A practical implementation of a PPM/FSK data transmission system using combined spectrum and time spreading

by Karl-Max Wagner and Ikuo Oka

1   System Basics

1.1   PPM









1.2   FSK

1.3   Conditions of how to combine both

















1.4   Spread Spectrum

























Show advantages

1.5   Spread time

1.5.1   Chirp filters









1.5.2   Generalized chirp filters









1.5.3   Convolution with arbitrary filter function in the frequency range









2   Hardware Layout

2.1   Analog system

















2.2   Digital system









3   Software Layout

3.1   Transmitter









3.2   Receiver

3.2.1   Common receiver problems

Consequence: We need a

These are essential in any practical receiver system.

3.2.2   Receiver block diagram

















3.2.3   Frequency deviation / signal detector

Theory of operation
















Details of operation








3.2.4   Signal acquisition unit









3.2.5   Signal decoding / operations sequencing unit









4   Implementation method

The software system is implemented using a library system for communications functions which is under development and poised to become a complete suite for communications, particularly softradio design from the inception over simulation to hardware programming to produce the actual system. Details will be disclosed at the softradio conference in Tokyo October 20. Interested parties are invited to attend.
This document was translated from LATEX by HEVEA and some homemade shell scripts.