Pub Date : 1993-11-01DOI: 10.1109/ACSSC.1993.342333
M. Dogan, J. Mendel
Cumulants can increase the effective aperture of an array, and they suppress non-Gaussian noise. Our earlier works showed these properties to be true for fourth-order cumulants. Here we show these properties are also true for third-order cumulants. We have done this because it is usually good practice to work with as lower an order cumulant as possible, if possible, in order to reduce cumulant estimation errors and to work with shorter data lengths. Our Virtual Cross-Correlation Computer (VC/sup 3/), which lets us compute cross-correlations and autocorrelations for all the sensors in an array, as well as for "virtual" sensors, using cumulants, is applicable to third- and fourth-order cumulants. It leads to increased aperture (much greater for fourth-order cumulants than for third-order cumulants), a virtual ESPRIT algorithm, and non-Gaussian noise suppression.<>
{"title":"Interpretation of cumulants for array processing","authors":"M. Dogan, J. Mendel","doi":"10.1109/ACSSC.1993.342333","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342333","url":null,"abstract":"Cumulants can increase the effective aperture of an array, and they suppress non-Gaussian noise. Our earlier works showed these properties to be true for fourth-order cumulants. Here we show these properties are also true for third-order cumulants. We have done this because it is usually good practice to work with as lower an order cumulant as possible, if possible, in order to reduce cumulant estimation errors and to work with shorter data lengths. Our Virtual Cross-Correlation Computer (VC/sup 3/), which lets us compute cross-correlations and autocorrelations for all the sensors in an array, as well as for \"virtual\" sensors, using cumulants, is applicable to third- and fourth-order cumulants. It leads to increased aperture (much greater for fourth-order cumulants than for third-order cumulants), a virtual ESPRIT algorithm, and non-Gaussian noise suppression.<<ETX>>","PeriodicalId":266447,"journal":{"name":"Proceedings of 27th Asilomar Conference on Signals, Systems and Computers","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128736558","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 : 1993-11-01DOI: 10.1109/ACSSC.1993.342607
A. Jaffer, W. Jones
In many signal processing applications, the need arises for the design of complex coefficient finite impulse response (FIR) filters to meet the specifications which cannot be approximated by real coefficient FIR filters. The paper presents a new technique for the design of complex FIR filters based on minimizing a weighted integral squared-error criterion subject to the constraint that the resulting filter response be affine phase (i.e., generalize linear phase), The technique makes use of the necessary and sufficient conditions for a causal complex FIR filter to possess affine phase which are explicitly derived in the present paper. The method is non-iterative and computationally efficient. Several illustrative filter design examples are presented with excellent results.<>
{"title":"Constrained least-squares design and characterization of affine phase complex FIR filters","authors":"A. Jaffer, W. Jones","doi":"10.1109/ACSSC.1993.342607","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342607","url":null,"abstract":"In many signal processing applications, the need arises for the design of complex coefficient finite impulse response (FIR) filters to meet the specifications which cannot be approximated by real coefficient FIR filters. The paper presents a new technique for the design of complex FIR filters based on minimizing a weighted integral squared-error criterion subject to the constraint that the resulting filter response be affine phase (i.e., generalize linear phase), The technique makes use of the necessary and sufficient conditions for a causal complex FIR filter to possess affine phase which are explicitly derived in the present paper. The method is non-iterative and computationally efficient. Several illustrative filter design examples are presented with excellent results.<<ETX>>","PeriodicalId":266447,"journal":{"name":"Proceedings of 27th Asilomar Conference on Signals, Systems and Computers","volume":"181 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116036406","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 : 1993-11-01DOI: 10.1109/ACSSC.1993.342307
L. C. Yun, M. Couture, J. Camagna, J. Linnartz
This paper derives the BER in synchronous (downlink) indoor direct-sequence CDMA transmission over a Ricean multipath channel with a non-uniform delay profile. Computational results will show that the performance is much better than that predicted by models which assume that all resolvable paths have i.i.d. power.<>
{"title":"BER for QPSK DS-CDMA downlink in an indoor Ricean dispersive pico-cellular channel","authors":"L. C. Yun, M. Couture, J. Camagna, J. Linnartz","doi":"10.1109/ACSSC.1993.342307","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342307","url":null,"abstract":"This paper derives the BER in synchronous (downlink) indoor direct-sequence CDMA transmission over a Ricean multipath channel with a non-uniform delay profile. Computational results will show that the performance is much better than that predicted by models which assume that all resolvable paths have i.i.d. power.<<ETX>>","PeriodicalId":266447,"journal":{"name":"Proceedings of 27th Asilomar Conference on Signals, Systems and Computers","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122513736","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 : 1993-11-01DOI: 10.1109/ACSSC.1993.342479
J.B. Burns, S. Rosenschein
The paper presents and demonstrates an efficient method of identifying objects via voting-based relational matching, a robust representation of the geometric and color arrangement of imaged object parts, and a method of effectively extracting blobs of perceptually uniform and distinct color.<>
