Selected Papers by DJ5HG

These are mainly papers concerning Digital Communication Techniques or The Validity of QSOs

The Cat and the Squirrel

This presentation gives an overview on basic principles of digital communication. Three cases are analysed: (1) the confident physical detection of a radio signal with known structure; (2) the unidirectional transfer of information via the radio path; and (3) the dialog via the radio path. Especially, the minimal bidirectional contact and the problem of internet use to communicate QSO-relevant information are investigated.

Download catsquirrel.pdf (120 kB)

Deep Search Cannot Communicate Callsigns

There has been some discussion on the validity of QSOs which use the deep search decoder of JT65. The goal of this paper is to explain the basic principle of deep search more intuitively, but without loss of correctness.

Download deepsearch.pdf (160 kB)

Digital Modes for Weak-Signal Communications

This is the Presentation on the VERON VHF-Day 2007 in Dwingeloo.

Download digitalmodes.pdf (3.3 MB)

Possibilities and Limitations of Forward Error Correction in Minimal QSOs

This presentation analyses Shannon's famous theoretical result on the maximum achievable inform­ation bitrate and applies the results to the case of a minimal QSO. It will be explained why the energy to communicate an optimally encoded callsign in a single transmission is more than twice that given by the Shannon limit and more than eight times in the case of an uncoded transmission.

Download limfec.pdf (1.1 MB)

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