Pub Date : 2011-03-17DOI: 10.1109/NCC.2011.5734701
A. Deshmukh, M. Parulekar, S. Kadam, A. Kadam, K. P. Ray
Commonly used technique to realize broadband microstrip antenna is by cutting the slots at an appropriate position inside the patch. The slot introduces a mode near the fundamental mode of the patch and yields broadband response. The bandwidth of an E-shaped microstrip antenna is further increased by cutting the pair of rectangular slots on one of its edge. This increase in bandwidth is due to another mode introduced by additional pair of slots. In this paper, modal variations, for this modified E-shaped antenna are studied. It has been observed that the slot affects the resonance frequency of higher order mode, which along with modes of E-shaped patch, realize higher bandwidth. Also the broadband proximity fed variation of modified E-shaped antenna in 950 MHz frequency range is proposed. This antenna gives a larger BW of 47% with broadside radiation pattern with a peak gain of approximately 10 dBi.
{"title":"Broadband proximity fed modified E-shaped microstrip antenna","authors":"A. Deshmukh, M. Parulekar, S. Kadam, A. Kadam, K. P. Ray","doi":"10.1109/NCC.2011.5734701","DOIUrl":"https://doi.org/10.1109/NCC.2011.5734701","url":null,"abstract":"Commonly used technique to realize broadband microstrip antenna is by cutting the slots at an appropriate position inside the patch. The slot introduces a mode near the fundamental mode of the patch and yields broadband response. The bandwidth of an E-shaped microstrip antenna is further increased by cutting the pair of rectangular slots on one of its edge. This increase in bandwidth is due to another mode introduced by additional pair of slots. In this paper, modal variations, for this modified E-shaped antenna are studied. It has been observed that the slot affects the resonance frequency of higher order mode, which along with modes of E-shaped patch, realize higher bandwidth. Also the broadband proximity fed variation of modified E-shaped antenna in 950 MHz frequency range is proposed. This antenna gives a larger BW of 47% with broadside radiation pattern with a peak gain of approximately 10 dBi.","PeriodicalId":158295,"journal":{"name":"2011 National Conference on Communications (NCC)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115566565","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 : 2011-03-17DOI: 10.1109/NCC.2011.5734725
Kh. Playtoni Meetei, A. George
Handoff management is a key element in mobile networks to sustain an ongoing session of a user. In this paper, we propose a handoff management technique to reduce handoff delay and call dropping. This handoff management technique incorporates a prediction component which will predict a UE's next cell and best handoff time. The prediction component is realized using a predictive model which uses earlier recorded mobility pattern of a user to make the prediction. Neural Network (Multi-layer Feedforward Network) has been used as predictive model. A data cleaning component is added using sequence mining technique to filter only relevant patterns from a large raw data to input to the predictive model. This process significantly improves the prediction accuracy and reduces the computational complexity involved with MFNN.
{"title":"Handoff management in wireless networks using predictive modelling","authors":"Kh. Playtoni Meetei, A. George","doi":"10.1109/NCC.2011.5734725","DOIUrl":"https://doi.org/10.1109/NCC.2011.5734725","url":null,"abstract":"Handoff management is a key element in mobile networks to sustain an ongoing session of a user. In this paper, we propose a handoff management technique to reduce handoff delay and call dropping. This handoff management technique incorporates a prediction component which will predict a UE's next cell and best handoff time. The prediction component is realized using a predictive model which uses earlier recorded mobility pattern of a user to make the prediction. Neural Network (Multi-layer Feedforward Network) has been used as predictive model. A data cleaning component is added using sequence mining technique to filter only relevant patterns from a large raw data to input to the predictive model. This process significantly improves the prediction accuracy and reduces the computational complexity involved with MFNN.","PeriodicalId":158295,"journal":{"name":"2011 National Conference on Communications (NCC)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124508621","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 : 2011-03-17DOI: 10.1109/NCC.2011.5734761
O. P. Acharya, A. Patnaik, B. Choudhury
Task of finding position and level of fault in antenna arrays from its far field pattern information is formulated as an optimization problem and solved using bacteria foraging optimization (BFO) technique. A Chebyshev array of specific sidelobe level is taken as the candidate antenna and the developed formulation is tested on it. Several different combinations of failures were considered in this work and successfully traced using the developed methodology. Although developed for a linear array, the principle can easily be extended for a planar array.
