UCLA Extension

3GPP LTE Physical Layer for Wireless/Mobile Communications

A 3-Day Short Course

The 3GPP LTE (long-term evolution) project aims to evolve the existing 3G mobile telephone standard into an attractive candidate technology for high data rate, low latency, packet-based mobile telephony. The LTE project has resulted in Release 8 of the 3GPP UMTS standard and features new evolutions, extensions, and various modifications to the UMTS system.

Complete Details

First-release 3G technology in the U.S. and Europe was based on spread spectrum and CDMA (code division multiple access) techniques for both uplink and downlink. Recent changes and additions to the 3GPP and 3GPP2 standards have introduced methods for Mbit/s data rates, such as EV-DO for the 3GPP2/CDMA2000 standard, and HSDPA and HSUPA for 3GPP/WCDMA standard. 3GPP LTE takes this “data” evolution further, the introduction of up to 4×4 antennas in a MIMO configuration will aim for peak download rates of over 100Mbit/s in 20MHz. LTE will also improve on the spectrum flexibility and bandwidth segments as low as 1.4MHz being useable (unlike UMTS/WCDMA which is 5MHz units).

It is therefore expected that 3GPP LTE will evolve the current 3G releases into essentially a fourth-generation wireless broadband Internet system, including voice and other integrated services, and given its nature will co-exist and work in unison with existing standards. The flexibility of this standard also makes it a very strong candidate for a global roll-out in the three main regions of the Americas, Europe, and Asia.

This course provides participants with an understanding of the LTE physical layer modulation and coding schemes defined in Release 8 of the 3GPP standards. This includes presentations, tutorials, and software simulation on the core physical layer technologies, such as OFDM, SC-FDMA, and MIMO, and their application within LTE. 3GPP LTE waveform generation software is used during the course to illustrate the concepts introduced.

Course objectives:

  • Describing the main 3GPP LTE parameters and numerology, and justifying the choice of values
  • Introducing the LTE physical layer processing chain
  • Describing the multiantenna techniques that are specified in LTE
  • Analyzing the role of the different multiantenna and MIMO techniques available in LTE
  • Using 3GPP LTE waveform generation software to illustrate concepts covered
  • Describing the physical channels and physical signals employed in LTE
  • Providing an understanding of the role of LTE physical channels and signals
  • Describing the uplink and downlink LTE modulation techniques
  • Explaining how high spectral efficiency is achieved in LTE
  • Describing the different channel coding techniques used in LTE and how they differ from those used in WCDMA
  • Looking ahead to the adoption and evolution from current standards to LTE
  • Providing an overview of the evolution of LTE

Course Materials

Lecture notes are distributed on the first day of the course. These notes are for participants only and are not for sale.

Coordinators and Lecturers

Daniel García-Alís, PhD, Chief DSP Engineer, Steepest Ascent Ltd., Glasgow, Scotland. Dr. García-Alís was one of the founders of Steepest Ascent, where he currently manages the professional DSP and communications consulting activity of the company as well as managing projects on areas such as DSP, system-level simulation, and MIMO channel modeling. He has extensive experience in the areas of DSP for mobile communications, including adaptive filtering and receivers for mobile/wireless communications. He also is part of the team developing Steepest Ascent’s 3GPP LTE PHY software simulation library. Prior to this, Dr. García-Alís worked for four years as a research assistant and research fellow for the Institute for Communications and Signal Processing, University of Strathclyde, Glasgow, Scotland. During this time he reached the position of manager of the DSP-enabled Communications (DSPeC) research group. He received an Ingeniero de Telecomunicación degree from the Universidad Politécnica de Valencia, Spain, in 1997 prior to obtaining a PhD degree in Electrical and Electronic Engineering in 2001 from the University of Strathclyde, where his work focused on adaptive receiver structures for spread spectrum systems.

