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Since Witsenhausen put forward his remarkable counterexample in 1968, there have been many attempts to develop efficient methods for solving this non-convex functional optimization problem. However there are few methods designed from game theoretic perspectives. In this paper, after discretizing the Witsenhausen counterexample and re-writing the formulation in analytical expressions, we use fading...
Closed-form expressions for the capacity of dual-selection combining and maximal-ratio combining diversity systems over slowly varying correlated Hoyt fading channels has been presented. Different power and rate adaptation techniques available in the literature has been considered for the capacity analysis. A study on the effects of correlation and fading parameters on the channel capacity of the...
In wireless networks, communication links may be subject to random fatal attacks: for example, sensor networks under sudden power losses or cognitive radio networks with unpredictable primary user spectrum occupancy. Under such circumstances, it is critical to quantify how fast and reliably information can be collected over attacked links. In our previous work, we studied such channels by considering...
Spectrum sensing is a crucial technology for cognitive radio networks. In this paper, we develop a novel spectrum sensing method for secondary users to sense the idle spectrum. The key idea of the proposed method is combining multiple slots energy detection. Firstly, we establish the probability model regarding the appearance of the primary user at each slot of a secondary user slots window structure...
The problems of resource allocation and the characterization of cooperative behavior in a two-user fading multiple-access channel (MAC) in the presence of uncertainty about the channel state information at the transmitters (CSIT) are considered. Game-theoretic techniques are used to characterize cooperative behavior and obtain the system operation point from an individualistic perspective. A two-user...
Ultra-wideband (UWB) has been considered a viable and an innovative solution for future short-range high-speed wireless communication systems. One of the big concerns for UWB devices to function properly is the narrow band interference (NBI) issue, which must be carefully studied. For this purpose, the performance of UWB communication system over indoor Lognormal fading channel in the presence of...
Distance estimation by the evaluation of RSSI measurements is a simple and well-known technique to predict the position of an unknown node. Therefore the infrastructure do not have to be extended by expensive hardware for synchronization or direction approximation. However, with the localization based on RSSI measurements common and proven systems can be used for the infrastructure. For indoor environments...
A hard-deadline, opportunistic scheduling problem in which B bits must be transmitted within T time-slots over a time-varying channel is studied: the transmitter must decide how many bits to serve in each slot based on knowledge of the current channel but without knowledge of the channel in future slots, with the objective of minimizing expected transmission energy. In order to focus on the effects...
An accurate model for analyzing the performance of wireless land mobile satellite (LMS) communication systems is the shadowed-Rice (SR) fading model. In this paper, new simple expressions for the probability density function (PDF) and the cumulative distribution function (CDF) of the sum of possibly correlated non identically distributed squared SR random variables are derived. To this end, a novel...
We study the transmission capacity of wireless ad hoc networks in this paper. Transmission capacity can not be got the close-form for general cases except for some special cases. In this paper we provide a new solution to this problem. By using Taylor series, the asymptotic expression for transmission capacity is derived. Comparing the asymptotic with the exact expressions shows that, the asymptotic...
User cooperation enables single antenna terminals to benefit from spatial diversity by partnering with other users to create a virtual transmit antenna array. A promising form of cooperation is called coded cooperation which integrates cooperation with channel coding, showing great performance gains. In this paper, we examine the performance of coded cooperation scheme in fixed relay system, where...
This paper proposes a simple series form formula of the bit error rate (BER) for DBPSK/OFDM signals under time selective nonlinear fading channels. The proposed approach derives the theoretical BER in the presence of non-linear distortion and time selective fading effects. Since the BER is represented by the simple series form formula, the proposed approach frees us from the time-consuming computer...
The rudimentary principle of SOA (service oriented architecture) is ldquoreuserdquo. In hub and spoke integration projects leveraging SOA, creating service components with high reuse becomes a huge challenge and results in the problem of either the service component just enabling integration which in turn has very poor reuse when new consumers are introduced or mere reuse theoretically but not enabling...
In this paper, making use of the relaying concept, which enables single-antenna devices to benefit from spatial diversity, a statistical analysis of dual-hop cooperative links using semi-blind (fixed gain) relays and partial relay selection, is provided. The selection scheme considers that the source monitors the connectivity among the nodes (relays) of the first hop only; an interesting assumption...
Decision fusion rules for wireless sensor networks in fading channel are investigated in this paper. Optimal Likelihood ratio rule has been presented under the assumption of single-sideband Gaussian channel model. However, acquiring channel information may be too costly for resource constrained sensor networks. Suboptimal likelihood ratio fusion rule is proposed which requires only the knowledge of...
Scattering problems with multiple canonical scatterers, like cylinders and spheres, may be modeled by utilizing the orders-of-scattering approach. This method provides an exact solution; however, being iterative in nature, the accuracy of the solution depends on the number of iterations; in other words, the number of higher-order scattered fields taken into account. The orders-of-scattering solutions...
In this paper temporal fading characteristics have been investigated for five different reception categories in a DVB-H system at 602 MHz in Ghent, Belgium. A method has been proposed to calculate the fade depth and the corresponding fade duration. Five reception categories have been defined and their fading characteristics have been compared. Categories with more traffic have more and deeper fades,...
We analyze the outage for distributed estimation over orthogonal fading channels as a function of the number of sensors, K. We consider a scenario of fixed power per-sensor with an asymptotically large number of sensors. We characterize the scaling law of the outage and show that the outage decays faster than exponentially in the number of sensors and slower than exp(-K log K).
Diversity order of linear equalization (LE) is investigated for the case of linearly precoded block transmission in doubly selective channels. A connection between the orthogonal deficiency od(.) of the effective channel matrix at the receiver and an earlier proof that LE achieves full diversity in frequency selective channels is highlighted. For doubly selective channels it is argued that od of the...
New, exact expressions for the bivariate Nakagami-q (Hoyt) processes with arbitrary correlation in a nonstationary environment are derived. More specifically, the following are obtained: joint probability density function, joint cumulative distribution function, power correlation coefficient, and some statistics related to the signal-to-noise ratio at the output of the selection combiner, namely,...
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