Log PUSCH power control variables via T trace GNB_MAC_PUSCH_POWER_CONTROL

Include plotting tool and README on how to log and visualize graphics.

tools/plots/README.md

@@ -32,3 +32,43 @@ The plots are saved in three formats: `.png`, `.pdf` and `.svg`.
 ### Example graphs:
 #### BER
 ![image](./ber_compare.svg)
+
+
+## `plot_power_control.sh`
+
+This plots the relevant graphs for power control at the gNB, exported through T
+and recorded via the [`csv` tracer](../../common/utils/T/DOC/T/csv.md) and
+plotted with `gnuplot`.
+
+Run first the `csv` tracer in one terminal, selecting the desired quantities, and
+write them out to a file:
+
+    ./common/utils/T/tracer/csv -d ../common/utils/T/T_messages.txt -s $'\t' -t time GNB_MAC_PUSCH_POWER_CONTROL time snrx10 phr tpc tb_size txpower_calc rbSize mcs > /tmp/pusch.csv
+
+in a second terminal, run the gNB with desired configuration, and pass the
+`--T_stdout 2` option to connect to the `csv` tracer:
+
+    sudo ./nr-softmodem -O <config> --T_stdout 2
+
+Note that you could also run both in one window, connecting both commands with
+a `&`.  In that case, it's important to run the `nr-softmodem` at second
+position, which will receive signals and stop the `csv` tracer when stopping
+the main process.
+
+After recovering the `pusch.csv` file, you could plot it with a script.
+
+    ./plot-power-control.gp.sh /tmp/pusch.csv
+
+The script prints four graphs:
+
+1. prints instantaneous SNR, and "deltaMCS" (the power used for the
+   transmission if in deltaMCS mode that accounts for MCS). It also prints an
+   average SNR, but this has to be manually post-processed from the instanteous
+   SNR values (`snrx10` above)
+2. TPC commands and PHR of the UE
+3. Resource blocks used for all transmissions, and the MCS
+4. transport block size of the transmission, to estimate the amount of traffic.
+
+The script should either auto-scale graphs or have sensible defaults. It prints
+on screen. There is code to print to a file; uncomment the relevant lines to
+achieve this.

tools/plots/plot-power-control.gp.sh

@@ -0,0 +1,49 @@
+#!/bin/bash
+
+function die() { echo "$@"; exit 1; }
+
+[[ $# == 1 ]] || die "usage: $0 <filename>"
+
+FILE=${1}
+
+#OUTPUT=/tmp/results.png
+#echo "dumping to $OUTPUT"
+gnuplot << EOF
+
+#set terminal pngcairo size 2000,2000 enhanced font 'Verdana,10'
+#set output "$OUTPUT"
+
+set format x '%H:%M:%S'
+set timefmt '%H:%M:%S'
+set datafile separator "\t"
+set xdata time
+#set xrange ['08:43:17':'08:43:18']
+set grid
+
+set multiplot layout 4,1
+
+set yrange [0:300]
+set ylabel "dB"
+plot "$FILE" using 1:2 w l title "SNRx10 (inst)", "$FILE" using 1:9 w l title "SNRx10 (smooth)", "$FILE" using 1:6 w l title "txpower-calc"
+
+set yrange [5:50]
+set ylabel "PHR (dB)"
+set y2range [0:3]
+set y2label "TPC"
+set boxwidth 0.1
+plot "$FILE" using 1:4 w points pt 7 axes x1y2 title "TPC", "$FILE" using 1:3 w l title "PHR"
+
+set yrange [0:60]
+set ylabel "RB"
+set y2range [0:27]
+set y2label "MCS"
+plot "$FILE" using 1:7 w l title "RB", "$FILE" using 1:8 w l axes x1y2 title "MCS"
+
+set yrange [0:1000]
+set ylabel "TB size (B)"
+plot "$FILE" using 1:5 w l
+
+unset multiplot
+
+pause mouse close
+EOF