[chapter3][5G-NR][Frame Structure ]
参考：
3GPP 38.211
https://www.sharetechnote.com/html/5G/5G_FrameStructure.html
目录：
1： Numerology - Subcarrier Spacing
2： Numerology and Slot Length
3： Numerology and Supported Channels
4： RB（3GPP TS 38101-1）
5： Radio Frame Structure
6： Numerology - Sampling Time
7： Slots
8: Resource Grid
一 Numerology - Subcarrier Spacing（3GPP 38.211-4.2）
，跟 LTE Numerologies（子载波间隔和符号长度）相比，您可以注意到的最突出的区别是NR支持多种不同类型的子载波间隔（在LTE中只有一种类型的子载波间隔，15 Khz）。
二 Numerology and Slot Length
NR subFrame 固定为1ms
slot 的时间定义为：
子载波间隔定义为：
可以画出如下图
三 Numerology and Supported Channels
不是每一种Numerology都可以用于每一个物理通道和信号。Numerology 和 physical channels 有指定的映射关系
四 RB（3GPP TS 38101-1）
1RB=12子载波。
以100Mz，μ=1为例，1RB理论上=30kHz*12=0.36MHz。
100M/0.36M=277.77（个）。
考虑频段边带保护，最后定为273。
3GPP TS 38101-1中对RB数量定义如下：
五 Radio Frame Structure
无线帧 Frame的长度总是10ms，并且子帧subFrame 的长度始终是1ms。
每个slot 固定对应14 symb
The number of consecutive OFDM symbols per subframe is
5.1 >
5.2
5.3 < Normal CP, Numerology = 2 >
在这种配置中，一个子帧中有4个时隙，
这意味着一个无线电帧中有40个时隙。一个时隙中的OFDM符号数为14
5.4 < Normal CP, Numerology = 3 >
在这种配置中，一个子帧中有8个时隙，
这意味着一个无线电帧中有80个时隙。一个时隙中的OFDM符号数为14
5.5 < Normal CP, Numerology = 4 >
5.6 < Normal CP, Numerology = 5 >
5.6 < Normal CP, Numerology = 6 >
5.7 < Extended CP, Numerology = 2 >
In this configuration, a subframe has 32 slots in it, it means a radio frame contains 160 slots in it. The number of OFDM symbols within a slot is 14.
六 Numerology - Sampling Time
Sampling time can be defined differently depending on Numerogy (i.e, Subcarrier Spacing) and in most case two types of Timing Unit Tc and Ts are used.
Tc = 0.509 ns 5G 里面最小采样时间
Ts = 32.552 ns 4G里面最小采样时间
为什么是该值，可以参考一下外文
七 slots
3GPP 38.211 给出来每个子帧对应的slot个数，以及每个slot对应的symb.
<38.213 v15.7 -Table 11.1.1-1: Slot formats for normal cyclic prefix>
D : Downlink, U : Uplink, F : Flexible
| Symbol Number in a slot | |||||||||||||
Format | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 |
0 | D | D | D | D | D | D | D | D | D | D | D | D | D | D |
1 | U | U | U | U | U | U | U | U | U | U | U | U | U | U |
2 | F | F | F | F | F | F | F | F | F | F | F | F | F | F |
3 | D | D | D | D | D | D | D | D | D | D | D | D | D | F |
4 | D | D | D | D | D | D | D | D | D | D | D | D | F | F |
5 | D | D | D | D | D | D | D | D | D | D | D | F | F | F |
6 | D | D | D | D | D | D | D | D | D | D | F | F | F | F |
7 | D | D | D | D | D | D | D | D | D | F | F | F | F | F |
8 | F | F | F | F | F | F | F | F | F | F | F | F | F | U |
9 | F | F | F | F | F | F | F | F | F | F | F | F | U | U |
10 | F | U | U | U | U | U | U | U | U | U | U | U | U | U |
11 | F | F | U | U | U | U | U | U | U | U | U | U | U | U |
12 | F | F | F | U | U | U | U | U | U | U | U | U | U | U |
13 | F | F | F | F | U | U | U | U | U | U | U | U | U | U |
14 | F | F | F | F | F | U | U | U | U | U | U | U | U | U |
