There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

It is shown that, particularly for terrestrial cellular telephony, the interference-suppression feature of CDMA (code division multiple access) can result in a many-fold increase in capacity over analog and even over competing digital techniques. A single-cell system, such as a hubbed satellite network, is addressed, and the basic expression for capacity is developed. The corresponding expressions for a multiple-cell system are derived. and the distribution on the number of users supportable per cell is determined. It is concluded that properly augmented and power-controlled multiple-cell CDMA promises a quantum increase in current cellular capacity. >

On the capacity of a cellular CDMA system

The Smart Grid, regarded as the next generation power grid, uses two-way flows of electricity and information to create a widely distributed automated energy delivery network. In this article, we survey the literature till 2011 on the enabling technologies for the Smart Grid. We explore three major systems, namely the smart infrastructure system, the smart management system, and the smart protection system. We also propose possible future directions in each system. colorred{Specifically, for the smart infrastructure system, we explore the smart energy subsystem, the smart information subsystem, and the smart communication subsystem.} For the smart management system, we explore various management objectives, such as improving energy efficiency, profiling demand, maximizing utility, reducing cost, and controlling emission. We also explore various management methods to achieve these objectives. For the smart protection system, we explore various failure protection mechanisms which improve the reliability of the Smart Grid, and explore the security and privacy issues in the Smart Grid.

/pdf/smart-grid-the-new-and-improved-power-grid-a-survey-4jypbbgv3j.pdf

Smart Grid — The New and Improved Power Grid: A Survey

Smart Grid - The New and Improved Power Grid:

For 100 years, there has been no change in the basic structure of the electrical power grid. Experiences have shown that the hierarchical, centrally controlled grid of the 20th Century is ill-suited to the needs of the 21st Century. To address the challenges of the existing power grid, the new concept of smart grid has emerged. The smart grid can be considered as a modern electric power grid infrastructure for enhanced efficiency and reliability through automated control, high-power converters, modern communications infrastructure, sensing and metering technologies, and modern energy management techniques based on the optimization of demand, energy and network availability, and so on. While current power systems are based on a solid information and communication infrastructure, the new smart grid needs a different and much more complex one, as its dimension is much larger. This paper addresses critical issues on smart grid technologies primarily in terms of information and communication technology (ICT) issues and opportunities. The main objective of this paper is to provide a contemporary look at the current state of the art in smart grid communications as well as to discuss the still-open research issues in this field. It is expected that this paper will provide a better understanding of the technologies, potential advantages and research challenges of the smart grid and provoke interest among the research community to further explore this promising research area.

/pdf/smart-grid-technologies-communication-technologies-and-1t7ewfweku.pdf

Smart Grid Technologies: Communication Technologies and Standards

List of Contributors. Preface. List of Acronyms. 1 Introduction (The Editors). References. 2 Channel Characterization (P. Amirshahi, F. Canete, K. Dostert, S. Galli, M. Katayama and M. Kavehrad). 2.1 Introduction. 2.2 Channel Modeling Fundamentals. 2.3 Models for Outdoor Channels: LV Case. 2.4 Models for Outdoor Channels: MV Case. 2.5 Models for Indoor Channels. 2.6 Noise and Disturbances. 2.7 MeasuringTechniques. 2.8 PLC Channel EmulationTools. 2.9 Reference Channels for Access Domain. 3 Electromagnetic Compatibility (H. Hirsch and M. Koch). 3.1 Introduction. 3.2 Parameters for EMC Considerations. 3.3 Electromagnetic Emission. 3.4 Electromagnetic Susceptibility. 3.5 EMC Coordination. 3.6 EMC Regulationin Europe. 3.7 Final Remarks. 4 Coupling (P. A. Janse van Rensburg). 4.1 Introduction. 4.2 Filtering Basics. 4.3 Transformer-Capacitor Coupler Design. 4.4 Impedance Adaptation Concepts. 4.5 Experimental Verification. 4.6 Further Possibilities. 5 Digital Transmission Techniques (M. Ardakani, G. Colavolpe, K. Dostert, H. C. Ferreira, D. Fertonani, T. G. Swart, A. M. Tonello, D. Umehara and A. J. H. Vinck). 5.1 Introduction. 5.2 Modulation and Coding for Narrowband PLC Systems. 5.3 Modulation and Coding for Broadband PLC Systems. 5.4 Conclusion. 6 Protocols for PLC Systems (G. Bumiller, H. Hrasnica, L. Lampe, M. Lobashov and T. Stockhammer). 6.1 Introduction. 6.2 Broadband PLC Media Access Control Layer. 6.3 Protocols for PLC Supporting Energy Management Systems. 6.4 Internet Protocol Television Over PLC. 7 Industrial and International Standards on PLC-based Networking Technologies (Galli, M. Koch, H. A. Latchman, S. Lee and V. Oksman). 7.1 Introduction. 7.2 PLC Standardization by Industrial Alliances. 7.3 International Standards on PLC-Networking Technology. 7.4 ETSI and CENELEC Standards. 7.5 International EMC Product Standardization. 8 Systems and Implementations (I. Berganza Valmala, G. Bumiller, H. A. Latchman, M. V. Ribeiro, A. Sendin Escalona, E. R. Wade and L. W. Yonge). 8.1 Introduction. 8.2 PLC Smart Grid Systems. 8.3 PLC Broadband Access Systems. 8.4 Multimedia PLC Systems. 8.5 DC-PLC Systems. 8.6 PLC in Emerging Countries. 9 Conclusions (The Editors). Index.

