MITIGATING INTERFERENCE TO GPS OPERATION USING VARIABLE FORGETTING FACTOR BASED RECURSIVE LEAST SQUARES ESTIMATION

Aseel AlRikabi and Taher AlSharabati 

Al-Ahliyya Amman University/Electronics and Communications Engineering Department, Jordan

ABSTRACT 

In this paper, an interference method based on signal processing is proposed. The approach is based on utilizing the maximum likelihood properties of the received signal. The approach is built on maximizing the probability of the desired data. The GPS data, which is constructed using Binary Phase Shift Keying (BPSK) modulation, is transmitted as “1’s” and as “0’s.” carried on 1575.42MHz carrier called the L1 frequency. The statistics of the GPS data and interference are utilized in terms of their distribution and variance. The statistics are used to update (adaptively) the forgetting factor (Lambda) of the Recursive Least Squares (RLS) filter. The proposed method is called Maximum Likelihood Variable Forgetting Factor (ML VFF). The adaptive update takes on assigning lambda to the maximum of the probabilities of the symbols based on the statistics mentioned. 

KEYWORDS 

Global Positioning System GPS, Recursive Least Squares (RLS) algorithm, Forgetting Factor (λ), interference, OTA carrier  

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THE EFFECT OF SEEKING OPERATION ON QOE OF HTTP ADAPTIVE STREAMING SERVICES

Toshiro Nunome and Hiroaki Tani1 

1Graduate School of Engineering, Nagoya Institute of Technology, Nagoya, Japan 

ABSTRACT 

In this paper, we assess multidimensional QoE (Quality of Experience) of HTTP-based streaming services in seeking operation to evaluate the effect of two transmission schemes: adaptive bitrate streaming and progressive download. We perform a subjective experiment with two contents and various network load conditions. In the experiment, subjects find pre-specified scenes by means of seeking the video as they want to see the scenes right now. We also perform the principal component analysis for the assessment result of multidimensional QoE. We then find that the adaptive bitrate streaming is not necessarily effective for QoE enhancement; the effectiveness of the scheme depends on the usage of the system and network conditions. 

KEYWORDS

 Audio and Video Transmission, QoE, Adaptive Bitrate Streaming, Progressive Download 

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DELAY-POWER PERFORMANCE COMPARISON OF MULTIPLIERS IN VLSI CIRCUIT DESIGN

 Sumit Vaidya1 and Deepak Dandekar2
1Department of Electronic & Telecommunication Engineering, OM College of Engineering, Wardha, Maharashtra, India
2Department of Electronic Engineering, B. D. College of Engineering, Wardha, Maharashtra, India

 Abstract

A typical processor central processing unit devotes a considerable amount of processing time in performing arithmetic operations, particularly multiplication operations. Multiplication is one of the basic arithmetic operations and it requires substantially more hardware resources and processing time than addition and subtraction. In fact, 8.72% of all the instruction in typical processing units is multiplication. In this paper, comparative study of different multipliers is done for low power requirement and high speed. The paper gives information of “Urdhva Tiryakbhyam” algorithm of Ancient Indian Vedic Mathematics which is utilized for multiplication to improve the speed, area parameters of multipliers. Vedic Mathematics suggests one more formula for multiplication of large number i.e. “Nikhilam Sutra” which can increase the speed of multiplier by reducing the number of iterations. 

Keywords 

Multiplier, Vedic Mathematics, VLSI design 

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THE QUANTIZED DIFFERENTIAL COMPARATOR IN FLASH ANALOG TO DIGITAL CONVERTER DESIGN

Meghana Kulkarni1 , V. Sridhar2 , G.H.Kulkarni3

 1Asst.Prof., E & C Dept, Gogte Institute of Technology, Bgm, Karnataka, India. 

