5.1a.26 Packet data block type 37 (DBS-7)
3GPP45.003GSM/EDGE Channel codingRelease 17TS
5.1a.26.1 Block constitution
If the message delivered to the encoder does not include a PAN, it has a fixed size of 941 information bits {d(0),d(1),…,d(940)}. If the message delivered to the encoder includes a PAN, it has a fixed size of 966 information bits {d(0),d(1),…,d(965).
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:
u(k) = d(k) for k = 0,…,2
h(k-3) = d(k) for k = 3,…,40
i1(k-41) = d(k) for k = 41,…,490
i2(k-491) = d(k) for k = 491,…,940
And if a PAN is included:
pn(k-941) = d(k) for k = 941,…,965
5.1a.26.2 USF coding
5.1a.26.2.1 BTTI configuration
The USF bits {u(0),u(1),u(2)} are block coded into 64 bits u’(0),u’(1),…,u’(63) according to the following table:
|
u(0),u(1),u(2) |
u’(0),u’(1),…,u’(63) |
|||
|
burst 0 |
burst 1 |
burst 2 |
burst 3 |
|
|
000 |
0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 |
0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 |
0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 |
0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 |
|
001 |
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 |
0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 |
0 0 1 1 0 0 1 1 1 1 1 1 1 1 1 1 |
1 1 1 1 1 1 1 1 0 0 1 1 0 0 1 1 |
|
010 |
1 1 1 1 1 1 1 1 0 0 1 1 0 0 1 1 |
1 1 1 1 1 1 1 1 0 0 1 1 0 0 1 1 |
1 1 1 1 1 1 1 1 0 0 1 1 0 0 1 1 |
1 1 1 1 1 1 1 1 0 0 1 1 0 0 1 1 |
|
011 |
0 0 1 1 0 0 1 1 1 1 1 1 1 1 1 1 |
1 1 1 1 1 1 1 1 0 0 1 1 0 0 1 1 |
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 |
0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 |
|
100 |
1 1 1 1 1 1 1 1 0 0 1 1 0 0 1 1 |
0 0 1 1 0 0 1 1 1 1 1 1 1 1 1 1 |
0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 |
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 |
|
101 |
0 0 1 1 0 0 1 1 1 1 1 1 1 1 1 1 |
0 0 1 1 0 0 1 1 1 1 1 1 1 1 1 1 |
0 0 1 1 0 0 1 1 1 1 1 1 1 1 1 1 |
0 0 1 1 0 0 1 1 1 1 1 1 1 1 1 1 |
|
110 |
0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 |
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 |
1 1 1 1 1 1 1 1 0 0 1 1 0 0 1 1 |
0 0 1 1 0 0 1 1 1 1 1 1 1 1 1 1 |
|
111 |
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 |
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 |
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 |
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 |
5.1a.26.2.2 RTTI configurations
If the USF is sent in RTTI USF mode (see 3GPP TS 45.002) when data blocks are transmitted in RTTI configuration, then the USF bits {u(0),u(1),u(2)} are block coded into 64 bits u’(0),u’(1),…,u’(63) as described in subclause 5.1a.26.2.1.
If the USF is sent in BTTI USF mode (see 3GPP TS 45.002) when data blocks are transmitted in RTTI configuration, then the three bits of the USF to be sent on the lower numbered PDCH of a corresponding downlink PDCH-pair are block coded into 64 bits uL(0),uL(1),…,uL(63) as described in subclause 5.1a.26.2.1; the three bits of the USF to be sent on the higher numbered PDCH of a corresponding downlink PDCH-pair are block coded into 64 bits uH(0),uH(1),…,uH(63) as described in subclause 5.1a.26.2.1.
NOTE: If BTTI USF mode is used when sending data blocks in RTTI configuration, then u(0),u(1),u(2) need not contain a USF; in this case, they are ignored by the encoder. How the USFs are delivered to the encoder in this case is implementation dependent.
If the data block is sent in the first 10ms of a 20ms block period, then:
u’(j)=uL(j), j=0…15
u’(j)=uH(j-16), j=16…31
u’(j)=uL(j-16), j=32…47
u’(j)=uH(j-32) j=48…63
If the data block is sent in the second 10ms of a 20ms block period, then:
u’(j)=uL(j+32), j=0…15
u’(j)=uH(j+16), j=16…31
u’(j)=uL(j+16), j=32…47
u’(j)=uH(j) j=48…63
NOTE: In case mixed modulation USF is used (see subclause 5.1), the USF bits sent during the other half of the 20 ms block period may be sent with a different modulation. In this case, the half of uL and uH not sent in the present data block will be discarded.
5.1a.26.3 Header coding
The header {h(0),…,h(37)} is coded as defined in subclause 5.1a.1.1, with N=38, resulting in a block of 138 bits, {C(0),…,C(137)}.
Some bits of the code are repeated in the following way:
hc(k) = C(k) for k = 0, 1, 2, … 137 and
hc(138) = C(0), hc(139) = C(22), hc(140) = C(49), hc(141) = C(69), hc(142) = C(91), hc(143) = C(118).
The result is a block of 144 coded bits, {hc(0),…,hc(143)}.
