MGFs for Rayleigh Random Variables

Expressions are given for the moment generating functions of the Rayleigh and generalized Rayleigh distributions.

A Tool for Unbiased Comparison between Logarithmic and Floating-point Arithmetic

For applications requiring a large dynamic, real numbers may be represented either in floating-point, or in the logarithm number system (LNS). Which system is best for a given application is difficult to know in advance, because the cost and performance of LNS operators depend on the target accuracy in a highly non linear way. Therefore, a comparison of the pros and cons of both number systems in terms of cost, performance and overall accuracy is only relevant on a per-application basis. To make such a comparison possible, two concurrent libraries of parameterized arithmetic operators, targeting recent field-programmable gate arrays, are presented. They are unbiased in the sense that they strive to reflect the state-of-the-art for both number systems. These libraries are freely available at .

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Hardware Organization to Achieve High-Speed Elliptic Curve Cryptography for Mobile Devices

Elliptic curve cryptography (ECC) is recognized as a fast cryptography system and has many applications in security systems. In this paper, a novel sharing scheme is proposed to significantly reduce the number of field multiplications and the usage of lookup tables, providing high speed operations for both hardware and software realizations.

An Expression for the Average Quantization Error

The quantization error for MIMO (multiple-input multiple-output) downlink channels is known to be the minimum of independent and identically distributed beta random variables. In this note, an exact expression is derived for the average quantization error. Computational issues relating to its correctness, usage and approximations are discussed.

Layereless Communications: From Dream to Reality?

The paper summarizes the main results of one of the key panel session of the Workshop, focused on the investigation about the possible translation of the “layerless communications” from a dreaming vision to reality.

Coding Schemes for Crisscross Error Patterns

This paper addresses two coding schemes which can handle emerging errors with crisscross patterns. First, a code with maximum rank distance, so-called Rank-Codes, is described and a modified Berlekamp–Massey algorithm is provided. Secondly, a Permutation Code based coding scheme for crisscross error patterns is presented. The influence of different types of noise are also discussed.

Role of Convergence in GIMCV Development: A Vision

Path to Global Information Multimedia Communication Village (GIMCV) can be seen as a convergence process among telephony, data exchange and television. Convergence refers not only to various services provided by the same operator but also by the same device, the same access network, the same transport network, etc. This paper present authors’ vision on how convergence will lead the GIMCV development.

Reduced stability testing set for a diamond-type family of quasipolynomials

A diamond-type family of quasipolynomials, for which vertex stability results hold, is presented. Both delay independent and delay-dependent stability conditions are given. In the first case, it suffices to check for the stability of a finite testing set of multivariate polynomials. While in the other one, it is also needed to check the stability of several edge sub-families of quasipolynomials.

A Rigorous Proof of MIMO Channel Capacity’s Increase with Antenna Number

It is well known that adding more antennas at the transmitter or at the receiver offers larger channel capacity in the multiple-input multiple-output communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receive antennas. The proof is based on the famous capacity formula of Foschini and Gans and uses matrix theory.

Improved Fractional Fourier Transform Based Receiver for Spatial Multiplexed MIMO Antenna Systems

In this work the performance of a Fractional Fourier transform (FrFT) based Minimum Mean Squared Error receiver for MIMO systems with space time processing over Rayleigh faded channels is presented. The proposed receiver called Optimum FrFT based MIMO receiver (OFMR) shows improved performance outperforming the simple MMSE receiver in Rayleigh faded channel.

Dynamic Sensor Self-Organization for Distributive Moving Target Tracking

To support distributive tracking of moving targets in a wireless sensor network, sensors that receive signal from the same target must collaborate to facilitate collaborative, distributed target tracking. We present an efficient dynamic sensor self-organizing algorithm that clusters sensors into groups without requiring a centralized control. Extensive simulations are conducted to verify the performance improvement as well as the communication reduction for the proposed methods.

Design of Power and Area Efficient Digital Down-converters for Broadband Communications Systems

This paper shows that when a digital receiver is designed utilizing two clock scopes, the digital down-converter can be designed to be efficient in terms of area and power consumption. The main design parameter that contributes to make the design efficient is the relationship between the transition band of the designed filter and its sampling frequency.

Error Probability Distribution and Density Functions for Rayleigh and Rician Fading Channels with Diversity

This paper analyzes the distribution and density functions of the probability of error for Rayleigh and Rician fading channels with diversity. An expression for the signal-to-noise ratio is derived for an asynchronous CDMA (A-CDMA) system with diversity. The error probability distribution and density functions are derived and plotted for different mean energy-to-noise ratios.

A New Routing Metric for Satisfying Both Energy and Delay Constraints in Wireless Sensor Networks

Besides energy constraint, wireless sensor networks should also be able to provide bounded communication delay when they are used to support real-time applications. In this paper, a new routing metric is proposed. It takes into account both energy and delay constraints. It can be used in AODV. By mathematical analysis and simulations, we have shown the efficiency of this new routing metric.

Capacity and SER Analysis of MIMO MRC Systems in an Interference-Limited Environment

The effect of co-channel interference (CCI) is considered in multiple-input multiple-output (MIMO) systems employing maximal ratio combining (MRC) under independent and identically distributed Rayleigh fading. Closed-form capacity and symbol error rate expressions are presented to evaluate the performance without any numerical integrations or statistical simulations. The analytical results are compared with Monte Carlo simulations and the good agreement is obtained.

Improving Spectral Capacity and Wireless Network Coverage by Cognitive Radio Technology and Relay Nodes in Cellular Systems

Methods to enhance the use of the frequency spectrum by automatical spectrum sensing plus spectrum sharing in a cognitive radio technology context have been presented and discussed in this paper. Ideas to improve the wireless transmission by orthogonal OFDM-based communication and to increase the coverage of cellular systems by future wireless networks, relay channels, relay stations and collaborate radio have been presented as well. A revised hierarchical deployment of the future wireless and wired networks are shortly discussed.

Fast PWM-Based Test for High Resolution ΣΔ ADCs

This work describes a novel test strategy that uses digital stimuli for cheap, fast, though accurate, testing of high resolution ΣΔ ADCs. Simulations and measurements showed a discrimination threshold on specification parameters up to −90 dBc. The proposed method helps to reduce the cost of ADC production test, to extend test coverage and to enable built-in self-test and test-based self-calibration.

Performance of MIMO System Through Nakagami Fading Channel with Arbitrary Fading Parameters

In this paper, the analytical and simulation results of the bit error rate (BER) performance for a multiple-input multiple-output (MIMO) system with an arbitrary number of transmit and receive antennas are developed for the uplink transmission. The fading channel is assumed to follow Nakagami-m distribution with correlation among branches. The BER is expressed in terms of Lauricella’s multivariate hypergeometric function for both independent and correlated antenna branches for BPSK system.

A Multimodal Approach to Communicative Interactivity Classification

The problem of modality detection in so called communicative interactivity is addressed. Multiple audio and video recordings of human communication are analyzed within this framework, based on fusion of the extracted features. At the decision level, support vector machines (SVMs) are utilized to segregate between the communication modalities. The proposed approach is verified through simulations on real world recordings.

Negative Save Sign Extension for Multi-term Adders and Multipliers

This paper outlines a new sign extension technique for use in carry save adder trees that reduces the computational complexity. The “Negative Save” technique presented is a modification to the Baugh–Wooley sign extension technique developed for array multipliers. Applying this sign extension technique to both parallel adder and multiplier partial product structures reduces the hardware required. The speed of the resulting structures is also improved.