Výsledky vyhledávání - "Ashraf Y. Hassan"

Akademický článek

A Frequency-Diversity System With Diversity Encoder and OFDM Modulation

Autor: Ashraf Y. Hassan

Publikováno v: IEEE Access, Vol 9, Pp 2805-2818 (2021)

In this work, a diversity encoder maps vectors of N modulated symbols to vectors of N diversity symbols using an orthogonal matrix. Each modulated symbol appears in N diversity symbols. An Orthogonal-Frequency-Division-Multiplexing (OFDM) modulator c

Externí odkaz: https://doaj.org/article/42dcbd75239e47668454f6c872836391

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Akademický článek

A Novel Dynamic Mathematical Model Applied in Hash Function Based on DNA Algorithm and Chaotic Maps

Autor: Nada E. El-Meligy, Tamer O. Diab, Ashraf S. Mohra, Ashraf Y. Hassan, Wageda I. El-Sobky

Publikováno v: Mathematics, Vol 10, Iss 8, p 1333 (2022)

This paper aims to improve SHA-512 security without increasing complexity; therefore, we focused on hash functions depending on DNA sequences and chaotic maps. After analysis of 45 various chaotic map types, only 5 types are selected in this proposal

Externí odkaz: https://doaj.org/article/b82b9975f9014dc4bafd06e86cb81857

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A Compact Diplexer Using Coupled π-CRLH Zeroth Resonators

Autor: Ahmed A. Abdel Aziz, Ashraf Y. Hassan, Mahmoud A. Abdalla, Mohamed F. Hagag

Publikováno v: IETE Journal of Research. :1-8

This paper presents a new diplexer design of a new-coupled composite right/left-handed (CRLH) resonator to serve the LTE applications. The realization of the diplexer is designed as coupled two zer...

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::4535831e5054a72ac1d240cfb64f75d1
https://doi.org/10.1080/03772063.2021.1909505

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A new approach for designing and implementing ADF equalization for 5G frequency selective channel based on two operating phases of LS and RLS algorithms

Autor: Ashraf Y. Hassan

Publikováno v: Telecommunication Systems. 77:543-562

In this paper, a new approach is proposed for implementing an adaptive decision feedback equalizer (ADFE) for the 5G channel. The proposed equalizer works in two phases. In the first phase, a least-squares (LS) algorithm with a variable-length traini

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::a1a1445f347696b2261383ac743a1324
https://doi.org/10.1007/s11235-021-00778-x

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The Effect of the Eigenvalues of the Zero-Forcing Detector on Its Performance in the Space-Division Multiplexing System

Autor: Ali Saleh, Ashraf Y. Hassan

Publikováno v: International Journal of Intelligent Engineering and Systems. 14:340-355

Zero-Forcing (ZF) detector is used in Space-Division Multiplexing (SDM) receiver to remove interference among the received symbols. Previous works showed that the power of channel noise is enhanced in the output of the ZF detector. They recommend usi

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::bcf2f4607e7df76944ea631dda9e3041
https://doi.org/10.22266/ijies2021.0228.32

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A Simple Time–Space Diversity Scheme Using Extended Shaping Pulse

Autor: Ashraf Y. Hassan

Publikováno v: Wireless Personal Communications. 113:821-841

This paper proposes a new time–space diversity scheme for data transmission through flat fading channels. Extended pulses are used to shape the modulated symbols at different time slots. The proposed transmitter does not change the transmission rat

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::1e879687bed7f4f7096f99798ed3fa7d
https://doi.org/10.1007/s11277-020-07254-w

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Enhancing Signal Detection in Frequency Selective Channels by Exploiting Time Diversity in Inter-symbol Interference Signal

Autor: Ashraf Y. Hassan

Publikováno v: Wireless Personal Communications. 106:1373-1395

Inter-symbol interference (ISI) causes many errors in modulated symbols, when they are transmitted through band-limited channels. According to the multipath delay profile of the channel, the modulated symbol may disperse over more than one symbol per

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::699bbe9ea5d65f2c4d4a4ac9161bf566
https://doi.org/10.1007/s11277-019-06220-5

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Design and Performance Evaluation of a Multiuser OFDM System Based on Differential Quadrature Chaos-Shift-Keying Spread Spectrum

Autor: Khaled T. Harb, H. El Hennawy, Ashraf Y. Hassan, Mahmoud O. El Beshry

Publikováno v: 2021 38th National Radio Science Conference (NRSC).

This paper aims to propose a multiuser OFDM system with non-coherent differential quadrature chaos-shift-keying (OFDM-DQCSK) modulation. The proposed system is based on direct sequence spread spectrum where chaotic codes replace conventional spreadin

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::729fbaa0a239f85ce9b04a3566a3884c
https://doi.org/10.1109/nrsc52299.2021.9509809

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Performance Analysis of LDPC Decoding Techniques

Autor: Ashraf Y. Hassan, Wageda I. Shaban, Sahar F. Abdel-Momen, Abdel Halim A. Zikry

Low density parity checking codes (LDPC) are one of the most important issues in coding theory at present. LDPC-code are a type of linear-block LDPC-codes. Channel coding might be considered as the finest conversant and most potent components of cell

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4f428e305d4f850d9f706682c8d5c390
https://zenodo.org/record/8023000

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