| 177 | | === (Optional) CFO Calibration for PAAM boards === |
| 178 | | **This section introduces how to calibrate the CFO between the PAAM boards. It is not a necessary step for users who wants to run this tutorial.** \\ |
| 179 | | \\ |
| 180 | | Since each 28 GHz PAAM board is driven by its own on-board phase lock loop (PLL), the CFO between two 28 GHz PAAM boards needs to be calibrated in order to establish a 28 GHz communication link. \\ |
| 181 | | The following shows a coarse CFO calibration scheme: \\ |
| 182 | | * In **terminal 1**, change the {{{cfoBS}}} value to be **0** in line 15 as: |
| 183 | | {{{#!shell |
| 184 | | vim PAAM_Control/main.py |
| 185 | | }}} |
| 186 | | * Configure and bring up the PAAM board as described previously: |
| 187 | | {{{#!shell |
| 188 | | root@srv1-lg1:~/PAAM_Control# python3 main.py |
| 189 | | }}} |
| 190 | | * In **terminal 2**, fix MATLAB licensing issue: |
| 191 | | {{{#!shell |
| 192 | | cd /usr/local/MATLAB/R2022b/bin |
| 193 | | root@srv1-lg1:/usr/local/MATLAB/R2022b/bin# ./deactivate_matlab.sh |
| 194 | | root@srv1-lg1:/usr/local/MATLAB/R2022b/bin# ./activate_matlab.sh |
| 195 | | }}} |
| 196 | | At the last step, MATLAB will ask for a username for the computer. Enter **root**. |
| 197 | | * In **terminal 2**, direct to the CFO calibration folder and run the CFO estimation pipeline in {{{MATLAB}}}: |
| 198 | | {{{#!shell |
| 199 | | cd 5G_Pipeline |
| 200 | | root@srv1-lg1:~/5G_Pipeline# matlab |
| 201 | | }}} |
| 202 | | In the prompted {{{MATLAB}}} command line, type and run: |
| 203 | | {{{#!shell |
| 204 | | >>main |
| 205 | | }}} |
| 206 | | * An example output would appear as: |
| 207 | | {{{#!shell |
| 208 | | CFO: 9.8310e+03 |
| 209 | | SNR: 22.5722 |
| 210 | | EVM: 12.7090 |
| 211 | | BER: 0 |
| 212 | | }}} |
| 213 | | * Back to **terminal 1**, turn off PAAM board by pressing **{{{CTRL+C}}} once** |
| 214 | | * Applied the above estimated CFO value to {{{cfoBS}}} in {{{5G_Pipeline/main.py}}} and restart the PAAM boards: |
| 215 | | {{{#!shell |
| 216 | | root@srv1-lg1:~/PAAM_Control# python3 main.py |
| 217 | | }}} |
| 218 | | |
| 219 | | Based on the measurements we performed over 100+ times shown in the following probability density distributions of the estimated CFO values between the two PAAM boards, the CFO can be seen as a relatively constant value, hence, we pre-set the CFO to the PAAM board to be {{{97400}}} |
| 220 | | {{{#!td |
| 221 | | || [[Image(CFO_DL.png, 400px)]] || |
| 222 | | }}} |
| 223 | | {{{#!td |
| 224 | | || [[Image(CFO_UL.png, 400px)]] || |
| 225 | | }}} |
| | 177 | |