OFDM and MIMO Wireless Technologies with Applications to WiMax and UMTS LTE

TECHNOLOGY FOCUS 
The expansion of information services in the last decade has affected the way we live and work. Notwithstanding dampened early unrealistic expectations, the Internet continues to grow faster than any other global infrastructure in history. Alongside the Internet, we have witnessed a phenomenal growth in wireless communications. Third Generation (3G) cellular service is widely available. Metropolitan area networks supported by the newly established IEEE 802.16 /WiMax standards are starting to appear in cities and towns around the world. Looking forward, UMTS Long Term Evolution (LTE) is being specified and it will provide a new physical layer and higher layer protocol architecture for the fourth generation (4G) of mobile communication systems. 

Increasingly, the driving force behind future growth in the telecommunications industries is seen to be broadband wireless access to the Internet and wireless data connectivity to mobile users. Orthogonal Frequency Division Multiplexing (OFDM) and Multiple Input Multiple Output (MIMO), which are increasingly seen as the physical layer technologies capable of supporting the ever-increasing appetite for capacity and data rates, are the topic of this course. 

COURSE CONTENT AND OBJECTIVES
The course focuses on two key wireless technologies, OFDM and MIMO, and it contains details on the applications of these technologies to new wireless systems such as WiMax and UMTS LTE. The course seeks to enable participants to acquire a thorough understanding of the underlying principles of OFDM and MIMO and their relation to the medium in which they operate. Design principles and tradeoffs are discussed in detail. Matlab software is used to demonstrate key concepts. Participants may use the software for hands-on analysis and simulations. At the end of each section, participants have the 
opportunity to work through review problems that reinforce key notions 
introduced in the section. The course will prepare participants to:

• Understand the limitations of current wireless systems as drivers for the development of emerging technologies.
• Become familiar with characteristics of the wireless transmission medium and use them to motivate the development of new wireless technologies.
• Become knowledgeable with the salient features of key new wireless technologies, including design principles and performance tradeoffs.
• Be able to appreciate the latest and emerging technologies in this fast-moving field.

Monday
Multicarrier Technologies 
We begin with the characteristics of the wireless channel. Fundamental concepts of OFDM are explained in the context of performance over multipath fading channels.

• OFDM: FFT-based OFDM, power spectrum
• Optimizing OFDM Transmission: Guard time, cyclic extension, pulse shaping, adaptive modulation, system design example
• Synchronization and System Imperfections: Preambles and pilots, time synchronization, frequency offset synchronization, phase noise, channel estimation, equalization, Matlab examples
• Channel Coding for OFDM: Convolutional coding, puncturing, performance over frequency-selective channels
• Matlab examples

Tuesday
OFDM for Multiple Users 
We now focus on multicarrier schemes for multiple users. Design tradeoffs and complexities are discussed. Performance metrics of the course are extended to the multiple user case. System design issues such as intra-user interference are addressed.

• Peak-power Problem: Harmonic distortions, techniques for reducing PAPR, 
  single-carrier frequency-domain equalization, clipping
• Multiple Access Techniques: OFDMA, MC-CDMA
• Multiuser Diversity
• Applications: Cognitive wireless networks (IEEE 802.22)

MIMO Principles 
The main concepts in exploiting the spatial dimension in wireless communications and the use of multiple antennas is discussed in depth for free-space and multipath channels. Multipath scattering is the enabler to huge communication gains. Key concepts such as spatial diversity and spatial multiplexing are discussed in depth. Systems with multiple antennas at the transmitter and at the receiver are contrasted.

• Properties of Adaptive Arrays, Beam Pattern, Array Gain, Transmit 
  and Receive Arrays
• MIMO Channel Models, Channel Estimation
• MIMO Capacity, Channel Known at the Transmitter

Wednesday
MIMO Systems and Techniques 
Multiple transmit antennas can be exploited to obtain diversity gains, spatial multiplexing gains, or both. Space-time codes combine the benefits of spatial diversity and coding gains. We discuss examples of space-time codes, their design, performance, and complexity and their emergence in various standards. This is followed by systems and techniques that focus on spatial multiplexing. The availability of channel state information (CSI) at the transmitter supports MIMO systems with enhanced data rate performance. Techniques utilizing CSI feedback from the receiver are presented.

• Diversity with Receive Antennas: MRC, optimum combining, correlated 
  channels, Matlab examples
• Diversity with Transmit Antennas, Alamouti's Scheme, Space-time Block Codes, Matlab Examples
• Transmit Diversity Schemes for 3GPP and 3GPP2
• Phase Sweeping, Delay Diversity, Cyclic Delay Diversity
• Spatial Mutliplexing Systems: BLAST, layered schemes, Matlab examples
• Closed Loop Systems: Diversity systems, spatial multiplexing over eigenmodes
• MIMO-OFDM

Thursday
UMTS LTE and WiMax Applications 
OFDM and MIMO will serve as the physical layer of two key technologies for future mobile communication systems: UMTS LTE and WiMax. In this part, we will discuss the role of OFDM and MIMO in the evolving standards for LTE and WiMax. LTE is the 4G evolution of cellular systems, while WiMax is a technology that is expected to deliver last mile wireless broadband access.

• Background to LTE: HSPA Release 7
• LTE Design Goals
• Frame Structure
• Downlink MIMO Modes
• Physical Resource Block
• LTE Oplink: Single Carrier (SC) - FDMA
• WiMax: Overview of MAC layer, MAC protocol data units
• Frame Structure
• Ranging
• Quality of Service Classification
• ARQ
• Scalable OFDMA
• Adaptive Modulation and Coding
• OFDMA Channelization: PUSC, FUSC, AMC, Matlab example
• Multiple Antenna Technology in WiMax

Said about the course from previous participants:
"Not too much mathematics, good explanation of complex matters."
"Professor Haimovich had the capabilities to explain a very complex topic in a very vivid way."
"Well-organized material with a review at the end of each section."
"The teacher had a good dialogue with the participants and was open to questions and the ability to join complex items with simple and clean explanations, letting the possibility to further dig into them."