Pub Date : 2000-10-29DOI: 10.1109/ACSSC.2000.911026
J. Mao, B. Champagne, M. O'Droma, K. Kwiat
To extract the frequencies and direction of arrivals (DOAs) of multiple sources from experimental data collected by a sensor array is a multiple parameter estimation problem. Some important algorithms for spatial-temporal processing have been developed in the past decades. A practical problem, not often considered, is that the different sensors in the array affect each other through mutual coupling. This effect varies with frequencies and degrades the performance of algorithms. Thus, a separable dimension subspace method to simultaneously estimate signal frequencies, direction of arrivals (DOAs) and sensor mutual coupling is proposed.
{"title":"Separable dimension subspace method for joint signal frequencies, DOAs and sensor mutual coupling estimation","authors":"J. Mao, B. Champagne, M. O'Droma, K. Kwiat","doi":"10.1109/ACSSC.2000.911026","DOIUrl":"https://doi.org/10.1109/ACSSC.2000.911026","url":null,"abstract":"To extract the frequencies and direction of arrivals (DOAs) of multiple sources from experimental data collected by a sensor array is a multiple parameter estimation problem. Some important algorithms for spatial-temporal processing have been developed in the past decades. A practical problem, not often considered, is that the different sensors in the array affect each other through mutual coupling. This effect varies with frequencies and degrades the performance of algorithms. Thus, a separable dimension subspace method to simultaneously estimate signal frequencies, direction of arrivals (DOAs) and sensor mutual coupling is proposed.","PeriodicalId":10581,"journal":{"name":"Conference Record of the Thirty-Fourth Asilomar Conference on Signals, Systems and Computers (Cat. No.00CH37154)","volume":"29 1","pages":"605-609 vol.1"},"PeriodicalIF":0.0,"publicationDate":"2000-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73646278","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 : 2000-10-29DOI: 10.1109/ACSSC.2000.911269
V. Hegde, S. Pai, W. Jenkins, T. B. Wilborn
This paper investigates the capability of the genetic algorithm to achieve convergence to the global minimum for a multi-section all-pass IIR adaptive filter used for digital receiver phase equalization. The effect of population size and mutation rate on the performance of the algorithm is considered. Adaptive crossover and mutation probabilities are used to improve the performance of the algorithm.
{"title":"Genetic algorithms for adaptive phase equalization of minimum phase SAW filters","authors":"V. Hegde, S. Pai, W. Jenkins, T. B. Wilborn","doi":"10.1109/ACSSC.2000.911269","DOIUrl":"https://doi.org/10.1109/ACSSC.2000.911269","url":null,"abstract":"This paper investigates the capability of the genetic algorithm to achieve convergence to the global minimum for a multi-section all-pass IIR adaptive filter used for digital receiver phase equalization. The effect of population size and mutation rate on the performance of the algorithm is considered. Adaptive crossover and mutation probabilities are used to improve the performance of the algorithm.","PeriodicalId":10581,"journal":{"name":"Conference Record of the Thirty-Fourth Asilomar Conference on Signals, Systems and Computers (Cat. No.00CH37154)","volume":"252 1","pages":"1649-1652 vol.2"},"PeriodicalIF":0.0,"publicationDate":"2000-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72891357","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 : 2000-10-29DOI: 10.1109/ACSSC.2000.910671
J. Kliewer, N. Gortz
In this contribution we utilize an optimal estimation approach for error-resilient transmission of compressed images over AWGN channels. In contrast to other methods, we mainly rely on the implicit residual redundancy inherent in the subband images and the bit-reliability information at the channel output for error protection. It is shown that by including a priori knowledge about the spatial correlations in the subband images, we obtain a highly increased quality of the reconstructed image. This holds especially for very noisy channels and a mean-square estimation of the subband source coefficients.
