Chapter 3 Radio-Interface Physical Layer Gerardo Gómez, David Morales-Jiménez, F. Javier López-Martínez, Juan J. Sánchez, and José Tomás Entrambasaguas Contents Physical Layer Overview 3.1.1 Physical Resource Structure 3.1.2 Reference Signals 3.1.3 Synchronization Signals 3.1.4 Physical Channels 3.1.5 OFDM/SC-FDMA Signal Generation Link Adaptation Techniques 3.2.1 Adaptive Modulation and Coding 3.2.2 Channel Coding 3.2.3 CRC and Segmentation 3.2.4 Coding Techniques in LTE 3.2.4.1 Tail Biting Convolutional Coding 3.2.4.2 Turbo Coding 3.2.4.3 Rate Matching 3.2.4.4 Coded Block Concatenation 3.2.5 Hybrid Automatic Repeat Request (HARQ) 3.2.6 Channel-Aware Scheduling © 2009 by Taylor & Francis Group, LLC Long Term Evolution: 3GPP LTE Radio and Cellular Technology Multiple Antennas 3.3.1 Introduction 3.3.2 Transmit Diversity 3.3.2.1 Cyclic Delay Diversity (CDD) 3.3.2.2 Space Frequency Block Coding (SFBC) 3.3.3 Spatial Multiplexing 3.3.3.1 Space Division Multiplexing (SU-MIMO) 3.3.3.2 Multiple Access 3.3.3.3 Precoding-Based Spatial Multiplexing 3.3.4 LTE Multiantenna Procedures 3.3.4.1 Antenna Mapping 3.3.4.2 LTE Multiantenna Configurations 3.3.4.3 Multiantenna Adaptation Procedures 3.4 Physical Layer Procedures 3.4.1 Synchronization 3.4.1.1 Synchronization in OFDMA DL 3.4.1.2 Synchronization in SC-FDMA UL 3.4.1.3 Cell Search Procedure 3.4.1.4 Other Synchronization Procedures 3.4.2 Channel Estimation 3.4.2.1 Channel Estimation in OFDMA DL 3.4.2.2 Channel Estimation in SC-FDMA UL 3.4.3 Random Access 3.4.3.1 Random Access Preamble 3.4.3.2 Random Access Procedure References Physical Layer Overview The long term evolution (LTE) physical layer is targeted to provide improved radio interface capabilities between the base station* and user equipment (UE) compared to previous cellular technologies like the universal mobile telecommunications sys- tem (UMTS) or high-speed downlink packet access (HSDPA). According to the initial requirements defined by the 3rd Generation Partnership Project (3GPP; 3GPP 25.913), the LTE physical l