The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In this article, we derive six distinct series representations of the generalized Nuttall Q-function. Interestingly, some of these expressions generalise some of the recent results on series representation of the Marcum Q-function since the Marcum Q-function is a special case of the Nuttall Q-function. To the best of our knowledge, five of these representations are novel and the other one is included...
Recent development in wireless communication has necessitated a high demand for radio resources. This has led to the development of cognitive radio technology in which radio equipments are now capable of identifying spectrum opportunity in their environment and take advantage of spectrum unused by licensed primary radio users for communication. One of the derivatives of the emerging technology is...
In this article, we have derived closed form moment generating function (MGF) of upper and lower bounds of the harmonic mean signal-to-noise ratio (SNR) of the two-hop cooperative amplify-and-forward (CAF) relay networks over Rice fading environments. The derived MGF formulas are then applied to the computation of ergodic capacity of optimal rate adaptation with constant power (ORA) and optimal joint...
In this paper, energy detector's performance is analyzed for the two-hop relay network using the area under the receiver operating characteristic (ROC) curve (AUC) in contrast to the ROC based analysis. AUC provides summary measures for the performance of a system. It provides meaningful performance analysis as it varies only from 0.5 to 1. In the worst case scenario, the practical detector's performance...
In this article, we consider the performance of energy detection in composite multipath/shadowing fading environment. We also investigate the mitigation of the effect of these fading components on detection performance with the use of diversity techniques. Single channel, maximum ratio combining (MRC), square law combining (SLC), and square-law selection (SLS) diversities are analyzed using the rapidly...
This paper investigates the effectiveness of a cross-layer design that combines adaptive modulation (AM) at the physical layer with an adaptive truncated automatic repeat request (ARQ) protocol at the data link layer to maximize the throughput of cooperative amplify-and-forward (CAF) relay networks under prescribed delay and/or error performance constraints. A by-product of our proposed analytical...
This article investigates the efficacy of a joint-design of adaptive modulation and coding (AMC) at the physical (PHY) layer with an adaptive Rmax-truncated selective-repeat automatic repeat request (ARQ) protocol at the medium access control (MAC) layer to maximize the throughput of cooperative amplify-and-forward (CAF) relay networks under prescribed delay and/or error performance constraints. Specifically,...
Cross-layer design breaks away from traditional wireless network design where each layer of the protocol stack is optimized independently. We develop a cross-layer design framework that judiciously combines adaptive modulation at the physical (PHY) layer, packet length adaptation strategy at the medium access control (MAC) layer, and source rate adaptation at the application (APP) layer in order to...
In this article, we develop an analytical framework for performance evaluation and comparison between decision and data fusion rules for cooperative relay based cognitive radio networks. Our unified analytical formulas for the data fusion rules are sufficiently general to tackle generalized stochastic channel models with independent but non-identically distributed (i.n.d) link statistics. We also...
This article develops a unified mathematical framework for maximization of the user throughput over generalized wireless channels using the symbol rate, packet length and constellation size of two distinct classes of digital modulation schemes (M-PSK and M-QAM) as optimization variables. First, we show that the throughput optimization problem for truncated selective-repeat automatic repeat request...
In this paper, energy detector's performance is investigated for the blind (fixed gain) amplify & forward (AF) dual-hop relay networks using the area under the receiver operating characteristic curve (AUC) metric. Different from the well-known receiver operating characteristics (ROC) metric, AUC is a single statistical parameter which can be used to describe and compare performance of different...
Cognitive radio network requires an efficient and effective means of detecting holes in the spectrum. Energy detection is one of the solutions that have been proposed for enabling opportunistic spectrum access. In this article, we present yet other simplified unified approaches to the analysis of performance of the energy detector under different fading channels. One is based on the kth order derivative...
In this article, we present three novel moment generating function (MGF) based approaches for performance evaluation of multi-hop, multi-relay cooperative amplify-and-forward (CAF) networks over a myriad of stochastic channel models. Method I is based on a recursive expansion of the MGF of effective SNR for a 2-hop CAF relay network developed in [15]. The second method is also similar to Method I...
Reliable spectrum sensing is the very task upon which the entire operation of cognitive radio rests. Blind sensing of spectral-holes using a radiometer (energy detectors) is one of the solutions that have been proposed for enabling opportunistic spectrum access. This article revisits the problem of energy detection of an unknown deterministic signal over a myriad of fading environments. Specifically,...
This paper investigates the performance of cooperative amplify-and-forward (CAF) relay networks with adaptive M-ary quadrature amplitude modulation (M-QAM) technique in Nakagami-m and Rice wireless fading environments. We derived closed form upper bound expression for the marginal MGF of end-to-end SNR of CAF relay system in Nakagami-m fading to compute average bit error rate (ABER), mean achievable...
In this article, we present a novel moment generating function (MGF) approach for performance evaluation of twohops cooperative non-regenerative multi-relay networks over a myriad of stochastic channel models. First, we develop very tight exponential approximations for the erfc(.) and erfc2(.) functions which will facilitate the development of a unified closed-form expression for the average symbol...
In this article, we present a unified approach for the asymptotic analysis of symbol error rates for two-hops cooperative non-regenerative multi-relay networks over a myriad of stochastic channel models. The analysis can be also extended to other types of cooperative strategies and multi-hop networks without much difficulty. The proposed moment generating function (MGF) framework is also sufficiently...
This article analyzes the performance of CSI-assisted cooperative amplify-and-forward (CAF) relay networks that employ both the optimal power allocation strategy among collaborating nodes and adaptive M-ary quadrature amplitude modulation (M-QAM) technique in Nakagami-m wireless fading environments. In particular, we advocate a simple yet unified numerical approach based on the marginal moment generating...
A simple measurement to analyze the signal detector's performance is desirable. Although, receiver operating characteristic (ROC) curve has long been used for characterizing system performance, area under the ROC curve (AUC) measurement provides meaningful insights of the system performance. Signal detector's performance can be characterized simply by average AUC, since average AUC varies from 0.5...
This article analyzes the performance of CSI-assisted cooperative amplify-and-forward (CAF) relay networks that employ both the optimal power allocation strategy among collaborating nodes and adaptive M-ary quadrature amplitude modulation (MQAM) technique in Nakagami-m wireless fading environments. In particular, we advocate a simple yet unified numerical approach based on the marginal moment generating...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.