<p>Harald Welte <strong>merged</strong> this change.</p><p><a href="https://gerrit.osmocom.org/9994">View Change</a></p><div style="white-space:pre-wrap">Approvals:
  Jenkins Builder: Verified
  Vadim Yanitskiy: Looks good to me, but someone else must approve
  Harald Welte: Looks good to me, approved

</div><pre style="font-family: monospace,monospace; white-space: pre-wrap;">coding: Fix (E)GPRS BER calculation to correctly account for puncturing.<br><br>Previously we didn't take into account puncturing and BER was always around<br>30% for GPRS/EDGE bursts because of they use puncturing coding unlike<br>"classical" GSM bursts.<br><br>Change-Id: I9da22e7051522d06d923fcec3b63cbed8db93910<br>---<br>M src/coding/gsm0503_coding.c<br>1 file changed, 24 insertions(+), 5 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/src/coding/gsm0503_coding.c b/src/coding/gsm0503_coding.c</span><br><span>index 215cc6d..1d06adb 100644</span><br><span>--- a/src/coding/gsm0503_coding.c</span><br><span>+++ b/src/coding/gsm0503_coding.c</span><br><span>@@ -528,16 +528,18 @@</span><br><span>        },</span><br><span> };</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">-/*! Convolutional Decode + compute BER</span><br><span style="color: hsl(120, 100%, 40%);">+/*! Convolutional Decode + compute BER for punctured codes</span><br><span>  *  \param[in] code Description of Convolutional Code</span><br><span>  *  \param[in] input Input soft-bits (-127...127)</span><br><span>  *  \param[out] output bits</span><br><span>  *  \param[out] n_errors Number of bit-errors</span><br><span>  *  \param[out] n_bits_total Number of bits</span><br><span style="color: hsl(120, 100%, 40%);">+ *  \param[in] data_punc Puncturing mask array. Can be NULL.</span><br><span>  */</span><br><span style="color: hsl(0, 100%, 40%);">-static int osmo_conv_decode_ber(const struct osmo_conv_code *code,</span><br><span style="color: hsl(120, 100%, 40%);">+static int osmo_conv_decode_ber_punctured(const struct osmo_conv_code *code,</span><br><span>     const sbit_t *input, ubit_t *output,</span><br><span style="color: hsl(0, 100%, 40%);">-    int *n_errors, int *n_bits_total)</span><br><span style="color: hsl(120, 100%, 40%);">+     int *n_errors, int *n_bits_total,</span><br><span style="color: hsl(120, 100%, 40%);">+     const uint8_t *data_punc)</span><br><span> {</span><br><span>       int res, i, coded_len;</span><br><span>       ubit_t recoded[EGPRS_DATA_C_MAX];</span><br><span>@@ -553,7 +555,8 @@</span><br><span>      if (n_errors) {</span><br><span>              *n_errors = 0;</span><br><span>               for (i = 0; i < coded_len; i++) {</span><br><span style="color: hsl(0, 100%, 40%);">-                    if (!((recoded[i] && input[i] < 0) ||</span><br><span style="color: hsl(120, 100%, 40%);">+                      if (((!data_punc) || (data_punc && !data_punc[i])) &&</span><br><span style="color: hsl(120, 100%, 40%);">+                         !((recoded[i] && input[i] < 0) ||</span><br><span>                                         (!recoded[i] && input[i] > 0)) )</span><br><span>                                          *n_errors += 1;</span><br><span>              }</span><br><span>@@ -565,6 +568,21 @@</span><br><span>     return res;</span><br><span> }</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+/*! Convolutional Decode + compute BER for non-punctured codes</span><br><span style="color: hsl(120, 100%, 40%);">+ *  \param[in] code Description of Convolutional Code</span><br><span style="color: hsl(120, 100%, 40%);">+ *  \param[in] input Input soft-bits (-127...127)</span><br><span style="color: hsl(120, 100%, 40%);">+ *  \param[out] output bits</span><br><span style="color: hsl(120, 100%, 40%);">+ *  \param[out] n_errors Number of bit-errors</span><br><span style="color: hsl(120, 100%, 40%);">+ *  \param[out] n_bits_total Number of bits</span><br><span style="color: hsl(120, 100%, 40%);">+ */</span><br><span style="color: hsl(120, 100%, 40%);">+static int osmo_conv_decode_ber(const struct osmo_conv_code *code,</span><br><span style="color: hsl(120, 100%, 40%);">+      const sbit_t *input, ubit_t *output,</span><br><span style="color: hsl(120, 100%, 40%);">+  int *n_errors, int *n_bits_total)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+  return osmo_conv_decode_ber_punctured(code, input, output,</span><br><span style="color: hsl(120, 100%, 40%);">+            n_errors, n_bits_total, NULL);</span><br><span style="color: hsl(120, 100%, 40%);">+}</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /*! convenience wrapper for decoding coded bits</span><br><span>  *  \param[out] l2_data caller-allocated buffer for L2 Frame</span><br><span>  *  \param[in] cB 456 coded (soft) bits as per TS 05.03 4.1.3</span><br><span>@@ -884,7 +902,8 @@</span><br><span>                        C[i] = 0;</span><br><span>    }</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">-   osmo_conv_decode_ber(code->data_conv, C, u, n_errors, n_bits_total);</span><br><span style="color: hsl(120, 100%, 40%);">+       osmo_conv_decode_ber_punctured(code->data_conv, C, u,</span><br><span style="color: hsl(120, 100%, 40%);">+              n_errors, n_bits_total, code->data_punc[p]);</span><br><span>      rc = osmo_crc16gen_check_bits(&gsm0503_mcs_crc12, u,</span><br><span>             data_len, u + data_len);</span><br><span>     if (rc)</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/9994">change 9994</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/9994"/><meta itemprop="name" content="View Change"/></div></div>

<div style="display:none"> Gerrit-Project: libosmocore </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-MessageType: merged </div>
<div style="display:none"> Gerrit-Change-Id: I9da22e7051522d06d923fcec3b63cbed8db93910 </div>
<div style="display:none"> Gerrit-Change-Number: 9994 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: Alexander Chemeris <Alexander.Chemeris@gmail.com> </div>
<div style="display:none"> Gerrit-Reviewer: Alexander Chemeris <Alexander.Chemeris@gmail.com> </div>
<div style="display:none"> Gerrit-Reviewer: Harald Welte <laforge@gnumonks.org> </div>
<div style="display:none"> Gerrit-Reviewer: Jenkins Builder </div>
<div style="display:none"> Gerrit-Reviewer: Vadim Yanitskiy <axilirator@gmail.com> </div>