4.6D Coding/Multiplexing for HS-SCCH type 4 (1.28 Mcps TDD only)

25.2223GPPMultiplexing and channel coding (TDD)Release 17TS

HS-SCCH shall be of type 4 when any of the following conditions is met:

– The UE is configured in MIMO mode, and the variable MIMO SF mode for HS-PDSCH dual stream is SF1.

– The UE is configured in MU-MIMO mode, and UE is not configured in MIMO mode.

– The UE is configured in MU-MIMO mode, and the UE is configured in MIMO mode with the variable MIMO SF mode for HS-PDSCH dual stream being SF1.

Note : For the UEs configured in MU-MIMO mode staying in CELL-FACH state, HS-SCCH shall be of type 1 for BCCH transmission [10].

HS-SCCH type 4 is used for single stream transmission in MIMO mode or in MU-MIMO mode. The following information is transmitted by means of the HS-SCCH type 4 physical channels.

– Type flag 1 (1 bit): xflag1,1

– Channelisation-code-set information (6 bits): xccs,1, xccs,2, …, xccs, 6

– Type flag 2 (1 bit): xflag2,1

– Time slot information (5bits): xts,1, xts,2, …, xts,5

– Modulation scheme information (1 bit): xms,1

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

– Hybrid-ARQ process information (4 bits): xhap,1, xhap,2, xhap,3, xhap,4,

– Redundancy version information (2 bits): xrv,1, xrv,2

– HS-SCCH cyclic sequence number (3 bits): xhcsn,1, xhcsn,2, xhcsn,3

– Midamble allocation scheme flag (1 bit): xflag,1

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

The following coding/multiplexing steps for HS-SCCH type 4 can be identified:

– multiplexing of HS-SCCH type 4 information (see subclause 4.6D.2)

– CRC attachment for HS-SCCH type 4 (see subclause 4.6D.3);

– channel coding for HS-SCCH type 4 (see subclause 4.6D.4);

– rate matching for HS-SCCH type 4 (see subclause 4.6D.5);

– interleaving for HS-SCCH type 4 (see subclause 4.6D.6);

– mapping to physical channels for HS-SCCH type 4 (see subclauses 4.6D.7 and 4.6D.8).

The general coding/multiplexing flow for HS-SCCH type 4 is shown in Figure 19C.

Figure 19C: Coding and Multiplexing for HS-SCCH type 4

4.6D.1 HS-SCCH type 4 information field mapping

4.6D.1.1 Type flag 1 mapping

The type flag 1 bit xflag1,1 is mapped as xflag1,1 =‘0’. The type flag 1 is used to distinguish HS-SCCH type 4 from other types.

4.6D.1.2 Type flag 2 mapping

The type flag 2 xflag2,1 is mapped as xflag2,1 =‘1’. The type flag 2 is used to distinguish HS-SCCH type 4 from other types.

4.6D.1.3 Channelisation code set information mapping

When the midamble allocation scheme flag bit xflag,1=’0′, the mapping of the channelisation code set information xccs,1, xccs,2, xccs,3, xccs,4, xccs,5, xccs,6 is performed according to section 4.6B.1.6.

When the midamble allocation scheme flag bit xflag,1=’1′, the bits xccs,1, xccs,2 are comprised of the special default midamble pattern indicator (xmpi,1, xmpi,2) and xccs,1= xmpi,1 and xccs,2= xmpi,2. The mapping is shown in Table 24A below.

The start code kstart is signalled by the bits xccs,3, xccs,4 and the stop code kstop by the bits xccs,5, xccs,6. The mapping in Table 24B below applies. If a value of kstart = 13 and kstop = 4 is signalled, a spreading factor of SF=1 shall be used for the HS-PDSCH resources. Other than this case, kstart > kstop are not used.

Table 24A: Special default midamble pattern mapping

Special default Mid-amble pattern

xmpi,1

xmpi,2

pattern 1A

0

0

pattern 1B

0

1

pattern 2A

1

0

pattern 2B

1

1

Table 24B: Channelisation code set information mapping

kstart

xccs,3

xccs,4

kstop

xccs,5

xccs,6

1

0

0

4

0

0

5

0

1

8

0

1

9

1

0

12

1

0

13

1

1

16

1

1

If NON_RECTANGULAR_RESOURCE_ALLOCATION_STATUS is FALSE, HS-PDSCH channelization codes of all the allocated timeslots are indicated by channelisation-code-set information field.