2 Principal, P.E.S. College of Engineering, Mandya, Karnataka, India. 

 3 Prof and Head, E & E Dept, Gogte Institute of Technology, Bgm, Karnataka, India 

ABSTRACT 

This paper proposes a Flash Analog to Digital Convsrter design based on the use of a Quantized Differential Comparator. The formulation explores the use of a systematically incorporated input offset voltage in a differential amplifier for quantizing the reference voltages necessary for Flash ADC architectures, thus eliminating the need for a passive resistor array for the purpose. This work is an attempt to extend the TIQ method, which uses systematic sizing of devices in a conventional CMOS inverter to accomplish the same. The formulation allows very small voltage comparison and complete elimination of resistor ladder circuit. The design has been carried out for the TSMC 0.18u technology at MOSIS. 

 KEYWORDS

 TIQ, Analog to Digital Converter.




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A 60 GHZ ANALOG PHASE SHIFTER IN 65 NM BULK CMOS PROCESS

 ETB.Samuel Jigme Harrison and Zhang Yue Ping 

Department of Electrical and Electronic Engineering, Nanyang Technological University, Singapore - 639798 

 ABSTRACT 

A 60 GHz Analog Phase Shifter in 65nm bulk CMOS process has been explored for microwave frequency applications. It is an analog phase shifter with three transistors in the form of an active circulator and a LC network to attain the desired phase shift. This phase shifter is designed to work at a high frequency of 60 GHz to attain phase shift range of 140o . The proposed phase shifter works at supply voltage lower than 2.5 V. The phase shifter exhibits low insertion loss of 3.73 dB and low power consumption which is a challenging result for circuits working in microwave frequencies. 

KEYWORDS 

60 GHz phase shifter, 65 nm CMOS, Active circulator


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COMPARATIVE INVESTIGATION FOR ENERGY CONSUMPTION OF DIFFERENT CHIPSETS BASED ON SCHEDULING FOR WIRELESS SENSOR NETWORKS

 Monica1 and Ajay K Sharma2 

Department of Computer Science and Engineering, Dr B R Ambedkar National Institute of Technology, Jalandhar, Punjab 

ABSTRACT 

Rapid progress in microelectromechanical system (MEMS) and radio frequency (RF) design has enabled the development of low-power, inexpensive, and network-enabled microsensors. These sensor nodes are capable of capturing various physical information, such as temperature, pressure, motion of an object, etc as well as mapping such physical characteristics of the environment to quantitative measurements. A typical wireless sensor network (WSN) consists of hundreds to thousands of such sensor nodes linked by a wireless medium. In this paper, we present a comparative investigation of energy consumption for few commercially available chipsets such as TR1001, CC1000 and CC1010 based on different scheduling methods for two types of deployment strategies. We conducted our experiment within the OMNeT++ simulator. 

Keywords 

 Wireless Sensor Networks, Scheduling Methods, Deployment, OMNeT++.

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A Cluster Based Replication Architecture for Load Balancing in Peer-to-Peer Content Distribution

S.Ayyasamy1 and S.N. Sivanandam2

 1Asst. Professor, Department of Information Technology, Tamilnadu College of Engineering Coimbatore-641 659, Tamil Nadu, INDIA. 

 2 Professor and Head, Department of Computer Science and Engineering, PSG College of Technology, Peelamedu, Coimbatore-641 004, Tamil Nadu, INDIA. 

Abstract

 In P2P systems, large volumes of data are declustered naturally across a large number of peers. But it is very difficult to control the initial data distribution because every user has the freedom to share any data with other users. The system scalability can be improved by distributing the load across multiple servers which is proposed by replication. The large scale content distribution systems were improved broadly using the replication techniques. The demanded contents can be brought closer to the clients by multiplying the source of information geographically, which in turn reduce both the access latency and the network traffic. In addition to this, due to the intrinsic dynamism of the P2P environment, static data distribution cannot be expected to guarantee good load balancing. If the hot peers become bottleneck, it leads to increased user response time and significant performance degradation of the system. Hence an effective load balancing mechanism is necessary in such cases and it can be attained efficiently by intelligent data replication. In this paper, we propose a cluster based replication architecture for load-balancing in peer-to-peer content distribution systems. In addition to an intelligent replica placement technique, it also consists of an effective load balancing technique. In the intelligent replica placement technique, peers are grouped into strong and weak clusters based on their weight vector which comprises available capacity, CPU speed, access latency and memory size. In order to achieve complete load balancing across the system, an intracluster and inter-cluster load balancing algorithms are proposed. We are able to show that our proposed architecture attains less latency and better throughput with reduced bandwidth usage, through the simulation results. 

