Digital Communications

Online Content underdevelopment (2024)

(Experimental Link)

Course Goals

• Introductory course on modern digital communication systems.
• The basic communication system theory, probability and random processes, baseband digital data transmission, coherent and non-coherent digital modulation techniques and analysis of bit error probability.
• Bandwidth efficiency and transmission of digital data through band-limited channels.

Support Videos

• Entropy (for data science) Clearly Explained!!! (Link)

Academic Years

2022/2023

Lecture Reference Books

Charan Langton
"Tutorials on Digital Communication"
(Weblink)

Marc Lichtman
"PySDR: A Guide to SDR and DSP using Python"
(Weblink)

Lab Reference Books

Paul Clark and David Clark
"Introduction to Software Defined Radio: Volume 1"
Meadow Registry, LLC, 2015

Paul Clark and David Clark
"Basic Analog Radio: Volume 2"
Meadow Registry, LLC, 2015

Paul Clark and David Clark
"Basic Digital Communications: Volume 3"
Meadow Registry, LLC, 2015

Software

• GNURadio

Course Modules

Module 1 - Introduction

• Fundamentals of Signal
  • Signal types, differences between discrete and digital
  • Information, carrier, modulated signals
  • Bandwidth, periodicity
  • Power and energy of signals
  • Sampling
  • Difference between information theory, communication theory, and signal processing
  • Noisy signals and random signals
  • Signal properties (e.g.: mean, variance, PDF, CDF)
  • Transform in signal processing (e.g.: FT & DFT, Laplace, Z-Transform)
• Frequency Domain
  • Fourier series
  • Time frequency pairs
  • Fourier transform
  • Time frequency properties
  • FFT
  • Negative frequencies (Complex Fourier)
  • Windowing
  • FFT sizing
  • Spectrum/waterfall

Module 2 - Analog Data to Analog Signals

• Baseband, passband signal
• AM modulation
• Side bands (SSB, DSB)
• VSB
• Demodulator
• Envelope detector
• Angle modulations (e.g.: FM, PM)

Module 3 - Digital Data to Analog Signals

• Basic concepts of modulation
• OOK (ASK)
• FSK and MSK
• Signal spaces and basis functions
• The concept of IQ channels
• IQ sampling (e.g.: quadrature sampling, carrier and down conversion, DC spike)
• Symbols, bits and bauds
• PSK modulations (e.g.: BPSK, QPSK, 8PSK, 16PSK, QAM, 16 QAM, 64 QAM)

Module 4 - Noise and dB

• Gaussian noise
• Decibels
• Noise in frequency domain
• Complex noise
• AWGN
• SNR and SiNR

Module 5 - Filters

• Basics of digital filters
• Representation, implementation and design tools
• Convolution
• Intro to pulse shaping

Module 6 - Pulse Shaping

• ISI
• Matched filter
• Splitting filter in half
• Specific pulse shaping filter
• Roll-off factor

Module 7 - Multipath Fading

• OFDM
• CDMA

Module 8 - Channel Coding

• Types of codes
• Code rate
• Modulation and coding
• Hamming code
• SDFT vs hard decoding
• Shannon limit
• State of the art codes

Module 9 - Link Budgets

• Signal power budget
• Noise power budget
• SNR
• BER
• Nyquist, Shannon limits
• Antennas
  • Characteristics, types, polarization
  • Noise mitigation
  • Connectors

Module 10 - Synchronization

• Time sync
• Time sync with interpolation
• Coarse frequency sync
• Fine frequency sync
• Frame sync