Ala Abu Alkheir

University of Ottawa · School of Electrical Engineering and Computer Science

Sequential reporting has the potential of reducing the duration of the reporting phase of the cooperative spectrum sensing (CSS) schemes, thereby increasing the overall system throughput. In this article, we study decision-based CSS using random medium-access sequential reporting and a K-out-of-M decision rule at the fusion center. Closed-form expr...

This article addresses a problem experienced by business incubators and accelerators, which are integral parts of the entrepreneurial ecosystem. Essential to the core mission of incubators is the ability to assess the commercial viability of early-stage ventures to identify those that should be incubated. This assessment also helps angel investors...

The powerful capabilities of Connected and Autonomous Electric Vehicles (CAEVs) will make it a popular provider of a wide range of services, including mobility, sensing, computing, traffic control, and energy management. This article uses a characterization of these services to devise a service management framework and pricing schemes.

This article gives exact statistical characterization of harvested RF-energy over a Nakagami-m fading channel. In [1], we have shown that the amount of harvested energy is a scaled version of the amount of received energy, which can be statistically modeled using the Sampling Theorem. However, harvesting only happens when the received Signal to Noi...

RF-energy harvesting has been one of the hottest research topics in wireless communications for the past few years. It found applications in cognitive radio networks, wireless sensor networks, personal area networks, device-to-device communications and a host of other wireless technologies. However, fundamental characteristics of the RF-energy harv...

Wireless energy transfer can extend the lifetime of wireless sensor networks deployed in hard-to-reach and/or harsh environments. A number of works have proposed using dedicated mobile chargers (e.g., robots, drones, or vehicles) to transmit Radio Frequency (RF) energy to sensor nodes, which, despite optimal route selection, remains an expensive ap...

This work summarizes the needs and preferences of Canadian firefighters pertaining to building information.

This is my recent work on the statistical characteristics of the harvested RF energy - Work is coming at the WPTC 2018 in Montreal

Multihop communication is widely used in cognitive radio networks to facilitate agile access to opportunistically available spectrum resources while adequately protecting Primary Users (PUs). However, the performance of this collaborative communication is sensitive to spectrum sensing accuracy and the unpredictable activities of PUs. To quantify th...

The Canadian public safety sector is at the verge of a technological evolution where smart mobile devices become an essential part of everyday operations of emergency responders. These devices (i.e., smartphones and tablets) will give emergency responders the ability to collect, share, and access different types of data that can ultimately enhance...

In 2011, the Defence R&D Canada, Centre for Security Science, released a report assessing the capability of the recently allocated 20MHz in the 700MHz spectrum band to meet the requirements of first responders (law enforcement, firefighters and emergency medical services) over the coming 20 years. A public safety broadband network (PSBN) is to be b...

Cognitive Radio Vehicular Ad hoc Networks (CR-VANETs) utilize CR technology to increase frequency bandwidth for vehicular communications. Cooperative Spectrum Sensing (CSS) exploits spatial and temporal diversity for fast and accurate detection of Primary Users (PUs). This paper provides an overview of CSS techniques for CR-VANETs. We review state...

This article studies the performance of decision-based cooperative spectrum sensing using random medium access. Unlike scheduled medium access, random medium access entails a non negligible probability of collision which affects the detection accuracy. Novel closed form expressions are derived for the detection probability, the false alarm probabil...

This article studies the problem of message dissemination in Cognitive Radio Ad Hoc (CRAHNs) over TV white bands. By exploiting the supreme propagation characteristics of low-frequency channels, this article proposes two message dissemination protocols that use acknowledged transmissions to guarantee dissemination reliability. These two protocols r...

The ability of wireless terminals to harvest energy from Radio Frequency (RF) signals is gaining tremendous momentum as a mean to prolong the lifetime of these terminals and to recycle the radiated energy. This article gives a much needed statistical analysis for the amount of harvested energy over a period of time T. By studying the input/output c...

Increasing the number of terminals in a cognitive radio network is known to improve the accuracy of cooperative spectrum sensing at the cost of reducing the useful communication time. This downside can be partially mitigated using decision-based fusion and/or sequential reporting. This paper proposes a novel selective decision-based cooperative spe...

