Majlesi Journal of Telecommunication Devices: 4 (4)

Open Access Article

1 - A method for the design of low-noise amplifiers in the frequency of 8GHz

Low-noise amplifiers (LNA) are considered one of the essential components of telecommunication wireless receiver. Since their performance will determine the system performance in the noise. In this paper with software Microwave office, a low-noise amplifier has been des More

Low-noise amplifiers (LNA) are considered one of the essential components of telecommunication wireless receiver. Since their performance will determine the system performance in the noise. In this paper with software Microwave office, a low-noise amplifier has been designed and simulated at the center frequency of 8 GHz with 10 dB of gain and noise figure less than 1.5dB in operating point 2 V and 10mA. Manuscript profile

Open Access Article

2 - A channel estimation algorithm based on Pilot structure for MIMO-OFDM Systems
Mohammad Mohammadian Mobarakeh

This paper proposes a simple and efficient method for MIMO-OFDM channel estimation using parameters similar to HIPERLAN/2. Both preamble and pilot structures are compared in a 2 transmit-2 receive Space Frequency Trellis Coded system and the Mean Squared Error is used a More

This paper proposes a simple and efficient method for MIMO-OFDM channel estimation using parameters similar to HIPERLAN/2. Both preamble and pilot structures are compared in a 2 transmit-2 receive Space Frequency Trellis Coded system and the Mean Squared Error is used as a metric for comparing the results. It is shown, via simulation, that the proposed methods incur a maximum loss of approximately 1 to 1.5dB as compared to perfect channel knowledge. Manuscript profile

Open Access Article

3 - Study of Band Structure Characteristics of Periodic Two-Dimensional of Photonic Crystals with Different Geometric Forms
Saeed Ghorbani Masoud Jabbbari

In this paper, new structures of two-dimensional periodic photonic crystals in the form of dielectric rods with different geometric shapes, are presented. All photonic crystals presented in this paper are in a square lattice. Band structure and photonic band gap limitat More

In this paper, new structures of two-dimensional periodic photonic crystals in the form of dielectric rods with different geometric shapes, are presented. All photonic crystals presented in this paper are in a square lattice. Band structure and photonic band gap limitation graph of these structures are obtained by using numerical methods of plane wave expansion (PWE) for TE and TM modes. The simulation results for these structures show different photonic band gap widths and places for different structures and modes. Manuscript profile

Open Access Article

4 - A Comparative Study of Space Search Algorithm

In this study, we propose a space search algorithm (SSA) and then introduce a hybrid optimization of ANFIS-based fuzzy models based on SSA and information granulation (IG). In comparison with conventional evolutionary algorithms (such as PSO), SSA leads not More

In this study, we propose a space search algorithm (SSA) and then introduce a hybrid optimization of ANFIS-based fuzzy models based on SSA and information granulation (IG). In comparison with conventional evolutionary algorithms (such as PSO), SSA leads not only to better search performance to find global optimization but is also more computationally effective. In the hybrid optimization of ANFIS-based fuzzy inference system, SSA is exploited to carry out the parametric optimization of the fuzzy model as well as to realize its structural optimization. IG realized with the aid of C-Means clustering helps to determine the initial values of the apex parameters of the membership function of fuzzy model. The overall hybrid identification of ANFIS-based fuzzy models comes in the form of two optimization mechanisms: structure identification (such as the number of input variables to be used, a specific subset of input variables, the number of membership functions, and polynomial type) and parameter identification (viz. the apexes of membership function). The structure identification is developed by SSA and C-Means while the parameter estimation is realized via SSA and a standard least square method. The evaluation of the performance of the proposed model was carried out by using three representative numerical examples such as Non-linear function, gas furnace, and Mackey-Glass time series. A comparative study of SSA and PSO demonstrates that SSA leads to improved performance both in terms of the quality of the model and the computing time required. The proposed model is also contrasted with the quality of some conventional fuzzy models already encountered in the literature. Manuscript profile

Open Access Article

5 - Nitric Oxide Diffusion Attributes in Biological and Artificial Environments

This paper presents a computational study on the dynamic of nitric oxide (NO) in both the biological and artificialenvironments, by the analysis of important nitric oxide diffusion attributes. We apply the compartmental model of NOdiffusion as a formal tool, using a com More

This paper presents a computational study on the dynamic of nitric oxide (NO) in both the biological and artificialenvironments, by the analysis of important nitric oxide diffusion attributes. We apply the compartmental model of NOdiffusion as a formal tool, using a computational neuroscience point of view. The main objective is the analyses of theemergence and dynamic of complex structures, essentially diffusion neighbourhood (DNB), in environments withvolume transmission (VT). The study is performed by the observation of the NO diffusion attributes, the NOdirectionality (NOD), the average influence (AI) and the center of DNB (CDNB). We present a study of the influencesand dependences with respect to associated features to the NO synthesis-diffusion process, and to the differentenvironments where it spreads (non-isotropy and non-homogeneity). The paper is structured into three sets ofexperiences which cover the aforementioned aspects: influence of the NO synthesis process, isolated and multipleprocesses, influence of distance to the element where NO is synthesized, and influence of features of the diffusionenvironment. The developments have been performed in mono bi-and three-dimensional environments, withendothelial cell features. The study contributes the needed formalism to management the dynamic of NO in artificialand biological environments also to quantify the information representation capacity that a type of NO diffusion-basedsignaling presents and their implications in many other underlying neural mechanisms, such as neural recruitment,synchronization of computations between neurons and in the brain activity in general. Manuscript profile

