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...
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...
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...
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...
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...
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...
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...
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...
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...
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...