Yaser Albagory

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Càndid Reig

Universitat de València

David Seamon

Kansas State University

Fatiha Djemili Tolba

Badji Mokhtar - Annaba University

Lyla B Das

National Institute of Technology, Calicut

Małgorzata Siennicka-Rahmstorf

University of Kassel

Sajadin Sembiring

Universitas Sumatera Utara

Viacheslav Kuleshov

Stockholm University

Journal of Computer Science IJCSIS

Maria V. Stanyukovich

Russian academy of sciences, Peter the Great Museum of Antropology and Ethnography

Ashok Paranjothi

Sri Sairam Institute Of Technology

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Papers by Yaser Albagory

Twodimensional switched-beam smart antennas for stratospheric platform cellular communications

by Yaser Albagory and Mohiy M. Hadhoud

Chaotic Interleaving for Robust Image Transmission with LDPC Coded OFDM

by Yaser Albagory, Waleed Al-Hanafy, and Fathi Abdul-samee3

Wireless Personal Communications, 2014

This paper presents a new technique for progressive image transmission over low-density parity-ch... more This paper presents a new technique for progressive image transmission over low-density parity-check coded orthogonal frequency division multiplexing (LDPC-OFDM) system. This technique adopts chaotic Baker map to improve the performance and reduce the peak-to-average power ratio (PAPR) of the OFDM signal. It helps improving the error resilient ability and also enhancing the efficiency of progressive image transmission over frequency selective fading channels. The proposed technique can effectively resist the fading impact of the frequency selective channels using simple frequency domain equalization. The proposed technique also utilizes the set partitioning in hierarchical trees as a source coding algorithm for the transmitted images. The distinctive feature of the proposed technique is that the transmitted data sequence has less data correlation, which leads to minimizing the PAPR. Simulation results show that the proposed technique improves the visual quality of the received images and reduces the PAPR of the OFDM signal as well.

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A modified array processing technique based on Kaiser window for concentric circular arrays

2012 International Conference on Multimedia Computing and Systems, 2012

Overview on modeling and design of stratospheric mobile cellular system

2012 International Conference on Multimedia Computing and Systems, 2012

ABSTRACT In this paper, cellular communications from Stratospheric Platforms (SPs) is studied and... more ABSTRACT In this paper, cellular communications from Stratospheric Platforms (SPs) is studied and the footprint analysis and design are demonstrated. In the analysis part two coverage schemes are discussed; flat-earth and real-earth models and the cell footprint is determined in each case. The flat-earth provides simple footprint equations describing the cell dimensions especially for cells of higher elevation angles while more accurate coverage equations can be obtained from the real-earth scheme which well determine the geometry of the cells of lower elevation angles. The design of a cellular system using the proposed coverage models is then demonstrated through a procedure that determines the cells locations and dimensions on the ground according. The procedure takes into consideration the cell broadening when going outwardly from the central cell to the outer cells and an update for the conventional terrestrial equations must be performed to properly locate the cells. The convergence in calculating the cell parameters have been shown to be fast and reach the final values after few updating cycles.

A novel cellular structure for stratospheric platform mobile communications

Proceedings of the Nineteenth National Radio Science Conference, 2002

A move1 cellular structure is proposed for the ambitious stratospheric platform mobile communicat... more A move1 cellular structure is proposed for the ambitious stratospheric platform mobile communications. The innovated structure adopts a multibeam scanning antenna array to create ringshaped cells instead of the classical honey cells. This helps in avoiding the impact of positional instability especially the rotational motion of the platform around its vertical axis. Furthermore the transmitted power is reduced as well as the handover and location updating rates. The adaptation of the cell area for traffic balancing is easier than using the traditional hexagonal one. The w-a.etry of the ring cell is analyzed in order to investigate the main parameters affecting the S Y S b performance such as the beam visiting time and the beam-scanning rate.

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Simplified Sidelobe Reduction Techniques for Concentric Ring Arrays

Wireless Personal Communications, 2013

ABSTRACT In this paper, a simplified sidelobe reduction technique for uniform concentric circular... more ABSTRACT In this paper, a simplified sidelobe reduction technique for uniform concentric circular antenna arrays (UCCA) is proposed. This technique is based on modifying some conventional windows to control the amplitude feeding instead of using adaptive techniques which require excessive processing and calculations and suffer from the lack of practical application especially for UCCA. The modified windows are applied to individual rings of the array that will taper the corresponding current amplitudes. The resulted sidelobe level, beamwidth and stability for amplitude errors are discussed for the different proposed windows where it shows a sidelobe reduction to about 49 dB as in the case of Binomial UCCA while the Hamming window shows the most immunity to tapered amplitude errors.

Smart cell design for high altitude platforms communication

AEU - International Journal of Electronics and Communications, 2013

ABSTRACT This paper proposes a novel design technique for irregular shaped cells in the high alti... more ABSTRACT This paper proposes a novel design technique for irregular shaped cells in the high altitude platforms (HAPs) cellular system. This technique is based on dividing the coverage area into a grid of small pixel spots and the desired cell is obtained by grouping some pixel spots to give the desired cell shape. These spots are formed with narrow and low sidelobe level beams using concentric ring array (CRA) to reduce the cochannel interference as well as improving the resolution of the design. The desired cell pattern is converted into a spatial mask that selects the desired pixel spots with a proper pre-weight smoothing function. The proposed cell design technique will optimize the cell shape according to the user distribution and behavior in the covered area and consequently is expected to reduce the frequent handoff and signaling traffic of location updating from moving users. Simulation results show that a cell with any irregular shape can be formed with as low as 40 dB sidelobe level using Gaussian CRA.

Tapered beamforming for concentric ring arrays

AEU - International Journal of Electronics and Communications, 2013

ABSTRACT

Complex Envelope Second-Order Statistics in High-Altitude Platforms Communication Channels

by Athanasios Kanatas and Yaser Albagory

Wireless Personal Communications, 2014

Twodimensional switched-beam smart antennas for stratospheric platform cellular communications

by Yaser Albagory and Mohiy M. Hadhoud

Chaotic Interleaving for Robust Image Transmission with LDPC Coded OFDM

by Yaser Albagory, Waleed Al-Hanafy, and Fathi Abdul-samee3

Wireless Personal Communications, 2014