Accepted Papers

  • Interference Effects On The Gps Receiver Acquisition
    Mhd. Kheir Khlil Bek, Ehab Efareed and Sherif Elgamel, Military Technical College, Egypt.
    ABSTRACT
    The objective of the acquisition process is to determine the GPS signal peak after the correlation process, and then compares it with a detection threshold. One of the threats that could interrupt such procedure is the presence of interference signals which may severely cause an incorrect or no correlation peak during the acquisition process. To this end; this paper investigates the performance of the GPS signal acquisition process in the presence of different types of interference signals such as: continuous wave interference, narrowband interference, partial band interference, and broadband interference. A novel classification to the interference signals is presented. This classification is divided into two categories based on the interference contribution to the acquisition's output mean or variance values. Novel expressions of both false alarm and detection probabilities in the presence of noise along with different types of interference signals are mathematically formulated. The comparison among the interference signals based on the receiver operation characteristic (ROC) is also performed. The impact of both coherent integration time and the phase shift between the GPS and the interference signals on the acquisition performance is analyzed.


  • Interference Effects On The Gps Receiver Tracking Loop
    Mhd. Kheir Khlil Bek, Ehab Efareed and Sherif Elgamel,Military Technical College, Egypt.
    ABSTRACT
    The carrier tracking loop is more sensitive to noise and interference than the code tracking loop. Therefore, the carrier tracking loop can be used as a means for investigating the GPS receiver performance in the presence of interference. In this paper, closed form analytical expressions for the carrier tracking loop phase error are derived in the presence of different types of interference signals such as: continuous wave interference, narrowband interference, partial band interference and broadband interference. Novel mathematical expressions were derived for the GPS receiver interference tolerance in the presence of previously mentioned interference types. The derived analytical expressions were validated with the aid of extensive simulation experiments.


  • Pulse Design And Nbi Mitigation For Ir-Uwb Communication Systems
    Mhd. Kheir Khlil Bek and Ehab Fareed,Military Technical College,Egypt.
    ABSTRACT
    This paper presents a novel spectrum shaping technique in impulse radio ultra-wideband (IR-UWB) communication systems in order to introduce spectral nulls to limit interference with narrowband signals. The idea depends on the addition and subtraction of several UWB Gaussian derivative pulses in order to design a new pulse that has spectral null at the in-band narrowband interference (NBI) operating frequencies. The use of the Gaussian derivative ensures that the UWB spectrum mask established by the Federal Communications Commission (FCC) is met. The bit error rate performance of the proposed technique is derived in a multi-path IEEE802.15.3a UWB fading channel models and validated with simulation. Results show that multiple NBI signals can be effectively suppressed by transmitting and matched filtering the new pulse with a single or multiple spectral nulls at the interference operating frequencies therefore improving the robustness of UWB systems to NBI signals. The NBI signals are modeled as either the wireless local area network (WLAN) IEEE802.11a which operates in the 5GHz frequency band or multiple tones signals. The derived analytical results are verified with the aid of simulations.


  • Cooperative Diversity with Relay Selection over Rayleigh Fading Channel
    Ahmed El-Mahdy and Nada Tarek,German University in Cairo, Egypt.
    ABSTRACT
    In this paper a relay selection algorithm for decode and forward relaying is proposed to select one relay from multirelay networks. The relay selected by the proposed algorithm is chosen to transmit only if the rely-to-destination link signal to noise ratio (SNR) is greater than the SNR of the sourcedestination. The proposed algorithm does not require cyclic redundancy check for error correction. Mathematical performance analysis for the proposed algorithm is provided. The performance of the algorithm is evaluated in terms of bit error rate and is compared with other existing schemes for relay selection for perfect and estimated channel. Numerical results show that the proposed algorithm has better performance than some of the schemes algorithms.


  • A Novel Remote Sensing Image Resolution and Contrast Enhancement Using DWT Interpolation and PCA Based Fusion.
    Reddivari Thriveni and Ramashri Tirumala,SVU College of Engineering, Sri Venkateswara University,India.
    ABSTRACT
    Remote sensing images are being used in many fields of research. One of the major issues of these types of images is their low contrast and poor resolution. In this paper, we propose a novel remote sensing image contrast as well as resolution enhancement technique based on the DWT interpolation and PCA based fusion operation. Resolution enhancement technique based on the interpolation of high-frequency subbands obtained by discrete wavelet transforms (DWT) and the input image. The proposed contrast and resolution enhancement technique uses DWT to decompose the input image into different subbands. Then, the high-frequency subband images and the input lowresolution image have been interpolated, combining all these images to generate new resolution-enhanced image by using inverse DWT, In order to achieve high contrast, an intermediate stage histogram equalization and PCA based fusion technique has been proposed. The proposed technique has been tested on remote sensing benchmark images. The quantitative (PSRN, MSE, RMSE, EME) and visual results show the superiority of the proposed technique over the conventional and state-of-art image resolution enhancement techniques.


