LimeSDR-QPCIe Board Configuration

Note

For DPD demonstration two transceiver channels are implemented in LimeSDR QPCIe board (named with channels A and B). Also, two power amplifiers are required that are connected to the two different transmit paths.

Hardware Configuration

Follow the steps explained below:

  • The LimeSDR QPCIe channel A output, the LimeSDR QPCIe LMS#1 TX1_1 port is connected to channel A PA#1 input.

  • For channel B, port LMS#1 TX2_1 port is used, and, it is connected to corresponding PA#2 input.

  • The output of one of the PAs is via RF attenuator connected to spectrum analyzer RF input. The other PA output can be terminated with 50 Ohms.

  • PA coupling outputs are over 10dB-20dB RF attenuators fed to two LimeSDR QPCIe receive inputs.

  • The on-board analogue multiplexer is used for selection of PA coupling output signals. The multiplexer input, the U.FL RF1, is dedicated for channel A receive input, while the U.FL RF3 is used as channel B input.

  • The analogue multiplexer output U.FL port RFC is connected to the U.FL LMS#1 RX1_W, which is used as DPD monitoring input.

LimeSuiteGUI settings

The CFR and DPD control is implemented in LimeSuiteGUI application. Follow the steps 1 to 8:

  1. Copy the content of folder DPD/sw (the subfolders and QADPDconfig.ini) into folder that belongs to LimeSuiteGUI installation: <LimeSuite install folder>/LimeSuite/build/bin.

  2. Open a terminal in this folder.

  3. Start the LimeSuiteGUI application with sudo:

    sudo ./LimeSuiteGUI

  4. Make the connection with the LimeSDR QPCIe board Options → Connection settings. Select the LimeSDR QPCIe board.

  5. Read the LMS7002M INI configuration file LMS1settings/LMS1settings_20_751.ini.

  6. In LimeSuiteGUI open the Calibrations tab, press buttons Calibrate Tx, then Calibrate Rx for static I/Q calibration.

  7. Open the window Board related controls through Modules → Board Controls. When opened, read the FPGA configuration file (with extension .ini2) which contains the CFRs settings and post-CFR FIR filter configuration. To do this press Read settings button and choose the file dedicated to 10MHz LTE waveform: FPGAsettings/FPGAsettings_10MHz.ini2.

  8. Now, select the test waveform by Modules → FPGA controls, then select the 10MHz LTE waveform lms7suite_wfm/LTE_DL_TM31_10MHZ.wfm. Check MIMO option and press button Custom to start the waveforms.