Power line communications : theory and applications for narrowband and broadband communications over power lines

We give a systems level overview of power line communications. Topics covered, include feasible applications of power line communications, and the impact of the currently evolving international standards on power line communications. The power line communications channel is discussed at some length. Existing communications systems and solutions are discussed. The results of some measurements on the channel, are presented.

Power line communications: an overview

We investigate binary, number-theoretic, bit insertion/deletion correcting codes as pioneered by Levenshtein (1965, 1966, 1989). The weight spectra and Hamming distance properties of single insertion/deletion error-correcting codes are analyzed. These relationships are then extended to investigate codes that can correct multiple random insertions and deletions. From these relationships, new bounds are derived and a general construction for multiple insertion/deletion correcting codes is proposed and evaluated.

On multiple insertion/deletion correcting codes

We apply techniques for the modeling of error sequences on digital communication channels to results of experiments undertaken on mobile VHF channels. The experiments were carried out using four different modulation schemes at some of the different standardized signaling rates. The modulation schemes used were: FSK @ 300 baud, DPSK @ 1200 baud, QPSK @ 1200 baud, and 8-ary PSK @ 1600 baud, and in each case, subcarrier modulation was used. The experiments were undertaken for urban as well as freeway environments. Fritchman-partitioned Markov chain models were derived throughout, and from the models, block error probability distributions were derived. These block error probability distributions or P(m,n) give the probability that a block of n bits will contain exactly m errors. We present P(/spl ges/m,n) for 7-, 15-, 31-, 63-, 127-, and 255-b blocks, for the above-mentioned modulation schemes, in the mobile VHF environments mentioned. P(/spl ges/m,n) denotes the probability that at least m errors will occur in a block of n bits. Furthermore, the P(/spl ges/m,n) information presented here, should give some indication of the performance to be expected from block error-correcting schemes. >

http://www.researchgate.net/profile/Hendrik_Ferreira/publication/3153746_Markov_characterization_of_digital_fading_mobile_VHF_channels/links/0a85e53302a0d156ee000000.pdf

Markov characterization of digital fading mobile VHF channels

We introduce the new concept of permutation trellis codes and present a generalized construction procedure, applying our technique of distance-preserving mappings. Minimum-distance decoding follows naturally, using the Viterbi algorithm. We furthermore investigate the performance of these codes when combined with multitone frequency-shift keying modulation and noncoherent detection in a diversity scheme, to make transmissions robust against narrowband, broadband, and background noise disturbances, such as those encountered in power-line communications.

Hendrik C. Ferreira

Papers

Power line communications : theory and applications for narrowband and broadband communications over power lines

Power line communications: an overview

On multiple insertion/deletion correcting codes

Markov characterization of digital fading mobile VHF channels

Permutation trellis codes