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Open Access Article
1 - From Market Defeat to Government DefeatMarket-inclined and Government-inclined Controversy in Modern Age
حجت کاظمیFrom controversial view that has been flowing with regard to governmental interference and market freedom since three last centuries, two approaches can be identified: market-inclined and gvernment-inclined. This distinction is based on the weight that each approach ass MoreFrom controversial view that has been flowing with regard to governmental interference and market freedom since three last centuries, two approaches can be identified: market-inclined and gvernment-inclined. This distinction is based on the weight that each approach assigns to one of these two institutions and its capacities for achievement of optimal economical efficiency. Controversy on this issue has a deep idealogic nature more than anything else and each approach tries to form historical evidence in their favors. In this paper, in addition to proposing the historical process of two approaches’ controversy and their internal varieties, we prove that in the shadow of achievements and failures of two approaches on one hand and proposing the alternative theoretical patterns and formation of developmental successful experience outside of conventional experiences that documented by two controversy parties on other hand, the grounds of the new pattern proposition of governmental interfernce extent have been provided since 1990 decade until now. The institution-inclined approach focusing on the topic of “quality” of interference instead of “quantity” of governmental interference is looking beyond the mentioned ideologic controversy and theorizing aboat the method and quality of positive governmental interaction with market institutions. Manuscript profile -
Open Access Article
2 - An Improved Method for TOA Estimation in TH-UWB System considering Multipath Effects and Interference
Mahdieh Ghasemlou Saeid Nader Esfahani Vahid Tabataba VakiliUWB ranging is usually based on the time-of-arrival (TOA) estimation of the first path. There are two major challenges in TOA estimation. One challenge is to deal with multipath channel, especially in indoor environments. The other challenge is the existence of interfer MoreUWB ranging is usually based on the time-of-arrival (TOA) estimation of the first path. There are two major challenges in TOA estimation. One challenge is to deal with multipath channel, especially in indoor environments. The other challenge is the existence of interference from other sources. In this paper, we propose a new method of TOA estimation, which is very robust against the interference. In this method, during the phase of TOA estimation, the transmitter sends its pulses in random positions within the frame. This makes the position of the interference relative to the main pulse to be random. Consequently, the energy of interference would be distributed, almost uniformly, along the frame. In energy detection methodes, a constant interference along the frame does not affect the detection of arrival time and only needs the adjustment of the threshold. Simulation results in IEEE.802.15.4a channels show that, even in presence of very strong interference, TOA estimation error of less than 3 nanoseconds is feasible with the proposed method. Manuscript profile -
Open Access Article
3 - PSO-Algorithm-Assisted Multiuser Detection for Multiuser and Inter-symbol Interference Suppression in CDMA Communications
Atefeh Haji Jamali Arani paeez azmiApplying particle swarm optimization (PSO) algorithm has become a widespread heuristic technique in many fields of engineering. In this paper, we apply PSO algorithm in additive white Gaussian noise (AWGN) and multipath fading channels. In the proposed method, PSO algor MoreApplying particle swarm optimization (PSO) algorithm has become a widespread heuristic technique in many fields of engineering. In this paper, we apply PSO algorithm in additive white Gaussian noise (AWGN) and multipath fading channels. In the proposed method, PSO algorithm was applied to solve joint multiuser and inter-symbol interference (ISI) suppression problems in the code-division multiple-access (CDMA) systems over multipath Rayleigh fading channel and consequently, to reduce the computational complexity. At the first stage, to initialize the POS algorithm, conventional detector (CD) was employed. Then, time-varying acceleration coefficients (TVAC) were used in the PSO algorithm. The simulation results indicated that the performance of PSO-based multiuser detection (MUD) with TVAC is promising and it is outperforming the CD. Manuscript profile -
Open Access Article
4 - A Linear Model for Energy-Aware Scheduling Problem Considering Interference in Real-time Wireless Sensor Networks
