| 247 |  | {{{param.gainTx}}} and {{{param.gainRx}}}: the TX/RX gain of the USRPs, whose range varies over different USRP types, which can be find by running {{{uhd_usrp_probe}}} command in the terminal. In sb2, the recommended values are {{{60}}}. | 
          
            | 248 |  |  | 
          
            | 249 |  | ==== Run the experiment ==== | 
          
            | 250 |  |  | 
          
            | 251 |  | ==== Observe the results ==== | 
          
            | 252 |  |  | 
          
            | 253 |  | ==== Finish the experiments ==== | 
          
            |  | 250 |  | 
          
            |  | 251 | {{{param.gainTx}}} and {{{param.gainRx}}}: the TX/RX gain of the USRPs, whose range varies over different USRP types, which can be find by running {{{uhd_usrp_probe}}} command in the terminal. In sb2, the recommended value for {{{param.gainTx}}} is {{{60}}}, for {{{param.gainRx}}} is {{{40}}}. | 
          
            |  | 252 |  | 
          
            |  | 253 | ==== Conduct the transmission ==== | 
          
            |  | 254 |  | 
          
            |  | 255 | In MATLAB, open {{{main.m}}}, and directly run this script. | 
          
            |  | 256 |  | 
          
            |  | 257 | The displayed information include: | 
          
            |  | 258 |  | 
          
            |  | 259 | {{{CFO}}}: carrier frequency offset | 
          
            |  | 260 |  | 
          
            |  | 261 | {{{SNR}}}: signal-to-noise ratio | 
          
            |  | 262 |  | 
          
            |  | 263 | {{{EVM}}}: error vector magnitude | 
          
            |  | 264 |  | 
          
            |  | 265 | {{{BLER}}}: block error rate (only one block is transmitted and it can be either 0 for success and 1 for failure); | 
          
            |  | 266 |  | 
          
            |  | 267 | {{{BER}}}: bit error rate | 
          
            |  | 268 |  | 
          
            |  | 269 | {{{CSI}}}: the amplitudes and the phases of the channel state information over all the subcarriers | 
          
            |  | 270 |  | 
          
            |  | 271 | {{{Constel.png}}}: the saved constellation plot. | 
          
            |  | 272 |  | 
          
            |  | 273 | ==== Change the SNR/MCS ==== | 
          
            |  | 274 |  | 
          
            |  | 275 | To change SNR, you may either | 
          
            |  | 276 |  | 
          
            |  | 277 | Change the amplitude (by default, 0.5) of the generated waveform in line 13 of main.m, or | 
          
            |  | 278 | Change the TX gain in GetParam.m | 
          
            |  | 279 | To change MCS, open GetParam.m and customize param.modu for modulation and param.code for code rate. | 
          
            |  | 280 |  | 
          
            |  | 281 | Note that we always assign the TX/RX port for transmission and RX2 port for reception. |