3GPP协议学习-TS 38.211-NR；物理信道与调制

2024-01-10 19:13:58

1，Frame structure and physical resources（框架结构和物理资源）

1.1 General

在本规范中，除非另有说明，时间域中各个字段的大小都以时间单位表示：

.......................................................①

....................................................②

.....................................................................③

由②③可得 Tc = 1/(4096*480*1000)s

另外：

所以Ts= 1/(2048*15*1000)s. 常量K = (4096*480)/(15*2048)=32*2=64

1.2 Numerologies

Multiple OFDM numerologies are supported as given by Table 4.2-1 where μ and the cyclic prefix for a downlink or uplink bandwidth part are obtained from the higher-layer parameters subcarrierSpacing and cyclicPrefix, respectively ,

参数μ由高层参数 subcarrierSpacing （子载波间隔）控制，Cyclic prefix 循环前缀由参数cyclicPrefix控制。

目前运营商现网配置的μ=1 也就是子载波间隔为30KHZ

1.3 Frame structure (帧结构)

1.3.1 帧和子帧

在上行下行和旁链传输上，帧发送周期为10ms，一共分为10个子帧，每个子帧周期为1ms.

每个帧又分为全等的两个半帧，Half-frame 0包含0-4 这5个子帧， Half-frame 1 包含5-9这5个子帧.

每个子帧上的连续的OFDM符号数量是

从UE发起的上行帧传输要比下行帧要早，msgA传输的时候，Nta =0

时间提前量TA（Timing Advance）的作用是为了补偿电波传输延迟,而根本目的则是为了提高信道编解码效率。

2.3.2 Slots(槽)

根据Mainland China的运营商，取值μ=1 推算：

Slot号码取值为{0，1},也就是有2个slot，如果μ=4,即使用240KHZ的子载波间隔，Slot取值范围为{0，15}也就是16个Slot。即2的μ次方个Slot.

当μ=2时候，也就是循环前缀为normal/extrend 的时候，一个Slot含有12个OFDM符号数，

当μ≠2的时候，一个slot含有14个符号数。

Mainland China： μ=1，SCS=30KHZ; 一个帧有2个Slot，一个slot有14个OFDM符号。

2.4 Physical resources（物理资源）

2.4.1 Antenna ports （天线端口）

An antenna port is defined such that the channel over which a symbol on the antenna port is conveyed can be inferred from the channel over which another symbol on the same antenna port is conveyed.

定义了天线端口，以便可以从传输天线端口上的另一个符号的通道推断出传输天线端口上的符号的通道

For DM-RS associated with a PDSCH, the channel over which a PDSCH symbol on one antenna port is conveyed can be inferred from the channel over which a DM-RS symbol on the same antenna port is conveyed only if the two symbols are within the same resource as the scheduled PDSCH, in the same slot, and in the same PRG as described in clause 5.1.2.3 of [6, TS 38.214].

DM-RS(解调参考信号，用于接收端（基站侧或者UE侧）进行信道估计，来用于物理信道的解调)与PDSCH, PDSCH符号的信道在一个天线端口转达了的通道可以推断DM-RS符号在同一天线端口是转达了只有两个符号在同一资源预定PDSCH,在相同的位置,和描述的一样PRG 5.1.2.3 (38.214 6, TS)

For DM-RS associated with a PDCCH, the channel over which a PDCCH symbol on one antenna port is conveyed can be inferred from the channel over which a DM-RS symbol on the same antenna port is conveyed only if the two symbols are within resources for which the UE may assume the same precoding being used as described in clause 7.3.2.2.

DM-RS与PDCCH, PDCCH符号的信道在一个天线端口转达了的通道可以推断DM-RS符号在同一天线端口是转达了只有两个符号内资源的问题可能承担相同的预编码被用作7.3.2.2描述的条款。

For DM-RS associated with a PBCH, the channel over which a PBCH symbol on one antenna port is conveyed can be inferred from the channel over which a DM-RS symbol on the same antenna port is conveyed only if the two symbols are within a SS/PBCH block transmitted within the same slot, and with the same block index according to clause 7.4.3.1.

