Ali Hakam

Novel unified expressions for error rates and ergodic channel capacity analysis over generalized fading subject to AWGGN

Many generalized fading distributions are given in terms of special functions, complicating the analysis of wireless performance metrics. This paper presents novel approximations to the extended incomplete gamma function, the modified Bessel function of the second type, and the generalized Q-function. New simpler and unified form for the probability density function of the extended generalized-K (EGK) and M-N distributions is developed, avoiding complicated and computationally-expensive functions, e.g. Fox and Meijer-G. Based on the new unified PDF and the proposed approximations, we derive novel generic and unified expressions for the average bit error rate and average channel capacity for the recently introduced six most generalized fading channels, namely the EGK, the M-N, the α-η-μ, α-λ-μ, α-κ-μ, and α-λ-η-μ, including the generalized-K, generalized Nakagami-m, the α-μ, the η-μ, the λ-μ, the κ-μ, the Nakagami-Lognormal, the Weibull, the Rice, the Hoyt, the Maxwell and other fading scenarios as special cases. The Additive White Generalized Gaussian Noise (AWGGN) is considered as the noise model, that includes the AWGN, the Laplacian, the Gamma and the impulsive noise as special cases, being an application to the generalized Q-function approximation. Moreover, novel analysis for Space-Time Block Codes in generalized-K fading is also developed as an application to the developed approximation of the modified Bessel function. The derived expressions are very simple and analytically traceable. Monte Carlo simulation and published work corroborate our obtained results.

Planar Ultra-Wideband elliptical antenna for communication applications

This paper introduces new design and implementation of low profile planner antenna for Ultra-Wideband (UWB) applications. This new antenna consists mainly of conducting elliptical patch and the partial conducting ground plane, with fabrication dimensions of 41.95×21.2×1.27 mm, the design was fabricated using Rogers 5880 LZ substrate. The impedance bandwidth of the designed antenna is between 3 GHz to 10.75 GHz and the selected ground length is 10 mm. VSWR and S11 are obtained for the new antenna through HFSS simulation for different ground plane lengths. Antenna group delay, maximum antenna gain and radiation pattern for this new antenna are studied and analyzed. We further take the design one step beyond the simulation and fabricate a prototype for testing. Simulation results and experimental results obtained from the fabrication show an excellent agreement, achieving the desired bandwidth.

Robust DOA Estimation Using a 2D Novel Smart Antenna Array

This paper investigate the problem of Direction of Arrival (DOA) estimation using a 2D novel smart antenna array configuration. The new proposed 2D configuration overcomes the problem of the uniform linear array (ULA), specifically, its inability to detect signals arriving at grazing incidence. The new configuration can reliably estimate signals arriving from narrowband plane wave sources close to the array endfire. Moreover, the proposed configuration consists of double crossed uniform linear arrays (ULAs), so that the size and computational load of the proposed array is identical to that of a 2N-element conventional ULA. Minimum Variance Distortionless Response (MVDR) is used as a tool of radio signal detection and estimation. A comparative study between conventional ULA and the proposed 2D proposed array is carried out by means of simulation under different Signal-to-Noise Ratio, number of scatterers, and number of snapshots.

Moment Generating Functions of Generalized Wireless Fading Channels and Applications in Wireless Communication Theory

In this paper, new exact and approximate moment generating functions (MGF) expression for generalized fading models are derived. Specifically, we consider the η-λ-μ, α-μ, α-η-μ, α-λ-μ, α-κ-μ, and α-λ-η-μ generalized fading distributions to derive approximate MGF expressions. The new expressions are very accurate and, in contrast to earlier results in the literature, avoid any complicated special functions, e.g. the Meijer-G and Fox H-functions. As such, the new MGF expressions allow easier and more efficient analytical manipulations, which also apply for their special cases such as the Rayleigh, Rice, and Nakagami-m fading. As an illustrative application, the average bit error rates for each of the fading models are evaluated using the new derived MGF expressions. The accuracy of the analytical results by using the numerically computed results as a basis of comparison as well as published results from the literature.

SRRs effect on circular antenna with elliptical rings for ultra-wide-band

This paper presents a novel microstrip antenna that consists of conducting circular patch with elliptical etched rings and partial conducting ground plane. The fabrication was done using Rogers 5880 LZ substrate, and the dimensions are selected to be 45mm × 31mm × 1.27 mm. Split Ring Resonators (SRRs) will be used to enhance gain performance for wide frequency band. The Split Ring Resonator design is simulated using HFSS (High Frequency Structure Simulator). The final antenna simulation results along with the SRR group delay, maximum antenna gain, radiation pattern, S11 and VSWR are illustrated. The presented antenna achieved the desired BW and the simulated S11 and VSWR are coherent, showing a unique performance.

Miniature planar ultra-wide-band microstrip antenna for breast cancer detection

Microwave imaging is explored as an imaging modality for early detection of breast cancer. When exposed to electromagnetic waves, the breast tumor has electrical properties that are substantially different from those of healthy breast tissue. This paper for the detection of breast cancer. We examine the ability to detect tumors by a UWB microstrip antenna operating at 6 GHz. Using a simple model in the form of a cone. This model consists of the breast skin, fat, and tumor tissues. The study is done according to several distances between the patch antenna and the model of the breast. Simulation and measured results are presented, namely, reflection coefficient, gain and radiation pattern of the antenna and the current density in the breast skin, fatty tissue and the tumor to give us a clear insight into the concept studied.

Minituarized printed L-shaped antenna with parasitic element for ultra-wideband applicatons

This paper presents a new compact printed L-shaped monopole antenna for applications in ultra-wideband (UWB) systems such as home networks and various wireless systems. A miniaturization of the proposed antenna has been accomplished by using a parasatic element, resulting in a design with dimensions 25 mm × 25 mm × 1.6 mm. The antenna is printed on FR4 epoxy and is fed by SMA female connector. The return loss (Su) and voltage standing wave ratio (VSWR) are obtained using both HFSS and CST for different ground plane lengths. The new L-shaped design illustrates good UWB characteristics since it is capable of operating in the range 2-12.31 GHz. Simulation results for Su and VSWR show strong consistency in terms of the bandwidth for UWB operation, under the general criteria of S11 less than -10 dB and VSWR less than 2:1.

Maximal ratio combining diversity analysis of underwater acoustic communications subject to к-μ shadowed fading channels

In this paper, a novel unified analytical expression for average bit error rates (ABER) and average channel capacity (ACC) is presented for the κ-μ shadowed fading model. This model has recently shown to be suitable for underwater acoustic wireless channel modeling using the measurements conducted by the Naval Research Laboratory [1], and is not so well covered in the public literature. Deploying the maximal ratio combining diversity (MRC) receiver, a new simple analytical expression for the probability density function (PDF) of the receivers output signal-to-noise ratio (SNR) is presented. Based on this new PDF, a novel unified ABER and ACC expression is derived. Moreover, to generalize the ABER analysis, the additive white generalized Gaussian noise model is assumed, which models different noise environments. The new unified expression is accurate, simple and generic, and is suitable for MRC analysis in this generalized shadowed fading and noise environment. Numerical techniques and published results from the literature prove the accuracy of our analysis and the generality of the derived unified expression.