If NON_RECTANGULAR_Resource_ ALLOCATION_STATUS is TRUE and non-rectangular resource specific timeslot set is not configured via higher layer signalling, the specific timeslot refers to the timeslot with the maximal timeslot index among all the timeslots scheduled to the UE and HS-PDSCH channelisation codes of the specific timeslot is indicated by channelisation-code set information field. The HS-PDSCH channelisation codes of timeslot 0 are signalled via higher layer signalling if timeslot 0 is scheduled to the UE. The HS-PDSCH channelisation codes of other scheduled timeslots are predefined, i.e. the entire resource of each timeslot is scheduled to the UE with SF=1.

If NON_RECTANGULAR_RESOURCE_ALLOCATION_STATUS is TRUE and non-rectangular resource specific timeslot set is configured via higher layer signalling, HS-PDSCH channelisation codes in the specific timeslot is indicated by channelisation-code set information field. The HS-PDSCH channelisation codes of other scheduled timeslots are predefined, i.e. the entire resource of the timeslot is scheduled to the UE with SF=1.

4.6D.1.4 Timeslot information mapping

The mapping of the time slot information xts,1, xts,2, … xts,5 is performed according to section 4.6.1.2.1.

4.6D.1.5 Modulation scheme information mapping

The mapping of the modulation scheme information xms,1 is performed according to section 4.6.1.3.

4.6D.1.6 Transport block size index mapping

The transport-block size information xtbs,1, xtbs,2, …, xtbs,6 is the unsigned binary representation of the transport block size index where xtbs,1 is MSB. The mapping is performed according to section 4.6.1.8.

4.6D.1.7 HARQ process identifier mapping

The hybrid-ARQ process information xhap,1, xhap,2, xhap,3, xhap,4 is unsigned binary representation of the HARQ process identifier where xhap,1 is MSB.

4.6D.1.8 Redundancy version information mapping

The redundancy version (RV) parameters r, s and constellation version parameter b are mapped jointly to produce the value Xrv. Xrv is alternatively represented as the sequence xrv,1, xrv,2 where xrv,1 is the MSB. The mapping is performed according to section 4.6C.1.8. If Xrv =0, the UE shall treat the corresponding transport block as an initial transmission.

4.6D.1.9 HS-SCCH cyclic sequence number

The HS-SCCH cyclic sequence number xhcsn,1, xhcsn,2, xhcsn,3 is mapped such that xhcsn,1 corresponds to the MSB and xhcsn,3 to the LSB.

4.6D.1.10 UE identity

The UE identity is the HS-DSCH Radio Network Identifier (H-RNTI) defined in [12]. This is mapped such that xue,1 corresponds to the MSB and xue,16 to the LSB, cf. [14].

4.6D.1.11 Midamble allocation scheme flag

When the midamble allocation scheme flag bit xflag,1=’0′, the default midamble allocation scheme is used. Otherwise when the midamble allocation scheme flag bit xflag,1=’1′, the special default midamble allocation scheme with four patterns is used.

4.6D.2 Multiplexing of HS-SCCH type 4 information

The information carried on the HS-SCCH type 4 is multiplexed onto the bits according to the following rule :

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

The sequence of bits , is calculated according to subclause 4.6.3.

4.6D.4 Channel coding for HS-SCCH type 4

Channel coding for the HS-SCCH type 4 shall be done with the general method described in 4.2.3 with the following specific parameters:

The rate 1/3 convolutional coding shall be used for HS-SCCH type 4.

4.6D.5 Rate matching for HS-SCCH type 4

Rate matching for HS-SCCH type 4 shall be done with the general method described in 4.6.5.

4.6D.6 Interleaving for HS-SCCH type 4

Interleaving for HS-SCCH type 4 shall be done with the general method described in 4.2.11.1.

4.6D.7 Physical Channel Segmentation for HS-SCCH type 4

Physical channel segmentation for HS-SCCH type 4 shall be done with the general method described in 4.2.10. The HS-SCCH consists of two physical channels HS-SCCH1 and HS-SCCH2.

4.6D.8 Physical channel mapping for HS-SCCH type 4

Physical channel mapping for the HS-SCCH type 4 shall be done with the general method described in subclause 4.2.12.