Achilleas\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/74df32/32.png) [@Achilleas\_A](https://www.ruby-forum.com/u/Achilleas_A)\ **Post date:** [January 29, 2015, 3:03am UTC](https://www.ruby-forum.com/t/re-gr-cdma/233943/6 "2015-01-29T03:03:49Z")
Sounds good. Can you please run your “txrx” simulation or separate “tx” “rx” simulation and screenshot me the output because I feel like what I am seeing is wrong. I want to be sure the output of the fft is correct. On the receiver side I am getting the message debug that tells me the packet number and packet length as well as if it’s detecting a failed packet. ``` On Tuesday, January 27, 2015 12:11 PM, Achilleas A. ``` [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: Frank, you can perform simulations and plot BER vs SNR using either of the two apps provided (ie, either the txrx or the separate tx and rx apps that communicate through FIFO). The file vs FIFO is irrelevant here: the FIFOs are just used for “emulating” the communication between the two different tx and rx applications. In both cases you can either dump the rx results to a file and compare with the “known” tx transmission, or you can add BER GRC blocks… All the above are not gr-cdma related, so i am sure you can find plenty of examples of how this is done in this list and in the gnuradio examples. Achilleas On Mon, Jan 26, 2015 at 10:01 PM, Frank P. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: Sounds good! I figured this already just wanted to be sure. And will I be able to plot the BER vs. Eb/NO by using the writing and reading to fifo or simply reading and writing to a file and importing the data to matlab for the BER vs Eb/NO plot? ``` On Friday, January 23, 2015 5:59 PM, Frank P. ``` [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: | Sounds good! I figured this already just wanted to be sure. And will I be able to plot the BER vs. Eb/NO by using the writing and reading to fifo or simply reading and writing to a file and importing the data to matlab for the BER vs Eb/NO plot? Sent from Yahoo Mail for iPhone At Jan 23, 2015, 5:53:58 PM, Achilleas A. wrote:The beautiful thing about open source is that all the detail are there for you to see! Looking at the cdma\_parameters.py file, you can see: pulse\_training = numpy.array((1,1,1,1,-1,1,1,-1))+0j pulse\_data =numpy.array((-1,1,-1,1,-1,-1,-1,-1))+0j so we are using 8 chips per symbol with two orthogonal codes for training and data. You can change them and put anything you like (they better be orthogonal AND each should have good autocorrelation properties-- or at least the training code should) best, Achilleas | ---
**Author:** ![Achilleas\_A](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/74df32/32.png) [@Achilleas\_A](https://www.ruby-forum.com/u/Achilleas_A)\ **Post date:** [January 30, 2015, 12:34pm UTC](https://www.ruby-forum.com/t/re-gr-cdma/233943/7 "2015-01-30T12:34:48Z")
On 01/29/2015 05:24 AM, Achilleas A. wrote: > As far as I am concerned this discussion thread has gone quite > long… > > We are looking forward to your contributions to the gnuradio > community. It seems like this thread has run its course, but I would like to emphasize what Achilleas pointed out. Frank, and everyone else who’s new to this list, we have put some effort into formalizing the etiquette for this mailing list, and you can find it all on this page: [http://gnuradio.org/redmine/projects/gnuradio/wiki/ReportingErrors](http://gnuradio.org/redmine/projects/gnuradio/wiki/ReportingErrors) (The page name is, at this point, rather inaccurate). Please respect these conventions. Mostly, you as the question-askers will be the prime beneficiary of sticking to these guidelines, as it will lead to better and faster responses. Also, it will make this whole list more fun for everyone. Cheers, Martin