Relay-assisted cooperative communications are promising solutions for error-performance improvement and cell coverage extension. In this thesis, we propose several efficient cooperative relay communication schemes. First, an efficient space-time coded cooperative relay communications scheme that employs linear precoding and transmission-pattern selection is proposed. This is built upon an existing block linear...
Hybrid automatic repeat request (HARQ) schemes combine packet retransmission with forward error correction to ensure a reliable communications. In multiple-input multiple output (MIMO) systems, interference cancellation (IC) detection is widely used where the detection and cancellation steps of the simultaneously transmitted data streams occur. In principle, the signal stream estimated...
Several hardware-based security improvements to Near Field Communication (NFC) and Radio-Frequency Identification (RFID) systems are developed and presented. The improvements are intended to be used in conjunction with software encryption to ensure robust security. Two main implementations for a more secure NFC or RFID system are presented: a jamming system,...
Stock loss and out-of-stocks are outcomes of poorly designed inventory management systems and can lead to significant revenue losses. Inventory management systems (IMS) based on radio frequency identification (RFID) have the potential to minimize these losses if they are properly designed and deployed. However, the placement of RFID readers to...
In this paper, based on coding theory concepts, new time scheduling algorithms for multihop packet radio networks are described. Each mobile host is assigned a word from an appropriate constant weight code of length n, distance d and weight w. The host can send a message at the j[superscipt th]...
Due to the rapid growth of wireless technology, there has been a growing interest in the capabilities of ad hoc networks connecting mobile phones, PDAs and laptop computers. The distributed and self-configurable capabilities of ad hoc networks make them very attractive for some applications such as tactical communication for military,...
This work focusses on the modeling and the development of efficient coupled simulation techniques for MEMS based RF oscillators. High-level models for MEMS based varactors have been discussed and their accuracy issues are identified, based on comparisons with numerical simulations. A faster simulation approach based on the time-domain shooting method...
A new coupled circuit and electrostatic/mechanical simulator (COSMO) for the design of RF MEMS VCOs is presented in this thesis. The numerical solution of device level equations is used to accurately compute the capacitance of a MEMS capacitor. This coupled with a circuit simulator facilitates the simulation of circuits incorporating...
Low-power millimeter-wave (mm-wave) transceivers are of interest for achieving energy-efficient high data rate short-reach wireless and guided-wave links.
Spatial modulation or space-shift keying (SSK) can provide energy efficiency improvements by using antenna-switching or transmission direction switching for data modulation. Such links are particularly attractive at millimeter-wave frequencies due to small...