Training Courses - Microwave Digital Systems

Motivation of this Training Program is briefly presented. Then, the Free Space Radio Link Equation is presented. Moving to terrestrial radio links, we discuss Link Budget and Fade Margin, which are the tools useful to predict radio hop Outage Probability.

Path Analysis, Obstructions

The propagation path of a radio wave through the atmosphere is discussed by introducing the k-factor concept. Possible deviations from standard conditions are identified, as well as the minimum k-factor value. Then the Fresnel ellipsoid is defined; partial obstructions of the ellipsoid lead to the obstruction loss estimate. Finally, ITU-R recommended Clearance Criteria are presented.

Multipath Fading

Refractivity conditions likely to produce multipath propagation are first considered. Received signal impairments and multipath activity statistics are described, introducing the multipath occurrence factor. Multipath models are applied to outage prediction (narrow- and wide-band systems). Finally, multipath countermeasures (adaptive equalization, diversity) are considered.

Rain Attenuation

First, the interaction of an EM wave with molecules or particles in the atmosphere is discussed. This leads to an estimate of rain specific attenuation, as a function of rain intensity, signal frequency and polarization. Worlwide statistical data on rain intensity are considered, as required by the ITU-R rain model to predict rain unavailability, at frequencies up to 90 GHz.

Session 1 : Absorption and Scattering

An EM Wave collides with Molecules and Particles (Video Lesson)

Complementary Notes (pdf)

Preliminary Test

Session 2 : Basic Radio Link Equation

How to Predict Outage caused by Rain (Video Lesson)

Complementary Notes (pdf)

Preliminary Test

Design Exercise (HERALD Lab)

Rain Outage in different Climates (Video Demo)

Final Test

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