Communications Systems

ENGR 456

Articles

• AM vs FM Modulation (Jodi and Eric)
• Single Side Band (SSB) Modulation (Nick Christman, in progress)

• Double Side Band (DSB) Modulation (Joshua Sarris)

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Links

PLL Links

• Phase Locked Loops
• Phase Locked Loops Feedback Theory
  • C++ code for three software PLLs
  • A MATLAB software PLL is down the page here.

Matched Filters

• Matched Filter A Posteriori Detector Paper

PSK31 Links

• Peter Martinez's original article from Radio Communications, December 1998
• The Official PSK31 Homepage
• ARRL PSK31 Specifications
• PSK31 Project of Ted, Trent and Travis
• The professor's PSK31 Modulator on GitHub
• PSK31 Demodulator Using Digital PLL
  • The design files and code for the PSK31 and RTTY demodulator above
• PSKcore DLL from Moe Wheatley
  • Documentation and Algorithms of PSKcore
  • NUE-PSK (this article describes an algorithm for encoding and decoding PSK31 based on PSKcore)
• Some PSK31 (and other) signals recorded off the air.

CW Decoder Links

• Jeff McDow's Senior Report on Morse Code Detection
• The sauditor program patched for fftw3.
• Audacity file for testing with your CW Decoder Project
• Jack Audio Connection Kit Manual
• Demorse
• Using a Pipe or Fifo
• More on Pipes and other C Functions
• Free Open Textbook on Communications Systems

Shannon's Papers On Information Theory

• Communications in the Presence of Noise, Proceedings of the IRE, January, 1949 This paper derives and explains Shannon's most important results. It is very understandable for someone who has taken Signals and Systems.

• Shannon's Bell Labs Technical Journal Articles 1948. These are more detailed.