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Über dieses Buch

This book serves as an easily accessible reference for wireless digital communication systems. Topics are presented with simple but non-trivial examples and then elaborated with their variations and sophistications. It includes numerous examples and exercises to illustrate key points. The book emphasizes both practical problem solving and a thorough understanding of fundamentals, aiming to realize the complementary relationship between practice and theory. Though the author emphasize wireless radio channels, the fundamentals that are covered are useful to different channels - digital subscriber line, coax, power lines, optical fibers, and even Gigabit serial interconnection.

This book is the outgrowth of the author’s hands-on experience in the telecommunication systems industry as a research and development engineer. It is written primarily for practitioners of wireless digital communication systems – engineers and technical leaders and managers – and for digital communication systems in general including new comers like graduate students and upper-division undergraduate students.

The material in chapters 5(OFDM), 6(Channel coding), 7(Synchronization) and 8(Transceivers) contains something new, not explicitly available in typical textbooks, and useful in practice. For example, in Chapter 5, all known orthogonal frequency division multiplex signals are formulated based on pulse shape and thus flexible, e.g., unlike currently predominant symbol block transmission, it can be serial transmission. In Chapter 6, we emphasize practical applications of powerful error coding such as LDPC to higher order modulations, fading, and non-linearity problem. In Chapter 7, new digital timing detectors are suggested for small access bandwidth shaping pulse, and a digital quadrature imbalance correction is also included along with digital carrier phase recovery. In Chapter 8, low IF digital image cancelling transceiver is treated in detail so that practical implementation can be readily done with advantages.

Inhaltsverzeichnis

Frontmatter

Chapter 1. Overview of Radio Communication Signals and Systems

This chapter introduces the intent of the book briefly and then overviews the content of it in a nontrivial manner thus a bit lengthy as an introduction. But, it is hoped that it stimulate a reader to the topics of the book. A new comer might find it a bit challenging for the first reading as an introduction, but one can move on since the topics will be elaborated later in detail.
List of sections in Chap. 1:
1.1
Examples of Wireless Communication Systems
 
1.2
Overview of Wireless Communication Systems
 
1.3
The Layered Approach
 
1.4
Historical Notes
 
1.5
Organization of the Book
 
1.6
Reference Example and its Sources
 
Sung-Moon Michael Yang

Chapter 2. Digital Modulations

We partition the communication signals into three – constellation, complex envelope (continuous I and Q baseband), and CW (real RF signal). Our focus in this chapter is on discrete-time representations, but we have to relate them to complex envelope and CW. This is done with binary cases – BPSK (2-PAM), OOK, and orthogonal (a form of FSK) using a rectangular pulse for converting to complex envelope and quadrature modulator to CW. Then binary modulations are extended to multi-level ones – PAM, QAM, and PSK. Additional topics that arise due to practical reasons are covered: offset QAM, scrambler, and 180° and 90° differential coding. PRS is an attempt to reduce the bandwidth. FSK is explored for noncoherent detection and its constant envelope property. The computation of PSD is explored analytically as well as numerically. Numerical simulation method is universally applicable even when no analytical solution is available.
List of sections in Chap. 2
2.1
Constellation, Complex Envelope, and CW
 
2.2
Power of Digitally Modulated Signals and SNR
 
2.3
MAP and ML Detectors
 
2.4
PAM, QAM, and PSK
 
2.5
BER and Different Forms of SNR
 
2.6
Offset QAM (or Staggered QAM)
 
2.7
Digital Processing and Spectrum Shaping
 
2.8
Frequency Modulation – FSK, MSK, and CPFSK
 
2.9
PSD of Digitally Modulated Signals
 
2.10
Chapter Summary and References
 
Sung-Moon Michael Yang

Chapter 3. Matched Filter and Nyquist Pulse

This chapter covers two major coupled topics: matched filter and Nyquist pulse. The former maximizes SNR at the sampling time, and the latter is intersymbol interference (ISI) free end-to-end pulse. Both considerations will guide how to design, transmit, and receive filters (shaping pulses). We cover two practical filter design cases: analog and digital hybrid and purely digital ones.
List of sections in Chap. 3:
3.1
Matched Filters
 
3.2
Nyquist Criterion: ISI-Free Pulse
 
3.3
Shaping Pulse (Filter) Design
 
3.4
Performance Degradation Due to ISI
 
3.5
Extension to Linear Channel and Nonwhite Noise
 
3.6
References
 
Sung-Moon Michael Yang

Chapter 4. Radio Propagation and RF Channels

This chapter covers RF channel models including propagation and antenna. From modem point of view, all the components in RF, e.g., LO, LNA, and PA, are part of channel. However, this chapter covers antenna, propagation media, frequency-selective fading due to surrounding terrains and obstacles, and time-selective fading due to the movement of transmitter and receiver. The measurement of RF channel is covered briefly as well. Channel models used in standards and LEO channel models are included as well.
List of sections in Chap. 4:
  • 4.1 Path Loss of Radio Channels
  • 4.2 Antenna Basic and Antenna Gain
  • 4.3 Path Loss Due to Reflection, Diffraction, and Scattering
  • 4.4 Multipath Fading and Statistical Models
  • 4.5 Channel Sounding and Measurements
  • 4.6 Channel Model Examples
  • 4.7 Summary of Fading Countermeasures
  • 4.8 Reference with Comments
Sung-Moon Michael Yang

