Pub Date : 2006-08-07DOI: 10.1109/WOCN.2006.1666556
M. Bhatnagar, R. Vishwanath
An iterative decoder is known for non time-selective MIMO channels only. We have modified the structure of the previously known iterative decoder so that it could work in the time-selective MIMO channels also. The performance results of this modified decoder are discussed and compared with the conventional training based approach in the paper
{"title":"Performance results of iterative decoder for time selective MIMO channels","authors":"M. Bhatnagar, R. Vishwanath","doi":"10.1109/WOCN.2006.1666556","DOIUrl":"https://doi.org/10.1109/WOCN.2006.1666556","url":null,"abstract":"An iterative decoder is known for non time-selective MIMO channels only. We have modified the structure of the previously known iterative decoder so that it could work in the time-selective MIMO channels also. The performance results of this modified decoder are discussed and compared with the conventional training based approach in the paper","PeriodicalId":275012,"journal":{"name":"2006 IFIP International Conference on Wireless and Optical Communications Networks","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132814531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-08-07DOI: 10.1109/WOCN.2006.1666609
S. Sengar, S. Joshi, S. Prasad
The use of orthogonal space time block codes (OSTBC) in conjunction with fractal modulation in the presence of frequency selective fading channels is considered. An L scale fractal modulation and coherent demodulation effectively converts the frequency selective channel into L flat fading channels per information symbol with random scale gains. The bit error performance analysis of the proposed scheme has been done. It has been shown that a diversity order of mTmRL can be achieved. This increase in diversity order in comparison with that achieved for the OFDM case is at a cost of lower spectral efficiency. The transceiver complexity is comparable with the IFFT/FFT operations used in case of OFDM
{"title":"Performance analysis of space time coded fractal modulation in the presence of frequency selective fading","authors":"S. Sengar, S. Joshi, S. Prasad","doi":"10.1109/WOCN.2006.1666609","DOIUrl":"https://doi.org/10.1109/WOCN.2006.1666609","url":null,"abstract":"The use of orthogonal space time block codes (OSTBC) in conjunction with fractal modulation in the presence of frequency selective fading channels is considered. An L scale fractal modulation and coherent demodulation effectively converts the frequency selective channel into L flat fading channels per information symbol with random scale gains. The bit error performance analysis of the proposed scheme has been done. It has been shown that a diversity order of mTmRL can be achieved. This increase in diversity order in comparison with that achieved for the OFDM case is at a cost of lower spectral efficiency. The transceiver complexity is comparable with the IFFT/FFT operations used in case of OFDM","PeriodicalId":275012,"journal":{"name":"2006 IFIP International Conference on Wireless and Optical Communications Networks","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132120347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-08-07DOI: 10.1109/WOCN.2006.1666598
Jyun-Yuan Cheng, S. Ruan, R. Cheng, Teng-Tai Hsu
The energy consumption is the most important issue in the wireless sensor network. In order to extend the lifetime of the wireless sensor network, clustering technique is considered as an effective way to achieve the power conservation, network scalability, and load balance. In this paper, we present a low energy clustering network architecture PADCP to prolong the network lifetime and to improve the performance of transceiver by adding several adaptive schemes: dynamic cluster range, dynamic transmission power, and cluster-heads re-election. Besides, our PADCP also improves the load balance when the sensor nodes are non-uniform dispersion. In addition, the mobility of the sensors is also taken into consideration in this paper. The experimental result proves that our proposed method is effective in saving power and load balance
