5G Technology, 2nd Edition

65G Physical Layer

Mihai Enescu, Keeth Jayasinghe, Karri Ranta-Aho, Karol Schober, and Antti Toskala

Nokia, Finland

CHAPTER MENU

• Introduction
• 5G Multiple Access Principle
• Physical Channels and Signals
• Basic Structures for 5G Frame Structure
• 5G Channel Structures and Beamforming Basics
• Random Access
• Downlink User Data Transmission
• Uplink User Data Transmission
• Uplink Signaling Transmission
• Downlink Signaling Transmission
• Physical Layer Procedures
• 5G MIMO and Beamforming Operation
• Channel Coding with 5G
• Dual Connectivity
• 5G Data Rates
• Physical Layer Measurements
• UE Capability
• Summary
• References

6.1 Introduction

5G multiple access, and the physical layer in general, has differences from Long Term Evolution (LTE) as discussed in Chapter 1. In the downlink direction, the multiple access is based on Orthogonal Frequency Division Multiple Access (OFDMA), similar to LTE. In the uplink direction, 5G has adopted both OFDMA and Single Carrier Frequency Division Multiple Access (SC-FDMA), while LTE uses only SC-FDMA. SC-FDMA is often denoted also as DFT-Spread OFDMA (DFT-S-OFDMA). Further, the use of beamforming is now much more built in, as with LTE, and the range of frequency bands supported extends to much higher frequencies than LTE can achieve. The frame structures with 5G offer more flexibility to cover different cases, depending on the frequency band to be used or whether one needs to optimize for high capacity or for low power consumption of the network and UEs. This chapter ...