{"title":"Recognition via blob representation and relational voting","authors":"J.B. Burns, S. Rosenschein","doi":"10.1109/ACSSC.1993.342479","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342479","url":null,"abstract":"The paper presents and demonstrates an efficient method of identifying objects via voting-based relational matching, a robust representation of the geometric and color arrangement of imaged object parts, and a method of effectively extracting blobs of perceptually uniform and distinct color.<<ETX>>","PeriodicalId":266447,"journal":{"name":"Proceedings of 27th Asilomar Conference on Signals, Systems and Computers","volume":"17 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120902253","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 : 1993-11-01DOI: 10.1109/ACSSC.1993.342592
J. Shynk, R. Gooch
The multistage CMA adaptive beamformer is capable of separating multiple narrowband sources without pilot or training signals. It is comprised of a cascade of CM (constant modulus) array subsections, each of which captures one of the signals impinging an the array. An adaptive signal canceller follows each CM array to remove captured signals from the input before processing by subsequent sections. Based an a stochastic analysis, we derive the steady-state convergence properties of the system, including its direction-finding capabilities. For mutually uncorrelated sources and noise, it is shown that the canceller exactly removes a captured signal, thereby reducing the rank of the effective array matrix of the next subsection by one.<>
{"title":"Convergence properties of the multistage CMA adaptive beamformer","authors":"J. Shynk, R. Gooch","doi":"10.1109/ACSSC.1993.342592","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342592","url":null,"abstract":"The multistage CMA adaptive beamformer is capable of separating multiple narrowband sources without pilot or training signals. It is comprised of a cascade of CM (constant modulus) array subsections, each of which captures one of the signals impinging an the array. An adaptive signal canceller follows each CM array to remove captured signals from the input before processing by subsequent sections. Based an a stochastic analysis, we derive the steady-state convergence properties of the system, including its direction-finding capabilities. For mutually uncorrelated sources and noise, it is shown that the canceller exactly removes a captured signal, thereby reducing the rank of the effective array matrix of the next subsection by one.<<ETX>>","PeriodicalId":266447,"journal":{"name":"Proceedings of 27th Asilomar Conference on Signals, Systems and Computers","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125706883","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 : 1993-11-01DOI: 10.1109/ACSSC.1993.342594
R. Pickholtz, K. Elbarbary
The constant modulus algorithm (CMA) has proved its ability to compensate the severe effect of the multipath interference and co-channel signals on the constant modulus signals. The application limitation of the CMA is mainly due to its slow rate of convergence. The paper presents a new algorithm which keeps the desired properties of the original CMA while it reduces the time required for convergence on the expense of some added mathematical complexity. The algorithm shows stable operations in both cases of compensating the effect of the multipath interference by an adaptive correction filter and separation of cochannel signals by an adaptive array followed by a signal canceler. The proposed algorithm is an order of magnitude faster than the original CMA on the average.<>
{"title":"The recursive constant modulus algorithm; a new approach for real-time array processing","authors":"R. Pickholtz, K. Elbarbary","doi":"10.1109/ACSSC.1993.342594","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342594","url":null,"abstract":"The constant modulus algorithm (CMA) has proved its ability to compensate the severe effect of the multipath interference and co-channel signals on the constant modulus signals. The application limitation of the CMA is mainly due to its slow rate of convergence. The paper presents a new algorithm which keeps the desired properties of the original CMA while it reduces the time required for convergence on the expense of some added mathematical complexity. The algorithm shows stable operations in both cases of compensating the effect of the multipath interference by an adaptive correction filter and separation of cochannel signals by an adaptive array followed by a signal canceler. The proposed algorithm is an order of magnitude faster than the original CMA on the average.<<ETX>>","PeriodicalId":266447,"journal":{"name":"Proceedings of 27th Asilomar Conference on Signals, Systems and Computers","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125740856","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 : 1993-11-01DOI: 10.1109/ACSSC.1993.342557
S. Heidari, C. Nikias
Local intrinsic dimension (LID) is a new approach to characterize chaotic signals. This method demonstrates more robustness to noise than the traditional fractal dimension (FD) estimation algorithms such as the Grassberger and Procaccia algorithm (GPA). In order to form the attractor in the phase space, the one-dimensional time-series of a signal needs to be embedded in a higher dimension. A significant limitation of the LID methods and the traditional FD methods is their sensitivity to the size of the higher embedding dimension (r) in the presence of noise. A new estimation method of the LID using higher-order statistics is proposed for chaotic signals corrupted by additive noise. In this work, estimation of the LID is based on the fourth-order, off-diagonal cumulant matrix and is shown to be less sensitive to noise and the size of the embedding dimension.<>