Maryam Hamidanvar rafeh rafehAn important factor in increasing quality of service in real-time wireless networks is minimizing energy consumption, which contradicts with increasing message delivery rate because of associating a time deadline to each message. In these networks, every message has a t MoreAn important factor in increasing quality of service in real-time wireless networks is minimizing energy consumption, which contradicts with increasing message delivery rate because of associating a time deadline to each message. In these networks, every message has a time deadline constraint and when the message is not delivered to its destination before its deadline constraint, it will drop. Therefore, scheduling methods that simultaneously consider both energy consumption and time deadline constraint are needed. An effective method for reducing energy consumption is multi-hop transmission of packets. However, this method takes longer time for transmission as compared to single-hop transmission. Parallel transmission is another approach which on one hand reduces the transmission time and on the other hand increases the network throughput. However, a main issue with parallel transmission is the presence of interference among nearby nodes. In this paper, we propose a linear model (ILP formulation) for energy aware scheduling problem in real-time wireless sensor networks using parallel transmission. The main objective of the model is to reduce energy consumption and packet loss using multi-hop routing and parallel transmission. Experimental results show that the proposed model finds the optimum solution for the problem and outperforms the sequential scheduling based on the TDMA protocol. Manuscript profile -
Open Access Article
5 - A New Capacity Theorem for the Gaussian Channel with Two-sided Input and Noise Dependent State Information
Nima S. Anzabi-Nezhad Ghosheh Abed HodtaniGaussian interference known at the transmitter can be fully canceled in a Gaussian communication channel employing dirty paper coding, as Costa shows, when interference is independent of the channel noise and when the channel input designed independently of the interfer MoreGaussian interference known at the transmitter can be fully canceled in a Gaussian communication channel employing dirty paper coding, as Costa shows, when interference is independent of the channel noise and when the channel input designed independently of the interference. In this paper, a new and general version of the Gaussian channel in presence of two-sided state information correlated to the channel input and noise is considered. Determining a general achievable rate for the channel and obtaining the capacity in a non-limiting case, we try to analyze and solve the Gaussian version of the Cover-Chiang theorem mathematically and information-theoretically. Our capacity theorem, while including all previous theorems as its special cases, explains situations that can not be analyzed by them; for example, the effect of the correlation between the side information and the channel input on the capacity of the channel that can not be analyzed with Costa’s “writing on dirty paper" theorem. Meanwhile, we try to exemplify the concept of “cognition" of the transmitter or the receiver on a variable (here, the channel noise) with the information-theoretic concept of “side information" correlated to that variable and known at the transmitter or at the receiver. According to our theorem, the channel capacity is an increasing function of the mutual information of the side information and the channel noise. Manuscript profile -
Open Access Article
6 - Modeling of the fold interference patterns from the northern Golpaygan metamorphic complex using MATLAB
Mohammad Reza SheikholeslamiModeling of geological structures plays an important role in understanding the geometry of the structures and their relationships. In recent years, digital modeling using computers has attracted the attention of engineers as well as researchers in basic sciences. "MATLA MoreModeling of geological structures plays an important role in understanding the geometry of the structures and their relationships. In recent years, digital modeling using computers has attracted the attention of engineers as well as researchers in basic sciences. "MATLAB" is one of the softwares that is used with its extensive facilities for data analysis and modeling in various sciences, including structural geology. In this paper, possible models of interference patterns of the three generations of folds in metamorphic rocks of the Golpayegan area were reconstructed using the script written in MATLAB software. The required data include the attitudes of the mean axis and the mean axial planes of three consecutive generations of folds which were obtained during field measurements. Field studies show that the first and second generation folds are almost coaxial, however the third generation folds have a different axial trend. The results of modeling indicate that four classical fold interference patterns may be formed in horizontal (map view) and vertical sections in Golpayegan metamorphic rocks. Modeled fold interference patterns are closely consistent with the natural fold interference patterns observed in the outcrop and regional scales. Using the modeling, it can be determined that the different interference patterns of the folds in the northern Golpayegan metamorphic rocks are related to superposition of the related fold generations. Manuscript profile -