{"title":"PADCP: power-aware dynamic clustering protocol for wireless sensor network","authors":"Jyun-Yuan Cheng, S. Ruan, R. Cheng, Teng-Tai Hsu","doi":"10.1109/WOCN.2006.1666598","DOIUrl":"https://doi.org/10.1109/WOCN.2006.1666598","url":null,"abstract":"The energy consumption is the most important issue in the wireless sensor network. In order to extend the lifetime of the wireless sensor network, clustering technique is considered as an effective way to achieve the power conservation, network scalability, and load balance. In this paper, we present a low energy clustering network architecture PADCP to prolong the network lifetime and to improve the performance of transceiver by adding several adaptive schemes: dynamic cluster range, dynamic transmission power, and cluster-heads re-election. Besides, our PADCP also improves the load balance when the sensor nodes are non-uniform dispersion. In addition, the mobility of the sensors is also taken into consideration in this paper. The experimental result proves that our proposed method is effective in saving power and load balance","PeriodicalId":275012,"journal":{"name":"2006 IFIP International Conference on Wireless and Optical Communications Networks","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126086251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-08-07DOI: 10.1109/WOCN.2006.1666585
I. Saha, L. K. Sambasivan, S.K. Ghosh, R. Patro
Topology control is an important problem in wireless ad-hoc sensor networks. The aim of the topology control is to maintain desired properties of the network topology to improve the performance of networking algorithms (e.g. routing). In this paper, we present a distributed algorithm for assigning minimum possible power to all the nodes in the wireless sensor networks, such that the network is K-connected. Extensive simulation has been performed to prove the optimality of the algorithm
{"title":"Distributed fault tolerant topology control in wireless ad-hoc sensor networks","authors":"I. Saha, L. K. Sambasivan, S.K. Ghosh, R. Patro","doi":"10.1109/WOCN.2006.1666585","DOIUrl":"https://doi.org/10.1109/WOCN.2006.1666585","url":null,"abstract":"Topology control is an important problem in wireless ad-hoc sensor networks. The aim of the topology control is to maintain desired properties of the network topology to improve the performance of networking algorithms (e.g. routing). In this paper, we present a distributed algorithm for assigning minimum possible power to all the nodes in the wireless sensor networks, such that the network is K-connected. Extensive simulation has been performed to prove the optimality of the algorithm","PeriodicalId":275012,"journal":{"name":"2006 IFIP International Conference on Wireless and Optical Communications Networks","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127826633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-08-07DOI: 10.1109/WOCN.2006.1666591
T. Srinath
In this paper, we provide a mechanism for the problem of localization in resource constrained sensor networks by extending the principles of in-range technique using a mobile beacon. The main advantage of this mechanism is that, it inherits all the advantages of in-range technique, eliminates the need to deploy beacons in the sensor network and satisfy the requirements of localization algorithms for the sensor networks. Location awareness of sensor nodes plays a critical role in most of the sensor network applications. Our mechanism assumes only a basic communication capability of sensor nodes and does not require any additional infrastructure. We employ a single mobile beacon equipped with a GPS receiver for localization. Each broadcast position of the mobile beacon acts as a stationary beacon at that point (known as a virtual beacon) thereby eliminating the need to deploy GPS equipped beacons in the sensor network. The motion of the mobile beacon localizes some of the sensor nodes, which in turn aid in localization of their neighbors using the iterative in-range technique. Simulation results are presented to evaluate the performance of the proposed mechanism. An implementation on sensor network of MICA2 motes is used to evaluate the functionality of the proposed algorithm
{"title":"Localization in resource constrained sensor networks using a mobile beacon with in-ranging","authors":"T. Srinath","doi":"10.1109/WOCN.2006.1666591","DOIUrl":"https://doi.org/10.1109/WOCN.2006.1666591","url":null,"abstract":"In this paper, we provide a mechanism for the problem of localization in resource constrained sensor networks by extending the principles of in-range technique using a mobile beacon. The main advantage of this mechanism is that, it inherits all the advantages of in-range technique, eliminates the need to deploy beacons in the sensor network and satisfy the requirements of localization algorithms for the sensor networks. Location awareness of sensor nodes plays a critical role in most of the sensor network applications. Our mechanism assumes only a basic communication capability of sensor nodes and does not require any additional infrastructure. We employ a single mobile beacon equipped with a GPS receiver for localization. Each broadcast position of the mobile beacon acts as a stationary beacon at that point (known as a virtual beacon) thereby eliminating the need to deploy GPS equipped beacons in the sensor network. The motion of the mobile beacon localizes some of the sensor nodes, which in turn aid in localization of their neighbors using the iterative in-range technique. Simulation results are presented to evaluate the performance of the proposed mechanism. An implementation on sensor network of MICA2 motes is used to evaluate the functionality of the proposed algorithm","PeriodicalId":275012,"journal":{"name":"2006 IFIP International Conference on Wireless and Optical Communications Networks","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124943667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-08-07DOI: 10.1109/WOCN.2006.1666620
