The design and evaluation of an end-to-end handoff management protocol

We introduce an efficient protocol for end-to-end handoff management in heterogeneous wireless IP-based networks. The protocol is based on the stream control transmission protocol (SCTP), and employs a soft-handoff mechanism that uses end-to-end semantics for signaling handoffs and for transmitting control messages. The design goal of this protocol is twofold—first, to reduce the home registration delay, and, second, to eliminate the tunnelling cost which exists in current proposals, such as Mobile IP and its derivatives. Furthermore, we propose successive enhancements to the initial mobility management framework for achieving better scalability. We present strong analytical and simulation-based results that show performance improvements over existing approaches. Antonios Argyriou is a Ph.D. candidate in the school of electrical and computer engineering, Georgia Institute of Technology. He received his M.S. degree from the Georgia Institute of Technology in 2003, and the diploma from Democritus University of Thrace in 2001, both in electrical and computer engineering. His research interests spawn in all aspects of computer networking while specific interests include wireless networks and multimedia communications. He is a student member of IEEE and ACM. Vijay Madisetti is a professor of electrical and computer engineering at the Georgia Institute of Technology. He splits his time among teaching, research and entrepreneurship. His interests are design, prototyping, and packaging of electronic systems, virtual prototyping, embedded software systems, and computer networks. He obtained his Ph.D. in electrical engineering and computer science from the University of California at Berkeley. He is a member of the IEEE and the Computer Society.     

On homomorphic deconvolution of bandpass signals

A convolution may be represented as x(.)=r(.)* w(.). The goal of deconvolution is to extract r(.) and w(.) from a knowledge of x(.) and it finds numerous applications in digital signal processing. Of practical interest in oil exploration is the case where w(.) is a seismic pressure wavelet, x(.) is the observed seismic response, and r(.) is the reflectivity of the Earth. A number of procedures have been proposed, including predictive, deterministic, and homomorphic deconvolution. Homomorphic deconvolution has been found to be particularly efficient for those cases where x(.) is known to be fullband. This paper presents a robust constructive procedure for efficient homomorphic deconvolution for those cases where x(.) is a bandpass signal. Extensive comparisons with other methods for deconvolving bandpass signals on measured seismic data traces (including the Novaya Zemlya event) illustrate the improvement in the deconvolution     

Electronic system, platform, and package codesign

Integrating multicore heterogeneous systems into a system-in-package has challenged many design and test engineers. To overcome these obstacles, we need a common EDA tool for digital, analog, RF, and thermal designs. This article proposes a platform-centric design methodology for modern electronic systems that could incorporate system-on-chip, system-in-package, and system-on-package technologies.     

Incorporating cost modeling in embedded-system design

The emergence of multimedia and wireless applications as growth leaders has created an increased demand for embedded systems. Examples of such applications range from digital cellular telephones to high-performance avionics systems. Along with the increased market share of these products, however, has come an increase in system complexity and cost. For example, the complexity of embedded avionics systems has quickly grown from millions to billions of operations per second. These systems, formerly implemented in hardwired or uniprocessor architectures, now must consist of programmable-multiprocessor arrays to meet performance requirements. Time-to-market and life-cycle costs are key factors in the success of these products in the competitive electronics marketplace. These costs, therefore, should have a dominant influence on the design of embedded microelectronic systems. In addition, these systems must meet rigid form factor (such as size, power, and weight) constraints, which further complicate the design task. For designers of high-end embedded microsystems or large-volume consumer products, rapidly prototyping cost-effective implementations that meet stringent performance, functional, timing, and physical requirements is a formidable challenge     

System partitioning of MCMs for low power

Meeting the design challenges inherent in complex multichip modules that also reduce power dissipation is a daunting task, considering the number of constraints and the nonlinear cost functions explored early in the prototyping process. Current algorithms do not do the job. A new systematic approach combines commercial software with simple size-reduction and linearization methods that are largely unknown in the industry. The authors present results obtained from experiments with a set of large ICs     

The Asymmetric Golden Code for Fast Decoding on Time-Varying Channels

The golden code is a full-rate full-diversity space–time code for the two-input two-output channel with good performance but high decoding complexity. The overlaid Alamouti codes were recently proposed as an alternative; in exchange for a slight performance penalty, they have lower decoding complexity on quasistatic channels with QAM alphabets. However, the complexity advantage of the overlaid codes vanishes for time-varying channels. This paper proposes the asymmetric golden code, a novel full-rate and full-diversity space–time code for the two-input two-output channel that offers reduced-complexity decoding on both quasistatic and time-varying channels.     

Closed-form for infinite sum in bandlimited CDMA

A closed-form expression is presented for an infinite sum that appears in the theoretical analysis of works in code-division multiple access (CDMA) that assume root-raised-cosine pulse shaping instead of rectangular pulse shaping. The expression derived is sufficiently general to work for arbitrary values of the roll-off factor. The expression is expected to contribute to the simplification of the analysis of CDMA systems with realistic pulse shaping.     

Reengineering legacy embedded systems

Systems that require reengineering are a fact of life in both the commercial and military arenas. The authors have developed a systematic methodology based on virtual prototyping, with accompanying tools and libraries, for rapidly upgrading electronic systems     

Conceptual prototyping of scalable embedded DSP systems

This systematic process uses model-based architectural synthesis and verification to ensure that early stages of the design are efficient, economical, and meet user requirements. Using a scalable, plug-and-play, model year methodology, designers can conceptually prototype complex, embedded digital systems in weeks instead of months