{"title":"Characterizing chaotic attractors using fourth-order off-diagonal cumulant slices","authors":"S. Heidari, C. Nikias","doi":"10.1109/ACSSC.1993.342557","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342557","url":null,"abstract":"Local intrinsic dimension (LID) is a new approach to characterize chaotic signals. This method demonstrates more robustness to noise than the traditional fractal dimension (FD) estimation algorithms such as the Grassberger and Procaccia algorithm (GPA). In order to form the attractor in the phase space, the one-dimensional time-series of a signal needs to be embedded in a higher dimension. A significant limitation of the LID methods and the traditional FD methods is their sensitivity to the size of the higher embedding dimension (r) in the presence of noise. A new estimation method of the LID using higher-order statistics is proposed for chaotic signals corrupted by additive noise. In this work, estimation of the LID is based on the fourth-order, off-diagonal cumulant matrix and is shown to be less sensitive to noise and the size of the embedding dimension.<<ETX>>","PeriodicalId":266447,"journal":{"name":"Proceedings of 27th Asilomar Conference on Signals, Systems and Computers","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127705154","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 : 1993-11-01DOI: 10.1109/ACSSC.1993.342571
C. Wei, D. Cochran
This paper presents methods for constructing bandlimited wavelets whose time-shifted and dyadically dilated replicates form orthonormal sets. The wavelets sets constructed have desirable spectral spreading properties when used as symbols for encoding digital communication signals, as has been proposed in recent literature.<>
{"title":"Bandlimited orthogonal wavelet symbols","authors":"C. Wei, D. Cochran","doi":"10.1109/ACSSC.1993.342571","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342571","url":null,"abstract":"This paper presents methods for constructing bandlimited wavelets whose time-shifted and dyadically dilated replicates form orthonormal sets. The wavelets sets constructed have desirable spectral spreading properties when used as symbols for encoding digital communication signals, as has been proposed in recent literature.<<ETX>>","PeriodicalId":266447,"journal":{"name":"Proceedings of 27th Asilomar Conference on Signals, Systems and Computers","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132405614","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 : 1993-11-01DOI: 10.1109/ACSSC.1993.342507
O. Adeyemi, S. Kadambe, G. Boudreaux-Bartels
The paper describes a simple method for detecting a class of first order or low dimensional discrete-time signals whose dynamical properties have the form of the logistic map. The authors have developed a maximum likelihood estimation (MLE) technique for the tuning parameter a and the initial condition of a logistic map embedded in zero-mean white Gaussian noise. They use the estimated values to determine the chaotic behavior of class of first order discrete time signals. They have also derived the recursive Cramer Rao lower bound (CRLB) for the tuning parameter a and the initial condition to characterize the performance of the developed estimators.<>
{"title":"The detection and characterization of a class of discrete time chaotic signals","authors":"O. Adeyemi, S. Kadambe, G. Boudreaux-Bartels","doi":"10.1109/ACSSC.1993.342507","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342507","url":null,"abstract":"The paper describes a simple method for detecting a class of first order or low dimensional discrete-time signals whose dynamical properties have the form of the logistic map. The authors have developed a maximum likelihood estimation (MLE) technique for the tuning parameter a and the initial condition of a logistic map embedded in zero-mean white Gaussian noise. They use the estimated values to determine the chaotic behavior of class of first order discrete time signals. They have also derived the recursive Cramer Rao lower bound (CRLB) for the tuning parameter a and the initial condition to characterize the performance of the developed estimators.<<ETX>>","PeriodicalId":266447,"journal":{"name":"Proceedings of 27th Asilomar Conference on Signals, Systems and Computers","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117219488","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 : 1993-11-01DOI: 10.1109/ACSSC.1993.342397
A. Zeira, B. Friedlander
Considers the problem of finding the directions of narrowband signals using a time-varying array, i.e., an array whose elements move during the observation interval in an arbitrary but known way. The authors derive the Cramer Rao bound and the maximum likelihood estimator for the direction-of-arrival estimates, for the Gaussian signal model. The single source case is studied in detail. Time-varying arrays are shown to be more robust to ambiguity errors than static arrays of comparable dimensions.<>
{"title":"Direction estimation using time-varying arrays","authors":"A. Zeira, B. Friedlander","doi":"10.1109/ACSSC.1993.342397","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342397","url":null,"abstract":"Considers the problem of finding the directions of narrowband signals using a time-varying array, i.e., an array whose elements move during the observation interval in an arbitrary but known way. The authors derive the Cramer Rao bound and the maximum likelihood estimator for the direction-of-arrival estimates, for the Gaussian signal model. The single source case is studied in detail. Time-varying arrays are shown to be more robust to ambiguity errors than static arrays of comparable dimensions.<<ETX>>","PeriodicalId":266447,"journal":{"name":"Proceedings of 27th Asilomar Conference on Signals, Systems and Computers","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130979484","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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