4.6B Coding for HS-SCCH type 3

25.2123GPPMultiplexing and channel coding (FDD)Release 17TS

4.6B.1 Overview

HS-SCCH type 3 is used when the UE is configured in MIMO mode. If one transport block is transmitted on the associated HS-PDSCH(s) or an HS-SCCH order is transmitted, the following information is transmitted by means of the HS-SCCH type 3 physical channel:

– Channelization-code-set information (7 bits): xccs,1, xccs,2, …, xccs,7

– Modulation scheme and number of transport blocks information (3 bits): xms,1, xms,2, xms,3

– Precoding weight information (2 bits): xpwipb,1, xpwipb,2

– Transport-block size information (6 bits): xtbspb,1, xtbspb,2, …, xtbspb,6

– Hybrid-ARQ process information (4 bits): xhap,1, xhap,2, …, xhap,4

– Redundancy and constellation version (2 bits): xrvpb,1, xrvpb,2

– UE identity (16 bits): xue,1, xue,2, …, xue,16

For an HS-SCCH order,

– xccs,1, xccs,2, …, xccs,7, xms,1, xms,2, xms,3, xpwipb,1, xpwipb,2 shall be set to ”111000000000’

– xtbspb,1, xtbspb,2, …, xtbspb,4 shall be set to ”1111’

– xtbspb,5, xtbspb,6 shall be set to xeodt,1, xeodt,2

– xhap,1, xhap,2, xhap,3, xhap,4, xrvpb,1, xrvpb,2 shall be set to xodt,1, xodt,2, xodt,3, xord,1, xord,2, xord,3

where xeodt,1, xeodt,2, xodt,1, xodt,2, xodt,3, xord,1, xord,2, xord,3 are defined in subclause 4.6C.

If two transport blocks are transmitted on the associated HS-PDSCHs (not applicable when single-stream restriction is configured), the following information is transmitted by means of the HS-SCCH type 3 physical channel:

– Channelization-code-set information (7 bits): xccs,1, xccs,2, …, xccs,7

– Modulation scheme and number of transport blocks information (3 bits): xms,1, xms,2, xms,3

– Precoding weight information for the primary transport block (2 bits): xpwipb,1, xpwipb,2

– Transport-block size information for the primary transport block (6 bits): xtbspb,1, xtbspb,2, …, xtbspb,6

– Transport-block size information for the secondary transport block (6 bits): xtbssb,1, xtbssb,2, …, xtbssb,6

– Hybrid-ARQ process information (4 bits): xhap,1, xhap,2,…, xhap,4

– Redundancy and constellation version for the primary transport block (2 bits): xrvpb,1, xrvpb,2

– Redundancy and constellation version for the secondary transport block (2 bits): xrvsb,1, xrvsb,2

– UE identity (16 bits): xue,1, xue,2, …, xue,16

Figure 19B below illustrates the overall coding chain for HS-SCCH type 3. Note that some information shown is not present if only one transport block is transmitted on the associated HS-PDSCH(s).

Figure 19B: Coding chain for HS-SCCH type 3

4.6B.2 HS-SCCH type 3 information field mapping

4.6B.2.1 Redundancy and constellation version coding

For each of the primary transport block and a secondary transport block if two transport blocks are transmitted on the associated HS-PDSCH(s), the redundancy version (RV) parameters r, s and constellation version parameter b are coded jointly to produce the values Xrvpb and Xrvsb respectively. The transmitted sequences xrvpb,1, xrvpb,2 and xrvsb,1, xrvsb,2 are the binary representations of Xrvpb and Xrvsb, respectively, where xrvpb,1 and xrvsb,1 are the MSBs.

For the primary transport block if only one transport block is transmitted on the associated HS-PDSCH(s), the redundancy version (RV) parameters r, s and constellation version parameter b are coded jointly to produce the value Xrvpb. The transmitted sequence xrvpb,1, xrvpb,2 is the binary representation of Xrvpb, where xrvpb,1 is the MSB.

