Pub Date : 1997-12-17DOI: 10.1109/ICPWC.1997.655479
S. Mahil
In electronic communication, a high-order filter may be realized by a state-space realization. For implementation, a canonical form is useful. In this paper, a block-diagonal state-space realization is determined by using singular value decomposition. Certain parity-orthogonal transformations are determined first which are then employed to determine a block-diagonal realization of a high-order filter. The realization can be implemented as a parallel structure of second-order networks, and is always obtainable when the spectrum of the system matrix of the state-space description is separable into distinct groups relative to the modulus of the eigenvalues-not an unusual constraint in filters. The procedure avoids the use of eigenstructure routines which are not helpful for ill-conditioned matrices. Also, the parity-orthogonal transformations share some properties of orthogonal matrices; the inverse is obtainable from the transpose. The computations are, hence, simplified. The transformations and the procedure is demonstrated by an example.
{"title":"Computation of a block-diagonal realization of a high-order filter via singular value decomposition","authors":"S. Mahil","doi":"10.1109/ICPWC.1997.655479","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655479","url":null,"abstract":"In electronic communication, a high-order filter may be realized by a state-space realization. For implementation, a canonical form is useful. In this paper, a block-diagonal state-space realization is determined by using singular value decomposition. Certain parity-orthogonal transformations are determined first which are then employed to determine a block-diagonal realization of a high-order filter. The realization can be implemented as a parallel structure of second-order networks, and is always obtainable when the spectrum of the system matrix of the state-space description is separable into distinct groups relative to the modulus of the eigenvalues-not an unusual constraint in filters. The procedure avoids the use of eigenstructure routines which are not helpful for ill-conditioned matrices. Also, the parity-orthogonal transformations share some properties of orthogonal matrices; the inverse is obtainable from the transpose. The computations are, hence, simplified. The transformations and the procedure is demonstrated by an example.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127578602","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 : 1997-12-17DOI: 10.1109/ICPWC.1997.655485
A. Kulshreshtha, K. Sivarajan
The maximum packing algorithm (MPA) is a greedy algorithm, that rejects a call only when it is forced to do so, even if this involves rearrangement of channels assigned to the ongoing calls, without dropping any of them. This paper mainly concentrates on the performance of this algorithm in terms of the total carried traffic. We model the channel reuse constraints in the cellular network by a hypergraph. Previously (1996) we demonstrated the optimality of MPA for low and moderate offered traffic in the system. In this paper, we envisage MPA as a practical channel assignment algorithm, for moderate sized systems, and suggest a good strategy to implement it. We comment on the complexity of the algorithm and suggest approximations to reduce it.
{"title":"Implementation of the maximum packing channel assignment algorithm in cellular networks","authors":"A. Kulshreshtha, K. Sivarajan","doi":"10.1109/ICPWC.1997.655485","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655485","url":null,"abstract":"The maximum packing algorithm (MPA) is a greedy algorithm, that rejects a call only when it is forced to do so, even if this involves rearrangement of channels assigned to the ongoing calls, without dropping any of them. This paper mainly concentrates on the performance of this algorithm in terms of the total carried traffic. We model the channel reuse constraints in the cellular network by a hypergraph. Previously (1996) we demonstrated the optimality of MPA for low and moderate offered traffic in the system. In this paper, we envisage MPA as a practical channel assignment algorithm, for moderate sized systems, and suggest a good strategy to implement it. We comment on the complexity of the algorithm and suggest approximations to reduce it.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127704010","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 : 1997-12-17DOI: 10.1109/ICPWC.1997.655566
A. Correia, F. Cercas
This work considers asynchronous DS-CDMA systems with single-user receivers. The focus, is on combined error control/PN sequence spreading. This work shows that the best performance is achieved when all the bandwidth expansion is by error control coding, instead of by PN sequences. This conclusion is valid for all types of fading channels. Comparisons of CDMA systems using different error control schemes are presented, keeping constant the total available bandwidth and the information rate. Both DBPSK and /spl pi//4 DQPSK modulation with noncoherent demodulation are analysed.
{"title":"On channel coding for CDMA over multipath Rayleigh fading channels","authors":"A. Correia, F. Cercas","doi":"10.1109/ICPWC.1997.655566","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655566","url":null,"abstract":"This work considers asynchronous DS-CDMA systems with single-user receivers. The focus, is on combined error control/PN sequence spreading. This work shows that the best performance is achieved when all the bandwidth expansion is by error control coding, instead of by PN sequences. This conclusion is valid for all types of fading channels. Comparisons of CDMA systems using different error control schemes are presented, keeping constant the total available bandwidth and the information rate. Both DBPSK and /spl pi//4 DQPSK modulation with noncoherent demodulation are analysed.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134513601","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 : 1997-12-17DOI: 10.1109/ICPWC.1997.655484
Ji-Won Jung, Myungsup Kim
A new simplified TCM decoding algorithm with parallel transition is proposed. Computation and speed of the algorithm are dominated by the number of add-compare-select operations and node number calculator operations. The proposed TCM decoder extends the scarce-station-type Viterbi decoder and path back method decoder. This paper shows that the proposed decoder is more efficient than any other conventional decoder by Monte-Carlo simulation in nonlinear satellite channels and non-selective Rician fading channels.
