Majlesi Journal of Telecommunication Devices: 17 (1)

Open Access Article

1 - A Survey and Comparing RFID Authentication Protocols Based on Elliptic Curve Cryptography
Negin Dinarvand Hamid Barati

Security and privacy are inherent problems in RFID systems communication. Many different ways and methods were presented to overcome these problems among which encryption, authentication and hardware techniques can be pointed out. Authentication protocols based on ellip More

Security and privacy are inherent problems in RFID systems communication. Many different ways and methods were presented to overcome these problems among which encryption, authentication and hardware techniques can be pointed out. Authentication protocols based on elliptic curve cryptography (ECC) is one of the methods used in authentication protocols in order to improve the security and privacy of RFID systems. This study aims at examining and comparing protocols that utilize this method in establishing security. Manuscript profile

Open Access Article

2 - Passive Target Geo-location Using Direction Finding Angles and Probability Density Matrix
Ali Dadashzadeh Kazem Haydari Rahman Salamat

Accurate geo-location of targets are extremely important in electronic warfare systems. In this paper we propose the use of probability density matrix (PDM), which is the sampled probability density function of observations, to evaluate the azimuth and elevation measure More

Accurate geo-location of targets are extremely important in electronic warfare systems. In this paper we propose the use of probability density matrix (PDM), which is the sampled probability density function of observations, to evaluate the azimuth and elevation measurements of sensor arrays. The three dimensional joint probability density matrix of the observations will have the sufficient information to extract the location of the target. We also propose a localization algorithm to efficiently adapt the PDM domain with the latest estimation points and decrease the computational complexity. The simulation results indicate that with appropriate settings the localization algorithm can reduce the estimation error about 50%. Manuscript profile

Open Access Article

3 - Comprehensive Comparison and Evaluation of Channel Estimation Methods using Statistical Information Channel in OFDM System
Minoo Mosahebi saeed Ghazi-Maghrebi

Radio channel (wireless) including channels that are highly regarded and have been used. These channels are affected by the environment and change. Multipath propagation leads to rapid fluctuations of the phase and amplitude of the signal. In contrast to these channels, More

Radio channel (wireless) including channels that are highly regarded and have been used. These channels are affected by the environment and change. Multipath propagation leads to rapid fluctuations of the phase and amplitude of the signal. In contrast to these channels, using Orthogonal Frequency Division Multiplexing (OFDM) technique is much better and more efficient. In order to access the basic information in the receiver, correct estimation impulse response is the main criterion. The current channel estimation methods can be classified into two categories. The first one is based on the pilots and the second one is not based on using pilot. A channel estimation method, the original channel estimation techniques using statistical information that are very useful and satisfying. This method provides our initial favorable data according to statistical information channel. In this paper presents, several common methods such as Wiener filter, Kalman filter and MMSE for channel estimation in OFDM system are evaluated and compared. Manuscript profile

Open Access Article

4 - Broad-Band Equivalent Circuit of Grid-Grounding System Considering Frequency Dependence of Electrical Parameters of Soil through Modified Vector Fitting Method

In this paper, wide band circuit model based on modified vector fitting method are proposed for the grid-grounding system. At first, the input impedance of the grid-grounding system in the frequency domain is computed by accurate methods such as the method of moments (M More

In this paper, wide band circuit model based on modified vector fitting method are proposed for the grid-grounding system. At first, the input impedance of the grid-grounding system in the frequency domain is computed by accurate methods such as the method of moments (MoM). The circuit models are then achieved through converting input impedance of the problem to rational functions via modified vector fitting method. These functions are formed in such a way that at first a set of starting poles in the frequency range of interest are chosen, and then the exact locations of poles are found via an iteration process by least square method. Finally, these rational functions are converted to equivalent circuits in time domain and then imported into EMTP software for modeling the ground system so that transient voltage of overhead lines subjected by lightning strikes is also efficiently evaluated. Manuscript profile

Open Access Article

5 - Monitoring Of The LANDSLIDE Phenomenon Using Wireless Sensor Networks

This paper presents a WSN-based method for monitoring the displacement in landslide susceptible slopes. In this method, an array of wireless transmitters installed on the target slope will broadcast regular signals, which will be received and interpreted by two synchron More

This paper presents a WSN-based method for monitoring the displacement in landslide susceptible slopes. In this method, an array of wireless transmitters installed on the target slope will broadcast regular signals, which will be received and interpreted by two synchronous receivers. The proposed system monitors the slope by measuring the phase difference between the two mentioned receivers before and after displacements, and shows promising reliability and accuracy for monitoring the status of landslide susceptible mountainous terrains. This approach did not have any field trial, but its results and accuracy has been evaluated through a series of comprehensive simulations performed for an array of six transmitter (Tx) and two receivers (Rx). Manuscript profile

Open Access Article

6 - Design and simulation of novel planar Micro-transformer with high quality factor
Bahram Azizollah Ganji Mohammad Molanzadeh

In this paper a novel planar micro-transformer with high quality factor is presented. Non-uniform current density distribution, especially in inner turn, increases the effective metal resistance due to skin and proximity effect .In order to overcome this problem, a nove More

In this paper a novel planar micro-transformer with high quality factor is presented. Non-uniform current density distribution, especially in inner turn, increases the effective metal resistance due to skin and proximity effect .In order to overcome this problem, a novel crossover connection between turns to equal the distance current path across the turns and uniform the current distribution, has been used. With diminished current crowding effects, the effective resistance is minimized, thereby increasing the performance-parameter values. Simulation has been taken by using ADS Momentum and HFSS software. The quality factor, self-inductance, mutual inductance and coupling factor at 3.5 GHz frequency are achieved about 42.6, 4.9 nH, 3.3 nH, 0.747 respectively, and occupied structure space is 860 um×860 um. Because of the structure is symmetric, the primary and secondary characteristic is same .compare to conventional micro-transformer 17% in quality factor,5% in coupling coefficient and more than 20% in self and mutual inductance, improvement are achieved. Manuscript profile

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