Pub Date : 1993-11-01DOI: 10.1109/ACSSC.1993.342532
S. Talwar, M. Viberg, A. Paulraj
We propose a novel approach for separating and estimating multiple co-channel digital signals arriving at an antenna array. The spatial response of the antenna array is known imprecisely or unknown. We exploit the discrete-alphabet property of digital signals to simultaneously determine the array response and the bit sequence for each signal. Uniqueness of the estimates is established for signals with BPSK modulation format. This new approach as applicable to an unknown array geometry and propagation environment, which is particularly useful in digital mobile communications. Simulation results demonstrate its promising performance.<>
{"title":"Blind estimation of multiple co-channel digital signals arriving at an antenna array","authors":"S. Talwar, M. Viberg, A. Paulraj","doi":"10.1109/ACSSC.1993.342532","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342532","url":null,"abstract":"We propose a novel approach for separating and estimating multiple co-channel digital signals arriving at an antenna array. The spatial response of the antenna array is known imprecisely or unknown. We exploit the discrete-alphabet property of digital signals to simultaneously determine the array response and the bit sequence for each signal. Uniqueness of the estimates is established for signals with BPSK modulation format. This new approach as applicable to an unknown array geometry and propagation environment, which is particularly useful in digital mobile communications. Simulation results demonstrate its promising performance.<<ETX>>","PeriodicalId":266447,"journal":{"name":"Proceedings of 27th Asilomar Conference on Signals, Systems and Computers","volume":"18 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":"128969697","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.1993.342533
H. Krishna, F. Mendis
This paper investigates the factorization properties of cyclotomic polynomials over the field of complex rational numbers. Based on this factorization and the Chinese remainder theorem, we analyze the mathematical structure of the associated algorithms for computing the cyclic convolution of data sequences.<>
{"title":"Complex cyclotomic polynomials and the related algorithms for cyclic convolution","authors":"H. Krishna, F. Mendis","doi":"10.1109/ACSSC.1993.342533","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342533","url":null,"abstract":"This paper investigates the factorization properties of cyclotomic polynomials over the field of complex rational numbers. Based on this factorization and the Chinese remainder theorem, we analyze the mathematical structure of the associated algorithms for computing the cyclic convolution of data sequences.<<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":"129274873","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.1993.342570
R. Orr, C. Pike, M. L. Bates, M. A. Tzannes, S. Sandberg
Atlantic Aerospace and Aware are developing a novel class of spread spectrum system architectures for covert communications based on the theory of wavelets. We describe a class of spread spectrum waveforms that are: (1) highly efficient in their use of signal energy; (2) indistinguishable in appearance from bandpass Gaussian noise; (3) devoid of second and fourth-order cyclostationary features; (4) reliably demodulated in the presence of narrowband or wideband interference; and (5) implementable with complexity comparable to that of competitive techniques. Detectability comparisons to other waveform categories that have been proposed for covert communications, i.e., QPSK are drawn.<>
{"title":"Covert communications employing wavelet technology","authors":"R. Orr, C. Pike, M. L. Bates, M. A. Tzannes, S. Sandberg","doi":"10.1109/ACSSC.1993.342570","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342570","url":null,"abstract":"Atlantic Aerospace and Aware are developing a novel class of spread spectrum system architectures for covert communications based on the theory of wavelets. We describe a class of spread spectrum waveforms that are: (1) highly efficient in their use of signal energy; (2) indistinguishable in appearance from bandpass Gaussian noise; (3) devoid of second and fourth-order cyclostationary features; (4) reliably demodulated in the presence of narrowband or wideband interference; and (5) implementable with complexity comparable to that of competitive techniques. Detectability comparisons to other waveform categories that have been proposed for covert communications, i.e., QPSK are drawn.<<ETX>>","PeriodicalId":266447,"journal":{"name":"Proceedings of 27th Asilomar Conference on Signals, Systems and Computers","volume":"91 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":"124654892","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.1993.342595
E. Satorius, J. J. Mulligan, N. Lay
An alternative methodology for blind adaptive array processing is presented which generalizes the class of cost functions that are currently used. The methodology is based on the separation of independent, but not necessarily identically distributed, statistical components at the array output. Sufficient admissibility criteria are presented for blind adaptive array processing cost functions and examples based on the magnitude of complex, standardized cumulants as well as on order statistics are provided. In addition, a simple procedure for devising new candidate cost functions is discussed that can easily incorporate any available statistical information regarding the specific signal/interference environment of interest.<>
{"title":"New criteria for blind adaptive arrays","authors":"E. Satorius, J. J. Mulligan, N. Lay","doi":"10.1109/ACSSC.1993.342595","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342595","url":null,"abstract":"An alternative methodology for blind adaptive array processing is presented which generalizes the class of cost functions that are currently used. The methodology is based on the separation of independent, but not necessarily identically distributed, statistical components at the array output. Sufficient admissibility criteria are presented for blind adaptive array processing cost functions and examples based on the magnitude of complex, standardized cumulants as well as on order statistics are provided. In addition, a simple procedure for devising new candidate cost functions is discussed that can easily incorporate any available statistical information regarding the specific signal/interference environment of interest.<<ETX>>","PeriodicalId":266447,"journal":{"name":"Proceedings of 27th Asilomar Conference on Signals, Systems and Computers","volume":"7 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":"130412652","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.1993.342519
