Ibrahem E. Atawi

Performance of Quadrature Spatial Modulation in Amplify-and-Forward Cooperative Relaying

Quadrature spatial modulation (QSM) is a recent digital multiple-input multiple-output (MIMO) transmission technique. Combined with cooperative relaying, QSM improves the overall spectral efficiency and enhances the communication reliability. This letter studies the performance of QSM amplify-and forward cooperative relaying systems. In particular, a closed-form expression for the average pair-wise error probability of the cooperative system is derived, which is used to calculate a tight upper bound of the average bit error probability (ABEP) over Rayleigh fading. In addition, a simple approximate, yet accurate expression is derived and analyzed asymptotically. Simulation results, which corroborate the numerical ones, show the effectiveness of combined QSM and cooperative relaying in improving the overall system performance.

Spectral-Efficient Quadrature Spatial Modulation Cooperative Amplify and Forward Spectrum-Sharing Systems

Quadrature spatial modulation (QSM) is a recent multiple-input–multiple-output (MIMO) digital transmission paradigm. Combining QSM with cooperative relaying in spectrum-sharing systems improves the overall spectral efficiency and enhances the communication reliability. In this paper, we study the performance of QSM-MIMO amplify-and-forward (AF) cooperative relaying spectrum-sharing systems, in which a multiantenna secondary source communicates with a secondary receiver with the help of a secondary AF relay in the presence of multiple primary receivers. In particular, a closed-form expression for the average pairwise error probability (PEP) of the secondary system is derived and used to obtain a tight upper bound of the average bit error probability (ABEP) over Rayleigh fading channels. In addition, a simple asymptotic, yet accurate, expression is derived and analyzed to show the effect of key parameters. Simulation results are presented to validate numerical analysis. Results reveal that QSM with cooperative relaying improves the spectrum-sharing systems performance.

Energy-detection based spectrum-sensing in cognitive radio networks over multipath/shadowed fading channels

The performance of spectrum-sensing based energy-detection (ED) in cognitive radio networks (CRNs) over the extended generalized-K (EGK) fading channels is analyzed. More specifically, exact and accurate analytical expressions for the average detection probability under different detection scenarios, such as, single channel (no diversity), diversity reception, and cooperative spectrum sensing, are derived and evaluated. The derived analytical framework can be used for both integer and non-integer values of the fading/shadowing parameters. The impact of the fading/shadowing parameters on the performance of energy detectors is studied in terms of receiver operating characteristics (ROC) curves. To verify the correctness of our analysis, the derived analytical expressions are corroborated via Monte-Carlo simulation results.

Spectrum-sensing in cognitive radio networks over composite multipath/shadowed fading channels

Performance of ED in CRNs over EGK fading channels is analyzed.Unified analytical expressions for the average detection probability are derived.Performance of diversity reception and cooperative sensing is analyzed. Display Omitted This paper analyzes the performance of spectrum-sensing-based energy detection (ED) in cognitive radio networks (CRNs) over generalized fading channels. The fading channel is modeled by the extended generalized-K (EGK) distribution. Exact and accurate analytical expressions for the average detection probability with different detection schemes, such as, single channel, diversity reception, and cooperative spectrum sensing, are derived and evaluated. Obtained expressions can be reduced to other well-known fading channels such as, Weibull, Nakagami-m, and Rayleigh. It is shown that the analytical framework can be used for both integer and non-integer values of the fading/shadowing parameters. The impact of key fading/shadowing parameters on the performance of energy detectors is discussed with receiver operating characteristics (ROC) curves. The accuracy of the derived analytical expressions is corroborated via Monte-Carlo simulation results.

Accurate performance evaluation of semi-blind dual-hop wireless relay systems under generalized fading

In current cooperative communication systems, a relay terminal is very often used as an intermediate node. Introducing this node may degrade or improve the overall system performance, depending on the power imbalance between the hops. In this paper a unified framework to estimate the performance of dual-hop fixed-gain relay system when each hop is subjected to κ-μ shadowed fading is presented. Specifically, new closed form expressions are derived for the outage probability, the generalized moments, the moment generating function (MGF), and the ergodic capacity. This unified analytical framework is obtained in terms of well-known and easily computable functions. The accuracy of the analytical results is verified through computer simulations.