Chapter 5. OFDM Signals and Systems

OFDM is a very special form of FDM signal applied to digital transmission by choosing the subcarrier spacing to be related with the subchannel symbol rate and the number of samples per symbol period. We need to choose the shaping filter of subcarrier to be the same. When it is a rectangular pulse, it becomes implicit, and most often it results in DMT with CP. In this chapter we extend this basic concept to filtered OFDM, and staggered OFDM, and further show that all different OFDMs can be implemented by commutating filter (polyphase form) in conjunction with IDFT-DFT. The commutating filter is a special form time-varying FIR filter. We consider practical issues, applications of filtered OFDM, and applications to doubly selective fading channels.
List of sections in Chap. 5:
  • 5.1 DMT with CP – Block Transmission
  • 5.2 CP Generalized OFDM – Serial Transmission
  • 5.3 Filtered OFDM
  • 5.4 OFDM with Staggered QAM
  • 5.5 Practical Issues
  • 5.6 OFDM with Coding
  • 5.7 Chapter Summary
  • 5.8 References
Sung-Moon Michael Yang

Chapter 6. Channel Coding

This chapter covers the topics of channel coding applicable to digital communications – introduction with repetition codes and coding with parity, cyclic algebraic code of BCH and RS and more, convolutional codes with Viterbi decoding and with BCJR decoding, LDPC, Turbo codes, and applications of coding to higher-order modulations as BICM and MLCM, to PAPR reduction, and to fading channels.
List of sections in Chap. 6;
  • 6.1 Code Examples and Introduction to Coding
  • 6.2 Linear Binary Block Codes
  • 6.3 Convolutional Codes
  • 6.4 LDPC
  • 6.5 Turbo Codes
  • 6.6 Coding Applications
  • 6.7 References with Comments
Sung-Moon Michael Yang

Chapter 7. Synchronization of Frame, Symbol Timing, and Carrier

The literature on synchronization is vast, and yet there seem no clear-cut fundamentals identified. Our approach here is to treat the topic from modern implementation point of view, namely, the most of demodulation functions are implemented digitally, after sampling, rather than by analog signal processing. Another point is a fast synchronization, in fact, aiming as fast as theoretically possible with minimum variance. An extensive development for TED is based on two or four samples per symbol, which works with a large carrier frequency offset.
List of sections in Chap. 7:
  • 7.1 Packet Synchronization Examples
  • 7.2 Symbol Timing Synchronization
    • Digital TEDs with 2 or 4 samples per symbol
    • Embedding digital TED into timing recovery loop
    • Simulations of Doppler clock frequency shift
  • 7.3 Carrier Phase Synchronization
  • 7.4 Quadrature Phase Imbalance Correction
  • 7.5 References with Comments
Sung-Moon Michael Yang

Chapter 8. Practical Implementation Issues

This chapter covers transceiver architectures – direct conversion, heterodyne conversion, and low digital IF image-cancelling transceiver – transmit RF signal generation, and receiver RF signal processing. We examine the required number of bits and the optimum power level for DAC and ADC. A particular emphasis is on low digital IF image-cancelling transceiver; it is described in great detail so that one skilled in the art of transceiver can implement. The quality measurement of quadrature modulator (demodulator) related with DC offset and quadrature imbalance is explained in detail so that they can be calibrated as well.
List of Sections
8.1.
Transceiver Architecture
  • Transceiver of low digital IF with image cancelling
  • Calibration of quadrature modulator/demodulator
 
8.2.
Practical Issues of RF Transmit Signal Generation
  • DAC
  • PA and non-linearity
 
8.3.
Practical Issues of RF Receive Signal Processing
  • ADC
  • RCV dynamic range and AGC
  • VLNA, NF, and receiver sensitivity threshold
 
8.4.
Chapter Summary and References with Comments
 
Sung-Moon Michael Yang

Chapter 9. Review of Signals and Systems and of Probability and Random Processes

This chapter is a collection of review materials from signals and systems – continuous and discrete – and conversion between them and from probability, random variable, and stochastic process.
List of sections in Chap. 9:
  • 9.1 Continuous-Time Signals and Systems
  • 9.2 Discrete-Time Signals and Systems
  • 9.3 Conversion Between Discrete-Time Signals and Continuous-Time Signals
  • 9.4 Probability, Random Variable, and Process
  • 9.5 Chapter Summary and References with Comments
Sung-Moon Michael Yang

Backmatter

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