{"title":"The performance analysis of proposed decoder for TCM with 8-ary PSK signal in fading and satellite channel","authors":"Ji-Won Jung, Myungsup Kim","doi":"10.1109/ICPWC.1997.655484","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655484","url":null,"abstract":"A new simplified TCM decoding algorithm with parallel transition is proposed. Computation and speed of the algorithm are dominated by the number of add-compare-select operations and node number calculator operations. The proposed TCM decoder extends the scarce-station-type Viterbi decoder and path back method decoder. This paper shows that the proposed decoder is more efficient than any other conventional decoder by Monte-Carlo simulation in nonlinear satellite channels and non-selective Rician fading channels.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"216 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115510855","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 : 1997-12-17DOI: 10.1109/ICPWC.1997.655522
J. Nah, Jea-Hoon Yu, Yoonju Lee
In order to design an IMT-2000 exchange, we study why the ATM (asynchronous transfer mode) exchange among the current exchanges has to be a basis system in the view of the service capability and service application. For the purpose of adding mobility to an ATM exchange we research the configuration and interfaces of the integrated wired/wireless IMT-2000 exchange. We probe the function entities of the IMT-2000 reference model in the view of balancing of the functionality division, and what physical configuration scenario is appropriate. On the basis of the IMT-2000 functional model, we present the signaling protocol structure for ATM-based IMT-2000 exchange.
{"title":"A signaling transport structure for ATM-based IMT-2000 exchange","authors":"J. Nah, Jea-Hoon Yu, Yoonju Lee","doi":"10.1109/ICPWC.1997.655522","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655522","url":null,"abstract":"In order to design an IMT-2000 exchange, we study why the ATM (asynchronous transfer mode) exchange among the current exchanges has to be a basis system in the view of the service capability and service application. For the purpose of adding mobility to an ATM exchange we research the configuration and interfaces of the integrated wired/wireless IMT-2000 exchange. We probe the function entities of the IMT-2000 reference model in the view of balancing of the functionality division, and what physical configuration scenario is appropriate. On the basis of the IMT-2000 functional model, we present the signaling protocol structure for ATM-based IMT-2000 exchange.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"131 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115620397","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 : 1997-12-17DOI: 10.1109/ICPWC.1997.655491
I. Demirkiran, V.N.S. Samarasooriya, P. Varshney, Donald D. Weiner, R. Mani, S. H. Nawab, S. Tyler
A knowledge-based interference rejection scheme for removal of narrow band interference (NBI) in direct sequence spread-spectrum systems (DSSS) is presented. The interference rejection system monitors the environment and identifies the types of interference embedded in the DSSS signal. An accurate estimate of the characteristics of the NBI is obtained and is used to direct the subsequent interference rejection schemes. The system performance is illustrated by means of simulation results.
{"title":"A knowledge-based interference rejection scheme for direct sequence spread-spectrum systems","authors":"I. Demirkiran, V.N.S. Samarasooriya, P. Varshney, Donald D. Weiner, R. Mani, S. H. Nawab, S. Tyler","doi":"10.1109/ICPWC.1997.655491","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655491","url":null,"abstract":"A knowledge-based interference rejection scheme for removal of narrow band interference (NBI) in direct sequence spread-spectrum systems (DSSS) is presented. The interference rejection system monitors the environment and identifies the types of interference embedded in the DSSS signal. An accurate estimate of the characteristics of the NBI is obtained and is used to direct the subsequent interference rejection schemes. The system performance is illustrated by means of simulation results.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115849934","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 : 1997-12-17DOI: 10.1109/ICPWC.1997.655471
M. Zonoozi, P. Dassabayake
Improvements to handover performance have been investigated in terms of achieving less delay in handover decision making. An analytical approach has been developed to obtain handover delay in both microcells and macrocells.
{"title":"Handover delay in cellular systems","authors":"M. Zonoozi, P. Dassabayake","doi":"10.1109/ICPWC.1997.655471","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655471","url":null,"abstract":"Improvements to handover performance have been investigated in terms of achieving less delay in handover decision making. An analytical approach has been developed to obtain handover delay in both microcells and macrocells.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122994841","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 : 1997-12-17DOI: 10.1109/ICPWC.1997.655478
S. Ahmadi, A. Spanias
This paper addresses the design, development, evaluation, and implementation of efficient low bit rate speech coding algorithms based on the sinusoidal model. A series of algorithms have been developed for pitch frequency determination and voicing detection, simultaneous modeling of the sinusoidal amplitudes and phases, and mid-frame interpolation. An improved sinusoidal phase matching algorithm is presented, where short-time sinusoidal phases are approximated using an elaborate combination of linear prediction, spectral sampling, delay compensation, and phase correction techniques. A voicing-dependent perceptual split vector quantization scheme is used to encode the sinusoidal amplitudes. The perceptual properties of the human auditory system are effectively exploited in the developed algorithms. The algorithms have been successfully integrated into a 2.4 kbps sinusoidal coder. The performance of the 2.4 kbps coder has been evaluated in terms of subjective tests such as the mean opinion score and the diagnostic rhyme test, as well as some perceptually-motivated objective distortion measures. Performance analysis on a large speech database indicates that the use of the proposed algorithms resulted in considerable improvement in temporal and spectral signal matching, as well as improved subjective quality of the reproduced speech.