A. Abbas, T. A. Abbasi
Design of disjoint multipath routing protocols in an ad hoc environment is a challenging task. In this paper, we discuss an analytical framework for disjoint multipath routing in mobile ad hoc networks. We analyze the probability that there exist k node disjoint paths between a pair of nodes. A major issue in the discovery of node disjoint paths is path diminution. We discuss the probability of path diminution in schemes commonly used to discover disjoint paths
{"title":"An analytical framework for disjoint multipath routing in mobile ad hoc networks","authors":"A. Abbas, T. A. Abbasi","doi":"10.1109/WOCN.2006.1666620","DOIUrl":"https://doi.org/10.1109/WOCN.2006.1666620","url":null,"abstract":"Design of disjoint multipath routing protocols in an ad hoc environment is a challenging task. In this paper, we discuss an analytical framework for disjoint multipath routing in mobile ad hoc networks. We analyze the probability that there exist k node disjoint paths between a pair of nodes. A major issue in the discovery of node disjoint paths is path diminution. We discuss the probability of path diminution in schemes commonly used to discover disjoint paths","PeriodicalId":275012,"journal":{"name":"2006 IFIP International Conference on Wireless and Optical Communications Networks","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131851596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-08-07DOI: 10.1109/WOCN.2006.1666659
S. Chandra, A. Vishnu Vardhanan, R. Gangopadhyay
Optical phase conjugation (OPC) and distributed Raman amplifier (DRA) combination (OPC-DRA) is demonstrated as a potential enabling solution for reduction of signal fading due to interplay of self-phase modulation and group velocity dispersion of a sub-carrier multiplexed (SCM) mm-wave radio-over-fiber (RoF) transmission link. The present work is focused on the use of OPC-DRA combination for system performance improvement in terms of carrier to noise ratio (CNR) and the bit error rate (BER) of the SCM-RoF link. The analysis further shows that, introduction of DRA with proper pumping scheme significantly reduce fiber non-linearity resulting in improvement of the system performance in terms of BER, compared to the situation where only mid-way optical phase conjugation is used
{"title":"Simultaneous dispersion and non-linearity compensation with OPC-DRA combination for a mm-wave radio-over-fiber transmission system","authors":"S. Chandra, A. Vishnu Vardhanan, R. Gangopadhyay","doi":"10.1109/WOCN.2006.1666659","DOIUrl":"https://doi.org/10.1109/WOCN.2006.1666659","url":null,"abstract":"Optical phase conjugation (OPC) and distributed Raman amplifier (DRA) combination (OPC-DRA) is demonstrated as a potential enabling solution for reduction of signal fading due to interplay of self-phase modulation and group velocity dispersion of a sub-carrier multiplexed (SCM) mm-wave radio-over-fiber (RoF) transmission link. The present work is focused on the use of OPC-DRA combination for system performance improvement in terms of carrier to noise ratio (CNR) and the bit error rate (BER) of the SCM-RoF link. The analysis further shows that, introduction of DRA with proper pumping scheme significantly reduce fiber non-linearity resulting in improvement of the system performance in terms of BER, compared to the situation where only mid-way optical phase conjugation is used","PeriodicalId":275012,"journal":{"name":"2006 IFIP International Conference on Wireless and Optical Communications Networks","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124627512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-08-07DOI: 10.1109/WOCN.2006.1666621
Xiaohui Xu, Xiaokang Lin
Based on the IEEE 802.11 distributed coordination function (DCF), a novel scheme named DCFf is proposed to improve the performance of wireless local area network (WLAN) in fading channel. An analytical model considering frame errors is presented to analyze the saturation throughput of DCF and DCFf. We explore the effect of frame errors, data rate and network size on the performance of both algorithms in the basic access mode. The analysis results show that our DCFf performs better than DCF in wireless fading channel
