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

Information Theory and Reliable Communication

: This thesis applies neural network feature selection techniques to multivariate time series data to improve prediction of a target time series. Two approaches to feature selection are used. First, a subset enumeration method is used to determine which financial indicators are most useful for aiding in prediction of the S&P 500 futures daily price. The candidate indicators evaluated include RSI, Stochastics and several moving averages. Results indicate that the Stochastics and RSI indicators result in better prediction results than the moving averages. The second approach to feature selection is calculation of individual saliency metrics. A new decision boundary-based individual saliency metric, and a classifier independent saliency metric are developed and tested. Ruck's saliency metric, the decision boundary based saliency metric, and the classifier independent saliency metric are compared for a data set consisting of the RSI and Stochastics indicators as well as delayed closing price values. The decision based metric and the Ruck metric results are similar, but the classifier independent metric agrees with neither of the other metrics. The nine most salient features, determined by the decision boundary based metric, are used to train a neural network and the results are presented and compared to other published results. (AN)

/pdf/nonlinear-time-series-analysis-1j3a35n4y3.pdf

Nonlinear Time Series Analysis.

This document provides updates to IEEE Std 802.16's MIB for the MAC, PHY and asso- ciated management procedures in order to accommodate recent extensions to the standard.

IEEE Standard for Local and Metropolitan Area Networks Part 16: Air Interface for Fixed Broadband Wireless Access Systems Draft Amendment: Management Information Base Extensions

A discrete traffic analysis of a star-topology communication network is presented. Fast switching capabilities are assumed in the central hub. The communication network is modelled as a discrete queueing system. First-in/first-out (FIFO) and random (RND) policies are examined for selection of messages to be routed from inputs to outputs of the central hub. The case of an infinite number of users is also considered to provide a tight upper-bound on actual performance.

http://ieeexplore.ieee.org/iel1/2191/7663/00317991.pdf

Discrete queueing analysis of a star network

The explosive growth of mobile traffic needs that the fifth generation of wireless systems supports a thousand-fold increase of network capacity, thanks to new paradigms such as network densification. However, in dense networks interference can be a limiting factor, and must be suitably managed. In this paper multiple cells coordinate to mitigate the mutual interference: cross-tier interference is limited by means of the traditional enhanced Inter Cell Interference Coordination approach, while a new co-tier interference management strategy based on Matching Theory is proposed. The objective is to provide a stable matching between the set of small cells and the set of available subframes left almost blank by the macrocell and used by the small cells to communicate with their most vulnerable users. The proposed solution aims at improving the throughput of most critical users with an affordable computational complexity. The effectiveness of the proposed scheme has been verified in comparison with benchmark methods.

Efficient Matching for Almost Blank Subframes Allocation in Ultra Dense Networks

This paper presents a Turbo Multiuser Detector for Turbo-Coded DS-CDMA wireless communication systems. The receiver is based on the utilization of a PIC and a bank of turbo decoders: particularly, the PIC performs interference cancellation after each decoding iterations of constituent decoder. A new enhanced estimator of the signal-to-noise-plus-interference-ratio is used in the decision device and in the MAP decoding algorithm. By means of computer simulations, we will show that the proposed receiver ouperforms other similar schemes for medium to very high system loads, in AWGN and multipath fading channel.

Improved iterative parallel interference cancellation for wireless ds-cdma communication systems

In this paper, we propose a novel architecture to address the problem of application Quality of Experience (QoE) management for rapidly evolving and heterogeneous network scenarios. The proposed architecture can be used for mixed Long Term Evolution Advanced (LTE-A) and Wi-Fi systems, and it can be used to enhance the effectiveness of next-generation Software Defined Network (SDN). Thanks to the elements described in this paper, the Applications can interact in a secure and controlled way with the network QoE management entities. This allows to have a better system flexibility, scalability and enables to use advanced QoE support mechanisms for rapidly evolving user scenarios.

Enhance the QoE for smartphone applications: An API approach for QoS control in LTE-A

Internet broadband access is becoming a reality in many countries. To fully exploit the benefits from high-speed connection, both suitable home network connectivity and advanced services support have to be made available to the user. In this article, issues relative to the upgrade of existing home networks, particularly in old buildings, together with networking and security requirements are addressed, and possible solutions are proposed.

Romano Fantacci

Papers

Discrete queueing analysis of a star network

Efficient Matching for Almost Blank Subframes Allocation in Ultra Dense Networks

Improved iterative parallel interference cancellation for wireless ds-cdma communication systems

Enhance the QoE for smartphone applications: An API approach for QoS control in LTE-A

Old Buildings Broadband Home Networks: Technologies and Services Overview