MIMO-OFDM-IDMA Based Underwater Acoustic Communication For Multiuser Multichannel

Vol. 3  Issue 4
Year: 2014
Issue:Aug-Oct
Title:MIMO-OFDM-IDMA Based Underwater Acoustic Communication For Multiuser Multichannel
Author Name:Manish Kumar Nandanwar and Karamtot Krishna Naik 
Synopsis:

The objective of this paper is to present Underwater Communication technique that provides uninterrupted and reliable service in shallow water for MIMO application. Acoustic sensor network is based on combination of Interleave-division multiple access (IDMA) and orthogonal frequency division multiplexing (OFDM), the OFDM is a modulation technique where signal splits into multiple sub-signals and simultaneously transmitted at different frequencies to the receiver. IDMA is an alternative of Code Division Multiple Access (CDMA) that distinguishes each user with the unique random interleaver code. The OFDM- IDMA is imperial design for reducing error bursts that occur in multi-access underwater applications. The authors have implemented above techniques for Multiple Inputs Multiple Outputs (MIMO), to transfer more data using same bandwidth at the same time, therefore technique is known as MIMO-OFDM-IDMA. MIMO-OFDM-IDMA which is a new concept, having the capability of high rate transmission and robustness against multi-path fading and other channel impairments. The results of MIMO-OFDM-IDMA have been analyzed with theory and simulation.

Low Power and Area Efficient Architecture of Pulse Shaping FIR Filter For Digital Up Converter

Vol. 3  Issue 4
Year: 2014
Issue:Aug-Oct
Title:Low Power and Area Efficient Architecture of Pulse Shaping FIR Filter For Digital Up Converter
Author Name:I. Vinodhini and M. Thangavel
Synopsis:

FIR filters are widely used in wireless mobile communication systems such as channel equalization, matched filtering, and pulse shaping, due to their stability and reconfigurability. In this paper, the pulse shaping FIR filter such as root-raised cosine filter is designed for multistandard digital up converter. The two bit binary common sub-expression based binary common sub-expression elimination algorithm is used to ignore the occurrences in identical bit pattern. The number of additions and multiplications are reduced using this technique. Carry save adder is used to generate the partial product which reduces the area and increases the speed. The area and speed of the filter design is synthesized and simulated using Xilinx ISE 12.1.

Theoretical Estimation of Electromagnetic Radiation From Different Cellular Networks

Vol. 3  Issue 4
Year: 2014
Issue:Aug-Oct
Title:Theoretical Estimation of Electromagnetic Radiation From Different Cellular Networks
Author Name:S. Venkatesulu, S. Varadarajan, M. Sadasiva, B. Dilli Kumar and K. Harshavardhan Reddy
Synopsis:

This paper focuses on the electromagnetic radiation from various emblematic cellular mobile base stations in the urban, semi urban and rural locations. Theoretical assessment of radiofrequency exposure due to cellular base station antennas is treated. The estimation of the Electric field with reference to macro cell towers Installation is derived. From the electric field thus evaluated, magnetic field and power density are determined. Finally, the received power is calculated for the given power density, receiver antenna gain and frequency of the cell towers.

The electric field, magnetic field, power density and radiated power are calculated for the different effective radiated powers, with different operating frequencies, and with distance ranging of 10 meters to 600 meters. The theoretical analysis of the field intensities of the radiation emitted from the RF source, and thus computing radiated power levels at various distances from the RF source, helps in estimating the radius of zone where the radiation level is hazardous.