J. O’Sullivan, S. Jacobs, M. Miller, D. Snyder
The identification of aircraft using high range resolution radars requires a close interaction between the tracker and the identification algorithm. The tracker produces as output not only the estimates of target position and orientation, but also a measure of the quality of those estimates. The identification algorithm performs a likelihood-based search over both target types and target positions and orientations. This search compares the measured data to predicted data obtained from surface models of the possible targets. The search constitutes a simultaneous target tracking and identification system.<>
{"title":"A likelihood-based approach to joint target tracking and identification","authors":"J. O’Sullivan, S. Jacobs, M. Miller, D. Snyder","doi":"10.1109/ACSSC.1993.342519","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342519","url":null,"abstract":"The identification of aircraft using high range resolution radars requires a close interaction between the tracker and the identification algorithm. The tracker produces as output not only the estimates of target position and orientation, but also a measure of the quality of those estimates. The identification algorithm performs a likelihood-based search over both target types and target positions and orientations. This search compares the measured data to predicted data obtained from surface models of the possible targets. The search constitutes a simultaneous target tracking and identification system.<<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":"129226238","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.1993.342362
T. Ramstad, S. Lepsøy
The paper presents a simple fractal or attractor coder model that has a very fast decoding algorithm and lends itself to comparisons with vector quantization (VQ) of the mean-gain-shape (MGSVQ) type. In fractal theory the transmission of the codebook is somewhat concealed. In our simple model the codebook is explicitly transmitted although with a double role. The main difference between MGSVQ and the fractal coder is that the codebook in MSGV is as statistically optimized from a set of training data whereas it is derived directly from the image to be coded for the fractal coder, and therefore can be viewed as adaptive. Experimental comparisons are given.<>
{"title":"Block-based attractor coding: potential and comparison to vector quantization","authors":"T. Ramstad, S. Lepsøy","doi":"10.1109/ACSSC.1993.342362","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342362","url":null,"abstract":"The paper presents a simple fractal or attractor coder model that has a very fast decoding algorithm and lends itself to comparisons with vector quantization (VQ) of the mean-gain-shape (MGSVQ) type. In fractal theory the transmission of the codebook is somewhat concealed. In our simple model the codebook is explicitly transmitted although with a double role. The main difference between MGSVQ and the fractal coder is that the codebook in MSGV is as statistically optimized from a set of training data whereas it is derived directly from the image to be coded for the fractal coder, and therefore can be viewed as adaptive. Experimental comparisons are given.<<ETX>>","PeriodicalId":266447,"journal":{"name":"Proceedings of 27th Asilomar Conference on Signals, Systems and Computers","volume":"18 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":"127750586","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.1993.342453
V. Algazi, N. Hiwasa
The design of very low bit rate coders, below 64 kilo-bits per second, presents a number of new challenges. Such low bit rate coders are targeted to small size images, say 176/spl times/144, or below and are limited to head and shoulders scenes. The authors compare and rate the performance of several still image encoding methods such as DCT, subband and wavelets, using a new quality scale based on properties of human vision. These still image coders are embedded into video coders such as the H261 coder. The relative importance of intraframe and interframe quality and contributions to the total bit rate provide an overall design framework for these low bit rate video coders. The authors discuss and illustrate, for the encoding of low bit rate video, the still image and motion impairments that are perceptually most important.<>
{"title":"Perceptual criteria and design alternatives for low bit rate video coding","authors":"V. Algazi, N. Hiwasa","doi":"10.1109/ACSSC.1993.342453","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342453","url":null,"abstract":"The design of very low bit rate coders, below 64 kilo-bits per second, presents a number of new challenges. Such low bit rate coders are targeted to small size images, say 176/spl times/144, or below and are limited to head and shoulders scenes. The authors compare and rate the performance of several still image encoding methods such as DCT, subband and wavelets, using a new quality scale based on properties of human vision. These still image coders are embedded into video coders such as the H261 coder. The relative importance of intraframe and interframe quality and contributions to the total bit rate provide an overall design framework for these low bit rate video coders. The authors discuss and illustrate, for the encoding of low bit rate video, the still image and motion impairments that are perceptually most important.<<ETX>>","PeriodicalId":266447,"journal":{"name":"Proceedings of 27th Asilomar Conference on Signals, Systems and Computers","volume":"93 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":"126206417","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.1993.342608
J.W. Adams, C. Ghadimi, B. Tucker, Qing Gao, J. L. Sullivan
