# QPSK Bit Error Rate

**URL:** <https://discuss.pynq.io/t/qpsk-bit-error-rate/5294>\
**Category:** Support\
**Created:** [March 1, 2023, 4:56pm UTC](https://discuss.pynq.io/t/qpsk-bit-error-rate/5294 "2023-03-01T16:56:55Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![rpet7](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.pynq.io/rpet7/32/4331_2.png) [@rpet7](https://discuss.pynq.io/u/rpet7)\
**Post date:** [March 1, 2023, 4:56pm UTC](https://discuss.pynq.io/t/qpsk-bit-error-rate/5294/1 "2023-03-01T16:56:55Z")

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Hello,  
I am using the RFSoC 4x2 version 2.7 with the Strathclyde University QPSK Demonstrator Jupyter Notebook. I am attempting to use the data in the plots in order to extend the code so that I would be able to get some numerical judgment of the signal integrity such as error vector magnitude or bit error rate. However, I have been unable to pull the data from the constellation plots in order to perform calculations on it. I have tried using the ol.qpsk\_rx.get\_data() command but it tells me that it is a method and not actually an array of data for example.  
For example, I am able to see these values for the plot but I am unable to pull those values from anywhere.

 ![image](https://us1.discourse-cdn.com/flex019/uploads/pynq1/original/2X/4/46a52afb0325dccb421d40f8c0f1d90b48190440.png)

Any help or direction would be very well appreciated. Thanks!

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**Author:** ![skalade](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.pynq.io/skalade/32/686_2.png) [@skalade](https://discuss.pynq.io/u/skalade)\
**Post date:** [March 2, 2023, 7:05pm UTC](https://discuss.pynq.io/t/qpsk-bit-error-rate/5294/2 "2023-03-02T19:05:03Z")

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Hi there,

Not sure if you can achieve that with that particular example without modifying the hardware design.

Maybe these posts will be helpful

> [@RFSoC ZCU111 Generate Custom Data in PS to send to PL RF Data Converter](https://discuss.pynq.io/t/rfsoc-zcu111-generate-custom-data-in-ps-to-send-to-pl-rf-data-converter/331):
>
> Hello all, I have a ZCU111 eval board and Vivado 2018.3. I have been able to successfully run the examples in the RFSoC Workshop git repo. I am trying to build something that is very similar, but essentially it allows me to send custom data to the RF data converter. I have written some code in python to generate a custom modulated message (sent continuously). This works in the pynq notebook that I have created. Now I want to create an overlay that will allow me to write data to the rf data conv…

> [@ZCU111 RF custom signal symbol generation](https://discuss.pynq.io/t/zcu111-rf-custom-signal-symbol-generation/3727):
>
> Hello! My requirement is simple: using the ZCU111 high-speed DAC output custom signal which doesn’t need the QPSK signal. But I have not seen the example. So follow the RFSoC Workshop example (RFSOC-QPSK) and try to modify it. My question is which function defines the signal sequence? By the way, I tried that QPSK example and connect the DAC port to the oscilloscope. In the running process, I have not seen the signal output. I don’t know why. Thank you!

Thanks  
Shawn