How can I simulate fading in radio?

How can I simulate fading in radio?

It is possible to perform such calculations by modifying the default pipeline stages used for radio communication. An example of slow fading calculations can be found in the cellphone standard model (<opnet_dir>/<release>/models/std/cellphone directory).The cell_bkgnoise.ps.c contains a pipeline stage that obtains a setting for whether the caller is in an urban, rural, or suburban environment to determine background noise. For fast fading caused by multipath effects due to terrain you can also replace default stages with your own customized pipleline stage (like power or path loss) to take into account of the terrain effect. The Terrain Modeling Module (TMM) does not currently include calculations for fading, however it doesprovide an easy way for you to create your own propogation model which couldinclude fading effects. The following are useful documentation references for describing wireless modelingin general, and about using antenna patterns in particular:Modeling Manual, Volume 1:Comec (Communication Mechanisms) Chapter, Communication Links: Radio Links sectionNddef (NOde Definitions) Chapter, Antenna Modules sectionModeling Manual, Volume 2:Ndref (Node Reference) Chapter, Antenna Object sectionExample Models Manual:Pipleline Stages: Radio Links chapter, Default Transmitter Antenna Gain Module section Wireless Module User Guide

Protocols->Wireless LAN