4.7 Coding for HS-SICH
25.2223GPPMultiplexing and channel coding (TDD)Release 17TS
The following information, provided by higher layers, is transmitted by means of the HS-SICH physical channel.
For 1.28 Mcps TDD, HS-SICH type 1 is not used for dual stream transmission when UE is configured in MIMO mode.
In this section, the terms "HS-SICH" and "HS-SICH type 1" are used interchangeably.
For 1.28 Mcps TDD, in the case of multi-frequency HS-DSCH transmission in one TTI, HS-PDSCH on each frequency shall be configured with associated HS-SICH(s) which is coded as following.
– Recommended Modulation Format (RMF) (1 bit): xrmf,1
– Recommended Transport-block size (RTBS) (n bits where n = 6 for 1.28 Mcps TDD and n = 9 for 3.84 Mcps TDD and 7.68Mcps TDD): xtbs,1, xtbs,2, …, xtbs,n
– Hybrid-ARQ information ACK/NACK (1 bit): xan,1
The following coding/multiplexing steps can be identified:
– separate coding of RMF, RTBS and ACK/NACK (see subclause 4.7.2);
– multiplexing of HS-SICH information (see subclause 4.7.3);
– interleaving for HS-SICH (see subclause 4.7.4);
– mapping to physical channels (see subclause 4.7.5).
The general coding/multiplexing flow is shown in the figure 20.
Figure 20: Coding and multiplexing for HS-SICH
4.7.1 HS-SICH information field mapping
4.7.1.1 RMF information mapping
The RMF information bit, xrmf,1, shall be mapped according to the mapping specified in subclause 4.6.1.3.
4.7.1.2 RTBS information mapping
The RTBS information bits, xtbs,1, xtbs,2, …, xtbs,n, shall be mapped according to the same mapping as is used for the transport block size information bits in subclause 4.6. This mapping is defined by higher layers [12].
4.7.1.3 ACK/NACK information mapping
The ACK/NACK information bit xan,1 shall be mapped according to the mapping given in Table 20 below.
Table 20: ACK/NACK information mapping
|
ACK/NACK |
xan,1 |
|
ACK |
1 |
|
NACK |
0 |
4.7.2 Coding for HS-SICH
4.7.2.1 Field Coding of ACK/NACK
The ACK/NACK bit xan,1 shall be repetition coded to 36 bits. The coded bits are defined as .
4.7.2.2 Field Coding of CQI
4.7.2.2.1 Field Coding of CQI for 1.28 Mcps TDD
The quality information consists of Recommended Transport Block Size (RTBS) and Recommended Modulation Format (RMF) fields. The 6 bits of the RTBS field are coded to 32 bits using a (32, 6) 1st order Reed-Muller code. The coding procedure is as shown in figure 21.
Figure 21: Field coding of RTBS information bits
The coding uses a subset basis sequences as the TFCI coder as described in subclause 4.3.1.1. The basis sequences that are used for RTBS coding are as follows in table 21.
Table 21: Basis sequences for (32,6) RTBS code
|
i |
Mi,0 |
Mi,1 |
Mi,2 |
Mi,3 |
Mi,4 |
Mi,5 |
|---|---|---|---|---|---|---|
|
0 |
1 |
0 |
0 |
0 |
0 |
1 |
|
1 |
0 |
1 |
0 |
0 |
0 |
1 |
|
2 |
1 |
1 |
0 |
0 |
0 |
1 |
|
3 |
0 |
0 |
1 |
0 |
0 |
1 |
|
4 |
1 |
0 |
1 |
0 |
0 |
1 |
|
5 |
0 |
1 |
1 |
0 |
0 |
1 |
|
6 |
1 |
1 |
1 |
0 |
0 |
1 |
|
7 |
0 |
0 |
0 |
1 |
0 |
1 |
|
8 |
1 |
0 |
0 |
1 |
0 |
1 |
|
9 |
0 |
1 |
0 |
1 |
0 |
1 |
|
10 |
1 |
1 |
0 |
1 |
0 |
1 |
|
11 |
0 |
0 |
1 |
1 |
0 |
1 |
|
12 |
1 |
0 |
1 |
1 |
0 |
1 |
|
13 |
0 |
1 |
1 |
1 |
0 |
1 |
|
14 |
1 |
1 |
1 |
1 |
0 |
1 |
|
15 |
1 |
0 |
0 |
0 |
1 |
1 |
|
16 |
0 |
1 |
0 |
0 |
1 |
1 |
|
17 |
1 |
1 |
0 |
0 |
1 |
1 |
|
18 |
0 |
0 |
1 |
0 |
1 |
1 |
|
19 |
1 |
0 |
1 |
0 |
1 |
1 |
|
20 |
0 |
1 |
1 |
0 |
1 |
1 |
|
21 |
1 |
1 |
1 |
0 |
1 |
1 |
|
22 |
0 |
0 |
0 |
1 |
1 |
1 |
|
23 |
1 |
0 |
0 |
1 |
1 |
1 |
|
24 |
0 |
1 |
0 |
1 |
1 |
1 |
|
25 |
1 |
1 |
0 |
1 |
1 |
1 |
|
26 |
0 |
0 |
1 |
1 |
1 |
1 |
|
27 |
1 |
0 |
1 |
1 |
1 |
1 |
|
28 |
0 |
1 |
1 |
1 |
1 |
1 |
|
29 |
1 |
1 |
1 |
1 |
1 |
1 |
|
30 |
0 |
0 |
0 |
0 |
0 |
1 |
|
31 |
0 |
0 |
0 |
0 |
1 |
1 |
The output RTBS code word bits {zi : i = 1, … , 32} are given by:
The RMF bit xrmf,1 is repetition coded to 16 bits to produce the bits . where nCQI = 48.
4.7.2.2.2 Field Coding of CQI for 3.84 Mcps TDD and 7.68Mcps TDD
RTBS and RMF bits are multiplexed onto the bits according to the following rule :
The bits are coded to produce the bits w1,w2,…w32 using a (32,10) sub-code of the second order Reed-Muller code as defined in subclause 4.3.1.1..
The bits w1,w2,…w32 are used to produce the CQI bits using a (4,1) repetition code, where nCQI=128, such that:
zn, zn+32, zn+64, zn+96 = wn n=1…32
4.7.3 Multiplexing of HS-SICH information fields
The CQI bits are multiplexed with the repetition coded ACK/NACK bits to produce the bits where is the number of physical channel bits carried by HS-SICH, according to the following rule.:
4.7.4 Interleaver for HS-SICH
Interleaver for HS-SICH shall be done with the general method described in 4.2.11.1.
4.7.5 Physical channel mapping for HS-SICH
Physical channel mapping for HS-SICH shall be done with the general method described in 4.2.12.