<p>pespin has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/c/osmo-trx/+/25331">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">computeCI: Document hardcoded multiplier<br><br>Logarithm change of base rule is used. Document it so it's clear where<br>it comes from.<br><br>Change-Id: Ia588e8dafda4e1abe0721f12491661949339a1ba<br>---<br>M Transceiver52M/sigProcLib.cpp<br>1 file changed, 7 insertions(+), 1 deletion(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">git pull ssh://gerrit.osmocom.org:29418/osmo-trx refs/changes/31/25331/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/Transceiver52M/sigProcLib.cpp b/Transceiver52M/sigProcLib.cpp</span><br><span>index 21978ff..df87f94 100644</span><br><span>--- a/Transceiver52M/sigProcLib.cpp</span><br><span>+++ b/Transceiver52M/sigProcLib.cpp</span><br><span>@@ -1478,7 +1478,13 @@</span><br><span>   /* Esimate Carrier power */</span><br><span>   C = xcorr.norm2() / ((N - 1) * sync->gain.abs());</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">-  /* Interference = Signal - Carrier, so C/I = C / (S - C) */</span><br><span style="color: hsl(120, 100%, 40%);">+  /* Interference = Signal - Carrier, so C/I = C / (S - C).</span><br><span style="color: hsl(120, 100%, 40%);">+   * Calculated in dB:</span><br><span style="color: hsl(120, 100%, 40%);">+   * C/I_dB = 10 * log10(C/I)</span><br><span style="color: hsl(120, 100%, 40%);">+   * C/I_dB = 10 * (1/log2(10)) * log2(C/I)</span><br><span style="color: hsl(120, 100%, 40%);">+   * C/I_dB = 10 * 0.30103 * log2(C/I)</span><br><span style="color: hsl(120, 100%, 40%);">+   * C/I_dB = 3.0103 * log2(C/I)</span><br><span style="color: hsl(120, 100%, 40%);">+   */</span><br><span>   return 3.0103f * log2f(C / (S - C));</span><br><span> }</span><br><span> </span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/osmo-trx/+/25331">change 25331</a>. To unsubscribe, or for help writing mail filters, visit <a href="https://gerrit.osmocom.org/settings">settings</a>.</p><div itemscope itemtype="http://schema.org/EmailMessage"><div itemscope itemprop="action" itemtype="http://schema.org/ViewAction"><link itemprop="url" href="https://gerrit.osmocom.org/c/osmo-trx/+/25331"/><meta itemprop="name" content="View Change"/></div></div>

<div style="display:none"> Gerrit-Project: osmo-trx </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-Change-Id: Ia588e8dafda4e1abe0721f12491661949339a1ba </div>
<div style="display:none"> Gerrit-Change-Number: 25331 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: pespin <pespin@sysmocom.de> </div>
<div style="display:none"> Gerrit-MessageType: newchange </div>