Improving quality and intelligibility of speech signals in mobile devices has been studied with great interest in the past. Speech information in communication channels is usually corrupted by additive acoustic noise, reverberation or channel noise. This paper explores into the possibilities of enhancing corrupted speech using the Spectral Subtraction (SS) and Linear Prediction...
The proposal of indistinguishable encryption in Randomized Arithmetic Coding(RAC) doesn’t make the system efficient because it was not encrypting the messages it sends. It recomputes the cipher form of every messages it sends that increases not only the computational cost but also increases the response time.Floating point representation in cipher increases the difficulty in...
The channel assignment problem in wireless mobile network is the assignment of appropriate frequency spectrum to incoming calls while maintaining a satisfactory level of electromagnetic compatibility (EMC) constraints. An effective channel assignment strategy is important due to the limited capacity of frequency spectrum in wireless mobile network. Most of the existing channel...
Service discovery technologies are exploited to enable services to advertise their existence in a dynamic way and can be discovered, configured and used by other devices with minimum of manual efforts. Automatic service discovery plays an important role in future network scenarios. Service discovery in distributed environment is difficult that too if the availability information...
Interest in broadband wireless access (BWA) has been growing due to increased user mobility and the need for data access at all times. IEEE 802.16e based WiMAX networks promise the best available quality of experience for mobile data service users. WiMAX networks incorporate several Quality of Service (QoS) mechanisms at the Media Access Control (MAC) level for guaranteed...
The most preferred mode for communication of multimedia data is through the TCP/IP protocol. But on the other hand the TCP/IP protocol produces huge packet loss unavoidable due to network traffic and congestion. In order to provide a efficient communication it is necessary to recover the loss of packets. The proposed scheme implements Hash based FEC with auto XOR scheme for this...
Vehicular Ad hoc Networks (VANET) has emerged as a recognized advancement in wireless technologies. Each node in the network may be either a vehicle or Road Side Unit (RSU) which has to be equipped with the necessary communication facility. Every vehicle in VANET must be authenticated to establish a reliable and secure network communication. The AODV routing protocol which is...
A printed dipole antenna for wireless communication applications is designed and simulated using ADS software. This paper presents the simulated results of array of printed dipole antennas for different configuration which are used in the MIMO systems. The antenna is designed and characterized by measuring return loss, directivity, gain and radiation pattern. It also presents the...
High data rates and spectral efficiency is the main requirements for wireless communication systems. Orthogonal Frequency Division Multiplexing (OFDM) is a special form of multi carrier transmission used to achieve high data rates of the various WLAN standards. WLAN uses an Inverse Fast Fourier Transform (IFFT) at the transmitter to modulate a high bit-rate signal onto a number...
Wireless communication is a major component of mobile computing. Transmission Control Protocol suffers from performance degradation in wireless environments. Due to high mobility and varying bit error rate in these environments, any packet loss that occurs is misinterpreted by the TCP as congestion and invokes congestion control mechanisms thereby degrading performance. Hence the...
Leakage power of CMOS VLSI Technology is a great concern. To reduce leakage power in CMOS circuits, a Leakage Power Minimiza-tion Technique (LPMT) is implemented in this paper. Leakage cur-rents are monitored and compared. The Comparator kicks the charge pump to give body voltage (Vbody). Simulations of these circuits are done using TSMC 0.35µm technology with various operating...
Bluetooth is a short range radio technology to form a small wireless system. It is used in low –cost, low power ad-hoc networks and it suffers from long service discovery delay and high power consumption. Bluetooth employs the 2.4 GHz ISM band, sharing the same bandwidth with the wireless LAN implementing the IEEE 802.11 standards. Thus it causes significantly lower interference...
Modern fighter aircrafts, ships, missiles etc need to be very low Radar Cross Section (RCS) designs, to avoid detection by hostile radars. Hence accurate prediction of RCS of complex objects like aircrafts is essential to meet this requirement. A simple and efficient numerical procedure for treating problems of wide band RCS prediction Perfect Electric Conductor (PEC) objects is...
Reducing energy consumption, primarily with the goal of extending the lifetime of battery-powered devices, has emerged as a fundamental challenge in wireless communication. The performance of the medium access control (MAC) scheme not only has a fairly significant end-result on the behaviour of the routing approach employed, but also on the energy consumption of the wireless...
A conformal mapping analysis of various coplanar waveguide structures is presented on silicon substrate. The analysis is based on quasi-TEM analysis which is used in formulating the electrical parameters of a transmission line. Different coplanar structure configurations are investigated. Simulation results are presented for coplanar waveguides etched on the surface of a...
RFID is a technology that used to identify the objects automatically. But identifying multiple objects simultaneously caused for collision which reduces the efficiency of the system. Because of the collision, some tags cannot be identified. This is a major disadvantage of the RFID system. The collision will lead to loss of data and tag identification. There are various anti...
In this paper, we present a MIMO (Multiple Input Multiple Output) communication system that uses the Alamouti algorithm for transmission with an appended Hopfield Encoder at the transmitter and Hopfield Decoder at the receiver. The Hopfield Encoders and Decoders are a part of the Hopfield Neural Network that can be used as an associative memory. At the transmitter, the symbols to...
MIMO Diversity is the technique which takes the advantage of multipath and mitigates the effect of fading and increases signal strength. Space Time Block code (STBC) is used in Multiple Input Multiple Output (MIMO) system to improve the performance by maximizing diversity gain. In this paper Math Works-SIMULINK platform is used for simulation. The performance of MIMO, Space Time...
This paper compares different character encoding schemes used to encode the characters in different languages. A new character encoding protocol called PANDITHAM has been developed to encode the characters in different languages. The languages English and Tamil are taken for a case study and its performance under networking environment is compared with regard to PANDITHAM...
The Impulse Radio based Ultra Wideband (IR-UWB) system transmits data by sending pulses, each with very small time duration followed by pauses that are approximately two hundred times that length. Rake receiver improves system performance by equalizing signals from different paths. This enables the use of Rake receiver techniques in UWB systems. For high data rate ultra-wideband...
Elliptic curve cryptography finds enormous applications because of its security offering using the remarkable property of elliptic curve. The Elliptic curve cryptography finds enormous applications in almost all the emerging areas. However in mobile networks, the usage of elliptic curve cryptography is limited. Moreover, the operation of mobile networks in an un-trusted...
In Gossip Sleep Protocol, network performance is enhanced based on energy resource. But energy conservation is achieved with the reduced throughput. In this paper, it has been proposed a new Protocol for Mobile Ad hoc Network to achieve reliability with energy conservation. Based on the probability (p) values, the value of sleep nodes is fixed initially. The probability value can...
In this paper we present alternate form of Radix-4/8 and split radix FFT’s based on DIF (decimation in frequency) version and discuss their implementation issues that further reduces the arithmetic complexity of power-of-two discrete Fourier Transform. This is achieved with circular shift operation on a subset of the output samples resulting from the decomposition in these FFT...
Speech Enhancement can be used as a preprocessing technique in any of the speech communication systems. Speech communication involves a speaker, listener and communication device. The background noise present in the speech signal while transmitting has to be removed from the noisy speech signal to increase the signal intelligibility and to minimize the listener fatigue. The...
Power consumption of nodes in ad hoc networks is a critical issue as they predominantly operate on batteries. In order to improve the lifetime of an ad hoc network, all the nodes must be utilized evenly and the power required for connections must be minimized. Energy management deals with the process of managing energy resources by means of controlling the battery discharge...