4.10 Coding for E‑AGCH
25.2123GPPMultiplexing and channel coding (FDD)Release 17TS
The following information is transmitted by means of the absolute grant channel (E‑AGCH):
– Absolute Grant Value: xagv,1, xagv,2, …, xagv,5
– Absolute Grant Scope: xags,1
4.10.1 Overview
Figure 24 below illustrates the overall coding chain for the E‑AGCH.
Figure 24: Coding for E‑AGCH
4.10.1A E-AGCH information field mapping
4.10.1A.1 Information field mapping of the Absolute Grant Value
The Absolute Grant Value information is specified in Table 16B and Table 16.B.1. The values are mapped such that xagv,1 corresponds to the MSB of the index.
Based on higher layer signalling, either Table 16B or Table 16.B.1 is selected.
Table 16B: Mapping of Absolute Grant Value
Absolute Grant Value |
Index |
(168/15)2x6 |
31 |
(150/15)2x6 |
30 |
(168/15)2x4 |
29 |
(150/15)2x4 |
28 |
(134/15)2x4 |
27 |
(119/15)2x4 |
26 |
(150/15)2x2 |
25 |
(95/15)2x4 |
24 |
(168/15)2 |
23 |
(150/15)2 |
22 |
(134/15)2 |
21 |
(119/15)2 |
20 |
(106/15)2 |
19 |
(95/15)2 |
18 |
(84/15)2 |
17 |
(75/15)2 |
16 |
(67/15)2 |
15 |
(60/15)2 |
14 |
(53/15)2 |
13 |
(47/15)2 |
12 |
(42/15)2 |
11 |
(38/15)2 |
10 |
(34/15)2 |
9 |
(30/15)2 |
8 |
(27/15)2 |
7 |
(24/15)2 |
6 |
(19/15)2 |
5 |
(15/15)2 |
4 |
(11/15)2 |
3 |
(7/15)2 |
2 |
ZERO_GRANT* |
1 |
INACTIVE* |
0 |
NOTE *: These values are specified in [16].
Table 16B.1: Alternative Mapping of Absolute Grant Value
Absolute Grant Value |
Index |
(377/15)2x4 |
31 |
(237/15)2x6 |
30 |
(168/15)2*6 |
29 |
(150/15)2*6 |
28 |
(168/15)2*4 |
27 |
(150/15)2x4 |
26 |
(134/15)2x4 |
25 |
(119/15)2x4 |
24 |
(150/15)2x2 |
23 |
(95/15)2x4 |
22 |
(168/15)2 |
21 |
(150/15)2 |
20 |
(134/15)2 |
19 |
(119/15)2 |
18 |
(106/15)2 |
17 |
(95/15)2 |
16 |
(84/15)2 |
15 |
(75/15)2 |
14 |
(67/15)2 |
13 |
(60/15)2 |
12 |
(53/15)2 |
11 |
(47/15)2 |
10 |
(42/15)2 |
9 |
(38/15)2 |
8 |
(34/15)2 |
7 |
(30/15)2 |
6 |
(27/15)2 |
5 |
(24/15)2 |
4 |
(19/15)2 |
3 |
(15/15)2 |
2 |
ZERO_GRANT* |
1 |
INACTIVE* |
0 |
NOTE *: These values are specified in [16].
4.10.1A.2 Information field mapping of the Absolute Grant Scope
The value of xags,1 is set as specified in Table 16C.
Table 16C: Mapping of Absolute Grant Scope
Absolute Grant Scope |
xags,1 |
"Per HARQ process" |
1 |
"All HARQ processes" |
0 |
4.10.1B Multiplexing of E-AGCH information
The Absolute Grant Value information xagv,1, xagv,2, …, xagv,5 and the Absolute Grant Scope information xags,1 are multiplexed together. This gives a sequence of bits xag,1, xag,2, …, xag, 6 where
xag,k = xagv,k k=1,2,…,5
xag,k = xags,7-k k=6
4.10.2 CRC attachment for E‑AGCH
The E-RNTI is the E‑DCH Radio Network Identifier defined in [13]. It is mapped such that xid,1 corresponds to the MSB.
From the sequence of bits xag,1, xag,2, …, xag,6 a 16 bit CRC is calculated according to clause 4.2.1.1. That 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,6 to form the sequence of bits y1, y2, …, y22 where
yi=xag,i i=1,2, …,6
yi=(ci-6 + xid,i-6) mod 2 i= 7, …, 22
4.10.3 Channel coding for E‑AGCH
Rate 1/3 convolutional coding, as described in Clause 4.2.3.1 is applied to the sequence of bits y1, y2, …, y22, resulting in the sequence of bits z1, z2, …, z90.
4.10.4 Rate matching for E‑AGCH
From the input sequence z1, z2, …, z90 the bits z1, z2, z5, z6, z7, z11, z12, z14, z15, z17, z23, z24, z31, z37, z44, z47, z61, z63, z64, z71, z72, z75, z77, z80, z83, z84, z85, z87, z88, z90 are punctured to obtain the output sequence r1, r2, …, r60.
4.10.5 Physical channel mapping for E‑AGCH
The E‑AGCH sub frame is described in [2]. The sequence of bits r1, r2, …, r60 is mapped to the corresponding E‑AGCH sub frame. The bits rk are mapped so that they are transmitted over the air in ascending order with respect to k. If the E‑DCH TTI is equal to 10 ms the same sequence of bits is transmitted in all the E‑AGCH sub frames of the E‑AGCH radio frame.