Simulation example: FSK

Under construction!

GNU Radio (GR) is an excellent tool for simulating a radio system and experimenting with changing parameters. This tutorial presents a simple Frequency Shift Keying (FSK) transmitter and receiver. It can be performed with either GR version 3.7 or 3.8 (and later). The Graphical User Interface gnuradio-companion (GRC) is used to create the flowgraph. No special hardware is required.

Prerequisites

• Intro to GR usage: GRC and flowgraphs
• Understanding sample rate

Simulating a transmitter and receiver

Using gnuradio-companion (GRC) and the following Block descriptions, build this flowgraph:

Setting variables and parameters

Most of the parameters can be set from the screenshot of the flowgraph.

• The Options block identifies the filename for the flowgraph, a title, author, etc.
  • id: FSK_example
  • Click on File -> Save As  Use the file name 'FSK_example'. the extension '.grc' is added automatically

For this tutorial I am using the baud rate for Baudot Radioteletype. It is defined as a bit time of 22 milliseconds, so the baud rate is set to 1/0.022 giving 45.4545

The repeat factor is (int)(samp_rate*0.022)

Testing