{"title":"Fault finding in antenna arrays using bacteria foraging optimization technique","authors":"O. P. Acharya, A. Patnaik, B. Choudhury","doi":"10.1109/NCC.2011.5734761","DOIUrl":"https://doi.org/10.1109/NCC.2011.5734761","url":null,"abstract":"Task of finding position and level of fault in antenna arrays from its far field pattern information is formulated as an optimization problem and solved using bacteria foraging optimization (BFO) technique. A Chebyshev array of specific sidelobe level is taken as the candidate antenna and the developed formulation is tested on it. Several different combinations of failures were considered in this work and successfully traced using the developed methodology. Although developed for a linear array, the principle can easily be extended for a planar array.","PeriodicalId":158295,"journal":{"name":"2011 National Conference on Communications (NCC)","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121689449","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 : 2011-03-17DOI: 10.1109/NCC.2011.5734722
S. Sameer, V. P. Thafasal Ijyas
This paper addresses the issue of joint maximum-likelihood (ML) estimation of carrier frequency offset (CFO), timing error and channel response for OFDMA uplink transmissions. A pilot preamble-based approach is proposed that makes use of the concept of signal decomposition. Earlier works have demonstrated that it is possible to decompose the multidimensional optimization involved in this joint estimation into a series of one-dimensional searches. The alternating projection (AP) algorithm is effectively used to determine the ML solution to this problem in many earlier works. In this work, we propose a new method of signal decomposition that can be combined with the conventional AP method to arrive at better parameter estimates. It achieves better performance in lesser number of estimation cycles and hence with lesser computational load. Another advantage is that it offers the flexibility of application to any generalized subcarrier assignment scheme in OFDMA systems. The performance advantages of this new method are substantiated through simulation studies.
{"title":"A joint ML estimation technique for timing, CFO and channel for OFDMA uplink transmissions","authors":"S. Sameer, V. P. Thafasal Ijyas","doi":"10.1109/NCC.2011.5734722","DOIUrl":"https://doi.org/10.1109/NCC.2011.5734722","url":null,"abstract":"This paper addresses the issue of joint maximum-likelihood (ML) estimation of carrier frequency offset (CFO), timing error and channel response for OFDMA uplink transmissions. A pilot preamble-based approach is proposed that makes use of the concept of signal decomposition. Earlier works have demonstrated that it is possible to decompose the multidimensional optimization involved in this joint estimation into a series of one-dimensional searches. The alternating projection (AP) algorithm is effectively used to determine the ML solution to this problem in many earlier works. In this work, we propose a new method of signal decomposition that can be combined with the conventional AP method to arrive at better parameter estimates. It achieves better performance in lesser number of estimation cycles and hence with lesser computational load. Another advantage is that it offers the flexibility of application to any generalized subcarrier assignment scheme in OFDMA systems. The performance advantages of this new method are substantiated through simulation studies.","PeriodicalId":158295,"journal":{"name":"2011 National Conference on Communications (NCC)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126181565","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 : 2011-03-17DOI: 10.1109/NCC.2011.5734735
Vaishali Patil, P. Rao
Aspiration is an important phonemic feature in several Indian languages. Unlike English, languages such as Marathi have lexicons in which words with different meanings differ only in the aspiration feature of the initial voiced or unvoiced stop. Thus the reliable discrimination of aspirated stops from their unaspirated counterparts is important in automatic speech recognition for such languages. The important acoustic distinctions include durational features as well as fine spectral structure features. Traditional frame-based spectral representations such as MFCCs used in HMM-based recognizers do not explicitly encode these cues. In this work, we explore various acoustic features for aspiration detection in voiced and unvoiced stops of Marathi. Enhancements to available methods of aspiration detection borrowed from voice quality measures are found to provide improved detection of phonemic aspiration in stops. The performance of a landmark-based acoustic feature classifier is compared with MFCC-HMM baseline system for the recognition of aspirated and unaspirated stops.
