LimeSDR-PCIe-5G Board Configuration

Connecting to the board

Install the Litepcie kernel https://gitlab.com/myriadrf/pcie_kernel_sw/-/tree/diff_dev_names by running setup.sh with super user privileges:

sudo ./setup.sh

After installing the kernel, LimeSDR-PCIe-5G board appears in the /dev/ hfolder. You can check this by typing:

ls /dev | grep Lime5G

LMS1 DPD Hardware Configuration

The LMS1 is used an LTE transceiver. For DPD demonstration the LMS1 and LMS3 are used. Two transmitter channels (named with channels A and B) are implemented by LMS1. The DPD monitoring paths are realized by two LMS3 receiver paths. The pre-driver TQM8M9079 PAs are embedded on the board, located in LMS1 transmit paths.

In DPD demonstration the TQM8M9079 PAs is being linearized.

Please, follow the steps explained below:

• The LMS1 A channel connections:

  • For LMS1 channel A TX output, use the U.FL connector TX1(J8) - the LMS1 TX1_1.

  • For channel A DPD monitoring input, the U.FL connector J4 is used. It is connected to LMS3 RX1_W input.

  • The channel A RX input is made via U.FL connector RX1(J1), connected to LMS1 RX1_H input port.

• The LMS1 B channel connections:

  • For LMS1 TX channel B output, the U.FL connector TX2(J9) located at the LMS1 TX2 port (the LMS1 TX2_1).

  • The U.FL connector J5 is used as channel B DPD monitoring input. It is connected to LMS3 RX2_W input.

  • The channel B RX input is U.FL connector RX2(J2), connected to LMS1 RX2_H input port.

• For DPD demonstration, for selected channel,

  • TX output (LMS1 TX 1) is connected to RF coupler input.

  • RF coupler output is connected to Spectrum Analyser RF input.

  • RF coupler coupling output is fed to DPD monitoring input (connected to LMS3 RX W input).

  • At DPD monitoring input, at board LimeSDR-PCIe-5G side, the 10 dB RF attenuator is placed for attenuation of RF coupler coupling output.

  • The other channel TX output can be terminated with 50 Ohms.

LMS1 DPD Software Configuration

The CFR and DPD control is implemented in LimeSuiteGUI application. Follow the steps 1 to 12:

1. Copy the QADPDconfig.ini into the 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-PCIe-5G board Options → Connection settings. Select the LimeSDR-PCIe-5G board.

5. Clocks for the LMS3 analog interfaces are provided by the onboard CDCM6208 clock generator.

   • Open Modules → CDCM6208.

   • Check the LMS2 Y0 CDCM output in the Frequency planning box. Enter frequency of 122.88 in the Frequency requested boxes. Click Calculate. Click Write All to write the new configuration into the CDCM6208 chip. Uncheck the Y0.

   • Check the LMS3 Y6 and Y7 CDCM outputs in the Frequency planning box. Enter frequency of 61.44 in the Frequency requested boxes. Click Calculate. Click Write All to write the new configuration into the CDCM6208 chip. Uncheck the Y6 and Y7.

6. To configure RF switches and amplifiers open the window Board related controls using Modules → Board Controls. When opened, please configure the following:

   • The LMS1 A channel settings:

     • the LMS1 TX1_EN is checked, the LMS1 RWSW_TX1 selection box is set to TX1_1 → TX1(J8), TX1DAC should is set to value od 52000,

     • the LMS1 RWSW_RX1 selection box should be set to option RX1_H ← RX1(J1),

   • The LMS1 B channel:

     • the LMS1 TX2_EN is checked, the LMS1 RWSW_TX2 selection box is TX2_1 → TX2(J9), TX2DAC should is set to value od 52000,

     • the LMS1 RWSW_RX2 selection box should be set to RX2_H ← RX2(J2),

7. Select the LMS1 chip in the LimeSuite GUI and read corresponding INI configuration file:

   • LMS1settings_dpd.ini

8. In LimeSuiteGUI select the LMS1 chip, open the Calibrations tab, press buttons Calibrate All.

9. Select the LMS2 and LMS3 LMS7002M chips in the LimeSuiteGUI and read corresponding INI configuration files:

   • LMS2settings_equ.ini

   • LMS3settings_dpd.ini

10. Open the window LMS1 CFR controls through Modules → LMS1 CFR, LMS3 RxTSP.

    • Read the FPGA configuration file (the file with extension .ini2) which contains the CFR and post-CFR FIR configuration.

    • To do this press Read button and choose the file dedicated to 10MHz LTE waveform:

    • FPGAsettings_LMS1_10MHz_LMS2_100MHz.ini2

    • check DPD cap.en.

11. Now, select the test waveform by Modules → FPGA controls,

    • Select the LMS1 option, and, read the 10MHz LTE waveform

    • LTE_DL_TM31_10MHZ.wfm

    • Press button Custom to start the waveform.

    • When MIMO operation is required, before pressing Custom button check MIMO option.

Note

• open Modules → LMS1 CFR, LMS3 RxTSP control window

  • check LMS3 Enable RxTSP for both channels

  • check ResetN, LMS1 txen, DPD/CFR enable, LMS3 mon.path

  • check DPD cap.en.

Note

In LimeSuiteGUI, for selected LMS3 chip, it is required:

• SXR tab → Enable SXR/SXT module is checked

• SXT tab → Enable SXR/SXT module is unchecked

• the previous two requirements are written in LMS3settings_dpd.ini

Note

When it is required to modify CFR or post-FIR CFR settings, LimeSuiteGUI must be used. Again, go to Modules → LMS1 CFR, LMS3 RxTSP, open LMS1 CFR, LMS3 RxTSP. After the CFR settings are modified, save new configuration into FPGA configuration file or replace the existing file.

