Darwish A. E. Mohamed

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A major drawback of orthogonal frequency-division multiplexing (OFDM) signals is their high peak-to-average power ratio (PAPR), which causes serious degradation in performance when a nonlinear power amplifier (PA) is used. Companding transform is a well-known method to reduce PAPR without restrictions on system parameters such as number of subcarriers,(More)
In this paper, Space Time Adaptive Processing (STAP) applied on wideband signals from uniformly spaced real elements using Direct Data Domain Least Squares (DLS). Two antenna configurations are used: an array of dipole antenna (narrowband antenna) and an array of patch antenna (wideband antenna). A frequency transformation technique is used only for the(More)
Control and manipulation of electromagnetic waves is at the heart of many industries from wireless communication, Internet and optical data storage to imaging and displays. Progress in these technologies places challenging demands on material properties and therefore structured electromagnetic materials. Metamaterials are a special class of structured(More)
In this paper, a printed elliptical slot antenna fed by different tapered microstrip line with U-shaped and Circular ring-shaped tuning stub is proposed for ultra-wideband (UWB) applications. The tapering aids in minimizing the reflection at the interface between the microstrip feed line and the tuning stub. Introduced is a new tapering profile that(More)
Space Time Adaptive Processing (STAP) applied on signal received from different configurations of real elements using D3LS (Direct Data Domain Least Squares). We will discuss the impact of each typical element-missing on the performance of this approach and the precision of the estimated strength of the SOI. We are interested in five different antenna(More)
A robust Direction of Arrival (DOA) estimation in multipath environment is proposed for efficient separation of coherent signals and data detection. The proposed method is applied for mobile communication system in the uplink direction by using Uniform Linear Array (ULA) in the receiver for the purpose of channel estimation and multipath effect rejection.(More)
The reconfigurability may be required in operating frequency, radiation pattern and/or polarization of the antenna. Application areas that drive the development of reconfigurable antennas include multifunction wireless devices, WLAN, multiple-input multiple-output (MIMO), ultra-wideband (UWB) systems, anti-jamming and secure communication. Recent(More)
The smart antenna systems combine antenna arrays with digital signal processing (DSP) algorithms. In a smart antenna system a specialized signal processor computes the direction of arrival (DOA) of a user and also adds the strength of the signals from each antenna element together to form a beam towards the direction as computed by DOA. If additional users(More)
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