Open Access Article
7 - A Critical Study of Seyyed Sharif Jurjani’s Reasoning Regarding the Simplicity of the Derivative
Seyyed Ahmad Hosseini Sangchal Mohammad SaeedimehrThe problem of the simplicity or combination of the derivative is one of the controversial issues which, in spite of its similarity to mentally-posited discussions, has sometimes affected philosophical debates. The present paper reports on the results of a critical stud MoreThe problem of the simplicity or combination of the derivative is one of the controversial issues which, in spite of its similarity to mentally-posited discussions, has sometimes affected philosophical debates. The present paper reports on the results of a critical study of Jurjani’s reasoning regarding the simplicity of the derivative. In his view, whenever the derivative is assumed to consist of “shayin lahu …”, in case of attaining the concept of “shay”, interference of general accident in differentia occurs. However, in case of attaining the extension of “shay”, the transformation of the possible proposition through the necessary happens. In the first case, the differentia fails to be a differentia, and in the second case the direction of possibility is removed from the world of reality. In order to explain the quality of the transformation, a solution has been presented which analyzes the concept of portion and the role of limitation and determination in the predicate. Here, the writers, in spite of considering this argument to be perfect, clarify that the given reason for demonstrating the simplicity of the derivative is inefficient and is only capable of deriving the concept or referent of “shay” from the truth of the derivative. Manuscript profile -
Open Access Article
8 - Blind Number of Active Users Estimation and Synchronization in CDMA Systems with Unequal Power’s Signal on Flat Fading Channel
S. Ghavami V. TabatabvakiliBlind estimation of number of active users and synchronization of those have important role in identification of system’s parameters, for the spectrum surveillance system design of multi-user direct sequence spread spectrum systems. For the number of active user estimat MoreBlind estimation of number of active users and synchronization of those have important role in identification of system’s parameters, for the spectrum surveillance system design of multi-user direct sequence spread spectrum systems. For the number of active user estimation, signal’s eigenvalues of the received signal covariance matrix is distinguished from those of noise using an adaptive threshold. Analytical results and computer simulations show that signal of users with limited received power difference (less than 1.5 dB) can be synchronized using maximizing the Frobenious norm of the received signal covariance matrix. Moreover, this method is robust against of the carrier frequency offset which is due to Doppler shift in the carrier frequency of different users. By increasing difference among received powers of processed signals, performance of this method will be degraded. Hence, an iterative algorithm for interference cancellation of users with higher received power is proposed, which can be synchronize and estimate the number of active users with lower received power. The proposed method for number of active user estimation reduces computational complexity in comparison with the traditional methods for number of active user estimation, such as MDL and AIC, while keep the accuracy of estimation in low SNR regime. The performance of blind synchronization method in the flat fading channel is degraded; hence, a multi-antenna receiver is proposed to improve the probability of correct synchronization. Manuscript profile -
Open Access Article
9 - Control of the Interference and Increasing Capacity by Creating a Phase Difference between the Signals Sent in LTE Network
H. Mirsalari N. NedaAccording to the entry of new networks such as LTE and WiMAX that is based OFDM in country, the need to research and evaluate the performance of these networks is inevitable. In this paper we investigated the performance of different frequency allocation schemes in an L MoreAccording to the entry of new networks such as LTE and WiMAX that is based OFDM in country, the need to research and evaluate the performance of these networks is inevitable. In this paper we investigated the performance of different frequency allocation schemes in an LTE network. We first introduced the frequency allocation schemes include Reuse-1, Reuse-3, partial frequency reuse, sectoring, cell division region and soft frequency reuse, and then by creating a phase difference between two signals in a MISO channel in standard LTE, and combine it with some of these schemes such as sectorization and cell division region with the sectoring interference will significantly decreased in such networks. The simulation results show that the phase differences between the signals(which it’s called the one pre-order scheme) in MISO channel, due to the rotation of the antenna radiation pattern depending on the position of mobile users, and also the soft frequency reuse scheme for the full allocation of OFDM carriers to each cell and sending with less power for users of the cell center, leads to the substantial gain in the total network capacity, under the different traffics. Manuscript profile -
