50 citations · 132 across the 22 of their papers we have counts for
12 papers · 1 filter
A New Relation Between Energy Efficiency and Spectral Efficiency in Wireless Communications Systems
Lokman Sboui, Zouheir Rezki, Ahmed Sultan +1
When designing wireless communication systems (WCS), spectral efficiency (SE) has been the main design performance metric. Recently, energy efficiency (EE) is attracting a huge int…
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…
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…
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…
Band Allocation for Cognitive Radios with Buffered Primary and Secondary Users
Ahmed El Shafie, Ahmed Sultan, Tamer Khattab
In this paper, we study band allocation of buffered secondary users (SUs) to orthogonal primary licensed bands, where each primary band is assigned…
Optimal Selection of Spectrum Sensing Duration for an Energy Harvesting Cognitive Radio
Ahmed El Shafie, Ahmed Sultan
In this paper, we consider a time-slotted cognitive radio (CR) setting with buffered and energy harvesting primary and CR users. At the beginning of each time slot, the CR user pro…
Cognitive Radio Transmission Strategies for Primary Markovian Channels
Ahmed ElSamadouny, Mohammed Nafie, Ahmed Sultan
A fundamental problem in cognitive radio systems is that the cognitive radio is ignorant of the primary channel state and, hence, of the amount of actual harm it inflicts on the pr…
Optimal Random Access and Random Spectrum Sensing for an Energy Harvesting Cognitive Radio
Ahmed El Shafie, Ahmed Sultan
We consider a secondary user with energy harvesting capability. We design access schemes for the secondary user which incorporate random spectrum sensing and random access, and whi…
Cooperative Cognitive Relaying with Ordered Cognitive Multiple Access
Ahmed El Shafie, Ahmed Sultan
We investigate a cognitive radio system with two secondary users who can cooperate with the primary user in relaying its packets to the primary receiver. In addition to its own que…
Inter-Sensing Time Optimization in Cognitive Radio Networks
Omar Mehanna, Ahmed Sultan
We consider a set of primary channels that operate in an unslotted fashion, switching activity at random times. A secondary user senses the primary channels searching for transmiss…
Cognitive MAC Protocols for General Primary Network Models
Omar Mehanna, Ahmed Sultan, Hesham El Gamal
We consider the design of cognitive Medium Access Control (MAC) protocols enabling a secondary (unlicensed) transmitter-receiver pair to communicate over the idle periods of a set…
Blind Cognitive MAC Protocols
Omar Mehanna, Ahmed Sultan, Hesham El Gamal
We consider the design of cognitive Medium Access Control (MAC) protocols enabling an unlicensed (secondary) transmitter-receiver pair to communicate over the idle periods of a set…