The filters in the paper permit the designer to control the tradeoff between the peak error and the total squared error. These filters are designed according to the peak-constrained least-squares (PCLS) optimality criterion. The authors presented quadratic programming approaches to designing PCLS digital filters in Adams (1991) and Adams et al. (1993). In the present paper, the authors present the ripple weighted least-squares (RWLS) algorithm for designing PCLS digital filters.<>
本文中的滤波器允许设计者控制峰值误差和总平方误差之间的权衡。这些滤波器是根据峰值约束最小二乘(PCLS)最优准则设计的。作者在Adams(1991)和Adams et al.(1993)中提出了二次规划方法来设计PCLS数字滤波器。本文提出了用于设计PCLS数字滤波器的纹波加权最小二乘(RWLS)算法。
{"title":"Ripple-weighted approach to designing peak-constrained least-squares digital filters","authors":"J.W. Adams, C. Ghadimi, B. Tucker, Qing Gao, J. L. Sullivan","doi":"10.1109/ACSSC.1993.342608","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342608","url":null,"abstract":"The filters in the paper permit the designer to control the tradeoff between the peak error and the total squared error. These filters are designed according to the peak-constrained least-squares (PCLS) optimality criterion. The authors presented quadratic programming approaches to designing PCLS digital filters in Adams (1991) and Adams et al. (1993). In the present paper, the authors present the ripple weighted least-squares (RWLS) algorithm for designing PCLS digital filters.<<ETX>>","PeriodicalId":266447,"journal":{"name":"Proceedings of 27th Asilomar Conference on Signals, Systems and Computers","volume":"3 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":"126421841","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.1993.342336
R. Kozick, S. Kassam
Many adaptive beamforming and angle of arrival estimation algorithms perform poorly when the signals arriving at the array are mutually correlated or coherent. We describe an improved technique for coherent signal decorrelation that is based on the idea of autocorrelation matrix smoothing (AMS). We begin with a brief review of the definition and properties of AMS, including a unified interpretation of several previously-proposed decorrelation methods as special cases of AMS. Then we use the AMS approach to formulate an improved decorrelation technique, and conclude with computer simulations that illustrate the performance of the new technique.<>
{"title":"Improved coherent source decorrelation by autocorrelation matrix smoothing","authors":"R. Kozick, S. Kassam","doi":"10.1109/ACSSC.1993.342336","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342336","url":null,"abstract":"Many adaptive beamforming and angle of arrival estimation algorithms perform poorly when the signals arriving at the array are mutually correlated or coherent. We describe an improved technique for coherent signal decorrelation that is based on the idea of autocorrelation matrix smoothing (AMS). We begin with a brief review of the definition and properties of AMS, including a unified interpretation of several previously-proposed decorrelation methods as special cases of AMS. Then we use the AMS approach to formulate an improved decorrelation technique, and conclude with computer simulations that illustrate the performance of the new technique.<<ETX>>","PeriodicalId":266447,"journal":{"name":"Proceedings of 27th Asilomar Conference on Signals, Systems and Computers","volume":"8 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":"128042227","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.1993.342293
D. Woods
Various digital equalization and detection schemes have been proposed for disk drive read channels and simulated as a Lorentzian channel [Moon and Carley, 1990]. With the design of linear recording densities greater than two channel bits per half amplitude pulsewidth (PW50), concerns over nonlinear distortions, such as partial erasure, require channel simulation with techniques other than the linear Lorentzian model. The paper describes the considerations a disk drive designer faces when optimizing the performance of digital read channels with a channel simulator that uses actual data obtained from a disk file environment. This real data channel simulator accomplishes equalization and detection in software using sampled data from a spinstand allowing the flexibility of investigating the performance of different channel schemes without having to build expensive hardware. Sample offtrack data for selected channels at various user (information) densities are shown, along with ontrack Lorentzian simulation. Goodness numbers for each channel are presented which approximately minimize bit error rate (BER) in a quick way, providing algorithms for a disk drive to check channel quality during adaptive adjustments.<>
{"title":"Comparison and optimization of digital read channels using actual data","authors":"D. Woods","doi":"10.1109/ACSSC.1993.342293","DOIUrl":"https://doi.org/10.1109/ACSSC.1993.342293","url":null,"abstract":"Various digital equalization and detection schemes have been proposed for disk drive read channels and simulated as a Lorentzian channel [Moon and Carley, 1990]. With the design of linear recording densities greater than two channel bits per half amplitude pulsewidth (PW50), concerns over nonlinear distortions, such as partial erasure, require channel simulation with techniques other than the linear Lorentzian model. The paper describes the considerations a disk drive designer faces when optimizing the performance of digital read channels with a channel simulator that uses actual data obtained from a disk file environment. This real data channel simulator accomplishes equalization and detection in software using sampled data from a spinstand allowing the flexibility of investigating the performance of different channel schemes without having to build expensive hardware. Sample offtrack data for selected channels at various user (information) densities are shown, along with ontrack Lorentzian simulation. Goodness numbers for each channel are presented which approximately minimize bit error rate (BER) in a quick way, providing algorithms for a disk drive to check channel quality during adaptive adjustments.<<ETX>>","PeriodicalId":266447,"journal":{"name":"Proceedings of 27th Asilomar Conference on Signals, Systems and Computers","volume":"17 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":"128148953","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：