{"title":"Acoustic features for detection of aspirated stops","authors":"Vaishali Patil, P. Rao","doi":"10.1109/NCC.2011.5734735","DOIUrl":"https://doi.org/10.1109/NCC.2011.5734735","url":null,"abstract":"Aspiration is an important phonemic feature in several Indian languages. Unlike English, languages such as Marathi have lexicons in which words with different meanings differ only in the aspiration feature of the initial voiced or unvoiced stop. Thus the reliable discrimination of aspirated stops from their unaspirated counterparts is important in automatic speech recognition for such languages. The important acoustic distinctions include durational features as well as fine spectral structure features. Traditional frame-based spectral representations such as MFCCs used in HMM-based recognizers do not explicitly encode these cues. In this work, we explore various acoustic features for aspiration detection in voiced and unvoiced stops of Marathi. Enhancements to available methods of aspiration detection borrowed from voice quality measures are found to provide improved detection of phonemic aspiration in stops. The performance of a landmark-based acoustic feature classifier is compared with MFCC-HMM baseline system for the recognition of aspirated and unaspirated stops.","PeriodicalId":158295,"journal":{"name":"2011 National Conference on Communications (NCC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131099225","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 : 2011-03-17DOI: 10.1109/NCC.2011.5734702
M.Z.A. Khan
In this paper we derive conditions under which Spatio-temporal power allocation provides exponential diversity when the quality of channel state information at the transmitter (CSIT) and receiver (CSIR) degrades. We show that exponential diversity is obtained provided two conditions are satisfied; 1)the feedback rate increases linearly with the signal-to-noise ratio (SNR) and 2) the channel estimate is obtained at a transmit power greater than or equal to the power to be allocated. Simulation results, corroborating the theoretical analysis are presented for Rayleigh fading channels.
{"title":"Achieving exponential diversity with spatiotemporal power allocation with imperfect channel state information","authors":"M.Z.A. Khan","doi":"10.1109/NCC.2011.5734702","DOIUrl":"https://doi.org/10.1109/NCC.2011.5734702","url":null,"abstract":"In this paper we derive conditions under which Spatio-temporal power allocation provides exponential diversity when the quality of channel state information at the transmitter (CSIT) and receiver (CSIR) degrades. We show that exponential diversity is obtained provided two conditions are satisfied; 1)the feedback rate increases linearly with the signal-to-noise ratio (SNR) and 2) the channel estimate is obtained at a transmit power greater than or equal to the power to be allocated. Simulation results, corroborating the theoretical analysis are presented for Rayleigh fading channels.","PeriodicalId":158295,"journal":{"name":"2011 National Conference on Communications (NCC)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130043260","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 : 2011-03-17DOI: 10.1109/NCC.2011.5734746
Ravi Kiran, K. Ramakrishnan, Y. Senthil Kumar, Anoop K
This paper describes a novel approach to the connected component labeling problem, derived from two fast labeling algorithms, Wu et al. and Park et al. We propose a method that improves over existing divide and conquer methods. We propose two new methods - First, hierarchical (coarse to fine) label propagation from various sub images. Second, the recursive boundary labeling method is only one neighbor based and thus is 4–6 times faster than the conventional 8 neighborhood scan. We study the theoretical labeling performance and speedup.
{"title":"An improved connected component labeling by recursive label propagation","authors":"Ravi Kiran, K. Ramakrishnan, Y. Senthil Kumar, Anoop K","doi":"10.1109/NCC.2011.5734746","DOIUrl":"https://doi.org/10.1109/NCC.2011.5734746","url":null,"abstract":"This paper describes a novel approach to the connected component labeling problem, derived from two fast labeling algorithms, Wu et al. and Park et al. We propose a method that improves over existing divide and conquer methods. We propose two new methods - First, hierarchical (coarse to fine) label propagation from various sub images. Second, the recursive boundary labeling method is only one neighbor based and thus is 4–6 times faster than the conventional 8 neighborhood scan. We study the theoretical labeling performance and speedup.","PeriodicalId":158295,"journal":{"name":"2011 National Conference on Communications (NCC)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126858439","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 : 2011-03-17DOI: 10.1109/NCC.2011.5734729
K. Nataraj, J. Jagbandhu, P. C. Pandey, M. Shah
Estimation of the vocal tract shape has applications in articulatory synthesis, speech recognition, and speech-training aids. LPC based analysis can be used to obtain the vocal tract shape during speech segments produced with glottal excitation and with fixed as well as transitional tract configurations. During the stop closures of vowel-consonant-vowel (VCV) utterances, the shape can be estimated by bivariate surface modeling of the shapes during transition segments. The shape obtained by LPC analysis of steady vowels shows variability with the position of the analysis frame. Low-pass filtering of the shapes across the frames for improving the consistency cannot be used during transition segments. A windowed energy index is calculated as the ratio of the energy of the windowed signal to the frame energy, and it is shown that the shapes in the frames corresponding to the valleys in this index have a reduced variability. Thus the selection of the frames based on this index can be used for improving the consistency of vocal tract shape estimation for various applications.