DM-RS与PBCH, PBCH符号的信道在一个天线端口转达了的通道可以推断DM-RS符号在同一天线端口是转达了只有两个符号在SS / PBCH块传输在同一位置,同一块指数据7.4.3.1条款。

Two antenna ports are said to be quasi co-located if the large-scale properties of the channel over which a symbol on one antenna port is conveyed can be inferred from the channel over which a symbol on the other antenna port is conveyed. The large-scale properties include one or more of delay spread, Doppler spread, Doppler shift, average gain, average delay, and spatial Rx parameters.

如果一个天线端口上的符号传输所经过的信道的大规模特性可以从另一个天线端口上的符号传输所经过的信道推断出来，那么就说两个天线端口是准同位的。大尺度特性包括一个或多个延迟扩展、多普勒扩展、多普勒频移、平均增益、平均延迟和空间Rx参数。

2.4.2 Resource grid(资源栅格)

主要看第一段末尾，Resource 由天线端口p.子载波间隔μ和传输方向（上行下行旁链）组成。

2.4.3 Resource elements（资源元素）

在资源格的独一无二的天线端口p和子载波间隔配置μ的元素被称为资源元素。

2.4.4 Resource blocks（资源块）

①：A resource block is defined as NscRB=12 consecutive subcarriers in the frequency domain

频域上连续12个连续的子载波被称为一个资源块，对于μ=1的国内运营商来说，一个资源块频域上市360KHZ.

②：Point A:

Point A serves as a common reference point for resource block grids and is obtained from:

- offsetToPointA for a PCell downlink where offsetToPointA represents the frequency offset between point A and the lowest subcarrier of the lowest resource block, which has the subcarrier spacing provided by the higher-layer parameter subCarrierSpacingCommon and overlaps with the SS/PBCH block used by the UE for initial cell selection, expressed in units of resource blocks assuming 15 kHz subcarrier spacing for FR1 and 60 kHz subcarrier spacing for FR2;

- absoluteFrequencyPointA for all other cases where absoluteFrequencyPointA represents the frequency-location of point A expressed as in ARFCN.

Point A是资源块网格的共同参考点，由offsetToPointA 和absoluteFrequencyPointA决定：

offsetToPointA表示Point A和最低资源块里的最低子载波之间的频率偏置，absoluteFrequencyPointA表示Point A在ARFCN中频率位置。

③ Common resource blocks（公共资源块）

Common resource blocks are numbered from 0 and upwards in the frequency domain for subcarrier spacing configuration μ . The center of subcarrier 0 of common resource block 0 for subcarrier spacing configuration μ coincides with 'point A'.

④ Physical resource blocks （物理资源块）

⑤Virtual resource blocks （虚拟资源块）

Virtual resource blocks are defined within a bandwidth part and numbered from 0 to where i is the number of the bandwidth part.

⑥ Interlaced resource blocks（交错资源块）

2.4.5 Bandwidth part（带宽部分）

带宽是一个连续公共资源块的合集。

A UE can be configured with up to four bandwidth parts in the downlink with a single downlink bandwidth part being active at a given time. The UE is not expected to receive PDSCH, PDCCH, or CSI-RS (except for RRM) outside an active bandwidth part.

UE可配置在下行链路中具有最多四个带宽部分，且在给定时间只有一个下行链路带宽部分处于活动状态。

A UE can be configured with up to four bandwidth parts in the uplink with a single uplink bandwidth part being active at a given time. If a UE is configured with a supplementary uplink, the UE can in addition be configured with up to four bandwidth parts in the supplementary uplink with a single supplementary uplink bandwidth part being active at a given time. The UE shall not transmit PUSCH or PUCCH outside an active bandwidth part. For an active cell, the UE shall not transmit SRS outside an active bandwidth part.

终端可配置上行链路中多达四个带宽部分，其中一个上行带宽部分在给定时间处于活动状态。如果终端配置了补充上行链路，则该终端还可以在补充上行链路中配置最多4个带宽部分，其中一个补充上行带宽部分在给定时间处于活动状态。UE不得在有源带宽部分外发送推送或压缩。对于一个活动单元，终端不应在活动带宽部分之外传输SRS。

Unless otherwise noted, the description in this specification applies to each of the bandwidth parts. When there is no risk of confusion, the index μ may be dropped from NBWP,istart,μ , NBWP,isize,μ , Ngrid,xstart,μ , and Ngrid,xsize,μ .