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Every year there are several million lightning discharges occur over world. In power system perspective, lightning is one of the most serious causes of over-voltages. These over-voltages may cause flashovers and serious damage to the equipment and thereby imperil the supply of power to customers. Much of the power equipment in use today is susceptible to damage or service interruption due to striking...
This article investigates the efficacy of a constant-power, rate-adaptive M-QAM transmission technique in amplify-and-forward cooperative wireless networks. Tight upper and lower bounds are derived for the mean achievable spectral efficiency, outage probability, and error probability performance of non-regenerative cooperative relay networks in Nakagami-m fading environments. We observe that the spectral...
Tight bounds for the mean achievable rates of amplify-and-forward cooperative relay networks are derived for three distinct source adaptive transmission policies in a myriad of fading environments: (i) constant power with optimal rate adaptation (ORA); (ii) optimal joint power and rate adaptation (OPRA); and (iii) fixed rate with truncated channel inversion (TCIFR). Our unified framework based on...
Future wireless communication systems and networks will be required to support a multitude of services with different reliability requirements. However, achieving such flexible systems are challenging in Mobile Ad-hoc Networks (MANET) due to limited battery resources at mobile nodes. However, by employing adaptive signaling techniques with Unequal Error Protection (UEP), we strive to improve the energy...
Tight bounds for the ergodic capacity of amplify-and-forward cooperative diversity networks are derived for three different adaptive source transmission policies in a myriad of fading environments: (i) constant power with optimal rate adaptation (ORA); (ii) optimal joint power and rate adaptation (OPRA); and (iii) fixed rate with truncated channel inversion (TCIFR). Our unified framework based on...
Tight bounds for the Shannon capacity of amplify-and-forward cooperative diversity networks are derived for three different adaptive source transmission policies in a myriad of fading environments: (i) constant power with optimal rate adaptation (ORA); (ii) optimal joint power and rate adaptation (OPRA); and (iii) fixed rate with truncated channel inversion (TCIFR). Our unified framework based on...
Cooperative communication systems that exploit spatial diversity to improve the performance of end-to-end communication in ad hoc wireless networks have gained a lot of attention in recent years. In this article, we examine the energy efficiency of a simple selective decode and forward (SDF) protocol. Different from previous studies on energy efficiency our analysis accounts for the imperfect regeneration...
Upper bounds on link spectral efficiency of amplify-and-forward cooperative diversity networks with independent but non-identically distributed wireless fading statistics are studied by deriving the Shannon capacity of three distinct adaptive source transmission techniques: (i) constant power with optimal rate adaptation (ORA); (ii) optimal joint power and rate adaptation (OPRA); and (iii) fixed rate...
This article develops a mathematical framework for analyzing the average bit error rate (ABER) performance of four different selection diversity combining (SDC) schemes over slow, frequency non-selective Nakagami-m fading channels. Aside from the traditional SDC, generalized selection combining (??-GSC) and 'maximum matched filter output' selection methods, two new selection rules based on choosing...
Compressive sampling (CS) is based on the principle of sampling signals according to their sparsity or compressibility as opposed to the rate specified by the Nyquist/Shannon sampling theorem. Shannon's separation principle of source and channel coding cannot always be used to improve CS reconstruction performance in the presence of noise, including conditions when the channel is time-varying and...
The current and future wireless systems need to support a multitude of services with a wide range of data rates and reliability requirements. The limited battery resource at the mobile terminals coupled with the hostile multipath fading channel makes the problem of providing reliable multimedia services challenging. In this article, we develop a novel method to mechanize a prioritized unicast transmission...
This paper presents a novel idea of Koay-Vaman (KV) transform coding technique which is based on block coding technique. It provides the ability to detect errors, correct errors and identifies the remaining block error in each of the transmission ensembles. Exploiting this property will allow design of bandwidth efficient MANET and sensor networks to support provisioning of multi-service applications...
We present a cross-layer and multilevel unequal error protection (UEP) approach for robust video transmission over noisy wireless channels. We combine the UEP schemes at the application layer (i.e., multi-level unequal importance of compressed H.264/AVC video data) and physical layer (multi-resolution asymmetric 8-PSK modulation). The proposed scheme multiplexes the video data by mapping it to the...
One of the challenges in Cognitive Radio (CR) is efficiently monitoring a wideband radio frequency (RF) spectrum in order to identify unoccupied bands. Compressive Sensing (CS) has recently been proposed to address this problem. Typical CS techniques, however, involve random projections followed by a computationally intensive signal reconstruction process. Since spectral monitoring does require full...
In several communication systems such as tactical communications, cognitive radio and intelligent transceiver designs; signal detection, estimation and classification is an essential integral part of such system. The ability to detect certain types of common signals without apriori information enhances design of such system. In this paper we present a model that is capable of detecting chirp signal,...
The distributed multiple-input-multiple-output (MIMO) system (e.g., intercluster communication via cooperating nodes in a wireless sensor network) is a topic of emerging interest. Many previous studies have assumed perfect synchronization among cooperating nodes and identically distributed communication links. Such assumptions are rarely valid in practical operating scenarios. This paper develops...
The current and future wireless systems need to support a multitude of services with a wide range of data rates and reliability requirements. The limited battery resource at the mobile terminals coupled with the hostile multipath fading channel makes the problem of providing reliable multimedia services challenging. In this article, we develop a novel method to mechanize a prioritized unicast transmission...
A new exponential-type integral for the generalized M-th order Marcum Q-function QM(alpha, beta) is obtained when M is not necessarily an integer. This new representation includes a classical formula due to Helstrom for the special case of positive integer order M and an additional integral correction term that vanishes when M assumes an integer value. The new form has both computational utility (numerous...
The main objective of the work is to propose a security alarm model for embedded crypto application considering the latency value of the process by different computational techniques. An embedded crypto application using Vernam ciphering is considered which may give an unexpected erroneous output in real time environment due to transients and deliberately injected faults. An advanced proactive security...
In this article, we investigate two variants of traditional automatic repeat request (ARQ) protocols that exploit the disparity in bit error protection levels of multi-resolution M-ary phase-shift-keying for prioritizing the transport of more ldquocriticalrdquo messages in integrated voice/data and delay-sensitive applications (e.g., audio/video streaming). This cross-layer design can lead to a substantial...
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