1，General description of layer 1（層1的基本型描述）
1.1 Relation to other layers（和其他層的關係）
1.1.1 General protocol architecture（一般協議體系結構）
圖1顯示了圍繞物理層(第一層)的NR無線電接口協議體系結構。
物理層接口第二層的介質訪問控制(MAC)子層和第三層的無線電資源控制(RRC)層。不同層/子層之間的圓圈表示服務訪問點(sap)。
物理層爲MAC提供一個傳輸通道。傳輸通道的特徵是信息如何在無線電接口上傳輸。MAC爲第二層的無線鏈路控制(RLC)子層提供不同的邏輯通道。邏輯通道的特徵是所傳輸的信息的類型。
1.2，General description of layer 1（層1的基本型描述）
1.2.1 多址接入：
NR物理層的多址接入方案是基於帶循環前綴的正交頻分複用(OFDM)。對於上行鏈路，也支持帶有CP的離散傅里葉變換-擴展- ofdm (DFT-s-OFDM)。爲了支持成對和非成對頻譜傳輸，需要使能FDD (Frequency Division Duplex)和TDD (Time Division Duplex)。
第一層基於資源塊以一種不考慮帶寬的方式定義，允許NR第一層適應各種頻譜分配。一個資源塊以給定的子載波間隔跨越12個子載波。
無線電幀的持續時間爲10ms，由10個子幀組成，子幀持續時間爲1ms。子幀由一個或多個相鄰槽組成，每個相鄰槽具有14個相鄰符號。
1.2.2 物理信道和調製：
The physical channels defined in the downlink are:
- the Physical Downlink Shared Channel (PDSCH),
- the Physical Downlink Control Channel (PDCCH),
- the Physical Broadcast Channel (PBCH),
The physical channels defined in the uplink are:
- the Physical Random Access Channel (PRACH),
- the Physical Uplink Shared Channel (PUSCH),
- and the Physical Uplink Control Channel (PUCCH).
The physical channels defined in the sidelink（旁/副/邊/側 鏈路，Sidelink用於終端之間不通過網絡設備進行直接傳輸） are:
- the Physical Sidelink Broadcast Channel (PSBCH),
- the Physical Sidelink Control Channel (PSCCH),
- the Physical Sidelink Feedback Channel (PSFCH),
- and the Physical Sidelink Shared Channel (PSSCH).
In addition, signals are defined as reference signals, primary and secondary synchronization signals.
The modulation schemes supported are
- in the downlink, QPSK, 16QAM, 64QAM, and 256QAM,
- in the uplink, QPSK, 16QAM, 64QAM and 256QAM for OFDM with a CP and π/2-BPSK, QPSK, 16QAM, 64QAM and 256QAM for DFT-s-OFDM with a CP
1.2.3 信道編碼：
傳輸塊的信道編碼方案爲準循環LDPC碼，每個基圖分別具有2個基圖和8組奇偶校驗矩陣。一個基圖用於編碼塊大於一定大小或初始傳輸碼率高於閾值;否則，使用另一個基本圖。在LDPC編碼之前，對於較大的傳輸塊，傳輸塊被分割成大小相等的多個代碼塊。針對PBCH和控制信息的信道編碼方案是基於嵌套序列的極性編碼。採用針刺法、縮短法和重複法進行速率匹配。
1.2.4 物理層過程：
這涉及到幾個物理層過程。物理層所涵蓋的這些過程是;
——小區搜索
——功率控制
—上行同步和上行定時控制
—隨機訪問的相關程序
- harq相關程序
-波束管理和CSI相關程序
-旁鏈相關程序
-信道接入程序
通過對物理層資源在頻域、時域和功率域的控制，在NR中提供了隱式的干擾協調支持。
1.2.5 物理層測量：
無線電特性由UE和網絡測量並報告給高層。這些包括:頻率內和頻率間切換的測量、系統間切換、時間測量和RRM的測量。
系統間切換的測量被定義爲支持切換到E-UTRA。
2，物理層規範的文檔結構
2.1 Overview:
物理層規範由一個通用文檔(TS 38.201)和七個文檔(TS 38.202、38.211到38.215和37.213)組成。圖2顯示了較高層環境中的物理層規範之間的關係。
2.2 TS 38.201: Physical layer; General description
The scope is to describe:
- The contents of the Layer 1 documents (TS 38.200 series);
- Where to find information;
2.3 TS 38.202: Physical layer services provided by the physical layer(物理層提供的服務)
The scope is to describe services provided by the physical layer, and to specify:
- Services and functions of the physical layer（物理層的業務和功能）;
- Model of physical layer of the UE（終端物理層的模型）;
- Parallel transmission of simultaneous physical channels and SRS（SRS和物理信道的並行傳輸）;
- Measurements provided by the physical layer（物理層的測量）.