Open Access Article

6 - Elliptical antenna array pattern synthesis with fixed side lobe level and suitable main beam beamwidth by genetic algorithm
Amirsaman Zare

In this paper, the design of uniform elliptical array (UEA) with optimum side lobe level reduction is presented. Multi-lobe pattern and adaptive nulling of the pattern is achieved by the control of the antenna elements phases in different states. This method is based on More

In this paper, the design of uniform elliptical array (UEA) with optimum side lobe level reduction is presented. Multi-lobe pattern and adaptive nulling of the pattern is achieved by the control of the antenna elements phases in different states. This method is based on genetic algorithm (GA). The method of genetic algorithm is used to determine an optimum set of array factor cost that provide a radiation pattern with maximum side lobe level reduction with constraint of a suitable main lobe beamwidth. The results show that synthesis of the uniform elliptical antenna array by using GA method provide a side lobe level reduction and main lobe beamwidth better than circular antenna array obtained by using IWO (Invasive Weeds Optimization) and also optimized elliptical antenna array by using EPL (The Excitations Of Elements Phases at Eccentricity Low Level). Manuscript profile

Open Access Article

7 - Spectrum Sensing of Multiband Signals using Periodic Non-uniform Sampling

In this essay, we propose a Multiband Spectrum Sensing (MSS) approach that utilizes randomized sampling and its spectral analysis to accomplish the sensing task using considerably low sampling rates. Since the spectrum sensing procedure does not necessitate signal recon More

In this essay, we propose a Multiband Spectrum Sensing (MSS) approach that utilizes randomized sampling and its spectral analysis to accomplish the sensing task using considerably low sampling rates. Since the spectrum sensing procedure does not necessitate signal reconstructing, it is shown that the sampling rates can be arbitrarily low for some randomized sampling schemes. Most importantly, general guidelines are provided to ensure that the developed MSS satisfies certain detection probabilities set by the user. Spectrum sensing involves scanning predefined part(s) of the radio spectrum in search of meaningful activity such as an ongoing transmission or the occurrence of an event. Standard communications laboratory test equipment, e.g. spectrum analyzers, can perform similar functionality. They conventionally sweep the spectrum using a narrowband tunable bandpass filter(s) and determine the energy within each of the scanned spectral bands. Manuscript profile

Open Access Article

8 - Monitoring stations TBS(Townborder system) based on wireless sensor networks
Sajjad Dehkordi

Monitoring the processing of gas transmitters, pressure, flow and temperature as SCADA systems, and now with the cost of communication is done Industrial Automation and Instrumentation design a monitoring system is proposed Industrial Automation and Instrumentation desi More

Monitoring the processing of gas transmitters, pressure, flow and temperature as SCADA systems, and now with the cost of communication is done Industrial Automation and Instrumentation design a monitoring system is proposed Industrial Automation and Instrumentation design a monitoring system is proposed. Gas dispatching system based on wireless sensor networks, SCADA systems, unlike the systems that have been used in gas dispatching centers,Configuration and reduce network deployment costs on the one hand and on the other hand, instead of installing thousands of feet of wire just Which are small devices about the size of a dime and put points on the network simply by adding more nodes expanded. The data collected and transferred to control room temperature and pressure measurements by monitoring input and output can be controlled more. In this article we describe an intelligent system for monitoring wireless sensor network is useful for applications in oil, gas company. Manuscript profile

Open Access Article

9 - Simulation and Reduction of Radar Cross Section the Unmanned Aerial Vehicle in X-band Using Shaping Technique
Hamid Heidar Naser Moradisoltani Omid Alihemati

Radar Cross Section (RCS) reduction is very important factor to increase survivability. This paper used a model of the Unmanned Aerial Vehicle (UAV) will be as a reference and focus on RCS reduction by using shaping methods. Simulation software CST was used to calculate More

Radar Cross Section (RCS) reduction is very important factor to increase survivability. This paper used a model of the Unmanned Aerial Vehicle (UAV) will be as a reference and focus on RCS reduction by using shaping methods. Simulation software CST was used to calculate the RCS of aerial targets. Four types of target geometries are simulated to find the final optimal design which will give a less value of RCS compared with the reference geometry over X-Band (8, 9,10,11,12 GHz are used for simulation then average value is drowned). Manuscript profile

Open Access Article

10 - Data and Image Transmission Over DS-PSK MIMO-UWB System in Multipath Fading Channel Using Multiple Description Coding (MDC) and OSTBC

UWB communication system is a new high performance technique with low power consumption which has a large application for very high data rates in wireless telecommunications. In this paper, the image transfer techniques using MIMO-UWB wireless environment is introduced More

UWB communication system is a new high performance technique with low power consumption which has a large application for very high data rates in wireless telecommunications. In this paper, the image transfer techniques using MIMO-UWB wireless environment is introduced in MDC deals. This idea is new and so far that there is no record of it. First, direct sequence ultra wide band performance techniques are analyzed for channels fading. Image transmission is then implemented with multiple description coding and with no multiple descriptions coding of image. The method of multiple description coding ensures that the version that the loss does not need to retransmit the missing version and acceptable quality of image obtain against the channel errors. Send a picture of the proposed system with different number of transmitter and receiver antennas have been numerous experiments confirm the success of the method. Experimental results show that the desired goals are reached. Manuscript profile

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