2 citations · 5 across the 31 of their papers we have counts for
37 papers
Novel Secret-Key-Assisted Schemes for Secure MISOME-OFDM Systems
Mohamed Marzban, Ahmed El Shafie, Naofal Al-Dhahir
We propose a new secure transmission scheme for uplink multiple-input single-output (MISO) orthogonal-frequency multiplexing (OFDM) systems in the presence of multiple eavesdropper…
On the Performance of Quickest Detection Spectrum Sensing: The Case of Cumulative Sum
Ahmed Badawy, Ahmed El Shafie, Tamer Khattab
Quickest change detection (QCD) is a fundamental problem in many applications. Given a sequence of measurements that exhibits two different distributions around a certain flipping…
Security-Enhanced SC-FDMA Transmissions Using Temporal Artificial-Noise and Secret-Key Aided Schemes
Mohamed F. Marzban, Ahmed El Shafie, Naofal Al-Dhahir +1
We investigate the physical layer security of uplink single-carrier frequency-division multiple-access (SC-FDMA) systems. Multiple users, Alices, send confidential messages to a co…
Securing Untrusted Full-Duplex Relay Channels in the Presence of Multiple External Cluster-Based Eavesdroppers
Ahmed El Shafie, Asma Mabrouk, Kamel Tourki +2
This letter investigates the physical layer security in a wireless cooperative network where communication is assisted by a full-duplex (FD) untrusted relay in the presence of mult…
Securing OFDM-Based Wireless Links Using Temporal Artificial-Noise Injection
Mohamed F. Marzban, Ahmed El Shafie, Rakan Chabaan +1
We investigate the physical layer security of wireless single-input single-output orthogonal-division multiplexing (OFDM) when a transmitter, which we refer to as Alice, sends her…
Thresholds Optimization for One-Bit Feedback Multi-User Scheduling
Mohammed Hafez, Ahmed El Shafie, Mohammed Shaqfeh +3
We propose a new one-bit feedback scheme with scheduling decision based on the maximum expected weighted rate. We show the concavity of the -user case and provide the optimal so…
Probabilistic Jamming/Eavesdropping Attacks to Confuse a Buffer-Aided Transmitter-Receiver Pair
Ahmed El Shafie, Kamel Tourki, Zhiguo Ding +1
We assume that a buffer-aided transmitter communicates with a receiving node in the presence of an attacker. We investigate the impact of a radio-frequency energy-harvesting attack…
Achievable Rates of Buffer-Aided Full-Duplex Gaussian Relay Channels
Ahmed El Shafie, Ahmed Sultan, Ioannis Krikidis +2
We derive closed-form expressions for the achievable rates of a buffer-aided full-duplex (FD) multiple-input multiple-output (MIMO) Gaussian relay channel. The FD relay still suffe…
Cooperative Access Schemes for Efficient SWIPT Transmissions in Cognitive Radio Networks
Ahmed El Shafie, Naofal Al-Dhahir, Ridha Hamila
We investigate joint information and energy cooperative schemes in a slotted-time cognitive radio network with a primary transmitter-receiver pair and a set of secondary transmitte…
A Secure Multiple-Access Scheme for Rechargeable Wireless Sensors in the Presence of an Eavesdropper
Ahmed El Shafie, Naofal Al-Dhahir
We propose a simple yet efficient scheme for a set of energy-harvesting sensors to establish secure communication with a common destination (a master node). An eavesdropper attempt…
An Artificial-Noise-Aided Hybrid TS/PS Scheme for OFDM-Based SWIPT Systems
Ahmed El Shafie, Kamel Tourki, Naofal Al-Dhahir
We propose a new artificial-noise aided hybrid time-switching/power-splitting scheme for orthogonal frequency-division multiplexing (OFDM) systems to securely transmit data and tra…
Secure Communications in the Presence of a Buffer-Aided Wireless-Powered Relay With Self-Energy Recycling
Ahmed El Shafie, Naofal Al-Dhahir
We consider a relay-assisted wireless network, where the energy-harvesting buffer-aided relay node is powered by radio-frequency signals from a source node wishing to communicate w…
