[S] Change in libosmocore[master]: coding: fix artificial bit errors for PDTCH CS2 and CS3
fixeria has uploaded this change for review. ( https://gerrit.osmocom.org/c/libosmocore/+/35754?usp=email ) Change subject: coding: fix artificial bit errors for PDTCH CS2 and CS3 ...................................................................... coding: fix artificial bit errors for PDTCH CS2 and CS3 GPRS coding schemes CS2 and CS3 (defined in 3GPP TS 45.003 sections 5.1.2 and 5.1.3, respectively) employ so-called puncturing, which can be described as intentional removal of coded bits. The goal of puncturing is to reduce the number of coded bits, so that they fit into 4 bursts. The receiving side recovers punctured bits, as if they were received corrupted. The puncturing is also used for other channel types like TCH/F9.6, TCH/F14.4, TCH/AFS and TCH/AHS, but only for CS2 and CS3 we're doing puncturing/depuncturing *manually*. This explains why we're seeing artificial bit errors only for CS2 and CS3. gsm0503_pdtch_decode() should not be reporting punctured bits as bit errors, fix this by using osmo_conv_decode_ber_punctured(). Change-Id: I024276d167e769396187998d881f8e7626461249 Related: OS#6342, OS#6200 --- M src/coding/gsm0503_coding.c M tests/coding/coding_test.ok 2 files changed, 36 insertions(+), 8 deletions(-) git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/54/35754/1 diff --git a/src/coding/gsm0503_coding.c b/src/coding/gsm0503_coding.c index 9272fdb..69a7ad4 100644 --- a/src/coding/gsm0503_coding.c +++ b/src/coding/gsm0503_coding.c @@ -1066,8 +1066,10 @@ cB[i] = 0; } - osmo_conv_decode_ber(&gsm0503_cs2_np, cB, - conv, n_errors, n_bits_total); + osmo_conv_decode_ber_punctured(&gsm0503_cs2_np, cB, conv, + n_errors, n_bits_total, + gsm0503_puncture_cs2); + /* 5.1.2.2 a) the three USF bits d(0),d(1),d(2) are precoded into six bits */ for (i = 0; i < 8; i++) { @@ -1102,8 +1104,9 @@ cB[i] = 0; } - osmo_conv_decode_ber(&gsm0503_cs3_np, cB, - conv, n_errors, n_bits_total); + osmo_conv_decode_ber_punctured(&gsm0503_cs3_np, cB, conv, + n_errors, n_bits_total, + gsm0503_puncture_cs3); /* 5.1.3.2 a) the three USF bits d(0),d(1),d(2) are precoded into six bits */ for (i = 0; i < 8; i++) { diff --git a/tests/coding/coding_test.ok b/tests/coding/coding_test.ok index 1fc2f1d..ad8a98d 100644 --- a/tests/coding/coding_test.ok +++ b/tests/coding/coding_test.ok @@ -270,7 +270,7 @@ 7f 7f 7f 81 7f 81 81 81 81 81 81 81 81 81 7f 7f 7f 7f 7f 81 81 81 81 7f 81 81 7f 7f 7f 7f 7f 81 81 7f 7f 7f 7f 7f 7f 81 7f 7f 81 81 7f 7f 7f 81 81 7f 81 7f 7f 7f 81 81 7f 81 7f 7f 81 81 7f 81 7f 7f 81 81 7f 81 7f 7f 81 7f 7f 81 7f 81 81 7f 7f 7f 7f 7f 81 7f 81 7f 7f 7f 7f 81 81 7f 7f 81 81 7f 7f 7f 7f 81 81 7f 81 81 7f 81 81 7f 7f 81 81 7f 81 81 7f 81 81 81 81 7f 81 7f 7f 7f 81 81 7f 7f 7f 7f 81 81 81 7f 7f 7f 81 7f 81 7f 7f 7f 81 81 81 7f 81 81 81 7f 7f 7f 81 81 81 7f 81 81 7f 81 81 7f 7f 81 81 7f 81 81 81 81 81 7f 7f 7f 7f 7f 81 81 81 81 7f 7f 7f 81 81 81 7f 7f 7f 81 81 7f 81 7f 7f 7f 81 81 7f 81 81 81 7f 7f 81 7f 81 81 81 7f 81 81 81 81 81 7f 81 7f 81 81 81 81 81 7f 81 81 7f 7f 81 81 Decoded: a3 af 5f c6 36 43 44 ab d9 6d 7d 62 24 c9 d2 92 fa 27 5d 71 7a 59 a8 42 a3 af 5f c6 36 43 44 ab a3 2f -pdtch_decode: n_errors=132 n_bits_total=588 ber=0.22 +pdtch_decode: n_errors=0 n_bits_total=588 ber=0.00 Encoding: a3 af 5f c6 36 43 44 ab d9 6d 7d 62 24 c9 d2 92 fa 27 5d 71 7a 59 a8 42 a3 af 5f c6 36 43 44 ab a3 af 5f c6 36 43 44 03 U-Bits: @@ -284,7 +284,7 @@ 81 81 7f 7f 7f 81 81 7f 7f 7f 7f 7f 7f 7f 81 7f 7f 7f 7f 81 7f 81 7f 81 7f 81 81 81 81 81 81 7f 81 7f 81 81 7f 7f 7f 81 81 81 7f 