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The migration of railway communication technology from GSM-based to LTE-based has been decided by International Union of Railway. This means that a future train control system will be one based on LTE accordingly. For the highest reliability of train operation in such a system, a fully duplicated network structure with overlaid radio cells is needed. Existing methods and results are often relied on...
Future mobile networks are known to deploy a two-tier architecture of macrocell — femtocell [1]. In the two-tier architecture, femtocell downlink channels can cause strong co-channel interference to downlink transmission of macrocell users (MUs) which use the same frequency. The co-channel downlink interference to the MU might cause the MU's QoS degradation. To maintain the QoS of the MU's connection,...
Radio energy harvesting model is an another method to extend the lifetime of wireless networks. In this paper, an energy harvesting model is given for amply-and-forward relay networks with aiding of ambient interferences. For this reason, the energy constrained relays harvest energy from the received signal and then use that harvested energy to amply and send that signal to the target. A time switching...
Spectrum sharing environment permits secondary users (SUs) to utilize radio spectrum of primary users (PUs) but creates cross-interference between SUs and PUs. Moreover, jamming signal is useful in improving information security by deliberately corrupting received signals at eavesdroppers. The current paper presents an analytical framework on communication reliability and information security, which...
The femtocell is a promising technology that can be employed to enhance next generation wireless network coverage. It possesses the potential to reduce network deployment risk, improve network operation efficiency and capacity. By utilizing femtocells spectrum utilization can be improved. Due to its key features, including low cost, high speed, and plug and play capability, network operators should...
Surprisingly little research has quantified the severity of Wi-Fi congestion in densely populated areas. We performed a high-fidelity 3D simulation of the performance of a realistic Wi-Fi deployment in a typical apartment block. Our results show that congestion leads to significant loss of performance, and that current channel selection procedures have only little effect. Also the strategy that is...
In this paper, we study how to provide optimal performance guarantee in multi-resource scenarios, such as Network Function Virtualization (NFV), where Virtual Network Function (VNF) resource demands of one Service Function Chain (SFC) are elastic and correlated with the end-to-end throughput of SFC. Previous works such as Dominant Resource Fairness (DRF) achieve this goal only if the demands are already...
Analog optics [1], commonly termed microwave photonics [2], is a decades-old field that offers well-cited advantages over analog and digital electronics. The two most important features in most, if not all, deployable use cases are low propagation loss in fiber and wide bandwidth. Indeed, the massive fiber telecommunications industry was born from simultaneous utilization of these two advantages over...
Indoor positioning systems (IPS) have gained a lot of traction within the research community in recent years. Received Signal Strength Indicator (RSSI) of wireless networks are the most commonly used metric for indoor localization. The objective of this paper is to see how Wi-Fi interferers of different data rates affect the packet RSSI values of TX-RX links in a ZigBee based indoor localization system...
Estimating energy consumption and data rate in LTE networks is a critical issue for some recently proposed applications such as collaborative Internet access and energy-aware cellular data scheduling. In this study, after collecting data via empirical measurements, we provide realistic modeling with respect to LTE signal parameters such as RSRP, RSRQ and SINR. We applied various regression methods...
Bringing to the market intelligent vehicles is one of the current challenges faced by car manufacturers. These vehicles must be able to communicate in order to cooperate and be more effective. The issue of inter-vehicle communications is an active research topic. This paper proposes a reliable geographical broadcasting protocol which has a twofold goal: limiting the risk of interference and reducing...
In digital communication systems the use of filters that fulfill the first Nyquist criterion (Nyquist-I), guarantees that a sequence of pulses will not be affected by inter-symbol interference (ISI) if the receiver samples signals at optimum and uniformly spaced instants. In this manuscript the Nyquist-I pulse, called exponential linear pulse (ELP), is evaluated in the time and frequency domain using...
We introduce the fast digital algorithms for the coherent demodulation of binary and four position differential phase-shift keyed signals. These algorithms can be practically implemented with the minimum number of simple arithmetic operations over the input signal period and they are is fully compatible with the modern hardware components available. We obtain the timing diagrams of the demodulators...
Direct Device-to-Device (D2D) communication permits to offload the network, increase the capacity, and extend the cellular coverage. In D2D systems, user equipments (UEs) do not necessarily communicate via evolved Node Base station (eNB); instead, they are allowed to communicate directly with each other. This underlying communication generates interference due to reusing the same resources of the...
In order to meet various requirements of the 5th generation (5G) communication system, larger amounts of spectrum are required. Television White Space (TVWS) and Licensed-Assisted Access (LAA) can only utilize the specific frequency band as shared frequency and have no mechanism for sharing the other frequency bands to obtain more frequency resources. We have proposed a dynamic frequency-sharing system...
Congestion in the Industrial, Scientific, and Medical (ISM) frequency band limits the expansion of the IEEE 802.11 Wireless Local Area Network (WLAN). Recently, due to the ‘digital switchover’ from analog to digital TV (DTV) broadcasting, a sizeable amount of bandwidth have been freed up in the conventional TV bands, resulting in the availability of TV white space (TVWS). The IEEE 802.11af is a standard...
An OVT based on Mach-Zehnder interferometer is proposed in this paper, which helps to convert the electro-optic phase delay into the displacement of the interference fringe. And then, the voltage applied to the electro-optic crystal is obtained by positioning the displacement of the fringe, and the effectiveness of this method is verified by experiments. The new OVT meets the requirements of 0.5%...
While trying to get a service from the Base station it happens that many devices will find themselves competing to get the cellular service, which means each device will use the maximum power possible to win the competition, but if there is another solution that will allow the device to get what it wanted with minimum of energy, how the device will react to it? In other words, we know that the communication...
In this paper, we employ a macroscopic traffic model and RBF neural network to address highway density control problem. This control system is a nonlinear feedback closed-loop system. Firstly, a popular traffic model called the LWR (Lighthill-Whitham-Richards) model is formulated. Secondly, a direct RBF neural network control for discrete-time nonlinear systems is introduced. The control algorithm...
In the field of video-based fire detection, traditional fire color models have poor adaptability and susceptibleness to environmental interference. As fire can be divided into fire core, inner fire and outer fire layers depending on its temperature and color, a new fire detection model based on dispersion of fire color components has been proposed by the author. In order to further reduce false alarm,...
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