Rajesh Mishra

A Cutsets-Based Unified Framework to Evaluate Network Reliability Measures

This paper presents a minimal cutsets-based unified framework to evaluate some commonly used reliability measures: g-terminal, 2-terminal, and k-terminal reliability. In doing so, the paper proposes a single algorithm, which generates the network node sets. From these node sets, depending on the reliability measure(s), only those node sets are kept, which contains at least one node from the specified node set. These selected node sets form link-minimal cutsets. These minimal cutsets are used as an input to multi-variable inversion-based sum-of-disjoint product approach to obtain the unreliability expression thereafter. By solving several network examples of varied complexities, the comparison with the existing approach is provided.

Applicability of Rough Set Technique for Data Investigation and Optimization of Intrusion Detection System

The very idea of intrusion detection can be perceived through the hasty advancement following the expansion and revolution of artificial intelligence and soft computing. Thus, in order to analyze, detect, identify and hold up network attacks a network intrusion detection system based on rough set theory has been proposed in this article. In this paper we have shown how the rough set technique can be applied to reduce the redundancies in the dataset and optimize the Intrusion Detection System (IDS).

Enumeration of Minimal Cutsets for Directed Networks with Comparative Reliability Study for Paths or Cuts

An active research field is the evaluation of the reliability of a complex network. The most popular methods for such evaluation often use Minimal Paths (MP) or Minimal Cuts (MC) of the network. This paper proposes an algorithmic approach to enumerate MC of the directed networks reliability measures. Another attempt has been made in this paper to provide an answer to the question as to when MP or MC are suitable for evaluating reliability measures. An exhaustive study has been conducted to provide some guidelines in this respect. Copyright

A Review on Wireless Network Security

Computer network is very essential part of our life by which we can share the information via different technologies such as wired or wireless. Generally the wireless is mostly adopted technology by us due to various advantages like ease of installation, mobility, reconfigure ability, low infrastructural cost etc. but suffers from more attacks as the wireless channel is open. Therefore, many researchers are working in this hot area to secure the wireless communication. In this paper, we discuss the WEP, WPA, WPA2 and the RSA protocols and give the comparative study.

Gain-phase mismatch correction technique for I/Q channel receiver

Every communication receiver that uses in-phase and quadrature channel signal processing technique encounters problems related to matching of gain and phase in both the channels. The gain and phase imbalances occur between Low Pass Filter and Local Oscillator used in both the channels and as a result the performance of the receivers and the quality of the received signals are degraded. The imbalances produced may cause insufficient attenuation in image frequency band leading to interference. The problem needs to be compensated. This paper represents novel architecture design and implementation of COordinate Rotation DIgital Computer (CORDIC) algorithm based Adaptive FIR filter using Trigonometric Least Mean Square (TLMS) algorithm to give a solution for correcting I/Q imbalances. The design of CORDIC in the vector rotation mode results in high system throughput due to its pipelined architecture where latency is reduced in each of the pipelined stage and finds its appropriate application in real time signal processing. The good convergence of CORDIC in the given LMS algorithm based adaptive filter facilitates in easy calculation of new filter weights.

Digital Equalization for Cancellation of Noise-Like Interferences in Adaptive Spatial Filtering

Adaptive equalizer is an indispensable component of many radar systems for the cancellation of interference which arises due to mismatches in radar channels. This paper presents a reformulated LMS algorithm-based pipelined architecture of adaptive transversal equalizer that uses CORDIC as a main processing element to update angles instead of filter coefficients. In this architecture, hardware complexity has been reduced to a larger extent by utilizing pipeline method throughout the architecture. The lacuna of real-time system remains in the speed at which multiplication can be executed. We have proposed a modified version of pipelined Booth multiplier which uses partial product reduction scheme using 4–2 adder to reduce the computational time significantly. The hardware realization of the design reveals that critical path delay, area utilization and power consumption are reasonably low and therefore proposed design can be suitably be accommodated in modern-day radar system. The efficacy of the proposed interference canceller has been justified with extensive MATLAB simulations as well as hardware synthesis result for mitigation of interference in multi-channel radar systems.

An Efficient Approach to Enumerate Cutsets Arising in Capacity Related Reliability Evaluation

Abstract This paper proposes an efficient approach to enumerate the subsets of cutsets group (SCG) of a communication network having heterogeneous link capacities to evaluate capacity related reliability (CRR) using minimal cutsets. The efficient methodologies in vogue use a priori information of either minimal pathsets or cutsets of the network, which can block or allow a required amount of flow through the network, termed as a first step in CRR evaluation. In the second step, the disjoint sets of the qualified cutsets or pathsets are obtained using an appropriate sum of disjoint product (SDP) approach. Efficient approaches do exist for the second step to obtain the mutually disjoint terms. In this paper, CRR evaluation uses minimal cutsets and an efficient technique to enumerate irredundant SCG. A comparison with respect to the number of subsets of cutsets generation, number of external/internal redundant subsets removal in obtaining irredundant SCG with recent algorithms have been made to show less computational efforts in using the proposed approach and thus a better performance than the existing approaches.

Design of Complex Non-Linear Adaptive Equalizer in Mitigating Severe Intersymbol Interferences

In this paper, we propose an efficient architectural design for Adaptive Decision Feedback Equalizer (ADFE) for high-speed reliable data transmission through wired as well as wireless communication channels to minimize Inter Symbol Interference (ISI). High hardware cost of the system makes an urge to redesign it in order to minimize overall circuit complexity and cost. Realization of CORDIC based pipelined ADFE architecture using reformulated LMS algorithm has not only reduced multipliers in its feed forward path, the flexibility and modularity of the components makes it possible for easy implementation also. The realization results area efficient, high speed and throughput with good convergence. The efficacy of the proposed equalizer is corroborated with MATLAB simulations for mitigation of severe channel distortion arise due to ISI in high speed communication systems.

Design of LMS Adaptive Radar Detector for Non-homogeneous Interferences

ABSTRACT The recent years have seen an unprecedented increase in the demand for superior performance of radar signal processor. The main challenge in a radar system is to maintain the probability of a false alarm rate constant even under an uncertain time-varying clutter environment. The objective of this paper is to develop a method for enhanced clutter/interference suppression by redesigning the radar detector in such a way to emphasize the target response and de-emphasize the clutter response. To achieve this, we have proposed a hardware architecture that implements least mean square algorithm-based adaptive filter along with a constant false alarm rate (CFAR) technique for the purpose of better detection of target under a non-homogeneous clutter environment. An adaptive design of the CFAR-filter technique has been used to improve probability of detection by increasing signal-to-noise ratio. The efficacy of the proposed architecture is corroborated with MATLAB simulations and hardware synthesis.

A Cross Layer Approach for Intrusion Detection in MANETs

paper, we propose a cross layer approach to detect the malicious node (Black hole attack) in MANET. In this approach, the malicious node is detected by the collaborative decision made by the network layer, MAC layer and physical layer on the basis of the parameters passed by the physical and the link layer to the network layer using cross layer design, and then the best path is selected among the various paths between the source node and the destination node. The routing protocol which is used in the simulation is AODV. The malicious node is then deleted from the routing table and the performance of our technique is proved by the simulation of our system model using the network simulator NS-2.