待解决问题
关于LTE中MCS/TBS与Modulation的疑问 (进入论坛模式)
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提问者:ufouser
|
提问时间:2012-10-11 21:51
在物理层协议里,MCS_index取值9和10,对应的TBS_index都是9,而ModulationOrder分别是QPSK和16QAM,请问有谁知道为什么要这么设计呢?为什么不设计成一一对应呢?
(36.213)
Modulation order determination
The UE shall use and Table 7.1.7.1-1 to determine the modulation order ( ) used in the physical downlink shared channel.
Table 7.1.7.1-1: Modulation and TBS index table for PDSCH
MCS Index
Modulation Order
TBS Index
0
2
0
1
2
1
2
2
2
3
2
3
4
2
4
5
2
5
6
2
6
7
2
7
8
2
8
9
2
9
10
4
9
11
4
10
12
4
11
13
4
12
14
4
13
15
4
14
16
4
15
17
6
15
18
6
16
19
6
17
20
6
18
21
6
19
22
6
20
23
6
21
24
6
22
25
6
23
26
6
24
27
6
25
28
6
26
29
2
reserved
30
4
31
6
(36.213)
Modulation order determination
The UE shall use and Table 7.1.7.1-1 to determine the modulation order ( ) used in the physical downlink shared channel.
Table 7.1.7.1-1: Modulation and TBS index table for PDSCH
MCS Index
Modulation Order
TBS Index
0
2
0
1
2
1
2
2
2
3
2
3
4
2
4
5
2
5
6
2
6
7
2
7
8
2
8
9
2
9
10
4
9
11
4
10
12
4
11
13
4
12
14
4
13
15
4
14
16
4
15
17
6
15
18
6
16
19
6
17
20
6
18
21
6
19
22
6
20
23
6
21
24
6
22
25
6
23
26
6
24
27
6
25
28
6
26
29
2
reserved
30
4
31
6
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