28 citations · 76 across the 48 of their papers we have counts for
21 papers · 1 filter
Multi-User Diversity with Optimal Power Allocation in Spectrum Sharing under Average Interference Power Constraint
Fotis Foukalas, Tamer Khattab
In this paper, we investigate the performance of multi-user diversity (MUD) with optimal power allocation (OPA) in spectrum sharing (SS) under average interference power (AIP) cons…
Interference Cancellation trough Interference Alignment for Downlink of Cognitive Cellular Networks
May Moussa, Fotis Foukalas, Tamer Khattab
In this letter, we propose the interference cancellation through interference alignment at the downlink of cognitive cellular networks. Interference alignment helps the spatial res…
Secret Key Generation Based on AoA Estimation for Low SNR Conditions
Ahmed Badawy, Tamer Khattab, Tarek Elfouly +3
In the context of physical layer security, a physical layer characteristic is used as a common source of randomness to generate the secret key. Therefore an accurate estimation of…
A Simple AoA Estimation Scheme
Ahmed Badawy, Tamer Khattab, Daniele Trinchero +2
We propose an intuitive, simple and hardware friendly, yet surprisingly novel and efficient, received signal's angle of arrival (AoA) estimation scheme. Our intuitive, two-phases c…
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…
Secure Degrees of Freedom of the Gaussian MIMO Wiretap and MIMO Broadcast Channels with Unknown Eavesdroppers
Mohamed Amir, Tamer Khattab, Tarek Elfouly +1
We investigate the secure degrees of freedom (SDoF) of the wiretap and the K user Gaussian broadcast channels with multiple antennas at the transmitter, the legitimate receivers an…
On the Degrees of Freedom of SISO X-Channel with Alternating CSIT
Ahmed Wagdy, Amr El-Keyi, Tamer Khattab +1
In this paper, we establish the degrees of freedom (DoF) of the two-user single input single output (SISO) X-channel with alternating channel state information at the transmitters…
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…
The asymmetric DoF Region for the 3-user MxN Interference Channel
Mohamed Khalil, Tamer Khattab, Amr El-Keyi +1
In this paper, the 3-user Gaussian MIMO interference channel is considered. The asymmetric distribution of the DoF, where different users have different number of DoF, is studied.…
A Novel Spectrally-Efficient Scheme for Physical Layer Network Coding
Ahmed G. Helmy, Tamer Khattab, Mazen O. Hasna
In this paper, we propose a novel three-time-slot transmission scheme combined with an efficient embedded linear channel equalization (ELCE) technique for the Physical layer Networ…
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…
A DoF-Optimal Scheme for the two-user X-channel with Synergistic Alternating CSIT
Ahmed Wagdy, Amr El-Keyi, Tamer Khattab +1
In this paper, the degrees of freedom (DoF) of the two-user single input single output (SISO) X-channel are investigated. Three cases are considered for the availability of channel…
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…
Optimal Cooperative Cognitive Relaying and Spectrum Access for an Energy Harvesting Cognitive Radio: Reinforcement Learning Approach
Ahmed El Shafie, Tamer Khattab, Hussien Saad +1
In this paper, we consider a cognitive setting under the context of cooperative communications, where the cognitive radio (CR) user is assumed to be a self-organized relay for the…
Maximum Throughput of a Cooperative Energy Harvesting Cognitive Radio User
Ahmed El Shafie, Tamer Khattab, H. Vincent Poor
In this paper, we investigate the maximum throughput of a saturated rechargeable secondary user (SU) sharing the spectrum with a primary user (PU). The SU harvests energy packets (…
On the Design of Relay--Assisted Primary--Secondary Networks
Ahmed El Shafie, Tamer Khattab, Ahmed Sultan +1
The use of cognitive relays to assist primary and secondary transmissions in a time-slotted cognitive setting with one primary user (PU) and one secondary user (SU) is investig…
Maximum Throughput for a Cognitive Radio Multi-Antenna User with Multiple Primary Users
Ahmed El Shafie, Tamer Khattab
We investigate a cognitive radio scenario involving a single cognitive transmitter equipped with antennas sharing the spectrum with primary users (PUs)…