{"title":"New algorithms for sinusoidal speech coding at low bit rates","authors":"S. Ahmadi, A. Spanias","doi":"10.1109/ICPWC.1997.655478","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655478","url":null,"abstract":"This paper addresses the design, development, evaluation, and implementation of efficient low bit rate speech coding algorithms based on the sinusoidal model. A series of algorithms have been developed for pitch frequency determination and voicing detection, simultaneous modeling of the sinusoidal amplitudes and phases, and mid-frame interpolation. An improved sinusoidal phase matching algorithm is presented, where short-time sinusoidal phases are approximated using an elaborate combination of linear prediction, spectral sampling, delay compensation, and phase correction techniques. A voicing-dependent perceptual split vector quantization scheme is used to encode the sinusoidal amplitudes. The perceptual properties of the human auditory system are effectively exploited in the developed algorithms. The algorithms have been successfully integrated into a 2.4 kbps sinusoidal coder. The performance of the 2.4 kbps coder has been evaluated in terms of subjective tests such as the mean opinion score and the diagnostic rhyme test, as well as some perceptually-motivated objective distortion measures. Performance analysis on a large speech database indicates that the use of the proposed algorithms resulted in considerable improvement in temporal and spectral signal matching, as well as improved subjective quality of the reproduced speech.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121769034","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 : 1997-12-17DOI: 10.1109/ICPWC.1997.655534
W. Akihiko, K. Ikuo
This paper proposes a method for reducing burst errors in a wideband CDMA system under the radio propagation conditions. When high-speed mobile communication in a Rayleigh fading environment is assumed; fading at the maximum fading frequency occurs due to the moving speed, resulting in communication quality degradation by burst errors. We discuss the use of interleaving and repetition techniques in combination to reduce the number of burst errors. The effects of path diversity, power control and time diversity were evaluated as burst error reduction methods. The effect of the time diversity and repetition in an area involving little multipath and a high fading frequency, where the path diversity and transmission power control effects cannot be expected, are also evaluated.
{"title":"Study on wideband CDMA system in burst error environment","authors":"W. Akihiko, K. Ikuo","doi":"10.1109/ICPWC.1997.655534","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655534","url":null,"abstract":"This paper proposes a method for reducing burst errors in a wideband CDMA system under the radio propagation conditions. When high-speed mobile communication in a Rayleigh fading environment is assumed; fading at the maximum fading frequency occurs due to the moving speed, resulting in communication quality degradation by burst errors. We discuss the use of interleaving and repetition techniques in combination to reduce the number of burst errors. The effects of path diversity, power control and time diversity were evaluated as burst error reduction methods. The effect of the time diversity and repetition in an area involving little multipath and a high fading frequency, where the path diversity and transmission power control effects cannot be expected, are also evaluated.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"24 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130270935","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 : 1997-12-17DOI: 10.1109/ICPWC.1997.655528
C. Dhawan
We first describe the components of a wireless computing solution, review various wireless data networks, discuss the state-of-art of wireless computing technology, and mention the implementation challenges faced by the practitioners in the western world. Then, we explore the virgin state of wireless infrastructure and the need for innovative use of wireless computing applications in the developing countries. This highlights the differences in the requirements and the opportunities in the two sectors of the world. After explaining these differences, we explore the business opportunities that developing nations can exploit for their own use or to assist the developed countries. The focus of this paper is on wireless data applications across an enterprise and on end-to-end systems integration of various components-wireless networks, mobile end-user devices, communications software, and business applications software. This paper is aimed at network professionals, systems integration practitioners, as well as for the research community.
{"title":"Unique applications and opportunities in wireless computing in developing countries","authors":"C. Dhawan","doi":"10.1109/ICPWC.1997.655528","DOIUrl":"https://doi.org/10.1109/ICPWC.1997.655528","url":null,"abstract":"We first describe the components of a wireless computing solution, review various wireless data networks, discuss the state-of-art of wireless computing technology, and mention the implementation challenges faced by the practitioners in the western world. Then, we explore the virgin state of wireless infrastructure and the need for innovative use of wireless computing applications in the developing countries. This highlights the differences in the requirements and the opportunities in the two sectors of the world. After explaining these differences, we explore the business opportunities that developing nations can exploit for their own use or to assist the developed countries. The focus of this paper is on wireless data applications across an enterprise and on end-to-end systems integration of various components-wireless networks, mobile end-user devices, communications software, and business applications software. This paper is aimed at network professionals, systems integration practitioners, as well as for the research community.","PeriodicalId":166667,"journal":{"name":"1997 IEEE International Conference on Personal Wireless Communications (Cat. No.97TH8338)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122480085","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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