Engineering Commons^™

Situation-Aware Rate And Power Adaptation Techniques For Ieee 802.11, Jay Nadeau

Electronic Thesis and Dissertation Repository

The current generation of IEEE 802.11 Wireless Local Area Networks (WLANs) provide multiple data rates from which the different physical (PHY) layers may choose. The rate adaptation algorithm (RAA) is an essential component of 802.11 WLANs which completely determines the data rate a device may use. Some of the key challenges facing data rate selection are the constantly varying wireless channel, selecting the data rate that will result in the maximum throughput, assessing the conditions based on limited feedback and estimating the link conditions at the receiver.

Current RAAs lack the ability to sense their environment and adapt accordingly. 802.11 …

Performance Analysis Of Channel-Aware Media Access Control Schemes, Abdulfattah Noorwali

Electronic Thesis and Dissertation Repository

This thesis proposes a new Channel-Aware MAC (CA-MAC) protocol that allows more than two simultaneous transmissions to take place within a single wireless collision domain. In this proposed work, Multiple-Input Multiple-Output (MIMO) system is used to achieve higher spectral efficiency. The MIMO-based PHY layer has been adopted to help in controlling the transmission and to avoid any collisions by using weights gains technique on the antenna transmission, and by recovering any possible collisions using ZigZag decoding. In order to develop CA-MAC algorithm, to exploit the full potential of MIMO system, the library of 802.11x standard has been modified. NS-2 based …

Delay Extraction Based Equivalent Elmore Model For Rlc On-Chip Interconnects, Shamsul Arefin Siddiqui

Electronic Thesis and Dissertation Repository

As feature sizes for VLSI technology is shrinking, associated with higher operating frequency, signal integrity analysis of on-chip interconnects has become a real challenge for circuit designers. For this purpose, computer-aided-design (CAD) tools are necessary to simulate signal propagation of on-chip interconnects which has been an active area for research. Although SPICE models exist which can accurately predict signal degradation of interconnects, they are computationally expensive. As a result, more effective and analytic models for interconnects are required to capture the response at the output of high speed VLSI circuits. This thesis contributes to the development of efficient and closed …

Security On Medical Wireless Sensor Networks, Eric D. Southern

Electronic Thesis and Dissertation Repository

Wireless technology is fast becoming a very important tool for all aspects of communication. An area that lacks a strong implementation for wireless communication is the medical field. Wireless systems could be used by clinicians to be better able to diagnose and monitor patients. The reason behind the lack of adoption in healthcare is due to the need to meet the legislated and perceived requirements of security and privacy when dealing with clinical information. The current methods of wireless authentication are investigated and an existing issue in mobile networks is described and solved with two novel solutions; one solution within …

A Total Electron Content Receiver For The E-Pop Mission, Dmitry Shatskiy

Electronic Thesis and Dissertation Repository

Ionospheric parameters, such as electron density have a highly irregular structure and vary greatly throughout the day and with the seasons. Complete knowledge of the ionospheric structure usually requires expensive and/or stationary equipment such as rocket probes or incoherent scatter radars.

A height-integrated electron density along the satellite – ground-based receiver path, called total electron content (TEC), is often used as a measure of ionospheric inhomogeneities and, when possible, for ionospheric tomography.

An inexpensive portable digital receiver was used to assess the background ionospheric TEC. GNU Radio, an open-source software radio toolkit, GNU/Linux Bash scripts, a code in Python, a …

Enabling Techniques Design For Qos Provision In Wireless Communications, Penghui Mi

Electronic Thesis and Dissertation Repository

Guaranteeing Quality of Service (QoS) has become a recognized feature in the design of wireless communications. In this thesis, the problem of QoS provision is addressed from different prospectives in several modern communication systems.

In the first part of the thesis, a wireless communication system with the base station (BS) associated by multiple subscribers (SS) is considered, where different subscribers require different QoS. Using the cross-layer approach, the conventional single queue finite state Markov chain system model is extended to multiple queues' scenario by combining the MAC layer queue status with the physical layer channel states, modeled by finite state …