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Information Systems and Telecommunication - Volume:1 Issue: 2, Apr-Jun 2013

Journal of Information Systems and Telecommunication
Volume:1 Issue: 2, Apr-Jun 2013

  • تاریخ انتشار: 1392/08/30
  • تعداد عناوین: 7
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  • Babak Haji Bagher Naeeni, Hamidreza Amindavar Page 73
    In this paper, we present Support Vector Machine (SVM)-based blind per tone equalization for OFDM systems. Blind per tone equalization using Constant Modulus Algorithm (CMA) and Multi-Modulus Algorithm (MMA) are used as the comparison benchmark. The SVM-based cost function utilizes a CMA-like error function and the solution is obtained by means of an Iterative Re-Weighted Least Squares Algorithm (IRWLS). Moreover, like CMA, the error function allows to extend the method to multilevel modulations. In this case, a dual mode algorithm is proposed. Dual mode equalization techniques are commonly used in communication systems working with multilevel signals. Practical blind algorithms for multilevel modulation are able to open the eye of the constellation, but they usually exhibit a high residual error. In a dual mode scheme, once the eye is opened by the blind algorithm, the system switches to another algorithm, which is able to obtain a lower residual error under a suitable initial ISI level. Simulation experiments show that the performance of blind per tone equalization using support vector machine has better than blind per tone equalization using CMA and MMA, from viewpoint of average Bit-Error Rate (BER).
    Keywords: Constant Modulus Algorithm (CMA), Multi, Modulus Algorithm (MMA), Support Vector Machine (SVM), Orthogonal Frequency Division Multiplexing (OFDM)
  • Sara Motamed, Ali Broumandnia, Azamossadat Nourbakhsh Page 79
    Feature selection is one of the best optimization problems in human recognition, which reduces the number of features, removes noise and redundant data in images, and results in high rate of recognition. This step affects on the performance of a human recognition system. This paper presents a multimodal biometric verification system based on two features of palm and ear which has emerged as one of the most extensively studied research topics that spans multiple disciplines such as pattern recognition, signal processing and computer vision. Also, we present a novel Feature selection algorithm based on Particle Swarm Optimization (PSO). PSO is a computational paradigm based on the idea of collaborative behavior inspired by the social behavior of bird flocking or fish schooling. In this method, we used from two Feature selection techniques: the Discrete Cosine Transforms (DCT) and the Discrete Wavelet Transform (DWT). The identification process can be divided into the following phases: capturing the image; pre-processing; extracting and normalizing the palm and ear images; feature extraction; matching and fusion; and finally, a decision based on PSO and GA classifiers. The system was tested on a database of 60 people (240 palm and 180 ear images). Experimental results show that the PSO-based feature selection algorithm was found to generate excellent recognition results with the minimal set of selected features.
    Keywords: Biometric, Genetic Algorithm (GA), Particle Swarm Optimization (PSO), Discrete Cosine Transform (DCT), Discrete Wavelet Transform (DWT)
  • Hadi Naderian, Ahmad Hakimi Page 89
    This paper presents a wideband low-noise mixer in CMOS 0.13-um technology that operates between 2–10.5 GHz. The mixer has a Gilbert cell configuration that employs broadband low-noise trans conductors designed using the negative-positive feedback technique used in low-noise amplifier designs. This method allows broadband input matching. The current-bleeding technique is also used so that a high conversion gain can be achieved. Simulation results show excellent noise and gain performance across the frequency span with an average double-sideband noise figure of 2.9 dB and a conversion gain of 15.5 dB. It has a third-order intermodulation intercept point of -8.7 dBm at 5 GHz.
    Keywords: Current, Bleeding, Feedback, Low, Noise, Noise Cancellation, Wideband
  • Mehdi Fasanghari, Mohsen Sadegh Amalnick, Reza Taghipour Anvari, Jafar Razmi Page 97
    Information Technology is recognized as a competitive enabler in today’s dynamic business environment. Therefore, alliance of business and Information Technology process is critical, which is mostly emphasized in Information Technology governance frameworks. On the other hand, Enterprise Architectures are deployed to steer organizations for achieving their objectives while being responsive to changes. Thus, it is proposed to align the business and Information Technology through investigating the suitability of Enterprise Architecture scenarios. In view of this fact, investigating a flexible decision making method for business and information technology alignment analysis is necessary, but it is not sufficient since the subjective analysis is always perturbed by some degree of uncertainty. Therefore, we have developed a new robust Data Envelopment Analysis technique designed for Enterprise Architecture scenario analysis. Several numerical experiments and a sensitivity analysis are designed to show the performance, significance, and flexibility of the proposed method in a real case.
    Keywords: Group Data Envelopment Analysis, Enterprise Architecture, IT Governance, COBIT, Robust Optimization
  • Hossein Emami, Hamed Ghanbari Foshtami, Ali Hashemi Talkhouncheh Page 113
    A broadband microstrip antenna based on log periodic technique was conceived and demonstrated practically. The antenna exhibits a wideband characteristic comparing with other microstrip antennas. Over the operation frequency range, i.e. 2.5-6 GHz, a 50 Ω
    Keywords: Microstrip Antenna, Log, Periodic, VSWR, Gain, Pattern
  • Abdalhossein Rezai, Parviz Keshavarzi Page 119
    This paper presents a new and efficient implementation approach for the elliptic curve cryptosystem (ECC) based on a novel finite field multiplication in GF(2m) and an efficient scalar multiplication algorithm. This new finite field multiplication algorithm performs zero chain multiplication and required additions in only one clock cycle instead of several clock cycles. Using modified (limited number of shifts) Barrel shifter; the partial result is also shifted in one clock cycle instead of several clock cycles. Both the canonical recoding technique and the sliding window method are applied to the multiplier to reduce the average number of required clock cycles. In the scalar multiplication algorithm of the proposed implementation approach, the point addition and point doubling operations are computed in parallel. The sliding window method and the signed-digit representation are also used to reduce the average number of point operations. Based on our analysis, the computation cost (the average number of required clock cycles) is effectively reduced in both the proposed finite field multiplication algorithm and the proposed implementation approach of ECC in comparison with other ECC finite field multiplication algorithms and implementation approaches.
    Keywords: Computational Complexity, Network Security, Cryptography, Elliptic Curve Cryptosystem (ECC), Finite Field Multiplication, Scalar Multiplication
  • Sara Nazari, Mohammad, Shahram Moin Page 131
    A novel approach for steganography cover selection is proposed, based on image texture features and human visual system. Our proposed algorithm employs run length matrix to select a set of appropriate images from an image database and creates their stego version after embedding process. Then, it computes similarity between original images and their stego versions by using structural similarity as image quality metric to select, as the best cover, one image with maximum similarity with its stego. According to the results of comparing our new proposed cover selection algorithm with other steganography methods, it is confirmed that the proposed algorithm is able to increase the stego quality. We also evaluated the robustness of our algorithm over steganalysis methods such as Wavelet based and Block based steganalyses; the experimental results show that the proposed approach decreases the risk of message hiding detection.
    Keywords: Steganography, Cover Selection, Run Length Matrix, Image Texture Features, SSIM