15 | F | F | F | F | F | F | U | U | U | U | U | U | U | U |
16 | D | F | F | F | F | F | F | F | F | F | F | F | F | F |
17 | D | D | F | F | F | F | F | F | F | F | F | F | F | F |
18 | D | D | D | F | F | F | F | F | F | F | F | F | F | F |
19 | D | F | F | F | F | F | F | F | F | F | F | F | F | U |
20 | D | D | F | F | F | F | F | F | F | F | F | F | F | U |
21 | D | D | D | F | F | F | F | F | F | F | F | F | F | U |
22 | D | F | F | F | F | F | F | F | F | F | F | F | U | U |
23 | D | D | F | F | F | F | F | F | F | F | F | F | U | U |
24 | D | D | D | F | F | F | F | F | F | F | F | F | U | U |
25 | D | F | F | F | F | F | F | F | F | F | F | U | U | U |
26 | D | D | F | F | F | F | F | F | F | F | F | U | U | U |
27 | D | D | D | F | F | F | F | F | F | F | F | U | U | U |
28 | D | D | D | D | D | D | D | D | D | D | D | D | F | U |
29 | D | D | D | D | D | D | D | D | D | D | D | F | F | U |
30 | D | D | D | D | D | D | D | D | D | D | F | F | F | U |
31 | D | D | D | D | D | D | D | D | D | D | D | F | U | U |
32 | D | D | D | D | D | D | D | D | D | D | F | F | U | U |
33 | D | D | D | D | D | D | D | D | D | F | F | F | U | U |
34 | D | F | U | U | U | U | U | U | U | U | U | U | U | U |
35 | D | D | F | U | U | U | U | U | U | U | U | U | U | U |
36 | D | D | D | F | U | U | U | U | U | U | U | U | U | U |
37 | D | F | F | U | U | U | U | U | U | U | U | U | U | U |
38 | D | D | F | F | U | U | U | U | U | U | U | U | U | U |
39 | D | D | D | F | F | U | U | U | U | U | U | U | U | U |
40 | D | F | F | F | U | U | U | U | U | U | U | U | U | U |
41 | D | D | F | F | F | U | U | U | U | U | U | U | U | U |
42 | D | D | D | F | F | F | U | U | U | U | U | U | U | U |
43 | D | D | D | D | D | D | D | D | D | F | F | F | F | U |
44 | D | D | D | D | D | D | F | F | F | F | F | F | U | U |
45 | D | D | D | D | D | D | F | F | U | U | U | U | U | U |
46 | D | D | D | D | D | F | U | D | D | D | D | D | F | U |
47 | D | D | F | U | U | U | U | D | D | F | U | U | U | U |
48 | D | F | U | U | U | U | U | D | F | U | U | U | U | U |
49 | D | D | D | D | F | F | U | D | D | D | D | F | F | U |
50 | D | D | F | F | U | U | U | D | D | F | F | U | U | U |
51 | D | F | F | U | U | U | U | D | F | F | U | U | U | U |
52 | D | F | F | F | F | F | U | D | F | F | F | F | F | U |
53 | D | D | F | F | F | F | U | D | D | F | F | F | F | U |
54 | F | F | F | F | F | F | f | D | D | D | D | D | D | D |
55 | D | D | F | F | F | U | U | U | D | D | D | D | D | D |
62-254 | Reserved | |||||||||||||
255 | UE determines the slot format for the slot based on tdd-UL-DL-ConfigurationCommon, or tdd-ULDL- ConfigurationDedicated and, if any, on detected DCI formats | |||||||||||||
八 Resource Grid
NR的资源网格定义如下图，你会认为它几乎与LTE资源网格相同。但是物理维度（即，子载波间隔、无线电帧内OFDM符号的数量）在NR中根据Numerology而变化。
上下行中分配的最大RB数量定义如下：
可以通过RRC 或者 DCI 消息中获得，
