[L] Change in libosmocore[master]: coding: implement TCH/F9.6, TCH/[FH]4.8, TCH/F14.4

fixeria has uploaded this change for review. ( https://gerrit.osmocom.org/c/libosmocore/+/32808 ) Change subject: coding: implement TCH/F9.6, TCH/[FH]4.8, TCH/F14.4 ...................................................................... coding: implement TCH/F9.6, TCH/[FH]4.8, TCH/F14.4 Implement all CSD specific channel modes, except TCH/{FH}2.4. The later is slightly more complicated and can be added later. It's not yet clear to me how to implement FACCH/[FH] for these new CSD specific channel modes. According to 3GPP TS 45.003, sections 4.2.5 and 4.3.5, a FACCH/[FH] does not steal but disturb some part of the CSD data blocks. Leaving this as TODO. Change-Id: Ib482817b5f6a4e3c7299f6e0b3841143b60fc93d Related: OS#1572 --- M include/osmocom/coding/gsm0503_coding.h M src/coding/gsm0503_coding.c M src/coding/libosmocoding.map 3 files changed, 284 insertions(+), 0 deletions(-) git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/08/32808/1 diff --git a/include/osmocom/coding/gsm0503_coding.h b/include/osmocom/coding/gsm0503_coding.h index 2afa049..67efcf1 100644 --- a/include/osmocom/coding/gsm0503_coding.h +++ b/include/osmocom/coding/gsm0503_coding.h @@ -86,4 +86,20 @@ int gsm0503_sch_encode(ubit_t *burst, const uint8_t *sb_info); int gsm0503_sch_decode(uint8_t *sb_info, const sbit_t *burst); +int gsm0503_tch_fr96_encode(sbit_t *bursts, const uint8_t *data); +int gsm0503_tch_fr96_decode(uint8_t *data, const sbit_t *bursts, + int *n_errors, int *n_bits_total); + +int gsm0503_tch_fr48_encode(sbit_t *bursts, const uint8_t *data); +int gsm0503_tch_fr48_decode(uint8_t *data, const sbit_t *bursts, + int *n_errors, int *n_bits_total); + +int gsm0503_tch_hr48_encode(sbit_t *bursts, const uint8_t *data); +int gsm0503_tch_hr48_decode(uint8_t *data, const sbit_t *bursts, + int *n_errors, int *n_bits_total); + +int gsm0503_tch_fr144_encode(sbit_t *bursts, const uint8_t *data); +int gsm0503_tch_fr144_decode(uint8_t *data, const sbit_t *bursts, + int *n_errors, int *n_bits_total); + /*! @} */ diff --git a/src/coding/gsm0503_coding.c b/src/coding/gsm0503_coding.c index 3fd440f..dab961d 100644 --- a/src/coding/gsm0503_coding.c +++ b/src/coding/gsm0503_coding.c @@ -3265,4 +3265,245 @@ return 0; } +/* + * GSM CSD transcoding + */ + +/*! Perform channel encoding of a TCH/F9.6 channel as per section 3.3. + * \param[out] bursts Caller-allocated buffer for symbols of 22 bursts, + * 22 * 2 * 58 == 2552 bits total. + * \param[in] data Data to be encoded (240 / 8 bytes). + * \returns 0 in case of success; negative on error */ +int gsm0503_tch_fr96_encode(sbit_t *bursts, const uint8_t *data) +{ + ubit_t iB[22 * 114], cB[4 * 114]; + ubit_t conv[244]; + + /* 3.3.2 Block code: b1(60) + b2(60) + b3(60) + b4(60) */ + osmo_pbit2ubit_ext(&conv[0], 0, &data[0], 0, 240, 1); + memset(&conv[240], 0, 4); /* + pad(4) */ + + /* 3.3.3 Convolutional encoder */ + osmo_conv_encode(&gsm0503_tch_f96, &conv[0], &cB[0]); + + /* 