4.10 Coding for E-AGCH
25.2223GPPMultiplexing and channel coding (TDD)Release 17TS
The E-AGCHs on the different carriers are coded independently.
For the 1.28 Mcps TDD, E-AGCH type 1 is used when the variable E_DCH_SPS_STATUS=FALSE and the UE is not configured in MU-MIMO mode by higher layers for a UE (as defined in [12]).
In this section, the terms "E-AGCH" and "E-AGCH type 1" are used interchangeably.
The E-AGCH carries the following fields multiplexed into w bits xag,1, xag,2, … xag,w. w is within the range 14 to 28 bits (for the 3.84Mcps option) and 15 to 29 bits (for the 7.68Mcps option) and 23 to 26 bits (for the 1.28Mcps option)
– Absolute grant (power) value (xpg,1, xpg,2, … xpg,5) {5 bits},
– Code resource related information (xc,1, xc,2, … xc,Nc), {Nc=5 bits for the 1.28Mcps and 3.84Mcps options, Nc=6 bits for the 7.68Mcps option}
– Timeslot resource related information (xt,1, xt,2, … xt,nTRRI), {nTRRI bits} [nTRRI =5 for 1.28Mcps, and is configured by higher layers for 3.84Mcps and 7.68Mcps options]
– E-AGCH Cyclic Sequence Number (ECSN) (xe,1, xe,2, xe,3) (3 bits)
– Resource duration indicator (3 bits if present) (xr,1, xr,2, xr,3) – [the presence of this field is configured by higher layers]
– E-HICH Indicator (xEI,1,xEI,2) (2 bits) (for 1.28Mcps TDD only)
– E-UCCH Number Indicator (xENI,1,xENI,2, xENI,3) (3 bits) (for 1.28Mcps TDD only)
Figure 25 illustrates the overall coding chain for the E-AGCH on one carrier.
Figure 25 – TrCH processing of E-AGCH
4.10.1 Information Field Mapping
4.10.1.1 Mapping of the Absolute Grant (Power) Value
The absolute grant (power) value (xpg,1, xpg,2,…xpg,5) is represented by 5 bits and corresponds to a dB value as specified in table 26 for 3.84Mcps and 7.68 Mcps TDD and in table 26A for 1.28Mcps TDD below. The values are mapped such that xpg,1 corresponds to the MSB of the index.
Table 26: Mapping of Absolute Grant Value (for 3.84Mcps and 7.68 Mcps TDD)
Absolute Grant Value |
Index |
31 dB |
31 |
30 dB |
30 |
29 dB |
29 |
28 dB |
28 |
27 dB |
27 |
26 dB |
26 |
25 dB |
25 |
24 dB |
24 |
23 dB |
23 |
22 dB |
22 |
21 dB |
21 |
20 dB |
20 |
19 dB |
19 |
18 dB |
18 |
17 dB |
17 |
16 dB |
16 |
15 dB |
15 |
14 dB |
14 |
13 dB |
13 |
12 dB |
12 |
11 dB |
11 |
10 dB |
10 |
9 dB |
9 |
8 dB |
8 |
7 dB |
7 |
6 dB |
6 |
5 dB |
5 |
4 dB |
4 |
3 dB |
3 |
2 dB |
2 |
1 dB |
1 |
0 dB |
0 |
Table 26A: Mapping of Absolute Grant Value (for 1.28Mcps TDD)
Absolute Grant Value |
Index |
19 dB |
31 |
18 dB |
30 |
17 dB |
29 |
16 dB |
28 |
15 dB |
27 |
14 dB |
26 |
13 dB |
25 |
12 dB |
24 |
11 dB |
23 |
10 dB |
22 |
9 dB |
21 |
8 dB |
20 |
7 dB |
19 |
6 dB |
18 |
5 dB |
17 |
4 dB |
16 |
3 dB |
15 |
2 dB |
14 |
1 dB |
13 |
0 dB |
12 |
-1 dB |
11 |
-2 dB |
10 |
-3 dB |
9 |
-4 dB |
8 |
-5 dB |
7 |
-6 dB |
6 |
-7 dB |
5 |
-8 dB |
4 |
-9 dB |
3 |
-10 dB |
2 |
-11 dB |
1 |
-12 dB |
0 |
4.10.1.2 Mapping of the Code Resource Related Information
The code resource related information (xc,1, xc,2,…xc,Nc) indicates which node on the OVSF code tree has been allocated and is represented by Nc bits where Nc=5 for 1.28Mcps and 3.84Mcps and Nc=6 for 7.68Mcps. The mapping between the allocated OVSF and the enumerated node 0…30 (for 1.28Mcps and 3.84Mcps) and 0…62 (for 7.68Mcps) on the OVSF code tree is as given in table 27 below, in which channelisation code "i" with spreading factor "Q" is denoted as Ci(Q). xc,1 corresponds to the MSB of the enumerated node. The right-most column of table 27 is only applicable for the 7.68Mcps option.