Joint coding of parameters r, s and constellation version parameter b is done according to tables 13A and 13B according to the modulation mode used. If Xrvpb = 0 or Xrvsb = 0, the UE shall treat the corresponding transport block as an initial transmission.

Table 13A: RV coding for 16QAM and 64QAM for HS-SCCH type 3

Xrvpb or Xrvsb (value)

Nsys / Ndata < 1/2

Nsys / Ndata ≥ 1/2

s

r

b

s

r

b

0

1

0

0

1

0

0

1

1

1

1

0

1

1

2

1

0

2

0

0

0

3

1

0

3

1

0

2

Table 13B: RV coding for QPSK for HS-SCCH type 3

Xrvpb or Xrvsb (value)

Nsys / Ndata <1/2

Nsys / Ndata ≥ 1/2

s

r

s

r

0

1

0

1

0

1

1

1

0

1

2

1

2

0

3

3

1

3

1

2

4.6B.2.2 Modulation scheme and number of transport blocks mapping

The number of transport blocks transmitted on the associated HS-PDSCH(s) and the modulation scheme information are jointly coded as shown in Table 14:

Table 14: Mapping of xms

xms,1, xms,2,
xms,3

Modulation for primary transport block

Modulation for secondary transport block

Number of transport blocks

111

16QAM

16QAM

2

110

16QAM

QPSK

2

101

64QAM

Indicated by xccs,7

Indicated by xccs,7

100

16QAM

n/a

1

011

QPSK

QPSK

2

010

64QAM

64QAM

2

001

64QAM

16QAM

2

000

QPSK

n/a

1

In case xms,1, xms,2, xms,3 equals “101” xccs,7 is used as an extra bit in modulation scheme information.

4.6B.2.3 Channelization code-set mapping

The channelization code-set bits xccs,1, xccs,2, …, xccs,7 are coded according to the following:

Given P (multi-)codes starting at code O, and given the HS-SCCH number if 64QAM is configured for the UE and xms,1, xms,2, xms,3 is equal to “101”, calculate the information-field using the unsigned binary representation of integers calculated by the expressions,

for the first three bits (code group indicator) of which xccs,1 is the MSB:

xccs,1, xccs,2, xccs,3 = min(P-1,15-P)

If 64QAM is not configured for the UE, or if 64QAM is configured and xms,1, xms,2, xms,3 is not equal to “101”, then

for the last four bits (code offset indicator) of which xccs,4 is the MSB:

xccs,4, xccs,5, xccs,6, xccs,7 = |O-1-P/8 *15|

Otherwise (i.e. if 64QAM is configured for the UE and xms,1, xms,2, xms,3 is equal to “101”),

P and O shall fulfil |O-1-P/8 *15| mod 2 = (HS‑SCCH number) mod 2, and then

xccs,4, xccs,5, xccs,6, xccs,dummy = |O-1-P/8 *15|, where xccs,dummy is a dummy bit that is not transmitted on HS-SCCH.

Furthermore,

xccs,7 = 0 if the modulation for the secondary transport block is QPSK, and

xccs,7 = 1 if the number of transport blocks = 1.

The definitions of P and O are given in [3]. The HS-SCCH number is given by the position in the list of HS-SCCH Channelisation Code Informations signalled by higher layers. The HS-SCCH number is associated with the code offset indicator and code group indicator as described above if 64QAM is configured for the UE and xms,1, xms,2, xms,3 is equal to “101”.

If two transport blocks are transmitted on the associated HS-PDSCH(s), the same set of channelization codes shall be used for both transport blocks.

4.6B.2.4 UE identity mapping

The UE identity is the HS-DSCH Radio Network Identifier (H-RNTI) defined in [13]. This is mapped such that xue,1 corresponds to the MSB and xue,16 to the LSB, cf. [14].