3.3.4 Interleaving */ + gsm0503_tch_f96_interleave(&cB[0], &iB[0]); + + /* 3.3.5 Mapping on a burst: as specified for TCH/FS in subclause 3.1.4 */ + for (unsigned int i = 0; i < 22; i++) { + memcpy(&bursts[i * 116], &iB[i * 114], 57); + memcpy(&bursts[i * 116 + 59], &iB[i * 114 + 57], 57); + /* TODO: properly set hl(B) or hu(B) for FACCH */ + } + + return 0; +} + +/*! Perform channel decoding of a TCH/F9.6 channel as per section 3.3. + * \param[out] data Caller-allocated buffer for decoded data. + * \param[in] bursts Buffer containing the symbols of 22 bursts, + * 22 * 2 * 58 == 2552 bits total. + * \param[out] n_errors Number of detected bit errors. + * \param[out] n_bits_total Total number of bits. + * \returns Length of bytes used in \a data output buffer; negative on error. */ +int gsm0503_tch_fr96_decode(uint8_t *data, const sbit_t *bursts, + int *n_errors, int *n_bits_total) +{ + sbit_t iB[22 * 114], cB[4 * 114]; + ubit_t conv[244]; + + /* 3.3.5 Mapping on a burst: as specified for TCH/FS in subclause 3.1.4 */ + for (unsigned int i = 0; i < 22; i++) { + memcpy(&iB[i * 114], &bursts[i * 116], 57); + memcpy(&iB[i * 114 + 57], &bursts[i * 116 + 59], 57); + /* TODO: check hl(B) or hu(B) for FACCH */ + } + + /* 3.3.4 Interleaving */ + gsm0503_tch_f96_deinterleave(&cB[0], &iB[0]); + + /* TODO: implement FACCH decoding */ + + /* 3.3.3 Convolutional encoder */ + osmo_conv_decode_ber(&gsm0503_tch_f96, &cB[0], &conv[0], n_errors, n_bits_total); + + /* 3.3.2 Block code: b1(60) + b2(60) + b3(60) + b4(60) */ + osmo_ubit2pbit_ext(&data[0], 0, &conv[0], 0, 240, 1); + + return 240 / 8; +} + +/*! Perform channel encoding of a TCH/F4.8 channel as per section 3.4. + * \param[out] bursts Caller-allocated buffer for symbols of 22 bursts, + * 22 * 2 * 58 == 2552 bits total. + * \param[in] data Data to be encoded (120 / 8 bytes). + * \returns 0 in case of success; negative on error */ +int gsm0503_tch_fr48_encode(sbit_t *bursts, const uint8_t *data) +{ + ubit_t iB[22 * 114], cB[4 * 114]; + ubit_t conv[120 + 32], d[2 * 60]; + + /* 3.4.2 Block code: + * + * Sixteen bits equal to 0 are added to the 60 information bits, the result + * being a block of 76 bits, {u(0),u(1),...,u(75)}, with: + * + * u(19k+p) = d(15k+p) for k = 0,1,2,3 and p = 0,1,...,14; + * u(19k+p) = 0 for k = 0,1,2,3 and p = 15,16,17,18. + * + * Two such blocks forming a block of 152 bits: u1 + u2. */ + osmo_pbit2ubit_ext(&d[0], 0, &data[0], 0, 2 * 60, 1); + for (unsigned int k = 0; k < 2 * 4; k++) { + memcpy(&conv[19 * k], &d[15 * k], 15); + memset(&conv[19 * k + 15], 0, 4); + } + + /* 3.4.3 Convolutional encoder */ + osmo_conv_encode(&gsm0503_tch_f48, &conv[0], &cB[0]); + + /* 3.4.4 Interleaving: as specified for the TCH/F9.6 in subclause 3.3.4 */ + gsm0503_tch_f96_interleave(&cB[0], &iB[0]); + + /* 3.4.5 Mapping on a burst: as specified for TCH/FS in subclause 3.1.4 */ + for (unsigned int i = 0; i < 22; i++) { + memcpy(&bursts[i * 116], &iB[i * 114], 57); + memcpy(&bursts[i * 116 + 59], &iB[i * 114 + 57], 