TD-LTE PHY Layer

3 days

Download brochureThe course is dedicated to the TDD (Time Division Duplex) version of the LTE system, also known as TD-LTE. It provides an in-depth description of the TD-LTE PHY layer. The course describes in detail the architecture of the two nodes of the TDD E-UTRA, namely TDD Evolved Node B (eNB) and TDD User Equipment (UE), by discussing every single component processing block and the generated signals. Special attention is given to all the differences between TDD and FDD (Frequency Division Duplex).

This course is heavily based on the LTE PHY Lab, which is a state-of-the art Link Level Simulator applied to generate and observe TDD waveforms, signals, channels and frames of the LTE air interface.

Introduction to E-UTRA TDD

• Evolution steps of the 3GPP systems, the goals for LTE
• E-UTRA and Evolved Packet Core network architecture
• Nodes: UE, eNB, SGW, MME and interfaces: Uu, X2, S1, S11
• Summary of the radioaccess techniques
• E-UTRAN protocol stack
• Channel bandwidths and RF limitations for FDD and TDD

Signal Processing for OFDMA, SC-FDMA and MIMO

• Fundamentals of multipath propagation (selectivity in time, frequency and space)
• OFDM transmission, orthogonality, subcarriers, separation between subcarriers
• Time-domain and frequency-domain representation of the OFDM signal
• Guard interval and Cyclic Prefix (CP) role
• Equalization for OFDM
• IDFT/DFT, IFFT/FFT
• Multiuser diversity and OFDMA
• SC-FDMA as a subclass of OFDMA, comparison between SC-FDMA and OFDMA
• Multiple antenna concept and related signal processing
• Open and closed loop spatial multiplexing
• Single-user and Multi-user MIMO

Signal Processing for the TDD Evolved Node B

• Architecture of the eNB transmitter and receiver including processing blocks and signals
• E-UTRA radio frame for FDD
• TDD Radio frame and special sub-frame configuration
• Coexistence with TD-SCDMA
• Downlink channel architecture
• eNB-originated signals and TDD PHY channels: RS, P-SS, S-SS, PBCH, PCFICH, PHICH, PDCCH, PDSCH
• TDD synchronization signal mapping
• 3GPP Rel. 8 MIMO processing with layer mapping, pre-coding and feedback

Signal Processing for the TDD User Equipment

• LTE UE categories
• Architecture of the UE transmitter and receiver including processing blocks and signals
• Uplink channel architecture
• UE-originated signals and TDD PHY channels: DRS, SRS, PUCCH, PUSCH, PRACH
• Evaluation of the eNB and UE Transceiver

Operation Under Various Conditions

• Impact of uncorrected multipath channels
• Peak-to-average-power-ratio and its influence on the transmitted signal
• Pulse shaping and filtering in the time domain and its influence on the transmitted signal
• Synchronization mismatches in the time and frequency domain and their influence on the received signal
• Influence of various types of interferers (single-dominant, non-single-dominant) on the received signal
• TDD DL and UL sub-frame mismatches

Radio Interface Procedures

• Various traffic allocations for the TDD downlink and uplink
• E-UTRA radio frame
• Synchronization and random access procedures
• Scheduling for FDD and TDD
• Hybrid ARQ operation for FDD and TDD; feedback consideration
• TDD HARQ bundling and multiplexing

Processing Improvements in E-UTRA 3GPP Rel. 9 and Rel. 10

• Usage of 8 antennas in the downlink for spatial multiplexing
• Transmit diversity in the uplink
• Spatial multiplexing in the uplink
• Coordinated MIMO
• Bandwidth aggregation