Informatics Publishing Limited

Rajashri P. Sonar ¹, Srija Unnikrishnan ¹

Affiliations
1 Fr. Conceicao Rodrigues College of Engineering, IN

Abstract

Handovers occur due to the movement of the mobile user from one area to another area. If we don‟t use handovers then whenever a user leaves the area of a particular cell then its ongoing call is immediately disconnected. The process of handovers requires a number of parameters e.g. what is the handover scheme we are using, how many channels are free. In the handover process we should also keep the QoS up to the standard. Vertical handover may be referred to as a process of transferring call connected to a network/data session from one channel connected in a cell to the core network of another. Vertical handover refers to automatic switching of the communication/ data session from one technology to the other. So, it‟s different from a horizontal handover among various wireless access points using the same technology. In future, people will have even more flexibility when true wireless internet and real-time multimedia are provided seamlessly over heterogeneous wireless networks. Optimally combining the capacity and services of the current and emerging networks requires a holistic view of mobility, resource and service management. A framework for the analysis of vertical handoff algorithm sensitivity to various mobility parameters including velocity, handoff delay and dwell time is introduced.

Keywords

Dynamic Factors, Dynamic Decision Model, Simulation Topology, Vertical Handoff Decision.

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Santosh S. Rokade ¹, Srija Unnikrishnan ¹, Ranjushree Pal ¹

Affiliations
1 Industrial Electronics Department, Mumbai University, Fr. Conceicao Rodrigues College of Engineering, Bandstand, Bandra (W), Mumbai-400050, IN

Abstract

This project proposes a text-dependent speaker identification system. Isolated digits 0-9 and their concatenations are used for speaking text. For each speech signal Linear Prediction Coefficients (LPC) are extracted and formed as feature vectors. Dynamic Time Warping (DTW) is used to measure distances between referenced and evaluated vectors. These distances, indicating nearness of unknown vectors to references, incorporated with K-Nearest Neighbor (K") decision technique are used for the identification process. In the verification test of the experiment. Consequently, we have experimented on the use of LPC with both DTW (using KNN as a decision rule) and ANN (a well-known Multilayer Perception (MLP) with back propagation learning algorithm). The systems were tested with 0-9 isolated digits. It has been shown that DTW with KNN gives better performance. It is affected by an attempt of ANN to recognize all of training patterns including any low quality voice. In this paper, further successive progress of our system is to deeply experiment on the use of DTW with KNN with concatenated digit, which will be a form of speaking-text in our application at last. This research will also purpose in selection of some acceptable digits to be included in our text-prompted speaker identification system.

Keywords

LPC, DTW.

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Sanjeev Ghosh ¹, Srija Unnikrishnan ²

Affiliations
1 Thakur College of Engineering and Technology, IN
2 Fr. Conceicao Rodrigues College of Engineering, IN

Abstract

Longevity of wireless sensor networks (WSN) is dependent on the optimal utilization of power supply. To make optimal utilization of power and increase the operational life of the network, we present two techniques with the goal of decreasing the consumption of power in a sensor node by incorporating queuing theory. We analyze the performance of wireless sensor networks that implement a M/G/1 queue with two different queuing policies. The analysis is done with respect to two important aspects: power consumption and latency delay. The results of the analysis illustrate the fact that the power consumed at a wireless sensor node can be reduced significantly by optimal selection of thresholds. We also compare the two policies in terms of power consumption and latency and find that the Min (N, T) policy is better equipped to not only reduce the power consumption but also reduces the latency delay caused due to the introduction of the queuing thresholds. The results indicate that the schemes studied can be implemented in practical scenarios as they are effective in reducing power consumption and increasing the operational life of a WSN.

Keywords

Energy, Latency, Probability, Queuing Analysis, Wireless Sensor Networks.

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Monica Khanore ¹, Srija Unnikrishnan ¹

Affiliations
1 Fr. Conceicao Rodrigues College of Engineering, IN

Abstract

Systems based on spread spectrum technique are inherently interference resistant. However, asynchronous transmission and multipath propagation causes manifestation of multiuser interference. Multiuser interference in a multiple access system limits the capacity of the system. Hence, it becomes imperative to mitigate the interference. This work presents the design and mathematical analysis of Hybrid Interference Cancellation (HIC) detector for direct-sequence code division multiple access (DS-CDMA). The detector is analysed for single path as well as multipath propagation over a Rayleigh fading channel. Simulation results are compared with the results of Successive Interference Canceller (SIC). Furthermore, the SIC and HIC detectors are tested for convergence. An HIC detector is proposed for MC-CDMA system. The interference canceller discussed in this paper dispenses with the RAKE receiver for diversity combining and data estimation, which averts the likelihood of errors because of incorrect data estimates.

Keywords

DS-CDMA, MC-CDMA, HIC, Multipath Propagation, Convergence.

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