2.4 TS 38.211: Physical channels and modulation（物理信道和調製）
The scope is to establish the characteristics of the Layer-1 physical channels, generation of physical layer signals and modulation, and to specify:
- Definition of the uplink, downlink and sidelink physical channels（定義上下行和旁鏈物理信道）;
- Frame structure and physical resources（幀結構和物理資源）;
- Modulation mapping (BPSK, QPSK, etc)（調製映射）;
- OFDM signal generation;
- Scrambling, modulation and upconversion（置亂、調製和上轉換）;
- Layer mapping and precoding（層映射和預編碼）;
- Physical shared channel in uplink, downlink and sidelink（上行鏈路、下行鏈路和旁鏈路中的物理共享信道）;
- Reference signal in uplink, downlink and sidelink（上行鏈路、下行鏈路和旁鏈路中的參考信號）;
- Physical random access channel（物理隨機接入信道）;
- Primary and secondary synchronization signals（主輔同步信號）.
2.5 TS 38.212: Multiplexing and channel coding（多路複用和信道編碼）
The scope is to describe the transport channel and control channel data processing, including multiplexing, channel coding and interleaving, and to specify:
- Channel coding schemes（信道編碼方案）;
- Rate matching（速率匹配）;
- Uplink transport channels and control information（上行傳輸信道和控制信息）;
- Downlink transport channels and control information（下行傳輸信道和控制信息）;
- Sidelink transport channels and control information（胖鏈傳輸信道和控制信息）.
2.6 TS 38.213: Physical layer procedures for control（物理信道的程序控制）
The scope is to establish the characteristics of the physical layer procedures for control, and to specify:
- Synchronization procedures（同步過程）;
- Uplink power control（上行功控）;
- Random access procedure（隨機接入過程）;
- UE procedure for reporting control information（UE程序報告控制信息）;
- UE procedure for receiving control information（UE接收控制信息的程序）.
2.7 TS 38.214: Physical layer procedures for data（數據的物理層程序）
The scope is to establish the characteristics of the physical layer procedures for data, and to specify:
- Power control（功控）;
- Physical downlink shared channel related procedures（物理下行共享信道和相關流程）;
- Physical uplink shared channel related procedure（物理上行共享信道相關流程）;
- Physical sidelink shared channel related procedure（物理旁鏈共享信道和相關流程）.
2.8 TS 38.215: Physical layer measurements（物理信道測量）
The scope is to establish the characteristics of the physical layer measurements, and to specify:
- Control of UE/NG-RAN measurements（UE/NG-RAN測量的控制）;
- Measurement capabilities for NR（NR的測量能力）.
2.9 TS 37.213: Physical layer procedures for shared spectrum channel access（物理層程序用於共享頻譜信道的訪問）
The scope is to establish the characteristics of the physical layer procedures for shared spectrum channel, and to specify:
- Downlink channel access procedures（下行信道接入過程）;
- Uplink channel access procedures（上行信道接入過程）.