81 7f 81 81 81 81 81 7f 7f 81 81 81 81 7f 7f 7f 81 7f 7f 7f 7f 81 81 7f 81 81 7f 7f 7f 81 81 7f 7f 81 81 7f 81 81 7f 7f 81 81 7f 81 81 7f 7f 7f 7f 81 7f 81 7f 7f 7f 7f 7f 81 7f 7f 7f 7f 7f 81 7f 81 81 7f 7f 81 81 81 7f 7f 81 81 81 7f 7f 7f 7f 81 7f 81 7f 7f 7f 7f 81 7f 7f 81 7f 7f 81 7f 81 7f 7f 81 7f 7f 7f 81 7f 7f 81 81 7f 81 7f 7f 81 81 81 7f 81 7f 7f 7f 7f 81 7f 81 81 81 7f 7f 7f 7f 7f 81 81 81 81 81 7f 7f 81 81 7f 7f 7f 7f 7f 81 81 7f 7f 81 7f 7f 81 81 7f 81 81 81 7f 81 7f 7f 81 81 81 81 7f 81 7f 7f 81 7f 81 7f 7f 81 81 81 81 7f 81 7f 7f 81 81 7f 7f 81 81 Decoded: a3 af 5f c6 36 43 44 ab d9 6d 7d 62 24 c9 d2 92 fa 27 5d 71 7a 59 a8 42 a3 af 5f c6 36 43 44 ab a3 af 5f c6 36 43 44 03 -pdtch_decode: n_errors=220 n_bits_total=676 ber=0.33 +pdtch_decode: n_errors=0 n_bits_total=676 ber=0.00 Encoding: a3 af 5f c6 36 43 44 ab d9 6d 7d 62 24 c9 d2 92 fa 27 5d 71 7a 59 a8 42 a3 af 5f c6 36 43 44 ab a3 af 5f c6 36 43 44 ab d9 6d 7d 62 24 c9 d2 92 fa 27 5d 71 7a 28 U-Bits: @@ -326,7 +326,7 @@ 7f 7f 81 7f 81 81 7f 7f 7f 81 7f 7f 7f 81 81 7f 81 7f 81 7f 7f 7f 7f 7f 81 7f 81 81 81 7f 81 7f 7f 7f 81 7f 7f 81 7f 7f 81 7f 7f 7f 81 7f 81 81 81 81 7f 81 7f 81 7f 7f 81 81 7f 7f 7f 7f 81 81 7f 7f 7f 7f 7f 81 81 7f 7f 7f 81 7f 7f 7f 81 81 7f 7f 7f 81 7f 7f 81 7f 81 7f 7f 7f 81 7f 7f 7f 7f 81 7f 7f 7f 7f 7f 7f 81 7f 7f 81 7f 81 7f 7f 81 7f 81 81 81 7f 81 7f 7f 81 7f 7f 81 81 7f 7f 81 7f 81 7f 7f 81 81 81 7f 81 7f 81 81 7f 81 7f 81 7f 81 7f 81 7f 7f 7f 7f 7f 7f 81 81 7f 81 7f 7f 7f 81 7f 7f 7f 7f 7f 81 7f 81 7f 81 7f 7f 7f 81 7f 81 7f 7f 81 7f 81 81 81 7f 7f 81 7f 7f 7f 81 7f 7f 7f 7f 81 81 7f 81 81 81 7f 7f 7f 81 7f 7f 7f 7f 81 81 81 7f 7f 7f 7f 81 7f 7f 81 7f 81 7f 7f 81 81 7f 7f 81 7f Decoded: 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f 10 11 12 13 14 15 16 17 00 00 00 00 00 00 00 00 00 00 00 -pdtch_decode: n_errors=132 n_bits_total=588 ber=0.22 +pdtch_decode: n_errors=0 n_bits_total=588 ber=0.00 Encoding: 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f 10 11 12 13 14 15 16 17 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 U-Bits: @@ -340,7 +340,7 @@ 81 7f 81 7f 81 81 7f 7f 7f 81 7f 81 7f 7f 81 7f 7f 7f 81 7f 7f 81 7f 7f 7f 7f 81 7f 7f 7f 7f 7f 81 81 7f 7f 7f 7f 7f 81 81 81 7f 7f 7f 7f 81 81 7f 81 7f 7f 7f 7f 7f 81 7f 7f 7f 7f 81 7f 81 81 7f 7f 7f 81 7f 81 81 7f 81 7f 7f 7f 81 7f 7f 7f 7f 81 7f 7f 7f 81 7f 7f 81 7f 7f 7f 7f 81 7f 81 7f 81 7f 7f 81 7f 81 7f 7f 7f 7f 7f 7f 7f 7f 81 81 81 7f 7f 7f 7f 81 7f 7f 7f 7f 81 7f 81 7f 7f 81 7f 7f 7f 7f 81 7f 81 7f 7f 7f 81 7f 7f 81 7f 7f 7f 81 81 7f 81 7f 7f 7f 81 7f 81 7f 7f 7f 7f 81 81 7f 81 7f 81 7f 7f 81 7f 81 7f 81 7f 81 7f 7f 7f 7f 7f 7f 81 7f 81 81 81 81 7f 7f 7f 7f 7f 7f 81 7f 7f 7f 81 81 7f 81 7f 81 7f 7f 7f 81 7f 7f 81 7f 81 81 7f 81 7f 81 7f 7f 7f 7f 81 7f 7f 7f 81 81 81 81 7f 7f 7f Decoded: 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f 10 11 12 13 14 15 16 17 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 -pdtch_decode: n_errors=220 n_bits_total=676 ber=0.33 +pdtch_decode: n_errors=0 n_bits_total=676 ber=0.00 Encoding: 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f 10 11 12 13 14 15 16 17 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 U-Bits: -- To view, visit https://gerrit.osmocom.org/c/libosmocore/+/35754?usp=email To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings Gerrit-Project: libosmocore Gerrit-Branch: master Gerrit-Change-Id: I024276d167e769396187998d881f8e7626461249 Gerrit-Change-Number: 35754 Gerrit-PatchSet: 1 Gerrit-Owner: fixeria <vyanitskiy@sysmocom.de> Gerrit-MessageType: newchange
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