LMS2 Equaliser Hardware Configuration

The LMS2 is used for 5G signal transmission and implements two transceiver chains. The TX chain includes the CFR block, specifically optimized for 100 MHz bandwidth waveforms, post-CFR FIR, static I/Q and DC offset correctors and Equaliser circuits.

Please, follow the steps explained below:

• The LMS2 A channel connections:

  • For LMS2 channel A TX output, use the U.FL connector TRX1(J10) connected to LMS2 TX1_1 output.

  • The channel A RX input is the U.FL connector RX1(J11), connected to LMS2 RX1_H input port.

• The LMS2 B channel connections:

  • For LMS2 channel B TX output, the U.FL connector TRX2(J12), connected to the LMS2 TX2_1 port.

  • The channel B RX input is U.FL connector RX2(J13), connected to LMS2 RX2_H input port.

LMS2 Equaliser Software Configuration

Follow the steps:

1. Open a terminal in the folder <LimeSuite install folder>/LimeSuite/build/bin.

2. Start the LimeSuiteGUI application with sudo:

   sudo ./LimeSuiteGUI
   

3. Make the connection with the LimeSDR-PCIe-5G board Options → Connection settings. Select the LimeSDR-PCIe-5G board.

4. Select the right LMS7002M chip (LMS1, LMS2 or LMS3) in the LimeSuiteGUI and read corresponding INI configuration files:

   • LMS1settings_dpd.ini

   • LMS2settings_equ.ini

   • LMS3settings_equ.ini

   Three INI files are provided with this document, one for each LMS7002M IC.

5. To configure RF switches and amplifiers open the window Board related controls using Modules → Board Controls. When opened, configure the following items:

   • The LMS2 A channel configuration:

     • the LMS2 TX1_EN is checked; the LMS2 RWSW_TRX1T selection box is TX1_1 → RFSW_TRX1; the LMS2 RWSW_TRX1 is RFSW_TRX1T → TRX1(J10),

     • the LMS2 RX1_LNA is checked; the LMS2 RWSW_RX1C is set to option RX1_H ← RFSW_RX1IN(LNA); the LMS2 RWSW_RX1IN selection box is RFSW_RX1C ← RX1(J11),

     • the LMS3 RWSW1_RX1 is RX1_H ← RX1_IN(J6),

   • The LMS2 B channel:

     • the LMS2 TX2_EN is checked; the LMS2 RWSW_TRX2T selection box is TX2_1 → RFSW_TRX2; the LMS2 RWSW_TRX2 is set to RFSW_TRX2T → TRX2(J12),

     • the LMS2 RX2_LNA is checked; the LMS2 RWSW_RX2C selection box is set to RX2_H ← RFSW_RX2IN(LNA); the LMS2 RWSW_RX2IN is RFSW_RX2C ← RX2(J13),

     • the LMS3 RWSW1_RX2 box is set to RX2_H ← RX2_IN(J7),

6. Clocks for the LMS2 and LMS3 analog interfaces are provided by the onboard CDCM6208 clock generator. Open Modules → CDCM6208.

   • Check the Y0 CDCM outputs in the Frequency planning box. Enter frequency of 245.76 in the Frequency requested boxes. Click Calculate, click Write All to write the new configuration into the CDCM6208 chip. Uncheck the Y0.

   • Check the Y4, Y5, Y6 and Y7 CDCM outputs in the Frequency planning box. Enter frequency of 122.88 in the Frequency requested boxes. Click Calculate. Click Write All to write the new configuration into the CDCM6208 chip. Uncheck the Y4, Y5, Y6 and Y7.

7. Open the window LMS1 CFR controls through Modules → LMS1 CFR, LMS3 RxTSP. Read the FPGA configuration file which contains the CFRs settings and post-CFR FIR filter configuration. To do this press Read button and choose the file:

   • FPGAsettings_LMS1_10MHz_LMS2_100MHz.ini2

8. Open the window LMS2 CFR controls through Modules → LMS2 CFR controls. Read the same FPGA configuration file. Press Read button and choose the file: FPGAsettings_LMS1_10MHz_LMS2_100MHz.ini2.

9. Execute the equAPI application to calibrate the Equaliser. Please follow the steps which can be found in the description of equAPI in UserGuide/Equaliser section.

10. When Equaliser is calibrated, go to Modules → FFTviewer, then, select the Data reading → LMS2SISO, 16-bit format. Press button Start to start receiving data on LMS2 channel A.

11. Go to Modules → FPGA controls, then select the LMS2 option. Select the waveform. Press button Custom to start the LMS2 channel A waveform. When MIMO operation is required, before pressing Custom button check MIMO option.

Note

• in LimeSuiteGUI

  • it is very important to open completely LMS2 analogue Receive and Transmit filters, 100MHz,-3dB bandwidth

  • in RxTSP and TxTSP tabs, for both LMS2 and LMS3, in both channels A and B, bypass (check the fields) all RxTSP and TxTSP blocks

  • in LMS3 TxTSP tab, select Input source -> Test signals option

  • check Enable MIMO for MIMO operation

• open Modules → LMS1 CFR, LMS3 RxTSP control window

  • check LMS3 Enable RxTSP for both channels

  • check ResetN, LMS1 txen, DPD/CFR enable, LMS3 mon.path

  • uncheck DPD cap.en.

• open Modules → LMS2 CFR controls window

  • check LMS2 En.RxTSP, En.TxTSP for both channels

  • uncheck bypasses for RxEQU and TxEQU for both channels

Warning

It is not allowed to run Equaliser calibration software and FFTViewer at the same time. Therefore, before starting the Equaliser calibration software, please stop LMS2 waveforms and close the FFTViewer.