Open Access Article
10 - Upper and Lower Bounds on ICI Power of FrFT-OFDM Systems in Frequency Selective Time Varying Channels
Z. Mokhtari M. SabbaghianIn this paper, we study the inter carrier interference (ICI) in fractional Fourier transform based orthogonal frequency division multiplexing (FrFT-OFDM) systems. In this analysis, we derive tight upper and lower bounds for ICI power of FrFT-OFDM systems in doubly dispe MoreIn this paper, we study the inter carrier interference (ICI) in fractional Fourier transform based orthogonal frequency division multiplexing (FrFT-OFDM) systems. In this analysis, we derive tight upper and lower bounds for ICI power of FrFT-OFDM systems in doubly dispersive channels. These bounds have considerably simpler expressions than the exact ICI formula. Thus, they provide deep and useful insight into the effect of Doppler frequency, symbol duration, channel delay spread, and angle of transform on the ICI power. This analysis confirms that in the special case of flat fast fading channels the FrFT-OFDM and Fourier transform based OFDM (FT-OFDM) systems exhibit analogous performance while in doubly dispersive channels FrFT-OFDM can achieve better performance than single carrier (SC) and FT-OFDM, if the angle of transform is selected accurately. Manuscript profile -
Open Access Article
11 - Covariance Matrix Design for SINR Enhancement in Presence of Signal-Dependent Interferers
M. Bolhasani S. Imani S. A. GhorashiIn this paper, the problem of covariance matrix design to increase signal-to-interference-plus-noise ratio (SINR) in receiver for multiple-input multiple-output (MIMO) radars is considered. Our goal is to design a covariance matrix which can suppress more interferers co MoreIn this paper, the problem of covariance matrix design to increase signal-to-interference-plus-noise ratio (SINR) in receiver for multiple-input multiple-output (MIMO) radars is considered. Our goal is to design a covariance matrix which can suppress more interferers compared to phased array radar and recent covariance matrix design methods. It can also result in a better SINR level compared to conventional MIMO radars. In this paper, maximum SINR of the proposed covariance matrix is calculated in closed form. Simulation results show that our proposed covariance matrix in addition to achieve better SINR performance, can suppress more interferers compared to phased array radar and recent covariance matrix design methods, by using waveform diversity with the same number of antennas. Simulation results also validate analytical achievements that presented in this paper. Manuscript profile -
Open Access Article
12 - Cell Association Combined with Interference Management in Heterogeneous Cellular Networks Using a Distributed Algorithm
Maryam Chinipardaz Seyed Majid NoorhosseiniDue to the growing demand of cellular networks, the need to increase the capacity of these networks has always been a challenge. Heterogeneous cellular networks using small base stations alongside macro base stations are low cost and effective solutions for this problem MoreDue to the growing demand of cellular networks, the need to increase the capacity of these networks has always been a challenge. Heterogeneous cellular networks using small base stations alongside macro base stations are low cost and effective solutions for this problem. However the differences between the various BSs in heterogeneous networks have created new challenges in terms of cell association and interference management compared with the traditional cellular networks. Therefore, the design of new and efficient methods for allocating cells and resources in these networks is an open research topic. This paper addresses the need for an efficient solution to simultaneously allocating cells and subbands in order to prevent interference for all users. The protocol interference model and its modeling methods in cellular networks have been studied. After modeling the system, the problem is formulated as an integer optimization problem. Then, by reformulating the problem and using a one-level dual decomposition, an algorithm with efficient complexity with near-optimal answers is attained. Thereafter, a distributed protocol is presented in which each user and each base station would only require local information for making decisions. The simulation results confirm the effectiveness of the proposed solution. Manuscript profile -
Open Access Article
13 - A DC-DC Interleaved Converter Based on Buck Topology with High Step-Down Conversion Ratio
