PSK31 Demodulation (Kurt & Michael): Difference between revisions

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Our receiver is split into several steps:
Our receiver is split into several steps:
# We read in the message from a wav file and generate utility signals and matrices.
# We read in the message from a wav file and generate utility signals and matrices.
# We run the signal through an FFT and average over the range of the FFT spike to obtain a carrier frequency guess.
# We run the signal through an FFT and take an average over the range of the FFT spike to obtain a carrier frequency guess.
# PID stuff '''''(Do you want to go into detail here Kurt?)'''''


=== Code ===
=== Code ===

Revision as of 21:18, 12 December 2012

Project Description

The goal of this project is to design and code a Matlab script that will encode and decode a PSK31 signal including signals with noise. The receiver should be able to read in signals (as a wav file) from other sources as well.


PSK31 is a audible text encoding that can be sent over the air by amateur radio operators. A computer's sound card can be used to send and receive the signal since the signal is audible. For more information regarding PSK31 see the Wikipedia article.[1]

Our Approach

Code Overview

Transmitter

Our code creates a PSK31 signal given an input carrier frequency and message. For testing our receiver code, the transmitter is setup to generate a random carrier frequency and phase. It also adds random noise to the signal before writing it to a wav file.

Receiver

Our receiver is split into several steps:

  1. We read in the message from a wav file and generate utility signals and matrices.
  2. We run the signal through an FFT and take an average over the range of the FFT spike to obtain a carrier frequency guess.
  3. PID stuff (Do you want to go into detail here Kurt?)

Code

Results/Problems