5.1a.8 Packet data block type 19 (UBS-5)

3GPP45.003GSM/EDGE Channel codingRelease 17TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

5.1a.8.1 Block constitution

If the message delivered to the encoder does not include a PAN, it has a fixed size of 479 information bits {d(0),d(1),…,d(478)}. If the message delivered to the encoder includes a PAN, it has a fixed size of 504 information bits {d(0),d(1),…,d(503).

NOTE: The presence of the PAN is indicated by the PANI field in the header (see 3GPP TS 44.060).

The message is separated into the following parts:

h(k) = d(k) for k = 0,…,28

i(k-29) = d(k) for k = 29,…,478

And if a PAN is included:

pn(k-479) = d(k) for k = 479,…,503

5.1a.8.2 Header coding

The header {h(0),…,h(28)} is coded as defined in subclause 5.1a.1.1, with N=29, resulting in a block of 111 bits, {C(0),…,C(110)}.

The code is punctured in such a way that the following coded bits:

{ C(37*k+36) for k=0,…,2} are not transmitted

This results in a block of 108 bits, {hc(0),…,hc(107)}.

5.1a.8.3 Data coding

The data, {i(0),…,i(449)}, is coded as defined in subclause 5.1a.1.2, with N=450, resulting in a coded block of 1404 bits, {C(0),…,C(1403)}.

The coded block is punctured depending on the value of the CPS field as defined in 3GPP TS 44.060. Two puncturing schemes named P1 or P2 are applied in such a way that the following coded bits are punctured:

Always punctured

Punctured only if a PAN is included

C(27*k+j) for k=0,…,51, j=5, 8, 11, 14, 17, 20, 23 and 26

C(27*k) for k=0,…,51; and

C(27*k+10) for k=0, 1, 3, 5, 7, 9, 11, 13, 14, 16, 18, 20, 22, 24, 26, 27, 29, 31, 33, 35, 37, 39, 40, 42, 44, 46, 48 and 50

C(27*k+j) for k=0,…,51, j=2, 4, 6, 12, 13, 18, 22 and 24

C(27*k+16) for k=0,…,51; and

C(27*k+9) for k=0, 2, 4, 6, 8, 10, 12, 13, 15, 17, 19, 21, 23, 25, 26, 28, 30, 32, 34, 36, 38, 39, 41, 43, 45, 47, 49 and 51

If a PAN is not included, the result is a block of 988 bits, {c(0),…,c(987)}.

If a PAN is included, the result is a block of 908 bits, {c(0),…,c(907)}.

5.1a.8.4 PAN coding

The PAN {pn(0),…,pn(24)}, if included, is coded as defined in subclause 5.1a.1.4, resulting in a block of 90 bits, {C(0),…,C(89)}.

The code is punctured in such a way that the following coded bits:

{C(11+k) , C(17+k), C(23+k,) C(32+k), C(41+k) for k = 0, 45} are not transmitted

This results in a block of 80 bits, {ac(0),…,ac(79)}.

5.1a.8.5 Interleaving

a) Header

The header, {hc(0),…,hc(107)}, is interleaved as defined in subclause 5.1a.2.1, with N_C=108 and a=23, resulting in a block of 108 bits, {hi(0),…,hi(107)}.

b) Data and PAN

If a PAN is not included, the following rule applies:

dc(k) = c(k) for k = 0,…,987

If a PAN is included, data and PAN are put together as one entity as described by the following rule:

dc(k) = ac(k) for k = 0,…,79

dc(k) = c(k-80) for k = 80,…,987

The block {dc(0),…,dc(987)} is interleaved as defined in subclause 5.1a.2.1, with N_C=988 and a=108, resulting in a block of 988 bits, {di(0),…,di(987)}.

5.1a.8.6 Mapping on a burst

The mapping is given by the rule:

For B=0,1,2,3, let

e(B,j) = di(247B+j) for j = 0,…,123

e(B,j) = hi(27B+j-124) for j = 124,…,137

e(B,j) = q(2B+j-138) for j = 138,139

e(B,j) = hi(27B+j-126) for j = 140,…,152

e(B,j) = di(247B+j-29) for j = 153,…,275

where

q(0),q(1),…,q(7) = 0,0,0,0,0,0,0,0 identifies the coding scheme UBS-5 or UBS-6.