Cognitive MIMO quadrature spatial modulation systems with mutual primary-secondary co-channel interference

Quadrature spatial modulation (QSM) in cognitive radio (CR) is a new spectral efficient multiple-input multiple-output (MIMO) digital modulation technique. In QSM, the spatial constellation diagram of conventional spatial modulation (SM) system is extended to include both in-phase and quadrature components of the data symbol. As such, QSM combined with CR techniques achieve significant improvement in the overall spectral efficiency while the advantages of SM are retained. In this paper, we study the performance of QSM-MIMO-CR systems in the presence of mutual primary-secondary co-channel interference. A closed-form expression for the average pair-wise error probability (PEP) of the secondary system is derived and used to calculate a tight upper bound of the average bit error rate (ABER) over Rayleigh fading. In addition, a simple asymptotic expression is derived and analyzed. Simulation results, which corroborate the numerical ones, show the importance of QSM in improving the overall secondary performance.

On the performance of fixed-gain amplify-and-forward dual-hop relay systems with beamforming under k — μ shadowed fading

Modern cooperative telecommunication networks are currently utilizing a relay terminal, which is frequently exploited as an intermediate stage. This technique is vitally significant for the sake of performance enhancement and coverage extension with no further increment of the transmitted RF power. These benifits can be further improved by introducing multiple antennas at both source and destination nodes. In this paper, a two-hop multi-antenna wireless transmission system which is equipped with a fixed-gain aided amplify and forward relay node is investigated. A complete analytical framework to estimate the end-to-end (e2e) performance when both the source-relay and relay-destination links are subjected to independent but non-identical (i.n.i.d) k - μ shadowed fading is derived. More specifically, new accurate and easy to compute mathematical expressions, using an accurate form of the e2e signal-to-noise ratio (SNR) density function, are derived for several fundamental performance metrics that fully describe the contemplated system, namely, the outage probability (Pout), the moment generating function (MGF), and the average symbol error probability (ASEP) for a single two-hop transmission system. This unified analytical framework is obtained in terms of well-known and easily computable functions. Finally, all the analytical results for the antecedent performance descriptors are verified through computer simulations in the respect of accuracy.

On the Average Bit Error Rate and Average Channel Capacity over Generalized Fading Channels

In this paper, we present unified analytical expressions for the average bit error rate (BER) and the average channel capacity of single-branch receivers operating over generalized fading channels. More specifically, novel closed-form expressions for the average BER and the average channel capacity over generalized η-μ fading channels in terms of the bivariate Foxs H-function/Meijers G-function are derived. The influence of the fading parameters η and μ on the system performance is analyzed and discussed through representative numerical examples. The correctness of our derivations is validated by means of Monte-Carlo simulations. In addition, our analytical results are in excellent agreement with the results that have been previously reported in literature.

An exact performance analysis for mobile communications over generalized fading channels

This paper derives novel, unified, and exact closed-form analytical expressions for the moment generating function (MGF), the generalized moments, and the average symbol error probability (SEP) of wireless communication systems that operate over the α - η - β fading channels. The derived expressions are then used to analyze the influence of the fading parameters on the system performance. However, to validate the accuracy of the derived expressions, we present a comparison between numerical results and Monte-Carlo simulations. Both results are in excellent agreement over a wide range of signal-to-noise ratio (SNR) and for different values of the fading parameters.

A unified approach to analyze the average bit error probability in generalized fading channels with additive generalized Gaussian noise

In this paper, we present a unified approach to analyze the average bit error probability (BEP) in generalized fading channels subject to additive generalized Gaussian noise (AGGN). Specifically, we assume that the fading channel is such that the received signal envelope, X, is a random variable that has the probability density function (pdf) given by the product of power and exponential functions with the modified Bessel function of the first kind, i.e., the pdf of the received envelop X follows the form fx (x) = xλ-1exp (-axβ)Iv (bxβ). As an example of such channels, and without loss of generality, we analyze the performance of the average BEP over the η-μ fading channels subject to AGGN. Analytical results accompanied with Monte-Carlo simulations are provided to validate our analysis.