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Course #58
Modern Digital Modulation Techniques for Wireless, Satellite,
and Wireline Communications
May 10-14, 2010. Cambridge, UK
October 4-8, 2010. Copenhagen, Denmark
INSTRUCTOR
Professor
Irving Kalet
Tel Hai College, Haifa, Israel, and Columbia University, New
York, USA
TECHNOLOGY FOCUS
Modern digital modulation techniques and multiple access techniques are basic building blocks of the physical or radio interface of all digital communication systems. OFDM, OFDMA, SOFDMA, SC-FDMA, DMT, MIMO and BLAST, and adaptive modulation and coding methods are becoming very important parts of the implementation of modern communications systems, especially for broadband wireless communications. These concepts are being utilized in new mobile and broadband wireless systems including 3G-LTE, Mobile Wi-Max (IEEE 802.16) and Wi-Fi (IEEE 802.11) systems, as well as xDSL systems, to greatly improve both bandwidth and power efficiency.
COURSE CONTENT
We will describe the digital modulation techniques used in the major wireless and wireline communication systems in use today and those planned for the near future. We begin with a discussion of the major communications channels including the fading channel of wireless communications. We continue with a description of the classic modulations, e.g., QPSK, QAM and GMSK. We will also discuss the important multiple access techniques, with special emphasis on OFDMA and CDMA. New techniques, including SOFDMA, SC-FDMA, OFDM-MIMO, Alamouti space-time coding, iterative techniques, and adaptive modulation and coding, are also described. We will also discuss the information theory limits on communications.
OBJECTIVES
After participating in this course, you will:
Understand the modulations and multiple access techniques in use in modern mobile wireless, broadband access and wireline communications
Understand OFDM, OFDMA, Scalable OFDMA, SC-FDMA and their DMT implementations
Understand the performance of classic modulations such as QPSK and QAM, as well as the CPM modulations, e.g., GMSK
Understand the space, time and frequency diversity techniques of wireless communications e.g., MIMO-BLAST, Alamouti Coding
Be familiar with the radio (or physical interface) of the Wi-Fi, Mobile Wi-Max and 3G-LTE broadband wireless systems
Monday
Rayleigh Fading Channel and Baseband Nyqvist Signaling
The course begins with a description of the channel models for mobile and/or wireless and wireline systems. This is followed by discussions of Nyquist baseband signalling, as well as ISI and linear equalization.
- System Model-The Channel
- The Multipath Channel (Rayleigh, Frequency-Selective Fading)
- Twisted-Pair Channel
- Brief Review of Fourier Transform, Power Spectral Density, White Noise
- Nyquist Signaling
- ISI, Optimum Filtering, Linear Equalization
- Partial Response Signals-Why the MLSE and the Viterbi Algorithm?
Tuesday
Signal Space, Optimum Detection
The concept of signal space is used to define the classical modulation techniques and derive the optimum detectors.
- Signal Space
- BPSK, QPSK, MPSK, QAM, BFSK and MFSK
- Optimum Detection of Binary Signals
- Matched Filter
The Rayleigh Fading Channel and Antenna Diversity-BLAST, MIMO
We now have an in-depth discussion of the performance of modulations, transmitted over Rayleigh fading channels, followed by the concept of space diversity (BLAST and MIMO), which is used to greatly improve spectral efficiency.
- Detectability Performance over Rayleigh Fading Channel
- Classic Antenna Diversity (SIMO)
- MIMO
- BLAST
Wednesday
MSK-type Signals
QPSK, SQPSK, and MSK are essentially constant envelope modulations, which are used in many satellite and wireless systems.
- QPSK, SQPSK, pi/4 - QPSK, EDGE "8PSK"
- MSK-type (MSK, SFSK) Signals
- Adjacent Channel Interference (ACI)
M-ary Signals
M-ary signals are used in many systems, e.g., analog modems, ADSL, VDSL, microwave radio, and in the EDGE-based 3G Physical Interface Standard.
- Optimum Detection of M-ary Signals
- MPSK
- QAM-Nyquist Signaling
- MFSK
Shannon Information Theory
Shannon information theory has led us to the concepts of multitone modulation (DMT), OFDM, and adaptive modulation and coding.
DMT and OFDM are the standards for the IEEE 802.11 and 16 broadband wireless systems, and 3G-LTE, as well as ADSL and VDSL. We present an in-depth discussion of OFDM, OFDMA, Scalable OFDMA and SC-FDMA
- Introduction to Shannon Information Theory
- Channel Capacity for Ideal and General Gaussian Channels
Multitone-DMT
- Discrete Multitone (DMT) - Implementation
- The Twisted Pair Channel
- Multitone over the Twisted Pair Channel (ADSL and VDSL)
OFDM-Orthogonal Frequency Division Multiplexing
- OFDM - for Broadband Wireless Communications
- Adaptive Modulation and Coding Techniques
- Physical Interfaces of IEEE 802.11 (Wi-Fi), IEEE 802.16 (Wi-Max and Mobile Wi-Max) and 3G-LTE
- OFDMA as a Multiple Access Technique
- Scalable OFDMA
- SC-FDMA (Single-Carrier FDMA-3G-LTE)
- OFDM-MIMO-Wi-Media Standard
- UWB-OFDM
Thursday
Trellis Coding and The Viterbi Algorithm
We continue with a description of trellis coded modulation concepts, including a discussion of the Viterbi Algorithm. We also include the topic of interleaving for improving the performance of modulations on Rayleigh fading channels.
- The Viterbi Algorithm (VA)
- Ungerboeck Trellis Coding
- The VA Equalizer
- Interleaving for Rayleigh Fading
Turbo-Coding-Introduction
A topic of increasing importance is the turbo-coding (iterative decoding) concept and its use in areas such as antenna diversity, equalization and OFDM.
- Turbo Coding
- Iterative Decoding Techniques
- Turbo-Equalization
- LDPC Codes
Capacity of Rayleigh Fading Channels
Shannon's work has been updated to include bounds on the performance of Rayleigh fading channels. This work led to the concept of MIMO and space-time (Alamouti) coding.
- Bounds on Communications for Fading Channels
- OFDM-MIMO-Coding
- Space-Time Coding
- Alamouti Coding
- Multi-User Diversity Techniques
CPM Type Modulations
CPM signals (e.g., GMSK) are constant envelope, bandwidth efficient modulations, suitable for use with nonlinear power efficient, transmitting power amplifiers.
- Continuous Phase Modulation (CPM)
- Gaussian MSK (GMSK)
- Tamed FM (TFM)
- Generalized TFM (GTFM)
- Adjacent Channel Crosstalk in CPM Signals
Friday
Non-Coherent Detection
- DPSK
- FM Detection of CPM Signals-Bluetooth, DECT
Cellular Communications-Radio or Physical Interface
We continue with a discussion of multiple access techniques, with emphasis on CDMA and
WCDMA. We describe the radio interfaces of the IMT-2000 WCDMA system, as well as GSM, IS-136, GPRS, 1xEV, EDGE and the physical interface of IS-95.
CDMA and WCDMA Systems
- The RAKE Receiver
- Pseudo-Random Sequences
- Power Control
- Intra and Inter-Cell Interference and Capacity
- IS-95 Physical Interface
- IMT-2000 WCDMA Physical Interface: Walsh and OVSF Functions
Ultra-Wideband Radio (Time-Permitting)
DFE and Tomlinson Filtering (Time-Permitting)
- Tomlinson Filter
- DFE
- Trellis Coding in an ISI Environment
- Tomlinson Filter and Trellis Coding, Implementation Using Decision Feedback Equalization
Summary
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