Table 27 – Channelisation code mapping
C1(1) [0] |
C1(2) [1] |
C1(4) [3] |
C1(8) [7] |
C1(16) [15] |
C1(32) [31] |
C2(32) [32] |
|||||
C2(16) [16] |
C3(32) [33] |
||||
C4(32) [34] |
|||||
C2(8) [8] |
C3(16) [17] |
C5(32) [35] |
|||
C6(32) [36] |
|||||
C4(16) [18] |
C7(32) [37] |
||||
C8(32) [38] |
|||||
C2(4) [4] |
C3(8) [9] |
C5(16) [19] |
C9(32) [39] |
||
C10(32) [40] |
|||||
C6(16) [20] |
C11(32) [41] |
||||
C12(32) [42] |
|||||
C4(8) [10] |
C7(16) [21] |
C13(32) [43] |
|||
C14(32) [44] |
|||||
C8(16) [22] |
C15(32) [45] |
||||
C16(32) [46] |
|||||
C2(2) [2] |
C3(4) [5] |
C5(8) [11] |
C9(16) [23] |
C17(32) [47] |
|
C18(32) [48] |
|||||
C10(16) [24] |
C19(32) [49] |
||||
C20(32) [50] |
|||||
C6(8) [12] |
C11(16) [25] |
C21(32) [51] |
|||
C22(32) [52] |
|||||
C12(16) [26] |
C23(32) [53] |
||||
C24(32) [54] |
|||||
C4(4) [6] |
C7(8) [13] |
C13(16) [27] |
C25(32) [55] |
||
C26(32) [56] |
|||||
C14(16) [28] |
C27(32) [57] |
||||
C28(32) [58] |
|||||
C8(8) [14] |
C15(16) [29] |
C29(32) [59] |
|||
C30(32) [60] |
|||||
C16(16) [30] |
C31(32) [61] |
||||
C32(32) [62] |
If NON_RECTANGULAR_RESOURCE_ALLOCATION_STATUS is FALSE, the OVSF code of all the allocated timeslots is indicated by Code Resource Related 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 closest to the timeslot in which HS-SICH and/or UL DPCH is allocated among all the uplink timeslot scheduled to the UE. The OVSF code of the specific timeslot is indicated by Code Resource Related Information field. The OVSF code of other scheduled timeslots is predefined, i.e. node 0.
If NON_RECTANGULAR_RESOURCE_ALLOCATION_STATUS is TRUE and non-rectangular resource specific timeslot set is configured via higher layer signalling, the OVSF code in the specific timeslot is indicated by Code Resource Related Information field. The OVSF code of other scheduled timeslots is predefined, i.e. node 0.
4.10.1.3 Mapping of the Timeslot Resource Related Information
For 3.84Mcsp and 7.68Mcps options, the timeslot resource related information (xt,1, xt,2,…xt,nTRRI) is a bitmap of length nTRRI indicating which of the timeslots configured for E-DCH use by higher layers have been allocated. The length of the field (nTRRI) is configured by higher layers up to a maximum of 12 bits. The bitmap is arranged such that the corresponding timeslots are in ascending numerical order, with xt,1 corresponding to LSB and lowest-numbered timeslot configured for E-DCH use.
For 1.28Mcps option, the timeslot resource related information (xt,1, xt,2,…xt,nTRRI) is also a bitmap of length 5 indicating the allocation for E-DCH resources from TS1 to TS5. If the bit is set (i.e. equal to 1), then the corresponding timeslot shall be used for E-DCH resources. The bitmap is arranged such that the corresponding timeslots are in ascending numerical order, with xt,1 corresponding to MSB.
4.10.1.4 Mapping of the E-AGCH Cyclic Sequence Number (ECSN)
The E-AGCH cyclic sequence number is mapped such that xe,1 corresponds to the MSB and xe,3 to the LSB.
4.10.1.5 Mapping of the Resource Duration Indicator
The resource duration indicator (xr,1, xr,2,xr,3) is mapped such that xr,1 corresponds to the MSB of the resource duration index described in [15].