4.6B.2.5 HARQ process identifier mapping

If two transport blocks are transmitted on the associated HS-PDSCH(s), the mapping relationship between the hybrid-ARQ processes and the transport blocks is such that when the HARQ-process with identifier HAPpb is mapped to the primary transport block, the HARQ-process with the identifier given by shall be mapped to the secondary transport block, where Nproc is the number of HARQ processes configured by higher layers. The combination of HARQ-processes is indicated by the hybrid-ARQ process information (4 bits) xhap,1, xhap,2, xhap,3, xhap,4 which are the unsigned binary representation of HAPpb where xhap,1 is MSB.

If only one transport block is transmitted on the associated HS-PDSCH(s), the above mapping is ignored and the hybrid-ARQ process information xhap,1, xhap,2, xhap,3, xhap,4 is the unsigned binary representation of the HARQ process identifier where xhap,1 is MSB.

4.6B.2.6 Transport block size index mapping

The transport-block size information xtbspb,1, xtbspb,2, …, xtbspb,6 is the unsigned binary representation of the transport block size index for the primary transport block, where xtbspb,1 is the MSB.

If two transport blocks are transmitted on the associated HS-PDSCH(s), the transport-block size information xtbssb,1, xtbssb,2, …, xtbssb,6 is the unsigned binary representation of the transport block size index for the secondary transport block, where xtbssb,1 is the MSB.

4.6B.2.7 Precoding Weight Information mapping

The precoding weight information for the primary transport block xpwipb,1, xpwipb,2 is derived from the precoding weight factor w2 as defined in [4], according to Table 14A.

Table 14A: Mapping of precoding weight information for primary transport block

w2

xpwipb,1, xpwipb,2

00

01

10

11

4.6B.3 Multiplexing of HS-SCCH type 3 information

The channelization-code-set information xccs,1, xccs,2, …, xccs,7, modulation-scheme and number of transport blocks information xms,1, xms,2, xms,3 and precoding weight information xpwipb,1, xpwipb,2 are multiplexed together. This gives a sequence of bits x1,1, x1,2, …, x1,12, where

x1,i = xccs,i i=1,2,…,7

x1,i = xms,i-7 i=8,9,10

x1,i = xpwipb,i-10 i=11,12

If one transport block is transmitted on the associated HS-PDSCH(s), the transport-block-size information xtbspb,1, xtbspb,2, …, xtbspb,6, Hybrid-ARQ-process information xhap,1,xhap,2, …, xhap,4 and redundancy-version information xrvpb,1, xrvpb,2 are multiplexed together. This gives a sequence of bits x2,1, x2,2, …, x2,12 where

x2,i = xtbs,i i=1,2,…,6

x2,i = xhap,i-6 i=7,8,…,10

x2,i = xrv,i-10 i=11,12

If two transport blocks are transmitted on the associated HS-PDSCHs, the transport-block-size information for the primary transport block xtbspb,1, xtbspb,2, …, xtbspb,6, transport-block-size information for the secondary transport block xtbssb,1, xtbssb,2, …, xtbssb,6, Hybrid-ARQ-process information xhap,1,xhap,2, …, xhap,4, redundancy-version information for the primary transport block xrvpb,1, xrvpb,2, and redundancy-version information for the secondary transport block xrvsb,1, xrvsb,2 are multiplexed together. This gives a sequence of bits x2,1, x2,2, …, x2,20 where

x2,i = xtbspb,i i=1,2,…,6

x2,i = xtbssb,i-6 i=7,8,…,12

x2,i = xhap,i-12 i=13,14,…,16

x2,i = xrvpb,i-16 i=17,18

x2,i = xrvsb,i-18 i=19,20

4.6B.4 CRC attachment for HS-SCCH type 3

If one transport block is transmitted on the associated HS-PDSCH(s), from the sequence of bits x1,1, x1,2, …, x1,12, x2,1, x2,2, …, x2,12 a 16-bit CRC is calculated according to Clause 4.2.1.1. This gives a sequence of bits c1, c2, …, c16 where

k=1,2,…,16

This sequence of bits is then masked with the UE Identity xue,1, xue,2, …, xue,16 and then appended to the sequence of bits x2,1, x2,2, …, x2,12 to form the sequence of bits y1, y2, …, y28, where

