The current state of research on gossip techniques for wireless broadcasting is very limited because past research efforts have mostly focused on using gossip techniques for multicast communication. On the other hand, those research efforts that have focused on using gossip techniques for wireless broadcast communications ignore energy efficiency and...
This work presents the design and implementation of a low power phased-array receiver frontend at 28 GHz in 65 nm CMOS. The frontend incorporates a low- power low-noise amplifier(LNA) and a passive reflection-type phase shifter (RTPS) capable of providing 360° phase shift with 5-bit phase resolution and low loss variation....
Optical wireless communication (OWC) is an alternative to radio frequency (RF)communication with a signi cantly larger and unregulated spectrum. In OWC systems, optical orthogonal frequency division multiplexing (O-OFDM) with intensity modulation and direct detection (IM/DD) is commonly used. There are two common signal structures in most OWC systems based on...
Wireless High Definition Video Transmission (WHDVT) over 802.11-based networks enjoys widespread deployment among today's multimedia solutions. Examples include Intel® Wireless Display and Apple Airplay®, to name a few. In these systems, peer-to-peer networks are established over which H.264-encoded video is transported wirelessly to be decoded and played back at the...
In this paper, we propose a credit-based resource allocation technique for dynamic spectrum access (DSA) systems that is robust against malicious and selfi sh behaviors and ensures good overall system fairness performance while also allowing spectrum users to achieve high amounts of service. We also propose a new objective function...
IS-95, an interim standard proposed for future digital personal communications
systems, uses two levels of encoding of digital data for error control and compatibility
with code-division multiple access (CDMA) transmission. The data is first
convolutionally encoded and the resulting symbols are interleaved and then groups are
encoded as orthogonal Walsh...
The increased use of mobile wireless devices that we have recently been witnessing, such as smartphones, tablets, e-readers, and WiFi enabled devices in general, is driving an unprecedented increase in the amount of data traffic. This fast market adoption of the wireless technology along with the tremendous success of multimedia...
The widespread use of TCP as a transport layer protocol for mobile ad-hoc networks and wireline networks has motivated the need to make its implementation highly power efficient specially with respect to ad hoc radio networks. Over the past years many researchers have developed energy efficient protocols for mobile ad-hoc...
The widespread use of Wireless Local Area Networks (WLAN) and the desire for such products from different vendors to operate together has generated a movement towards standardization. Over the last decade, several organizations worldwide have researched and developed such standards, this includes the IEEE 802.11 committee. One of the important...
Direct-conversion architecture would dominate the modern low power wireless receiver architecture if problems such as offset cancellation, even-order distortion, and flicker noise were solved. Among those problems, offset is the most serious one. This thesis will discuss and analyze one approach to cancel offsets in direct-conversion receivers. First, we explain...
The quest to achieve reliable communication has always existed. Error Correcting codes have made communication systems even more reliable under high signal to noise ratios. A new class of codes called Turbo codes have proved to be more effective compared to the other classes of codes and achieve performance close...
The thesis presents a new algorithm and structure that is to be used in conjunction with a specially modified CMOS Gilbert cell mixer to remove time-varying DC offsets in direct conversion receivers. In our approach, the DC offset is detected at the output of the mixer using a dedicated coarse...
Dynamic DC offset is one of the biggest problems preventing the implementation of single chip receivers. This thesis presents a 2.4GHz downconversion mixer designed to work with adaptive DC offset cancellation for a fully integrated direct conversion receiver. Offset can be removed by dynamically changing the PFET load bias in...
Power is a valuable resource. It is invaluable when for mobile devices. Mobile devices, due to their mobility cannot get a continuous source of power and derive their power from a battery contained in them. The main consumer of power in the mobile is its transmitter. With a limited power...
Ad Hoc networks are multi-hop wireless networks consisting of mobile hosts. They do not have any pre-existing network infrastructure and are characterized by constantly changing topology, limited battery power and bandwidth. Typical applications of such networks are battlefield networks, medical relief during natural calamities or disasters, conference room networking, and...
The problem of ensuring Quality of Service (QoS) on a TCP/IP based fixed-infrastructure network has been well studied and several working proposals exist. An allied problem is that of ensuring QoS on an ad-hoc wireless network, where the requirements are similar, but the operating conditions are different enough to warrant...
Physical-Layer Network Coding (PNC) is a promising technique that has great potentials for improving the achievable data rates of end-to-end flows through higher packet transmission rates, thereby increasing the overall network throughput. In this thesis, we study the performance of the PNC transmission techniques for unidirectional end-to-end flows in multi-hop...
The world's demand for energy is an ongoing challenge, which has yet to be overcome.
The efforts to find clean energy alternatives to fossil fuels have been hampered by the
lack of investment in technology and research. Among these clean energy alternatives
are ocean waves and wind. Wind power is...
Recently, the demand for higher data rates of transmission has increased in
many wireless communication applications. Using multi-transmit and multi-receive
antennas has been shown to be a solution, since it can increase the channel capacity to
accommodate higher transmission rates. Among the popular techniques developed to
exploit the use of...
Recent developments in computing technology have generated a demand for more streamlined and effective test systems. By replacing traditional in-chassis wired interconnects with a broadcast wireless system, fault detection and error susceptibility will drastically improve, input/output capabilities will expand, and routing complexity will decrease. Ultra-wideband impulse radio's (UWB-IR) characteristic multipath-immunity...
Until a few years ago, wireless-capable laptops were considered novelties by many. It is now hard to find a laptop or a hand-held computing device that is not wireless-ready. As wireless devices are becoming commodities, they have also become an indispensable part of the modern society. Not surprisingly, research in...
Rapid advances in wireless networking have led to more mobile phones, PDAs, and other digital mobile devices becoming ubiquitously connected to the Internet. As the demand of delay sensitive real-time applications for these portable devices increases, providing seamless connectivity to wireless networks becomes a critical issue. For this reason, a...
Transmission over wireless networks presents multiple technical challenges due to
noise, interference, fading, power constraints and bandwidth limitation. Different
solutions have been propposed to overcome these issues and some of them are
treated here. Cooperative diversity has been proposed as an implementation for
networks where terminals are restricted to using...