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Open access

Okoyeigbo Obinna, Okokpujie Kennedy, Omoruyi Osemwegie and Nkordeh Nsikan

Abstract

The ever-growing need for high data rate, bandwidth efficiency, reliability, less complexity and less power consumption in our communication systems is on the increase. Modern techniques have to be developed and put in place to meet these requirements. Research has shown, that compared to conventional Single Input Single Output (SISO) systems, Multiple- Input Single Output (MISO), and Multiple-Input Multiple- Output (MIMO) can actually increase the data rate of a communication system, without actually requiring more transmit power or bandwidth. This paper aims at the investigation of the existing channel estimation techniques. Based on the pilot arrangement, the block type and comb type are compared, employing the Least Square estimation (L.S) and Minimum Mean Squared Error (MMSE) estimators. Pilots occupy bandwidth, minimizing the number of pilots used to estimate the channel, in order to allow for more bandwidth utilization for data transmission, without compromising the accuracy of the estimates is taken into consideration. Various channel interpolation techniques and pilot-data insertion ratio are investigated, simulated and compared, to determine the best performance technique with less complexity and minimum power consumption. As performance measures, the Mean Squared Error (MSE) and Bit Error Rate (BER) as a function of Signal to Noise power Ratio (SNR) of the different channel estimation techniques are plotted, in order to identify the technique with the most optimal performance. The complexity and energy efficiency of the techniques are also investigated. The system modelling and simulations are carried out using Matlab simulation package. The MIMO gives the optimum performance, followed by the MISO and SISO. This is as a result of the diversity and multiplexing gain experienced in the multiple antenna techniques using the STBC.

Open access

Ahmed Rhbanou, Seddik Bri and Mohamed Sabbane

Abstract

In this paper, the substrate integrated waveguide (SIW) resonator is designed to study the influence of dielectric materials on its operating parameters (insertion loss, fractional bandwidth and unloaded Q-factor). The results obtained show that the use of high permittivity substrate in the SIW resonator by increasing its thickness allows reducing the size of resonator by causing the increase in its unloaded Q-factor. A SIW bandpass filter is designed using low temperature co-fired ceramic (LTCC) technology and high permittivity substrate. The filter has a fractional bandwidth of 27 % centered at 14.32 GHz with insertion loss of 0.7 dB.

Open access

Tanmoy Saha, Shreyasi Chakrabarty, Subhankar Bhattacharjee and Sanjib Sil

Abstract

There are abundant methods to mitigate PAPR in OFDM signals among which algorithm based tone reservation is of great popularity owing to its low complexity as well as decent BER. Here we have put forward a new distinct algorithm based Tone Reservation technique which is not only less complex and calculates its own threshold as well as PRT signal (unlike other algorithms requiring predetermined threshold and PRT) but also aptly modifies the data by bit by bit comparison with a modified copy of itself (algorithm modified) thus scaling the peaks as and providing a decent BER and good PAPR reduction.

Open access

Borislav Stoyanov, Krzysztof Szczypiorski and Krasimir Kordov

Abstract

We propose a novel pseudorandom number generator based on R¨ossler attractor and bent Boolean function. We estimated the output bits properties by number of statistical tests. The results of the cryptanalysis show that the new pseudorandom number generation scheme provides a high level of data security.

Open access

Marcin Woźniak and Dawid Połap

Abstract

Increasingly popular use of verification methods based on specific characteristics of people like eyeball, fingerprint or voice makes inventing more accurate and irrefutable methods of that urgent. In this work we present voice verification based on Gabor transformation. Proposed approach involves creation of spectrogram, which serves as a habitat for the population in selected heuristic algorithm. The use of heuristic allows for feature extraction to enable identity verification using classical neural network. The results of the research are presented and discussed to show efficiency of the proposed methodology.

Open access

Marcin Golański, Radosław O. Schoeneich, Dawid Zgid, Marek Franciszkiewicz and Michał Kucharski

Abstract

This paper presents the Reliable Bidirectional Control Protocol (RBCP) protocol, which is a transport protocol for Wireless Sensor Networks (WSN), focused on managing sensors’ behaviour. It aims to be a utility for reliable control data transferring from source to destination unit in the network. Considering the related studies on transport protocols, which are mostly dedicated to a single-direction reliable data transport, RBCP is the answer for the lack of control mechanisms in WSNs based on bidirectional communication. The first part of this paper is focused on general presentation of the proposed solution. In the next part, evaluation of the idea and final functionality are discussed. It will finally show the results of undergone testing stage.

Open access

V. C. Prasad

Abstract

Two new problems are posed and solved concerning minimal sets of prime implicants of Boolean functions. It is well known that the prime implicant set of a Boolean function should be minimal and have as few literals as possible. But it is not well known that min term repetitions should also be as few as possible to reduce power consumption. Determination of minimal sets of prime implicants is a well known problem. But nothing is known on the least number of (i) prime implicants (ii) literals and (iii) min term repetitions , any minimal set of prime implicants will have. These measures are useful to assess the quality of a minimal set. They are then extended to determine least number of prime implicants / implicates required to design a static hazard free circuit. The new technique tends to give smallest set of prime implicants for various objectives.

Open access

Zineb M’harzi, Mustapha Alami and Farid Temcamani

Abstract

In this paper, a new active grounded inductor controlled in current is described. This structure is realized using negative second generation current controlled conveyors and a single grounded capacitor, with no external resistance. The proposed circuit offers many advantages, such as: operation at high frequencies, simple circuit, tuning by the bias current, low power dissipation, etc. Comparison between this topology and those presented in literature is done to highlight the benefits of our structure. As an application, a bandpass filter based on the proposed active inductance is constructed to confirm the usability of the circuit and illustrate these performances. The filter center frequency and quality factor can be tuned independently. Simulation results, given under PSPICE software, present good agreement with the theoretical ones.

Open access

Steffen Wendzel, Luca Caviglione, Wojciech Mazurczyk and Jean-Francois Lalande

Abstract

Science 2.0 aims at using the information sharing and collaborative features of the Internet to offer new features to the research community. Science 2.0 has been already applied to computer sciences, especially bioinformatics. For network information hiding, a field studying the possibility of concealing a communication in networks, the application of Science 2.0 is still a rather uncovered territory. To foster the discussion of potential benefits for network information hiding, we provide a disquisition for six different Science 2.0 aspects when applied to this domain.

Open access

Bhavani Prasad, Kamaraju Maddu and Venkata Lakshmi

Abstract

In this paper the main goal is to study the principle structure and characteristics of single and multiple memristors and also the temperature effects. The complete analysis described here is done by using matlab Simulink. The relationship between the on resistance, off resistance and ionic mobility with respect to temperature has been analyzed and shown graphically. The memristor can be used as a High speed switch and it can be used in non volatile computer memories due to its higher switching speeds.