yi = x2,i i=1,2,…,12

yi = (ci-12 + xue,i-12 ) mod 2 i=13,14,…,28

If two transport blocks are transmitted on the associated HS-PDSCHs, from the sequence of bits x1,1, x1,2, …, x1,12, x2,1, x2,2, …, x2,20 a 16-bit CRC is calculated according to Clause 4.2.1.1. This gives a sequence of bits c1, c2, …, c16 where

k=1,2,…,16

This sequence of bits is then masked with the UE Identity xue,1, xue,2, …, xue,16 and then appended to the sequence of bits x2,1, x2,2, …, x2,20 to form the sequence of bits y1, y2, …, y36, where

yi = x2,i i=1,2,…,20

yi = (ci-20 + xue,i-20) mod 2 i=21,22,…,36

4.6B.5 Channel coding for HS-SCCH type 3

Rate 1/3 convolutional coding, as described in Clause 4.2.3.1, is applied to the sequence of bits x1,1,x1,2, …,x1,12. This gives a sequence of bits z1,1, z1,2, …, z1,60.

If one transport block is transmitted on the associated HS-PDSCH(s), rate 1/3 convolutional coding, as described in Clause 4.2.3.1, is applied to the sequence of bits y1, y2, …, y28. This gives a sequence of bits z2,1, z2,2, …, z2,108.

If two transport blocks are transmitted on the associated HS-PDSCHs, rate 1/3 convolutional coding, as described in Clause 4.2.3.1, is applied to the sequence of bits y1, y2, …, y36. This gives a sequence of bits z2,1, z2,2, …, z2,132.

Note that the coded sequence lengths result from the termination of K=9 convolutional coding being fully applied.

4.6B.6 Rate matching for HS-SCCH type 3

From the input sequence z1,1, z1,2, …, z1, 60 the bits z1,1, z1,2, z1,4, z1,6, z1,8, z1,12, z1,15, z1,18, z1,21, z1,24, z1,37, z1,40, z1,43, z1,46, z1,49, z1,53, z1,55, z1,57, z1,59, z1,60 are punctured to obtain the output sequence r1,1,r1,2…r1,40.

If one transport block is transmitted on the associated HS-PDSCH(s), from the input sequence z2,1, z2,2, …, z2,108 the bits z2,1, z2,2, z2,3, z2,4, z2,5, z2,6, z2,7, z2,8, z2,12, z2,14, z2,15, z2,24, z2,42, z2,48, z2,63, z2,66, z2,93, z2,96, z2,98, z2,99, z2,101, z2,102, z2,103, z2,104, z2,105, z2,106, z2,107, z2,108 are punctured to obtain the output sequence r2,1,r2,2…r2,80.

If two transport blocks are transmitted on the associated HS-PDSCHs, from the input sequence z2,1, z2,2, …, z2,132 the bits z2,1, z2,2, z2,3, z2,4, z2,5, z2,6, z2,7, z2,8, z2,10, z2,11, z2,13, z2,14, z2,16, z2,19, z2,22, z2,25, z2,28, z2,31, z2,34, z2,37, z2,40, z2,43, z2,46, z2,49, z2,55, z2,61, z2,72, z2,78, z2,84, z2,87, z2,90, z2,93, z2,96, z2,99, z2,102 , z2,105, z2,108, z2,111, z2,114, z2,117, z2,119, z2,120, z2,122, z2,123, z2,125, z2,126, z2,127, z2,128, z2,129, z2,130, z2,131, z2,132 are punctured to obtain the output sequence r2,1,r2,2…r2,80.

4.6B.7 UE specific masking for HS-SCCH type 3

The output bits s1,1,s1,2…s1,40 are calculated as described in subclause 4.6.7.

4.6B.8 Physical channel mapping for HS-SCCH type 3

The HS-SCCH sub-frame is described in [2]. The physical channel mapping is carried out as described in subclause 4.6.8.