M. Ghanbari M. R. YazdaniHigh step-down conversion ratio cannot be achieved by the conventional buck converter. Also, the switch voltage stress is another drawback of the regular buck converter for high input voltages. In this paper, a DC-DC switching converter using interleaved method is propo MoreHigh step-down conversion ratio cannot be achieved by the conventional buck converter. Also, the switch voltage stress is another drawback of the regular buck converter for high input voltages. In this paper, a DC-DC switching converter using interleaved method is proposed based on the buck topology to achieve a high step-down conversion ratio. In the structure of this converter, a coupled inductor is used without need of another auxiliary winding. After presenting key waveforms and analysis of the proposed converter, the conversion ratio curves are offered. Moreover, simulation waveforms of a 240 W converter prototype with the input voltage of 150 V and the output voltage of 24 V are shown to verify the theoretical analysis. Manuscript profile -
Open Access Article
14 - Optimal and Sub-optimal Transmitter-Receiver Design in Dense Wireless Sensor Networks and the Internet of Things
Farzad H. Panahi Fereidoun H. Panahi Zahra Askarizadeh ArdestaniWith the rapid development of new technologies in the field of internet of things (IoT) and intelligent networks, researchers are more interested than ever in the concept of wireless sensor networks (WSNs). The emergence of these densely structured networks in recent ye MoreWith the rapid development of new technologies in the field of internet of things (IoT) and intelligent networks, researchers are more interested than ever in the concept of wireless sensor networks (WSNs). The emergence of these densely structured networks in recent years has raised the importance of the use of telecommunications technologies, such as ultra-wideband (UWB) technology with high reliability, industrial applications, and appropriate communication security. However, there are still numerous concerns about the extent of inter-network interference, particularly owing to undesired spectral discrete lines in this technology. As a result, it is necessary to provide an optimal solution to eliminate interference and control the power spectrum, and then design the optimal transmitter-receiver structures while considering high sensitivities to the synchronization problem in WSNs based on UWB technology. These goals are pursued in the present study by employing the optimal spectral strategy in the signal model, the structure of the transmitter sensor, and then constructing the optimal or sub-optimal receiver sensor structures, the results of which indicate improved communication performance in WSNs. Manuscript profile -
Open Access Article
15 - Sum Rate and Energy Efficiency Maximization in a Cognitive Radio Network with a Successive Relay Primary User
elahe maddah Mohammad lariIn this paper, we propose a cognitive radio network which consists of a number of secondary users and one primary user. The primary user utilized a successive relay performance. The successive relaying technique creates a full duplex relay performance by two half duplex MoreIn this paper, we propose a cognitive radio network which consists of a number of secondary users and one primary user. The primary user utilized a successive relay performance. The successive relaying technique creates a full duplex relay performance by two half duplex relays, which improves spectral efficiency. In the presence of secondary users, we use successive relay technique in the primary user to ensure its acceptable performance. Also, the sum rate of secondary users is increased. The challenges of this network are inter-relay interference and inter user interference. The interference alignment method is utilized to eliminate the interferences in the successive relay technique and in the cognitive radio network. Besides, the minimum transmitted power of the primary user is derived to guarantee its quality of service requirement. Two power allocations algorithms are proposed to maximize the sum rate of secondary users and the energy efficiency of the network. In both power allocations algorithms, satisfying the quality of service of the primary user is considered. The closed-form solutions of these algorithms are studied. The fractional programing approach was employed to solve the energy efficiency optimization in two steps. Manuscript profile -
Open Access Article
16 - Implementation of Uplink and Downlink Non-Orthogonal Multiple Access (NOMA) on Zync FPGA Device
