Changes between Version 14 and Version 15 of Tutorials/k0SDR/Tutorial20

Timestamp:

Mar 8, 2017, 3:12:36 AM (8 years ago)

Author:

nilanjan

Comment:

—

Tutorials/k0SDR/Tutorial20

@@ -37 +37 @@
 4) Open a ssh session into the controller node and run the hardware interface application to start streaming the receiver. The list of USRP devices, frequency, rate, gain, etc.. are all described in the XML file.
 {{{
-root@node21-1:> ./rf_hw_intf --conf "mimo1.xml,/devices/mimo_rx" --rx-only --cmd-port 5111
+root@node21-1:> ./rf_hw_intf --conf "devices.xml,/devices/mimo_rx" --rx-only --cmd-port 5111
 
 
@@ -108 +108 @@
 }}}
 
-Create a signal from an octave script and pass it to the transmit signal handler application for transmission every 500 microseconds.
-{{{
-root@node19-1:> samps="octave -qf awgn256.m"
+Create a signal consisting of a short sync sequence followed by a signal with phased-shifted angles and transmit this sequence every 500 microseconds.
+{{{
+root@node19-1:> samps="octave -qf sync.m";
 root@node19-1:> ./sigtran --sig "`$samps`" --intv 500
 }}}
 
-Upon transmission of the signal, the boxplot of the received signal strength will update to reflect the transmitted signal. As an exercise modify the signal generated in awgn256.m and rerun the application. 
+Upon transmission of the signal, the boxplot of the received signal strength will update to reflect the transmitted signal.
+
+==  Plot the IQ Constellation of received signal ==
+Halt the signal transmission and rerun the signal transmission app with a half second internal.
+{{{
+root@node19-1:> samps="octave -qf sync.m";
+root@node19-1:> ./sigtran --sig "`$samps`" --intv 500
+}}}
+
+2) Set up tunneling via ssh from your local port 5101 to the grid.orbit-lab.org:5101 
+{{{
+my_laptop> ssh -L 5101:grid.orbit-lab.org:5101 username@grid.orbit-lab.org
+}}}
+  
+3) Start another web proxy daemon from the console
+{{{
+nilanjan@.grid:~$ run-websock 5101 node21-1:5101 --daemon
+WebSocket server settings:
+  - Listen on :5101
+  - Flash security policy server
+  - No SSL/TLS support (no cert file)
+  - proxying from :5101 to node21-1:5101
+}}}
+
+4) Make sure the prior signal processing app is stopped. Launch the next processing application with the parameters shown below to start tracking the transmitted sync sequence and trace the phased shifted samples following it.
+{{{
+root@node21-1> sync="octave -qf sync.m";
+root@node21-1> ./sigproc_start_idx --sync  "`$sync`" --cmd-port 5101 --time 900
+}}}
+
+5) If all goes well click here to view the updating constellation plot of the received signal. 
+
+ || [[Image(mimo_rx_scatter.png, width=600px)]] ||
 
 === Multi-channel Uhd STreamer (MUST) ===