{"title":"Error-resilient transmission of compressed images over very noisy channels using soft-input source decoding","authors":"J. Kliewer, N. Gortz","doi":"10.1109/ACSSC.2000.910671","DOIUrl":"https://doi.org/10.1109/ACSSC.2000.910671","url":null,"abstract":"In this contribution we utilize an optimal estimation approach for error-resilient transmission of compressed images over AWGN channels. In contrast to other methods, we mainly rely on the implicit residual redundancy inherent in the subband images and the bit-reliability information at the channel output for error protection. It is shown that by including a priori knowledge about the spatial correlations in the subband images, we obtain a highly increased quality of the reconstructed image. This holds especially for very noisy channels and a mean-square estimation of the subband source coefficients.","PeriodicalId":10581,"journal":{"name":"Conference Record of the Thirty-Fourth Asilomar Conference on Signals, Systems and Computers (Cat. No.00CH37154)","volume":"111 1","pages":"1035-1039 vol.2"},"PeriodicalIF":0.0,"publicationDate":"2000-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73615927","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 : 2000-10-29DOI: 10.1109/ACSSC.2000.911273
Y.H. Cho, D. Brunke, G. E. Allen, B. Evans
Three-dimensional real-time digital sonar beamforming requires 4 to 12 GFLOPS, 1 to 2 GB of memory, and about 100 MB/s of I/O bandwidth. G.E. Allen and B.L. Evans have implemented a 4-GFLOP sonar beamformer in real-time on a Sun UltraSPARC II server with 16 333-MHz processors by utilizing the Visual Instruction Set (VIS) single-instruction multiple-data (SIMD) extensions. In this paper, we rewrite the horizontal and vertical beamforming kernels to use AltiVec SIMD extension for the PowerPC. AltiVec can execute up to four 32-bit floating-point multiply and accumulate (MAC) operations per instruction. In the PowerPC implementation, we prefetch and realign data for the I28-bit SIMD registers of AltiVec. We evaluate the performance of these beamforming kernels on the PowerPC and the UltraSPARC-II to evaluate the impact of the compiler, SIMD word alignment, and cache block alignment on performance.
{"title":"Optimization of vertical and horizontal beamforming kernels on the PowerPC G4 processor with AltiVec technology","authors":"Y.H. Cho, D. Brunke, G. E. Allen, B. Evans","doi":"10.1109/ACSSC.2000.911273","DOIUrl":"https://doi.org/10.1109/ACSSC.2000.911273","url":null,"abstract":"Three-dimensional real-time digital sonar beamforming requires 4 to 12 GFLOPS, 1 to 2 GB of memory, and about 100 MB/s of I/O bandwidth. G.E. Allen and B.L. Evans have implemented a 4-GFLOP sonar beamformer in real-time on a Sun UltraSPARC II server with 16 333-MHz processors by utilizing the Visual Instruction Set (VIS) single-instruction multiple-data (SIMD) extensions. In this paper, we rewrite the horizontal and vertical beamforming kernels to use AltiVec SIMD extension for the PowerPC. AltiVec can execute up to four 32-bit floating-point multiply and accumulate (MAC) operations per instruction. In the PowerPC implementation, we prefetch and realign data for the I28-bit SIMD registers of AltiVec. We evaluate the performance of these beamforming kernels on the PowerPC and the UltraSPARC-II to evaluate the impact of the compiler, SIMD word alignment, and cache block alignment on performance.","PeriodicalId":10581,"journal":{"name":"Conference Record of the Thirty-Fourth Asilomar Conference on Signals, Systems and Computers (Cat. No.00CH37154)","volume":"39 1","pages":"1670-1674 vol.2"},"PeriodicalIF":0.0,"publicationDate":"2000-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74614215","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 : 2000-10-29DOI: 10.1109/ACSSC.2000.911244
M. DeVore, N. Schmid, J. O’Sullivan
Many automatic target recognition systems are designed based on training data. In model-based approaches, parameters are estimated from the training data and used in the actual implementation of the system. Often for a fixed-size training set, as the complexity of the model increases, the performance gets better initially then worsens. While this phenomenon is well-known in the statistics community, its importance in the design of target recognition systems is often neglected. For target recognition systems with decisions based on likelihood ratios using estimated parameters, we present complementary analytical and experimental results on this phenomenon. Analytical results assume independent samples for training and assume the existence of an underlying true distribution on the data that is not known. For several model classes, an optimal model complexity can be derived. Experimentally, these results are used to guide the design of target recognition systems for synthetic aperture radar data collected in the MSTAR program using probability of error for performance.