Ahmed Belhani Hichem Semira Rania Kheddara Ghada HassisThe non-orthogonal access schemes are one of the multiple access techniques that are candidates to become an access technique for the next generation access radio. Power-domain non-orthogonal multiple-access (NOMA) is among these promising technologies. Improving the ne MoreThe non-orthogonal access schemes are one of the multiple access techniques that are candidates to become an access technique for the next generation access radio. Power-domain non-orthogonal multiple-access (NOMA) is among these promising technologies. Improving the network capacity by providing massive connectivity through sharing the same spectral resources is the main advantage that this technique offers. The NOMA technique consists of exploiting the power domain which multiplex multiple users on the same resources applying a superposition coding then separating the multiplexed users at the receiver side. Due to the non-orthogonality access technique, the main disadvantage of NOMA is the presence of interferences between users. That is why this scheme is based on a successive interference cancelation (SIC) detector that separates the multiplexed signals at the receiver. In this paper, an embedded system is considered for designing and implementation of the power-NOMA For two users. The implementation is realized by employing a Zynq FPGA (Field programmable gate array) device through the Zybo-Z7 board using MATLAB/Simulink environment and Xilinx System Generator. The features offered by this device, hemps to consider the design of an uplink and a downlink scenario over Rayleigh fading channel in additive white Gaussian noise (AWGN) environment. Manuscript profile -
Open Access Article
17 - An Analysis of the Signal-to-Interference Ratio in UAV-based Telecommunication Networks
hamid jafaripour Mohammad FathiOne of the most important issues in wireless telecommunication systems is to study coverage efficiency in urban environments. Coverage efficiency means improving the signal-to-interference ratio (SIR) by providing a maximum telecommunication coverage and establishing hi MoreOne of the most important issues in wireless telecommunication systems is to study coverage efficiency in urban environments. Coverage efficiency means improving the signal-to-interference ratio (SIR) by providing a maximum telecommunication coverage and establishing high-quality communication for users. In this paper, we use unmanned aerial vehicle (UAVs) as air base stations (BS) to investigate and improve the issue of maximizing coverage with minimal interference. First, we calculate the optimal height of the UAVs for the coverage radius of 400, 450, 500, 550, and 600 meters. Then, using simulation, we calculate and examine the value and status of SIR in UAVs with omnidirectional and directional antenna modes in symmetric and asymmetric altitude conditions, with and without considering the height of the UAVs. The best SIR is the UAV system with a directional antenna in asymmetric altitude conditions where the SIR range varies from 4.44db (the minimum coverage) to 52.11dB (maximum coverage). The worst SIR is the UAV system with an omnidirectional antenna in symmetrical height conditions without considering the height of the UAV. We estimate the range of SIR changes for different coverage ranges between 1.39 and 28dB. Factors affecting the SIR values from the most effective to the least, respectively, are coverage range and the antenna type, symmetrical and asymmetric height, and finally, considering or not considering the height of the UAV. Manuscript profile -
Open Access Article
18 - Investigating the effect of object intervention on attachment and anger of female heads of households in Isfahan city
armita nooien Belgheis Einali<p>The aim this study was to investigate the effect of object relations intervention on attachment and anger of female heads of households in Isfahan city. This semi-experimental research with a pre-test-post-test design was carried out in the statistical population of More<p>The aim this study was to investigate the effect of object relations intervention on attachment and anger of female heads of households in Isfahan city. This semi-experimental research with a pre-test-post-test design was carried out in the statistical population of female heads of households referring to Isfahan Social Work Clinic in 1401. Among these women, 30 people were randomly selected and placed in two experimental (15 people) and control (15 people) groups. Using Spielberger's (1962) anger questionnaires and Hazen and Shaver's (1987) attachment styles, anger and attachment were evaluated before the start of the intervention sessions and after the end. Data analysis was done using spss20 software and covariance test to analyze hypotheses. The results of data analysis showed that object intervention on anger and its components (angry feeling, tendency to express anger verbally, tendency to physical expression of anger, angry mood, angry reaction, occurrence of external anger, occurrence of internal anger, management external anger and internal anger management) had a significant effect and caused an increase in anger management and a decrease in other components (P<0.05). Also, object intervention has had a significant effect on attachment styles among female heads of households in Isfahan city and has increased secure attachment and decreased ambivalent and avoidant attachment (P<0.05).</p> Manuscript profile
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