57); + /* TODO: properly set hl(B) or hu(B) for FACCH */ + } + + return 0; +} + +/*! Perform channel decoding of a TCH/F4.8 channel as per section 3.4. + * \param[out] data Caller-allocated buffer for decoded data. + * \param[in] bursts Buffer containing the symbols of 22 bursts, + * 22 * 2 * 58 == 2552 bits total. + * \param[out] n_errors Number of detected bit errors. + * \param[out] n_bits_total Total number of bits. + * \returns Length of bytes used in \a data output buffer; negative on error. */ +int gsm0503_tch_fr48_decode(uint8_t *data, const sbit_t *bursts, + int *n_errors, int *n_bits_total) +{ + sbit_t iB[22 * 114], cB[4 * 114]; + ubit_t conv[120 + 32], d[2 * 60]; + + /* 3.4.5 Mapping on a burst: as specified for TCH/FS in subclause 3.1.4 */ + for (unsigned int i = 0; i < 22; i++) { + memcpy(&iB[i * 114], &bursts[i * 116], 57); + memcpy(&iB[i * 114 + 57], &bursts[i * 116 + 59], 57); + /* TODO: check hl(B) or hu(B) for FACCH */ + } + + /* 3.4.4 Interleaving: as specified for the TCH/F9.6 in subclause 3.3.4 */ + gsm0503_tch_f96_deinterleave(&cB[0], &iB[0]); + + /* TODO: implement FACCH decoding */ + + /* 3.4.3 Convolutional encoder */ + osmo_conv_decode_ber(&gsm0503_tch_f48, &cB[0], &conv[0], n_errors, n_bits_total); + + /* 3.4.2 Block code: + * + * Sixteen bits equal to 0 are added to the 60 information bits, the result + * being a block of 76 bits, {u(0),u(1),...,u(75)}, with: + * + * u(19k+p) = d(15k+p) for k = 0,1,2,3 and p = 0,1,...,14; + * u(19k+p) = 0 for k = 0,1,2,3 and p = 15,16,17,18. + * + * Two such blocks forming a block of 152 bits: u1 + u2. */ + for (unsigned int k = 0; k < 2 * 4; k++) + memcpy(&d[15 * k], &conv[19 * k], 15); + osmo_ubit2pbit_ext(&data[0], 0, &d[0], 0, 2 * 60, 1); + + return (2 * 60) / 8; +} + +/*! Perform channel encoding of a TCH/H4.8 channel as per section 3.5. + * \param[out] bursts Caller-allocated buffer for symbols of 22 bursts, + * 22 * 2 * 58 == 2552 bits total. + * \param[in] data Data to be encoded (240 / 8 bytes). + * \returns 0 in case of success; negative on error */ +int gsm0503_tch_hr48_encode(sbit_t *bursts, const uint8_t *data) +{ + return gsm0503_tch_fr96_encode(bursts, data); +} + +/*! Perform channel decoding of a TCH/H4.8 channel as per section 3.5. + * The algorithm is identical to TCH/F9.6, so it's just a wrapper. + * \param[out] data Caller-allocated buffer for decoded data. + * \param[in] bursts Buffer containing the symbols of 22 bursts, + * 22 * 2 * 58 == 2552 bits total. + * \param[out] n_errors Number of detected bit errors. + * \param[out] n_bits_total Total number of bits. + * \returns Length of bytes used in \a data output buffer; negative on error. */ +int gsm0503_tch_hr48_decode(uint8_t *data, const sbit_t *bursts, + int *n_errors, int *n_bits_total) +{ + return gsm0503_tch_fr96_decode(data, bursts, n_errors, n_bits_total); +} + +/*! Perform channel encoding of a TCH/F14.4 channel as per section 3.8. + * \param[out] bursts Caller-allocated buffer for symbols of 22 bursts, + * 22 * 2 * 58 == 2552 