5.1a.26.4 Data coding
Each data part, {i1(0),…,i1(449)} and {i2(0),…,i2(449)}, is coded as defined in subclause 5.1a.1.3, with N=450, resulting in two coded blocks of 1398 bits, {C1(0),…,C1(1397)} and {C2(0),…,C2(1397)}.
Each 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.
The parameter values used for rate matching are: swap=0, =466,=996 and =956.
P1 puncturing is generated according to 5.1a.1.3.5
P2 (Type 1) puncturing is generated according to 5.1a.1.3.5.
If a PAN is not included, the result is two blocks of 996 bits, {c1(0),…,c1(995)} and {c2(0),…,c2(995)}.
If a PAN is included, the result is two blocks of 956 bits, {c1(0),…,c1(955)} and {c2(0),…,c2(955)}.
NOTE: C1 and c1 correspond to i1, and C2 and c2 to i2.
5.1a.26.5 PAN coding
The PAN coding is the same as for UBS-5 as specified in subclause 5.1a.8.4.
5.1a.26.6 Interleaving
a) Header
The header, {hc(0),…,hc(143)}, is interleaved as defined in subclause 5.1a.2.1, with NC=144 and a=5, resulting in a block of 144 bits, {hi(0),…,hi(143)}.
b) Data and PAN
If a PAN is not included, data are put together as one entity as described by the following rule:
dc(k) = c1(k) for k = 0,…,995
dc(k) = c2(k-996) for k = 996,…,1991
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) = c1(k-80) for k = 80,…,1035
dc(k) = c2(k-1036) for k = 1036,…,1991
The block {dc(0),…,dc(1991)} is interleaved as defined in subclause 5.1a.2.1, with NC=1992 and a=325, resulting in a block of 1992 bits, {di(0),…,di(1991)}.
5.1a.26.7 Mapping on a burst
a) Straightforward mapping
The mapping is given by the rule:
For B=0,1,2,3, let
e(B,j) = di(498B+j) for j = 0,…,248
e(B,j) = hi(36B+j-249) for j = 249,…,271
e(B,j) = q(2B+j-272) for j = 272,273
e(B,j) = hi(36B+j-251) for j = 274,…,275
e(B,j) = u’(16B+j-276) for j = 276,…,291
e(B,j) = hi(36B+j-267) for j = 292,…,302
e(B,j) = di(498B+j-54) for j = 303,…,551
where
q(0),q(1),…,q(7) = 0,0,0,0,0,0,0,0 identifies the coding scheme DBS-7 or DBS-8.
b) Bit swapping
After this mapping the following bits are swapped:
For B = 0,1,2,3,
Swap e(B,224+k) with e(B,250+k) for k=0, 4, 8, 12, 16, 20, 24.
Swap e(B,221+k) with e(B,251+k) for k=0, 4, 8, 12, 16, 20, 24.
Swap e(B,304+k) with e(B,294+k) for k=0, 1, 4, 5, 8.
In RTTI configuration, the bursts with B = 0,2 shall be mapped on the PDCH having the lower timeslot number, whereas the bursts with B = 1,3 shall be mapped on the PDCH having the higher timeslot number, see 3GPP TS 45.002.
c) PAN bit swapping
In case a PAN is included in the radio block, the following additional bits are swapped after the bit swapping in b):
For B = 0
Swap e(B,47) with e(B,120)
Swap e(B,110) with e(B,160)
Swap e(B,131) with e(B,177)
Swap e(B,199) with e(B,81)
Swap e(B,271) with e(B,201)
Swap e(B,358) with e(B,368)
Swap e(B,379) with e(B,444)
Swap e(B,426) with e(B,340)
Swap e(B,447) with e(B,329)
Swap e(B,510) with e(B,500)
Swap e(B,531) with e(B,405)
For B = 1
Swap e(B,30) with e(B,40)
Swap e(B,51) with e(B,120)
Swap e(B,114) with e(B,177)
Swap e(B,182) with e(B,0)
Swap e(B,203) with e(B,81)
Swap e(B,250) with e(B,201)
Swap e(B,275) with e(B,160)
Swap e(B,430) with e(B,368)
Swap e(B,451) with e(B,405)
Swap e(B,514) with e(B,444)
For B = 2
Swap e(B,34) with e(B,120)
Swap e(B,55) with e(B,160)
Swap e(B,123) with e(B,40)
Swap e(B,186) with e(B,81)
Swap e(B,207) with e(B,201)
Swap e(B,254) with e(B,177)
Swap e(B,303) with e(B,444)
Swap e(B,350) with e(B,340)
Swap e(B,371) with e(B,500)
Swap e(B,434) with e(B,368)
Swap e(B,455) with e(B,405)
Swap e(B,523) with e(B,329)
For B = 3
Swap e(B,38) with e(B,160)
Swap e(B,106) with e(B,81)
Swap e(B,127) with e(B,120)
Swap e(B,190) with e(B,201)
Swap e(B,211) with e(B,177)
Swap e(B,302) with e(B,340)
Swap e(B,354) with e(B,500)
Swap e(B,375) with e(B,405)
Swap e(B,438) with e(B,444)
Swap e(B,506) with e(B,329)
Swap e(B,527) with e(B,368)