Keywords 

Replica, Overlay, Clusters, QoS, Content, Routing


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Binary Location-Search Based Scalable Routing Protocol For Ad Hoc Networks

 Anuradha Banerjee1 and Paramartha Dutta2 

1Department of Computer Applications, Kalyani Govt. Engg. College, Nadia, West Bengal, India 2Visva-Bharati University, Santiniketan, West Bengal, India

ABSTRACT 

In this article, we present a binary location search based scalable routing protocol (BinLS) for ad hoc networks. It is completely distributed and based on a location management strategy that keeps the overhead of routing packets significantly small. The network is divided into some equal sized rectangular grid cells. Each node is assigned a home grid cell from where it starts its activity (transmission, reception and forwarding of messages). Nodes residing near the periphery of respective grid cells store information about all nodes present in the cell. Simulation results and detailed mathematical analysis of BinLS emphasize its merit compared to other schemes addressing the issue of scalability in ad hoc networks. 

KEYWORDS 

Ad hoc network, binary search, grid cell, routing, scalability.


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Performance Evaluation of an OMPR Algorithm for Route Discovery in Noisy MANETs

Hussein Al-Bahadili and Rami Jaradat

 The Arab Academy for Banking & Financial Sciences, Jordan

 2 The Hashemite University, Jordan

 ABSTRACT 

It has been revealed in the literature that pure multipoint relaying (MPR) algorithms demonstrate both simplicity and outstanding performance, as compared to other flooding algorithms in wireless networks. One drawback of pure MPR algorithms is that the selected forwarding set may not represent the optimum selection. In addition, little efforts have been carried-out to investigate the performance of such algorithms in noisy mobile ad hoc networks (MANETs) suffering from high packet-loss and node mobility. In this paper, we develop and evaluate the performance of an optimal MPR (OMPR) algorithm for route discovery in noisy MANETs. The main feature of this new algorithm is that it calculates all possible sets of multipoint relays (MPRs) and then selects the set with minimum number of nodes. The algorithm demonstrates an excellent performance when it is compared with other route discovery algorithms as it achieves the highest cost-effective reachability. 

KEYWORDS

Multipoint Relaying Algorithms, MANETs, Routing Protocols, Route Discovery, Flooding Techniques.  

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Hybrid Coding Gain and Hybrid ARQ Based on Conception of Majority Voting

 Hsin-Kun Lai and Erl-Huei Lu

 Chin Min Institute of Technology, Chang Gung University No. 110, Syuefu Rd., Toufen Township, Miaoli County, Taiwan 351, R.O.C. 259 Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan, Taiwan 333, R.O.C. 

Abstract. 

Based on the conception of majority voting, a hybrid ARQ scheme for binary linear block codes over AWGN channel is presented. At each transmission, the received word is kept in memory buffers if errors are detected. If there are still errors after a number of transmissions, the re-transmission stops to improve the throughput efficiency. From the received words, the decoding process of proposed hybrid ARQ first determines each bit as 1 or 0 based on the majority of the corresponding bits in the received words. The word resulting from voting is then decoded by algebraic decoder as the output code word. Simulation results show that the proposed hybrid ARQ scheme outperforms ARQ scheme in both error-correcting performance and throughput efficiency, particularly under low SNR. Additionally, a criterion in terms of throughput and coding gain is proposed for overall evaluation of hybrid ARQ schemes compared to that of ARQ scheme. Comparisons between plurality-based hybrid ARQ and majority-based hybrid ARQ are also made on the basis of proposed hybrid coding gain. 

Keywords:

hybrid ARQ, throughput, majority voting, coding gain.  

