فهرست مطالب

Majlesi Journal of Telecommunication Devices
Volume:1 Issue: 3, Sep 2012

  • تاریخ انتشار: 1391/08/13
  • تعداد عناوین: 6
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  • Fatemeh Eghtedari, Javad Haddadnia Pages 74-78
    Software Defined-Radio (SDR) is a wireless communication system which consists of a transmitter and a receiver that are controlled by means of software. Its goal is to provide a single radio transceiver with multi-mode multi-standard wireless communications capability. This advantage will help the designers to have a more precise technological look at the performance and processing principles of this structure and have better designs for their structure. In this work, discrete-time signal processing of a direct-sampling discrete-time receiver which is used for radio Bluetooth applications, is modeled in Simulink environment. The results show that, when the BPSK signal is entered to the receiver with an additive white gaussian noise (AWGN), the system had the best performance. In this simulation the signal time domain and its spectrum is shown in each stage of receiver, in order to display the noise removal process and the original signal extraction from noisy signal.
  • Mohsen Cheraghizade, Ramin Yousefi, Farid Jamali-Sheini, Abdolhossein Saaedi Pages 79-82
    Photoluminescence analysis is a useful method to study the optical properties of semiconductor nanostructures. Distinct processes take place to result in the light emission from the nanostructure. Various deposition methods and morphologies changed the emission band in semiconductor nanostructures. Three different morphology of Lead Sulfide structures such as nonospheres, star-shaped and dendrite nanostructures have been analyzed and the Photoluminescence results were compared. In three cases, band emissions are in visible region and it was observed that the incidence of quantum limits in resulting of increasing surface to volume ratio is impressive to optical properties.
  • Sajjad Dehkordi Pages 83-85
    Traditional database systems provide communication between humans and however wsn communication with the physical world. System performance monitoring and remote reading of gas stations and the expansion of the transmission networks and gas distribution,change in gas prices and the need to measure and manage the accurate measurement of gas consumption growth in provincial gas companies. Needs of provincial gas companies due to the design and interpretation of remote monitoring system. Design and implementation of monitoring systems for gas stations, data aggregation under the standard protocol,monitored to ensure accuracy of information, using knowledge to implement this system in the country, lead to avoid a using trial and error method. Since the communication system is achievable using software relocation of a large system, Many major industries such as oil & gas, petrochemical, power generation, chemical industry and. .. Without proper monitoring systems are not able to continue his work. In this simulation, pressure transmitters, flow and temperature are collected by a wireless network by monitoring software to monitor and control equipment in the control room will be implemented.
  • Mojtaba Behzad Fallahpour Pages 91-96
    In this paper a new LNA with image rejection filter is presented. Furthermore, after determining topology, a proposed CAD (Computer Aided Design) with a proposed multi objective genetic algorithm will be used to optimize the LNA. By performing the algorithm, several results will be obtained as they have no priority to each other, so the designer can select each of them according to his need. Simulation results show that the proposed plan weakens the image considerably; it also increases LNA gain without changing the noise figure (NF), output matching and input matching. The proposed multi objective genetic algorithm program is written by MATLAB and the circuit simulated by HspiceRF with 0.18μ technology.
  • Sadegh Pasban, Arash Larki Mohammadi, Roya Amjadifard Pages 97-101
    The goal of edge detection in image processing is to determine the frontiers of all represented objects, based on automatic processing of color or gray level information contained in each pixel. This procedure has many applications in image processing, computer vision and biological and robotic vision [1], [2], and [3].Edge detection is an important preprocessing step in image analysis. Successful results of image analysis extremely depend on edge detection [1]. This paper presents a new approach for edge detection in situations where the image is corrupted by noise. Traditional edge detections are sensitive to noise. The structure of our proposed edge detector, to make the process robust against noise, is a combination of wavelet transform, fuzzy inference system and adaptive median filter. The proposed method is tested under noisy conditions on several images and also compared with conventional edge detectors such as Sobel and Prewitt and Canny. Experimental results reveal that the proposed method exhibits better performance and may efficiently be used for the detection of edges in images corrupted by noise.
  • Farnaz Forootan, Majid Ebnali Heidari, Hossein Emami Pages 102-108
    We propose an optofluidic based on two dimensional (2D) rod-type silicon photonic crystal (PhC) waveguide that support self-collimation effect over a large frequency and angle range without any defect or nano-scale variation in the PhC geometry. By analyzing the Equi-Frequency contour (EFC) of a triangular rod PhC-bands, we verify the optimum band of the structure that is suitable for self-collimation of light beams. By varying the refractive index of fluid which is being infiltrated into the background of PhC, we perform a systematic study of optofluidic self-collimation of light beams to achieve a wide range of angles and low loss of light. By means of selective microfluidic infiltration, and remarkable dispersion properties we show it is possible to design, auto-collimator, and negative refraction devices based on self-collimation effect with high transmission. We use the plane wave method (PWM) for analyzing the EFC and the finite difference time domain (FDTD) method for simulating the transmission properties.