5G NR/LTE学习笔记:下行物理过程

从大的方面来看，要学会下行过程，要从以下四个方面系统入手。

1. Transport channel processing

1.1 Processing Steps

1.1.1 CRC Insertion Per Transport Block

1.1.2 Code-Block Segmentation and Per-Code-Block CRC Insertion

1.1.3 Channel Coding

1.1.4 Rate Matching and Physical-Layer Hybrid-ARQ Functionality

1.1.5 Bit-Level Scrambling

1.1.6 Data Modulation

1.1.7 Antenna Mapping

1.1.8 Resource-Block Mapping

1.2 Localized and Distributed Resource Mapping

2. Downlink reference signals

3. Multi-antenna transmission

4. Downlink L1/L2 control signal