  • Clustered Compressive Sensing-Based Image denoising using Bayesian framework
    Solomon Tesfamicael1 and Faraz Barzideh2 ,1 Trøndelag University College (HiST),Norway and 2University of Stavanger (UiS),Norway.
    ABSTRACT
    This paper provides a compressive sensing (CS) method of denoising images using Bayesian framework. Some images, for example medical images like magnetic resonance images (MRI) are usually very weak due to the presence of noise and due to the weak nature of the signal itself. So denoising boosts the true signal strength. Under Bayesian framework we have used two different priors: sparsity and clusterdness in an image data as a prior information. In this work, after developing the Bayesian framework, we applied our method on synthetic data, Shepp-logan phantom and sequences of fMRI images. The results show that applying the clustered compressive sampling give better results than LASSO.


  • LSB Steganography with Improved Embedding Efficiency and Undetectability
    Omed Khalind and Benjamin Aziz,University of Portsmouth, Portsmouth, United Kingdom.
    ABSTRACT
    In this paper, we propose a new method of non-adaptive LSB steganography in still images to improve the embedding efficiency from 2 to 8/3 random bits per one embedding change even for the embedding rate of 1 bit per pixel. The method takes 2-bits of the secret message at a time and compares them to the LSBs of the two chosen pixel values for embedding, it always assumes a single mismatch between the two and uses the second LSB of the first pixel value to hold the index of the mismatch. It is shown that the proposed method outperforms the security of LSB replacement, LSB matching, and LSB matching revisited by reducing the probability of detection with their current targeted steganalysis methods. Other advantages of the proposed method are reducing the overall bit-level changes to the cover image for the same amount of embedded data and avoiding complex calculations. Finally, the new method results in little additional distortion in the stego image, which could be tolerated.


  • Robust And Real Time Detection Of Curvy Lanes (Curves) Having Desired Slopes For Driving Assistance And Autonomous Vehicles
    Amartansh Dubey and Kisore Burchandi,Visvesvaraya Natioanal Institute of Technology,India.
    ABSTRACT
    One of the biggest reasons for road accidents is curvy lanes and blind turns. Even one of the biggest hurdles for new autonomous vehicles is to detect curvy lanes, multiple lanes and lanes with a lot of discontinuity and noise. This paper presents very efficient and advanced algorithm for detecting curves having desired slopes (especially for detecting curvy lanes in real time) and detection of curves (lanes) with a lot of noise, discontinuity and disturbances. Overall aim is to develop robust method for this task which is applicable even in adverse conditions. Even in some of most famous and useful libraries like OpenCV and Matlab, there is no function available for detecting curves having desired slopes , shapes, discontinuities. Only few predefined shapes like circle, ellipse, etc, can be detected using presently available functions. Proposed algorithm can not only detect curves with discontinuity, noise, desired slope but also it can perform shadow and illumination correction and detect/ differentiate between different curves.


  • A Very Efficient Pseudo-Random Number Generator Based On Chaotic Iterations To Secure Adpcm Encoder
    Mimoun Hamdi, Rhouma Rhouma and Safia Belghith,Ecole Nationale d'Ingéenieurs de Tunis, Tunisia.
    ABSTRACT
    This paper presents a very simple and efficient encryption scheme based on chaotic iterations and applied to secure ADPCM (Adaptive Differential Pulse Code Modulation) encoder. This encryption algorithm includes two logistic maps based on two types of keys. It has important properties of randomness and can pass NIST batteries of tests. The evaluation of the secure scheme showed better performance in terms of speed and security. As an illustrative example, an application on an encoder type commonly used in communications, standard ITU-T G.726, is presented.


  • Medical Image Segmentation By Transferring Ground Truth Segmentation Based Upon Top Down And Bottom Up Approach
    Aseem Vyas and Won-Sook Lee,University of Ottawa,Canada.
    ABSTRACT
    In this paper, we present a novel method for image segmentation of the hip joint structure. The key idea is to transfer the ground truth segmentation from the database to the test image. The ground truth segmentation of MR images is done by medical experts. The process includes the top down approach which register the shape of the test image globally and locally with the database of train images. The goal of top down approach is to find the best train image for each of the local test image parts. The bottom up approach replaces the local test parts by best train image parts, and inverse transform the best train image parts to represent a test image by the mosaic of best train image parts. The ground truth segmentation is transferred from best train image parts to their corresponding location in the test image.