The performance of energy detection using outdated channel state information (CSI) over Rayleigh fading is studied where a closed form expression for the average probability of detection is derived. This expression unveils the dependence of the probability of detection on the estimated CSI as well as the fading correlation function. Using this depe...

This article studies the impact of Radio Frequency (RF) energy harvesting on the design and performance of cooperative spectrum sensing in Cognitive Radio Networks (CRNs). While recent literature have primarily focused on mode selection and sensing-throughput optimization at the terminal level; this article discusses the challenges of mode selectio...

This article studies the performance of three decision-fusion rules for cooperative spectrum sensing using sequential reporting. The studied rules give the fusion center the ability to trade agility for reliability by properly choosing the decision threshold. The performance of these rules is analyzed in terms of detection and false alarm probabili...

This paper proposes a novel approximation for the exponential integral function, E1[x], using a sum of exponential functions. This approximation facilitates studying the error probability of a number of communication techniques in the presence of Co-Channel Interference (CCI). These include Hybrid Automatic Repeat Request (HARQ) with soft combining...

This article proposes a novel spectrum sensing method based on the instantaneous Signal to Interference plus Noise Ratio (SINR) of the received signal. This method allows the terminals of a Cognitive Radio Network (CRN) to momentarily detect the presence of Co-Channel Interferers (CCI), whether Primary Users (PUs) or other Cognitive Radio (CR) user...

This article proposes a joint power control, rate adaptation and channel selection strategy for Cognitive Radio Networks (CRNs) operating over vacant TV bands, also known as TV Bands Devices (TVBDs). To exploit the abundance of vacant channels available at the disposal of these devices, we combine the well-studied power and rate adaptation strategi...

This article studies the performance of Decode and Forward Incremental Relaying (DF-IR) in the presence of multiple dissimilar sources of Co-Channel Interference (CCI) at both, the relay and the destination. In particular, we consider the case where all links experience flat Rayleigh fading with Kr and Kd sources of CCI affecting the relay and the...

This article analyzes the outage performance of Decode and Forward (DF) incremental relaying when used in an overlay spectrum sharing environment. The terminals of a secondary network exploit the instances of silence of a neighboring primary user to communicate with each other. Secondary terminals utilize an arbitrary spectrum sensing method that i...

This article analyzes the performance of a Decode-and-Forward (DF)-based selection relaying scheme in a Cognitive Radio Relay Network (CRRN). In particular, exact closed form expressions are derived for the outage and error probabilities over dissimilar and independent and identically distributed (i.i.d.) Rayleigh fading channels. The derived expre...

This article proposes a novel Cooperative Spectrum Sensing (CSS) scheme for Cognitive Radio Networks (CRN). The proposed scheme, referred to as the Selective Cooperative Spectrum Sensing (SCSS) scheme, is capable of jointly reducing the reporting overhead and mitigating faulty reporters at the Base Station (BS). These goals are achieved by exclusiv...

This article studies the outage capacity of bidirectional relaying using Decode and Forward (DF) in cognitive relay networks. We consider a communication system where two sources attempt to exchange their messages through a set of cognitive relay nodes. Only relays with successful decoding and spectrum acquisition are allowed to participate in the...

In this paper, the time-space correlation function for narrowband MIMO channels is derived. We consider two 3D models, the cylinder model and the sphere model. In both cases, Rician fading is assumed. Scatterers are assumed around the mobile station alone to model macrocell situation. The results show that under reasonable assumptions, both models...

In this paper, a general space time correlation function is derived for narrowband (MIMO) Rayleigh fading channels assuming 3D scattering around the mobile station (MS). Non-isotropic scattering is assumed, and the Von Mises PDF of the angle of arrival (AOA) is used. The resulting 3D based correlation functions contain general non-isotropic 2D base...

This paper presents a new autoregressive (AR) stochastic modeling and tracking method of doubly selective fading channels. The AR model is used to generate a wide-sense stationary uncorrelated scattering (WSSUS) channel impulse response. A Kalman-based tracking algorithm is then designed to continuously track the channel at the receiver.