Iain G. Stirling, PhD, Software Programmer and DSP Engineer, Steepest Ascent Ltd., Glasgow, Scotland. Dr. Stirling is a founding member of Steepest Ascent and has roles as a software programmer, DSP engineer, and training course lecturer. He was the lead programmer in the company’s recent EV-DO and DVB/ISDB simulation products, as well as programming and developing training course materials for the 3GPP LTE, 3GPP WCDMA/HSPA, and CDMA2000 1xRTT/EV-DV standards. Dr. Stirling graduated from the University of Strathclyde in 2000 with a First Class Honours degree in Computer and Electronic Systems. He also holds a PhD from the University of Strathclyde, obtained in 2005 for research on rake receiver architectures for 3GPP FDD basestations.

Course Program

Introduction to 3GPP Long-Term Evolution

  • 3GPP evolution from R5 to R10
  • Requirements
  • Spectrum flexibility
  • General characteristics
  • Multi-user scheduling
  • Resource allocation
  • Frequency reuse planning

OFDM Theory Review

  • Motivation for multi-carrier vs. single-carrier
  • Introduction to OFDM
  • The structure of an OFDM signal
  • Generation of OFDM symbols using the IFFT
  • Cyclic prefix (guard interval)
  • Windowing to reduce out-of-band emissions
  • Oversampling and upconversion
  • Peak-to-average power ratio (PAR)
  • Techniques for reducing PAR

LTE Frames, Slots, and Resources

  • LTE generic frame structure
  • Downlink and uplink slot formats
  • Resource elements and resource blocks
  • Physical channels and signals

LTE Multiplexing and Channel Coding

  • Transport channels and control information: DL-SCH, PCH, BCH, DCI, CFI, HI, UL-SCH, and UCI
  • Mapping of transport channels to physical channels
  • CRC coding
  • CRC masking of DCI messages
  • BCH coding
  • Code block segmentation
  • Convolutional and turbo coding
  • Rate matching, bit selection and pruning
  • Transport channels and control information processing chains
  • HARQ: incremental redundancy, stop and waitResource elements, and resource blocks

LTE Downlink Physical Layer Modulation

  • Downlink physical channel processing
  • Codewords and layers
  • Scrambling and modulation
  • Downlink multiantenna processing
  • Transmission schemes
  • Diversity, spatial multiplexing, and beamforming
  • Synchronization signals: PSS and SSS
  • Reference signals: cell and UE specific, MBSFN
  • Downlink physical channels: PBCH, PCFICH, PDSCH, and PDCCH
  • The control region
  • REGs and CCEs, PDCCH search spaces
  • Resource grid mapping

MIMO Background

  • Spectral efficiency and capacity
  • Transmit and receive diversity
  • The Alamouti Scheme
  • Delay diversity and cyclic delay diversity
  • Beamforming
  • Spatial multiplexing
  • Singular value decomposition
  • Equalizing and predistortion in MIMO systems
  • Precoding and combining in MIMO systems
  • Codebooks for MIMO

MIMO in LTE

  • Codewords to layers mapping
  • Precoding for spatial multiplexing
  • Precoding for transmit diversity
  • Beamforming in LTE
  • Cyclic delay diversity-based precoding
  • Precoding codebooks

LTE Uplink Physical Layer Modulation

  • Uplink physical channel processing chain
  • Scrambling and modulation
  • SC-FDMA review
  • Single carrier FDMA symbol construction
  • Uplink reference signals: DRS and SRS
  • Uplink physical channels: PUSCH, PUCCH, PRACH
  • Control information: CQI, RI, PMI, HI, and SR
  • Control signalling on PUSCH and PUCCH
  • PUCCH formats
  • Uplink physical channels and physical signals

Procedures

  • Cell search
  • Cell identities in cell search
  • Symbol synchronization
  • Frame and cell synchronization
  • System information acquisition: MIBs and SIBs
  • Timing synchronization procedures
  • Uplink power control

Release 9

  • Release 9 features
  • MBMS support
  • Home eNodeB
  • Positioning support
  • Transmission schemes

LTE Advanced

  • IMT advanced technologies
  • LTE Release 10 features
  • Carrier aggregation
  • Spatial multiplexing
  • Uplink multiantenna transmission
  • Downlink multipoint transmission

For more information contact the Short Course Program Office:
shortcourses@uclaextension.edu | (310) 825-3344 | fax (310) 206-2815

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