{"title":"Throughput enhancement of the IEEE 802.11 DCF in fading channel","authors":"Xiaohui Xu, Xiaokang Lin","doi":"10.1109/WOCN.2006.1666621","DOIUrl":"https://doi.org/10.1109/WOCN.2006.1666621","url":null,"abstract":"Based on the IEEE 802.11 distributed coordination function (DCF), a novel scheme named DCFf is proposed to improve the performance of wireless local area network (WLAN) in fading channel. An analytical model considering frame errors is presented to analyze the saturation throughput of DCF and DCFf. We explore the effect of frame errors, data rate and network size on the performance of both algorithms in the basic access mode. The analysis results show that our DCFf performs better than DCF in wireless fading channel","PeriodicalId":275012,"journal":{"name":"2006 IFIP International Conference on Wireless and Optical Communications Networks","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115078959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-08-07DOI: 10.1109/WOCN.2006.1666552
M. Bhatnagar, R. Vishwanath, M. Arti
In this paper we propose a novel blind estimator of frequency offsets in time varying MIMO channels. Space-Time data has a unique periodic property which has been discovered in this paper. This periodicity is utilized to derive a very efficient and simple blind estimator of the frequency offsets. This estimator provides far better estimates of the frequency offsets than the conventional data-aided estimator. As a result it enhances the performance of receiver to a large extent
{"title":"On blind estimation of frequency offsets in time varying MIMO channels","authors":"M. Bhatnagar, R. Vishwanath, M. Arti","doi":"10.1109/WOCN.2006.1666552","DOIUrl":"https://doi.org/10.1109/WOCN.2006.1666552","url":null,"abstract":"In this paper we propose a novel blind estimator of frequency offsets in time varying MIMO channels. Space-Time data has a unique periodic property which has been discovered in this paper. This periodicity is utilized to derive a very efficient and simple blind estimator of the frequency offsets. This estimator provides far better estimates of the frequency offsets than the conventional data-aided estimator. As a result it enhances the performance of receiver to a large extent","PeriodicalId":275012,"journal":{"name":"2006 IFIP International Conference on Wireless and Optical Communications Networks","volume":"6 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130641508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-08-07DOI: 10.1109/WOCN.2006.1666673
A.K. Das, P. Sahu
In this paper, we have demonstrated two mode interference (TMI) coupler using the material SiO2/SiON having index contrast (Deltan) of 2% and 5% and the corresponding compact beat lengths are observed as ~103 mum and ~50 mum, respectively. The reduction of the beat length with Deltan and the corresponding width of the coupling zone are analyzed and compared with the experimental results. We also analyzed the coupling coefficients for the TMI couplers and the directional couplers (DC) and observed that the coupling coefficient of a DC with small gap (les 0.02 mum) is same to that of a TMI coupler. We have demonstrated a DC with small gap (<1 mum) and Deltan of 2% and the corresponding beat length is ~207 mum. The wavelength multiplexing/demultiplexing using the TMI couplers is also discussed
{"title":"Compact integrated optical devices using high index contrast waveguides","authors":"A.K. Das, P. Sahu","doi":"10.1109/WOCN.2006.1666673","DOIUrl":"https://doi.org/10.1109/WOCN.2006.1666673","url":null,"abstract":"In this paper, we have demonstrated two mode interference (TMI) coupler using the material SiO2/SiON having index contrast (Deltan) of 2% and 5% and the corresponding compact beat lengths are observed as ~103 mum and ~50 mum, respectively. The reduction of the beat length with Deltan and the corresponding width of the coupling zone are analyzed and compared with the experimental results. We also analyzed the coupling coefficients for the TMI couplers and the directional couplers (DC) and observed that the coupling coefficient of a DC with small gap (les 0.02 mum) is same to that of a TMI coupler. We have demonstrated a DC with small gap (<1 mum) and Deltan of 2% and the corresponding beat length is ~207 mum. The wavelength multiplexing/demultiplexing using the TMI couplers is also discussed","PeriodicalId":275012,"journal":{"name":"2006 IFIP International Conference on Wireless and Optical Communications Networks","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133874442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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