{"title":"Improving the consistency of vocal tract shape estimation","authors":"K. Nataraj, J. Jagbandhu, P. C. Pandey, M. Shah","doi":"10.1109/NCC.2011.5734729","DOIUrl":"https://doi.org/10.1109/NCC.2011.5734729","url":null,"abstract":"Estimation of the vocal tract shape has applications in articulatory synthesis, speech recognition, and speech-training aids. LPC based analysis can be used to obtain the vocal tract shape during speech segments produced with glottal excitation and with fixed as well as transitional tract configurations. During the stop closures of vowel-consonant-vowel (VCV) utterances, the shape can be estimated by bivariate surface modeling of the shapes during transition segments. The shape obtained by LPC analysis of steady vowels shows variability with the position of the analysis frame. Low-pass filtering of the shapes across the frames for improving the consistency cannot be used during transition segments. A windowed energy index is calculated as the ratio of the energy of the windowed signal to the frame energy, and it is shown that the shapes in the frames corresponding to the valleys in this index have a reduced variability. Thus the selection of the frames based on this index can be used for improving the consistency of vocal tract shape estimation for various applications.","PeriodicalId":158295,"journal":{"name":"2011 National Conference on Communications (NCC)","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127710255","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 : 2011-03-17DOI: 10.1109/NCC.2011.5734766
S. Sreekumaran, K. Sivalingam
Tracking mobile targets is an important wireless sensor network application in both military and civilian fields. Often, it may be necessary for sending additional resources to the vicinity of the mobile target. In such a scenario, it is pertinent to provide continuous guidance to the friendly resource moving towards the mobile target. This paper presents a mechanism for the guidance of a friendly object towards the mobile target, and associated performance analysis in terms of the time taken to reach the target.
{"title":"Guided navigation of friendly object towards mobile target in wireless sensor networks","authors":"S. Sreekumaran, K. Sivalingam","doi":"10.1109/NCC.2011.5734766","DOIUrl":"https://doi.org/10.1109/NCC.2011.5734766","url":null,"abstract":"Tracking mobile targets is an important wireless sensor network application in both military and civilian fields. Often, it may be necessary for sending additional resources to the vicinity of the mobile target. In such a scenario, it is pertinent to provide continuous guidance to the friendly resource moving towards the mobile target. This paper presents a mechanism for the guidance of a friendly object towards the mobile target, and associated performance analysis in terms of the time taken to reach the target.","PeriodicalId":158295,"journal":{"name":"2011 National Conference on Communications (NCC)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132348680","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 : 2011-03-17DOI: 10.1109/NCC.2011.5734726
B. Senthil
We analyze the frequency diversity of intercarrier interference (ICI) reduction methods in the presence of phase noise over multipath fading channels. Based on analysis, we propose an enhanced symmetric data conjugate (ESDC) method to exploit the frequency diversity in multipath fading channel. We derive carrier-to-interference ratio (CIR) expression of proposed ICI reduction scheme. The BER performance of the proposed system is compared with conventional ICI reduction methods such as adjacent data conjugate and symmetric data conjugate methods. Simulation results show that the proposed ICI reduction scheme provides an improvement in BER performance over a fading channel and it is also better than conventional ICI reduction techniques in the presence of ICI due to phase noise.
{"title":"An ICI reduction scheme with enhanced frequency diversity for OFDM systems","authors":"B. Senthil","doi":"10.1109/NCC.2011.5734726","DOIUrl":"https://doi.org/10.1109/NCC.2011.5734726","url":null,"abstract":"We analyze the frequency diversity of intercarrier interference (ICI) reduction methods in the presence of phase noise over multipath fading channels. Based on analysis, we propose an enhanced symmetric data conjugate (ESDC) method to exploit the frequency diversity in multipath fading channel. We derive carrier-to-interference ratio (CIR) expression of proposed ICI reduction scheme. The BER performance of the proposed system is compared with conventional ICI reduction methods such as adjacent data conjugate and symmetric data conjugate methods. Simulation results show that the proposed ICI reduction scheme provides an improvement in BER performance over a fading channel and it is also better than conventional ICI reduction techniques in the presence of ICI due to phase noise.","PeriodicalId":158295,"journal":{"name":"2011 National Conference on Communications (NCC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134032589","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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