Posts Tagged - digital-communications

Tech Report: IEEE 802.11 and Propagation Modeling: A Survey and a Practical Design Approach

Technical Report, Masood Khosroshahy (2007)

Abstract—Due to known difficulties of researchers in the networking domain regarding experimentation of their ideas in actual networks, network simulators have become indispensable tools for investigating and validating various ideas in all layers of the network. In this survey, we inspect the implementations of IEEE 802.11 PHY-MAC and propagation models of some of the well-known, open-source network simulators. The chosen simulators are: NS-2, OMNeT++, GloMoSim, J-Sim and JiST/SWANS. The study concentrates on the availability and implementation flexibility of MAC modes, physical layer features and propagation models. This survey could help the research community in determining the state-of-the-art of IEEE 802.11 implementations and, to the best of our knowledge, is the first such study published in the open literature. To facilitate the ongoing and future network simulator developments, we also present our design and implementation approaches in successfully developing a prototype of a detailed IEEE 802.11a PHY layer along with the propagation models.

Index Terms—IEEE 802.11, Network Simulators, Propagation Models, WiFi

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Project: Simulink and Code Generation using Real-Time Workshop : Rayleigh Fading Channel

Date Completed: September 18, 2003

Fading is one of the important obstacles which limits the wireless transmission. Deep fading will cause loss of signal at the receiver. The transmitted signal will arrive at the receiver antenna through multiple paths which causes what is known as multipath fading. Each path has its own delay and attenuation and the received signal amplitude is the collective effect of the signals arrived through different paths.

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Project: A DSP Educational Package

Date Completed: June 09, 2003

This project has been conducted in a teamwork manner. Some important concepts of an introductory course on DSP were chosen. First, few were responsible for implementing the code in Matlab using M-files, and at the next stage, others were responsible for transferring the code to GUIs so that the users can enjoy the comfort of windows-based execution. This package was supposed to serve as an educational aid package for the DSP course at MS level and the book “Discrete-time signal processing” by: Alan V. Oppenheim, Roland W. Schafer, and John R. Buck was chosen as the reference.

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