Security of Rechargeable Energy-Harvesting Transmitters in Wireless Networks
Ahmed El Shafie, Dusit Niyato, Naofal Al-Dhahir
In this letter, we investigate the security of a single-antenna rechargeable source node in the presence of a multi-antenna rechargeable cooperative jammer and a potential single-a…
Physical-Layer Security of a Buffer-Aided Full-Duplex Relaying~System
Ahmed El Shafie, Ahmed Sultan, Naofal Al-Dhahir
This letter proposes a novel hybrid half-/full-duplex relaying scheme to enhance the relay channel security. A source node (Alice) communicates with her destination node (Bob) in t…
Sparsity-Cognizant Multiple-Access Schemes for Large Wireless Networks With Node Buffers
Ahmed El Shafie, Naofal Al-Dhahir, Ridha Hamila
This paper proposes efficient multiple-access schemes for large wireless networks based on the transmitters' buffer state information and their transceivers' duplex transmission ca…
Cognitive Access Protocol for Alleviating Sensing Errors in Cognitive Multiple-Access Systems
Ahmed El Shafie
This letter studies a time-slotted multiple-access system with a primary user (PU) and a secondary user (SU) sharing the same channel resource. We propose a novel secondary access…
Optimal Spectrum Access for a Rechargeable Cognitive Radio User Based on Energy Buffer State
Ahmed El Shafie, Mahmoud Ashour, Amr Mohamed +1
This paper investigates the maximum throughput for a rechargeable secondary user (SU) sharing the spectrum with a primary user (PU) plugged to a reliable power supply. The SU maint…
On Spectrum Sharing Between Energy Harvesting Cognitive Radio Users and Primary Users
Ahmed El Shafie, Mahmoud Ashour, Tamer Khattab +1
This paper investigates the maximum secondary throughput for a rechargeable secondary user (SU) sharing the spectrum with a primary user (PU) plugged to a reliable power supply. Th…
Power-Optimal Feedback-Based Random Spectrum Access for an Energy Harvesting Cognitive User
Mahmoud Ashour, Ahmed El Shafie, Amr Mohamed +1
In this paper, we study and analyze cognitive radio networks in which secondary users (SUs) are equipped with Energy Harvesting (EH) capability. We design a random spectrum sensing…
Energy-Efficient Cooperative Cognitive Relaying Schemes for Cognitive Radio Networks
Ahmed El Shafie, Tamer Khattab, Amr El-Keyi
We investigate a cognitive radio network in which a primary user (PU) may cooperate with a cognitive radio user (i.e., a secondary user (SU)) for transmissions of its data packets.…
Maximum Throughput of a Secondary User Cooperating with an Energy-Aware Primary User
Ahmed El Shafie, Ahmed Sultan, Tamer Khattab
This paper proposes a cooperation protocol between a secondary user (SU) and a primary user (PU) which dedicates a free frequency subband for the SU if cooperation results in energ…
On Orthogonal Band Allocation for Multi-User Multi-Band Cognitive Radio Networks: Stability Analysis
Ahmed El Shafie, Tamer Khattab
In this work, we study the problem of band allocation of buffered secondary users (SUs) to primary bands licensed to (owned by) buffered primary users (PUs). The…
Probabilistic Band-Splitting for a Buffered Cooperative Cognitive Terminal
Ahmed El Shafie, Ahmed Sultan, Tamer Khattab
In this paper, we propose a cognitive protocol that involves cooperation between the primary and secondary users. In addition to its own queue, the secondary user (SU) has a queue…
Cooperative Cognitive Relaying Under Primary and Secondary Quality of Service Satisfaction
Ahmed El Shafie, Tamer Khattab
This paper proposes a new cooperative protocol which involves cooperation between primary and secondary users. We consider a cognitive setting with one primary user and multiple se…