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A PORTAL SYSTEM AND ITS APPLICATION BASED ON DACS WEB SERVICE

 Kazuya Odagiri¹ , Naohiro Ishii² , Rihito Yaegashi³ and Masaharu Tadauchi 

1Advanced Institute of Industrial Technology, Japan, 2Aichi Institute of Technology, Japan, 3Shibaura Institute of Technology, Japan, 4Toyota Technological Institute, Japan

ABSTRACT

 DACS (Destination Addressing Control System) Scheme is developed as a new network management scheme. DACS Scheme performs the network management and services efficiently by communication control of client computers. Through the communication control, a whole network is managed. In the network with DACS Scheme, new network services and information systems are realized. As examples of those, we have developed a new portal system and DACS Web Service. DACS Web Service is a network service for realizing a portal system where each user can create the customized Web page as Personal Portal freely and easily. We show the proposed portal system and its application based on DACS Web Service. 

KEYWORDS 

Personal Portal, DACS Scheme, Web Service, CGI

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Using DSR for Routing Multimedia Traffic in MANETs

Ronald Beaubrun and Badji Molo 

Department of Computer sciences and software engineering Laval University Québec (Québec), G1K 7P4 CANADA 

Abstract 

In mobile ad hoc networks (MANETs), links are created and destroyed in an unpredictable way, which makes quite challenging the determination of routes between each pair of nodes. In this paper, we propose a formulation of the routing problem in multi-services MANETs, as well as the implementation of an adaptation of the dynamic source routing (DSR) protocol. Simulation results reveal that DSR enables to provide end-to-end delay less than 0.11 s, as well as packet delivery ratio higher than 99% and normalized routing load less than 13%, for low mobility level and low traffic intensity. 

Keywords

DSR, MANET, Multimedia traffic, routing.


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SEMANTIC ASSOCIATION-BASED SEARCH AND VISUALIZATION METHOD ON THE SEMANTIC WEB PORTAL

Myungjin Lee , Wooju Kim , June Seok Hong and Sangun Park 

1Dept. of Information and Industrial Engineering, Yonsei University, Seoul, Korea 

2Division of Business Administration, Kyonggi University, Kyonggi, Korea

ABSTRACT 

As the information on the web dramatically increases, the existing web reveals more and more limitations in information search because web pages are designed only for human consumption by mixing content with presentation. In order to improve this situation, the Semantic Web based on ontology comes on the stage by W3C, and it will bring a significant advancement in web search. To do this, the Semantic Web must provide novel search and visualization methods which can help users instantly and intuitively understand why and how the results are retrieved. In this paper, we propose a semantic associationbased search methodology that consists of how to find relevant information for a given user’s query in the ontology, that is, a semantic network of resources and properties, and how to provide proper visualization and navigation methods on the results. From this work, users can search the semantically associated resources with their query and also navigate such associations between resources.

KEYWORDS

Semantic Web, Semantic Web Portal, Ontology, Ontology Retrieval, Semantic Search, Semantic Visualization



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Key technologies for distributed wireless networking and ECMA-368 MAC layer LSI design challenges

Kazuyuki Sakoda, Yuichi Morioka, Chihiro Fujita, Erica Tanimoto, Kenzoh Nishikawa, Mitsuhiro Suzuki 

Communication Technology Lab., System Technologies Labs., Sony Corporation 5-1-12 Kitashinagawa Shinagawa-ku, Tokyo, 141-0001 Japan 

Abstract.

Distributed wireless networking enables opportunistic operation of personal area networks (PANs). In PAN scenario, it is desirable that each device can establish a wireless connection among devices near by, without a help of access point (AP) or central coordinator. Distributed Media Access Control (MAC) is one of the key technologies enabling distributed wireless networking, and WiMedia Alliance worked on the specification of distributed wireless networking technologies. The specifications developed by WiMedia Alliance were standardized published as ECMA- 368 – High Rate Ultra Wideband PHY and MAC Standard, and ECMA-369 – MAC-PHY Interface for ECMA-368. This paper introduces the technology overview of ECMA-368 MAC and the MAC LSI design challenges. This MAC LSI is intended to offer a generic communication platform to meet various application needs, and was certified to be compliant to the specification by WiMedia. The MAC design includes not only standardized protocol set, but also some additional enhancement features to achieve better performance or to meet certain application requirements. 

Keywords:

WiMedia, UWB, MAC, ECMA-368, ECMA-369, adhoc network, PAN, Superframe, Beacon Period, DRP, PCA, Block ACK, LSI, ECMA-387.  

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