Category: Telecommunications

In a previous post Ref.1 I looked at VOACAP and it’s use in a simple off air receive situation. In this post I will delve a little further into the software and compare the results against some simple mathematical models. VOACAP (Voice of America Coverage Analysis Program) is free professional high-frequency (HF) propagation prediction software… Continue reading VOACAP – CHU to VE3PKC+

VOACAP (Voice of America Coverage Analysis Program) is free professional high-frequency (HF) propagation prediction software from NTIA/ITS, originally developed for Voice of America (VOA). In this video we will study the propagation between the time signal station CHU located in Ottawa Canada with a receiver located at VE3PKC in Toronto Canada. The actual received signal… Continue reading VOACAP – CHU to VE3PKC

Introduction The unit impulse or Dirac Delta function δ(t) is an essential building block of modern telecommunications, similar in importance to the FFT that was examined in the previous post. The function came about as a result of research done by the British Physicist Paul Dirac on the modelling of a point charge (Ref.1). It… Continue reading Dirac Delta Function – δ(t)

The FFT or Fast Fourier Transform was described by Cooley & Tukey in their 1965 paper “An Algorithm For The Machine Calculation of Complex Fourier Series” (Ref.1). The method has earlier roots in the works of Carl Gauss and others (Ref.2). The purpose of the FFT is to reduce the calculation complexity of the DFT… Continue reading FFT – A Telecommunications Revolution

In the previous post, I discussed using Splat! to predict the receive level of an RF signal. In particular I considered CBLFT UHF CH25 as received from the CN Tower as shown above in Figure 1. In order to study ATSC_8VSB which is the DTV standard used in North America, GNU Radio can be used… Continue reading GNU Radio ATSC_8VSB Transmitter Simulation