Informatics Publishing Limited

V. Kejalakshmi ¹, R. Thilagavathy ², S. Arivazhagan ³

Affiliations
1 Anna University of Technology, Trichy, IN
2 K.L.N College of Engineering Anna University, Chennai, IN
3 College of Engineering, Guindy, Anna University, Chennai, IN

Abstract

Particle Swarm Optimization algorithm (PSO) is used in the optimization of Multi user Multi Input and Multi Output (MU-MIMO) communication systems. Linear precoding is employed in MU-MIMO communication system to improve the system capacity and to minimize the receiver complexity. The previous works on optimization algorithm to design a linear precoder to maximize the system capacity is assumed to have perfect channel state information (CSI) at the base station (BS) and antenna size 4x4. However the CSI available at the BS is imperfect due to channel estimation errors. Hence, in this paper, the precoder is designed to maximize system capacity by considering the channel estimation error. Further, the PSO algorithm is used to find the precoding matrix and also analyze the performance of capacity and bit error rate with different variance values and with different antenna sizes. The simulation results show that the system capacity performance of the proposed precoder which considers channel estimation error outperforms the previously proposed precoder.

Keywords

CSI, PSO, SDMA, SINR, DPDC, THP, BD, ZF, MMSE.

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R. Thilagavathy ¹, A. Murugan ¹

Affiliations
1 Department of Computer Science, Dr. Ambedkar Government Arts College (Autonomous), University of Madras, Chennai - 600039, Tamil Nadu, IN

Abstract

Background: Cloud computing is a model whereby users access compute resources from a service provider through internet. The Cloud Computing has great capability to boost productivity and minimize cost, hence many organizations are migrating to the new technology, but at the same time it constitutes many security risks and challenges. Methods: DNA and ID base cryptography methods are used for cloud computing security. Findings: Cloud computing can address the problems when user moves from single cloud to multi-clouds. In this paper, we provide an extensive survey of cloud computing security challenges and different technologies taken to tackle the issues. Improvements: Highlighting the security issues of cloud computing, the proposed system is, DNA technology and JPEG Zigzag coding with an encryption scheme. We conclude the paper with a critical analysis of challenges that have not yet been fully met, and highlight directions for future work.

Keywords

Cloud Computing, Cloud Security Risks and Challenges, CSP, Cryptography, DNA, Encryption Scheme, Privacy, Security.

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R. Thilagavathy ¹, A. Murugan ¹

Affiliations
1 PG and Research Department of Computer Science, Dr. Ambedkar Government Arts College (Autonomous), Chennai - 600039, Tamil Nadu, IN

Abstract

Objectives: To overcome the cloud data security challenges, a few recommendations have been proposed along with RSA encryption algorithm. Methods: The RSA algorithm can be defined as an asymmetric key algorithm which is used to develop the strong security model. In cloud computing so many encryption schemes are used for security. In the proposed model the RSA is used to build new security model because it is tightly secured algorithm. Findings: Many organizations are migrating to cloud environment, it is imperative to understand the data security issues surrounding cloud computing. The data security is attained by using modified RSA algorithm. Improvements: In this paper we propose a modified RSA encryption algorithm with longest common sub sequence of a string (LCS). The encrypted and decrypted files are compared and the correctness of proposed system is proved.

Keywords

Cloud Computing, DNA, LCS Algorithm, RSA Algorithm, Security.

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