{"title":"Analytical and experimental performance-complexity tradeoffs in ATR","authors":"M. DeVore, N. Schmid, J. O’Sullivan","doi":"10.1109/ACSSC.2000.911244","DOIUrl":"https://doi.org/10.1109/ACSSC.2000.911244","url":null,"abstract":"Many automatic target recognition systems are designed based on training data. In model-based approaches, parameters are estimated from the training data and used in the actual implementation of the system. Often for a fixed-size training set, as the complexity of the model increases, the performance gets better initially then worsens. While this phenomenon is well-known in the statistics community, its importance in the design of target recognition systems is often neglected. For target recognition systems with decisions based on likelihood ratios using estimated parameters, we present complementary analytical and experimental results on this phenomenon. Analytical results assume independent samples for training and assume the existence of an underlying true distribution on the data that is not known. For several model classes, an optimal model complexity can be derived. Experimentally, these results are used to guide the design of target recognition systems for synthetic aperture radar data collected in the MSTAR program using probability of error for performance.","PeriodicalId":10581,"journal":{"name":"Conference Record of the Thirty-Fourth Asilomar Conference on Signals, Systems and Computers (Cat. No.00CH37154)","volume":"520 1","pages":"1519-1523 vol.2"},"PeriodicalIF":0.0,"publicationDate":"2000-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77358890","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 : 2000-10-29DOI: 10.1109/ACSSC.2000.911261
S. Nagaraj, Yih-Fang Huang
We consider a novel scheme to facilitate downlink beamforming over fading channels. A new feedback scheme is proposed, the main features of which being significantly reduced feedback. An adaptive set-membership filtering solution to channel estimation is proposed at the base-station, which, by its very formulation, requires only sparse and selective feedback of information from the mobile. Further, information-theoretic downlink capacity analysis shows that such a beamformer is near optimal in terms of capacity.
{"title":"Downlink transmit beamforming with selective feedback","authors":"S. Nagaraj, Yih-Fang Huang","doi":"10.1109/ACSSC.2000.911261","DOIUrl":"https://doi.org/10.1109/ACSSC.2000.911261","url":null,"abstract":"We consider a novel scheme to facilitate downlink beamforming over fading channels. A new feedback scheme is proposed, the main features of which being significantly reduced feedback. An adaptive set-membership filtering solution to channel estimation is proposed at the base-station, which, by its very formulation, requires only sparse and selective feedback of information from the mobile. Further, information-theoretic downlink capacity analysis shows that such a beamformer is near optimal in terms of capacity.","PeriodicalId":10581,"journal":{"name":"Conference Record of the Thirty-Fourth Asilomar Conference on Signals, Systems and Computers (Cat. No.00CH37154)","volume":"54 1","pages":"1608-1612 vol.2"},"PeriodicalIF":0.0,"publicationDate":"2000-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74456814","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 : 2000-10-29DOI: 10.1109/ACSSC.2000.910638
V. Lefèvre, J. Muller
The IEEE 754 standard for floating-point arithmetic requires that the four arithmetic operations and the square root should be correctly rounded. This has improved the accuracy, reliability and portability of numerical software. Unfortunately, such a requirement does not exist for the elementary functions. As a consequence, some libraries that are used everyday are rather poor. The problem of correctly rounding these functions is called the "Table Maker's Dilemma". After a survey on this problem, we give some new results. They show that correctly rounded functions could be provided at a reasonable cost.
{"title":"Correctly rounded functions for better arithmetic","authors":"V. Lefèvre, J. Muller","doi":"10.1109/ACSSC.2000.910638","DOIUrl":"https://doi.org/10.1109/ACSSC.2000.910638","url":null,"abstract":"The IEEE 754 standard for floating-point arithmetic requires that the four arithmetic operations and the square root should be correctly rounded. This has improved the accuracy, reliability and portability of numerical software. Unfortunately, such a requirement does not exist for the elementary functions. As a consequence, some libraries that are used everyday are rather poor. The problem of correctly rounding these functions is called the \"Table Maker's Dilemma\". After a survey on this problem, we give some new results. They show that correctly rounded functions could be provided at a reasonable cost.","PeriodicalId":10581,"journal":{"name":"Conference Record of the Thirty-Fourth Asilomar Conference on Signals, Systems and Computers (Cat. No.00CH37154)","volume":"102 1","pages":"875-878 vol.2"},"PeriodicalIF":0.0,"publicationDate":"2000-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74626191","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 : 2000-10-29DOI: 10.1109/ACSSC.2000.910673
Zhihai He, Tian-Hu Yu, S. Mitra
By introducing the concepts of characteristic rate curves and rate curve decomposition, a novel framework for rate-distortion (R-D) analysis and source modeling is developed in this work. With this framework, a fast algorithm is proposed to accurately estimate the R-D curve before quantization and coding for wavelet-based image coders. The proposed algorithm is applied to the SPIHT (set partitioning in hierarchical trees) and stack-run (SR) encoders. Our extensive experimental results show that the relative R-D curve estimation error is less than 5%.