bits total. + * \param[in] data Data to be encoded (296 / 8 bytes). + * \returns 0 in case of success; negative on error */ +int gsm0503_tch_fr144_encode(sbit_t *bursts, const uint8_t *data) +{ + ubit_t iB[22 * 114], cB[4 * 114]; + ubit_t conv[294]; + + /* 3.8.2 Block code: b(290) + pad(4) */ + osmo_pbit2ubit_ext(&conv[0], 0, &data[0], 0, 290, 1); + memset(&conv[290], 0, 4); /* + pad(4) */ + + /* 3.8.3 Convolutional encoder */ + osmo_conv_encode(&gsm0503_tch_f144, &conv[0], &cB[0]); + + /* 3.8.4 Interleaving */ + gsm0503_tch_f96_interleave(&cB[0], &iB[0]); + + /* 3.8.5 Mapping on a burst: as specified for TCH/FS in subclause 3.1.4 */ + for (unsigned int i = 0; i < 22; i++) { + memcpy(&bursts[i * 116], &iB[i * 114], 57); + memcpy(&bursts[i * 116 + 59], &iB[i * 114 + 57], 57); + /* TODO: properly set hl(B) or hu(B) for FACCH */ + } + + return 0; +} + +/*! Perform channel decoding of a TCH/14.4 channel as per section 3.8. + * \param[out] data Caller-allocated buffer for decoded data. + * \param[in] bursts Buffer containing the symbols of 22 bursts, + * 22 * 2 * 58 == 2552 bits total. + * \param[out] n_errors Number of detected bit errors. + * \param[out] n_bits_total Total number of bits. + * \returns Length of bytes used in \a data output buffer; negative on error. */ +int gsm0503_tch_fr144_decode(uint8_t *data, const sbit_t *bursts, + int *n_errors, int *n_bits_total) +{ + sbit_t iB[22 * 114], cB[4 * 114]; + ubit_t conv[294]; + + /* 3.8.5 Mapping on a burst: as specified for TCH/FS in subclause 3.1.4 */ + for (unsigned int i = 0; i < 22; i++) { + memcpy(&iB[i * 114], &bursts[i * 116], 57); + memcpy(&iB[i * 114 + 57], &bursts[i * 116 + 59], 57); + /* TODO: check hl(B) or hu(B) for FACCH */ + } + + /* 3.8.4 Interleaving: as specified for the TCH/F9.6 in subclause 3.3.4 */ + gsm0503_tch_f96_deinterleave(&cB[0], &iB[0]); + + /* TODO: implement FACCH decoding */ + + /* 3.8.3 Convolutional encoder */ + osmo_conv_decode_ber(&gsm0503_tch_f144, &cB[0], &conv[0], n_errors, n_bits_total); + + /* 3.8.2 Block code: b(290) + pad(4) */ + osmo_ubit2pbit_ext(&data[0], 0, &conv[0], 0, 290, 1); + + return (290 + 6) / 8; /* 6 unused bits */ +} + /*! @} */ diff --git a/src/coding/libosmocoding.map b/src/coding/libosmocoding.map index ff6ea80..aba7453 100644 --- a/src/coding/libosmocoding.map +++ b/src/coding/libosmocoding.map @@ -128,5 +128,14 @@ gsm0503_detect_afs_dtx_frame2; gsm0503_detect_ahs_dtx_frame2; +gsm0503_tch_fr96_encode; +gsm0503_tch_fr96_decode; +gsm0503_tch_fr48_encode; +gsm0503_tch_fr48_decode; +gsm0503_tch_hr48_encode; +gsm0503_tch_hr48_decode; +gsm0503_tch_fr144_encode; +gsm0503_tch_fr144_decode; + local: *; }; -- To view, visit https://gerrit.osmocom.org/c/libosmocore/+/32808 To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings Gerrit-Project: libosmocore Gerrit-Branch: master Gerrit-Change-Id: Ib482817b5f6a4e3c7299f6e0b3841143b60fc93d Gerrit-Change-Number: 32808 Gerrit-PatchSet: 1 Gerrit-Owner: fixeria &lt;vyanitskiy(a)sysmocom.de&gt; Gerrit-MessageType: newchange