Survey on Mutual Coupling Reduction Techniques for Imaging Radar Application

Vol. 3  Issue 3
Year: 2014
Issue:May-Jul
Title:Survey on Mutual Coupling Reduction Techniques for Imaging Radar Application
Author Name:C. Mekala et al.,
Synopsis:
Mutual Coupling is the general problem occurring in arrays used in Imaging Radars. It is the electromagnetic phenomena, which is produced from absorption of radiating energy of one antenna by another. It significantly affects input impedance of the antenna, performance of array processing algorithm, magnitude and phase of the re-radiated waves, radiation pattern and also the received element voltage. Hence this paper provides the review of different methods to protect system from these effects by reducing mutual coupling. This survey on mutual coupling reduction techniques of antenna array in Imaging RADARs are discussed deeply. The discussion initiates with the effect of mutual coupling in antenna and covers the topics such as, parameters affected by coupling effect, coupling reduction techniques and also about the functionality of these techniques in performance improvement. Concludes with the selection of specific reduction scheme for suitable application. This survey also concentrates on comparison of coupling effect reduction through arrangement of array element in square and triangular lattice of array.

A Comparative Analysis of Reversible Data Hiding in H.264/AVC and H.265/HEVC Video Streams

Vol. 3  Issue 3
Year: 2014
Issue:May-Jul
Title:A Comparative Analysis of Reversible Data Hiding in H.264/AVC and H.265/HEVC Video Streams
Author Name:Kiruthika.T and P. Sundaravadivel
Synopsis:
In the course of the past decade, data hiding technologies had progressed from limited use to pervasive deployment. With the swift advancement of smart mobile devices, the need to protect valuable exclusive information has generated a surplus new methods and technologies. Using cryptographic techniques to encrypt data before transmission may overcome any type of security problems. But the camouflaged appearance of the encrypted data may arouse suspicion. A technique for hiding data with two level of security to embed data along with good perceptual quality and high payload capacity is proposed. This gives rise to improved version of dual steganography which will provide better security. An improved scheme of data hiding directly in the compressed version of H.264/AVC video stream and H.265/HEVC video stream is proposed, which includes the following three parts, i.e., data encryption, video compression, data embedding, and data extraction. A comparative analysis is made which proves that H.265 video stream provides a better compression and at the same time preserving the video quality. The scheme can ensure both the format compliance and the strict file size preservation.

MSE and SER Compare For LS, MMSE and SMMSE for BCE Technique in OFDM

Vol. 3  Issue 3
Year: 2014
Issue:May-Jul
Title:MSE and SER Compare For LS, MMSE and SMMSE for BCE Technique in OFDM
Author Name:Divya Pandey and K. Neelam Dewangan
Synopsis:
Orthogonal frequency division multiplexing (OFDM) technique is the modulation technique provides less bandwidth usage and speed communication and hence preferred in many areas now a days. Channel estimation techniques are used to know the behavior of the channel and then that information is further used by receiver to eliminate the irregularities introduced by channel on transmitted signal. This paper includes Block type pilot assisted channel estimation technique (BCE).least square (LS), minimum mean square error (MMSE) and simplified minimum mean square error (SMMSE) techniques are used here. SMMSE technique is simplified MMSE technique which is similar to MMSE but with reduced complexity. The results are obtained by using MATLAB software. Performance evaluation is done by comparing values of mean squared error (MSE) and symbol error rate (SER) for different values of SNR. Performance of LS in comparison with other two techniques is less. MMSE and SMMSE have almost same performance, seen from results.

Performance Analysis of Co-Operative Spectrum Sensing Using Rayleigh Fading Channel in Cognitive Radio

Vol. 3  Issue 3
Year: 2014
Issue:May-Jul
Title:Performance Analysis of Co-Operative Spectrum Sensing Using Rayleigh Fading Channel in Cognitive Radio
Author Name:Yamini Verma and K. Neelam Dewangan
Synopsis:
One of the emerging techniques in wireless communication is cognitive radio which is used for the efficient utilization of radio frequency spectrum. One important requirement of cognitive radio is spectrum sensing. In this paper, various types of spectrum sensing techniques are mentioned. Cooperative sensing seemed to be the best method among all spectrum sensing techniques applied to overcome the problem of detection and false alarm associated by using single user. This paper studies the cooperative spectrum sensing scheme as means of optimizing the sensing performance in Rayleigh channels. Plot of SNR versus probability of detection for different values of false alarm is shown in this paper. All this output is achieved using MATLAB.