{"title":"Fast and accurate rate prediction and picture quality control for wavelet image coding","authors":"Zhihai He, Tian-Hu Yu, S. Mitra","doi":"10.1109/ACSSC.2000.910673","DOIUrl":"https://doi.org/10.1109/ACSSC.2000.910673","url":null,"abstract":"By introducing the concepts of characteristic rate curves and rate curve decomposition, a novel framework for rate-distortion (R-D) analysis and source modeling is developed in this work. With this framework, a fast algorithm is proposed to accurately estimate the R-D curve before quantization and coding for wavelet-based image coders. The proposed algorithm is applied to the SPIHT (set partitioning in hierarchical trees) and stack-run (SR) encoders. Our extensive experimental results show that the relative R-D curve estimation error is less than 5%.","PeriodicalId":10581,"journal":{"name":"Conference Record of the Thirty-Fourth Asilomar Conference on Signals, Systems and Computers (Cat. No.00CH37154)","volume":"103 1","pages":"1040-1044 vol.2"},"PeriodicalIF":0.0,"publicationDate":"2000-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76560579","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 : 2000-10-29DOI: 10.1109/ACSSC.2000.910770
S. Stańczak, H. Boche
The paper investigates the influence of correlation properties of spreading sequences on the sum capacity of a CDMA channel, in which all users are in exact synchronism at their transmitters but the signals pass through multipath channels with small delay spread and one strong path. It is shown that if spreading sequences have favorable periodic correlation properties, the sum capacity can be maximized at the expense of the sequence length when the power is uniformly distributed over the paths.
{"title":"Influence of periodic correlation properties of sequences on the sum capacity of CDMA systems","authors":"S. Stańczak, H. Boche","doi":"10.1109/ACSSC.2000.910770","DOIUrl":"https://doi.org/10.1109/ACSSC.2000.910770","url":null,"abstract":"The paper investigates the influence of correlation properties of spreading sequences on the sum capacity of a CDMA channel, in which all users are in exact synchronism at their transmitters but the signals pass through multipath channels with small delay spread and one strong path. It is shown that if spreading sequences have favorable periodic correlation properties, the sum capacity can be maximized at the expense of the sequence length when the power is uniformly distributed over the paths.","PeriodicalId":10581,"journal":{"name":"Conference Record of the Thirty-Fourth Asilomar Conference on Signals, Systems and Computers (Cat. No.00CH37154)","volume":"4 1","pages":"1288-1292 vol.2"},"PeriodicalIF":0.0,"publicationDate":"2000-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75750907","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 : 2000-10-29DOI: 10.1109/ACSSC.2000.910689
R. Bonneau
In moving target radar scenarios temporal nonstationarities can profoundly effect performance of spatial target detectors. These nonstationarities are often ignored simply because it has been computationally inefficient, or mathematically intractable to handle them. This nonstationary noise, however can often be localized in spatial frequency. A spatial multiresolution Markov structure can thus be used to isolate these temporal nonstationarities. In this paper we employ a multiresolution-Markov matched filter detection scheme that integrates Kalman conditioning criteria to remove temporal nonstationarities and thereby improve radar detection performance.
{"title":"Adaptive spectral conditioning for improved radar detection","authors":"R. Bonneau","doi":"10.1109/ACSSC.2000.910689","DOIUrl":"https://doi.org/10.1109/ACSSC.2000.910689","url":null,"abstract":"In moving target radar scenarios temporal nonstationarities can profoundly effect performance of spatial target detectors. These nonstationarities are often ignored simply because it has been computationally inefficient, or mathematically intractable to handle them. This nonstationary noise, however can often be localized in spatial frequency. A spatial multiresolution Markov structure can thus be used to isolate these temporal nonstationarities. In this paper we employ a multiresolution-Markov matched filter detection scheme that integrates Kalman conditioning criteria to remove temporal nonstationarities and thereby improve radar detection performance.","PeriodicalId":10581,"journal":{"name":"Conference Record of the Thirty-Fourth Asilomar Conference on Signals, Systems and Computers (Cat. No.00CH37154)","volume":"6 1","pages":"1122-1124 vol.2"},"PeriodicalIF":0.0,"publicationDate":"2000-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79789853","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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