4.10.1.6 Mapping of the E-HICH Indicator (1.28Mcps option only)
The E-HICH indicator consists of 2 bits used to indicate the UE which E-HICH will be used to convey the acknowledgement indicator in the following schedule period for 1.28Mcps TDD only. The bits (xEI,1, xEI,2) are mapped such that xEI,1 corresponds to the MSB and xEI,2 to the LSB.
4.10.1.7 Mapping of the E-UCCH Number Indicator (1.28Mcps option only)
The E-UCCH number indicator is composed of 3bits which is used to calculate the number of E-UCCH for 1.28Mcps TDD only. The bits (xENI,1, xENI,2, xENI,3) are mapped such that xENI,1 corresponds to the MSB and xENI,3 to the LSB. The number of the used E-UCCH is equal to ENI+1.
4.10.2 Field Multiplexing
The absolute grant (power) value, code resource related information, timeslot resource related information, resource duration indicator (if present), ECSN, E-HICH indicator (for1.28Mcps TDD only) and E-UCCH number indicator (for1.28Mcps TDD only) are multiplexed together to give a sequence of bits xag,1, xag,2, …, xag,w where:
For the 1.28Mcps option:
xag,k = xpg,k k=1, 2, .., 5
xag,k = xc,k-5 k=6, 7, …, 10
xag,k = xt,k-10 k=11, …, 15
xag,k = xe,k-15 k=16,17,18
if resource duration indicator (RDI) present:
xag,k = xr,k-18 k=19,20,21
xag,k = xEI,k-21 k=22,23
xag,k = xENI,k-23 k=24,25,26
or if resource duration indicator (RDI) does not present:
xag,k = xEI,k-18 k=19,20
xag,k = xENI,k-20 k=21,22,23
For the 3.84Mcps option:
xag,k = xpg,k k=1, 2, .., 5
xag,k = xc,k-5 k=6, 7, …, 10
xag,k = xt,k-10 k=11, …, 10+nTRRI
xag,k = xe,k-10-nTRRI k=11+nTRRI, …, 13+nTRRI
xag,k = xr,k-13-nTRRI k=14+nTRRI, …, 16+nTRRI {if resource duration indicator present}
and for the 7.68Mcps option:
xag,k = xpg,k k=1, 2, .., 5
xag,k = xc,k-5 k=6, 7, …, 11
xag,k = xt,k-11 k=12, …, 11+nTRRI
xag,k = xe,k-11-nTRRI k=12+nTRRI, …, 14+nTRRI
xag,k = xr,k-14-nTRRI k=15+nTRRI, …, 17+nTRRI {if resource duration indicator present}
4.10.3 CRC attachment
The E-RNTI (xid,1, xid,2, …, xid,16) is the E‑DCH Radio Network Identifier defined in [12]. It is mapped such that xid,1 corresponds to the MSB.
From the sequence of bits xag,1, xag,2, …, xag,w a 16 bit CRC is calculated according to section 4.2.1.1. This gives the sequence of bits c1, c2, …, c16 where:
k=1,2,…,16
This sequence of bits is then masked with xid,1, xid,2, …, xid,16 and appended to the sequence of bits xag,1, xag,2, …, xag,w to form the sequence of bits y1, y2, …, yw+16 where
yi=xag,i i=1,2, …,w
yi=(ci-w + xid,i-w) mod 2 i=w+1, …, w+16
4.10.4 Channel Coding
1/3 rate convolutional channel coding is applied to the sequence y1, y2,…, yw+16 in accordance with section 4.2.3.1, resulting in the sequence of bits z1, z2, …, z3(w+24).
4.10.5 Rate Matching
Rate matching is applied to the input sequence z1, z2, …, z3(w+24) to obtain the output sequence r1, r2, …, rU, where U = 242 for burst type 1 and U = 274 for burst type 2 for 3.84Mcps and 7.68Mcps options while U=172 for 1.28Mcps option.
4.10.6 Interleaving
Interleaving is performed as per section 4.2.11.1 (frame-related 2nd interleaving).
4.10.7 Physical Channel Segmentation
Physical channel segmentation is performed as per section 4.2.10. For 1.28Mcps TDD, the E-AGCH consists of two physical channels E-AGCH1 and E-AGCH2,whereas for 3.84Mcps and 7.68Mcps TDD the E-AGCH only uses one physical channel, see[7].Note that physical channel segmentation is transparent when only one physical channel exists
4.10.8 Physical Channel Mapping
Physical channel mapping is performed as per section 4.2.12.