Pub Date : 2008-07-21DOI: 10.1109/SAM.2008.4606898
Y. Noam, H. Messer
This paper explores the hybrid Cramer-Rao lower-bound (HCRLB) for a Gaussian generalized linear estimation problem in which some of the unknown parameters are deterministic while the other are random. In general, the HCRLB on the non-Bayesian parameters is not asymptotically tight. However, we show that for the generalized Gaussian linear estimation problem, the HCRLB of the deterministic parameters coincides with the CRLB, so it is an asymptotically tight bound. In addition, we show that the ML/MAP estimator [Van Trees and Bell, 2007] is asymptotically efficient for the non-Bayesian parameters while providing optimal estimate of the Bayesian parameters. The results are demonstrated on a signal processing example. It is shown the Hybrid estimation can increase spectral resolution if some prior knowledge is available only on a subset of the parameters.
本文研究了一类未知参数为随机而未知参数为确定性的高斯广义线性估计问题的混合Cramer-Rao下界问题。一般来说,非贝叶斯参数上的HCRLB不是渐近紧的。然而,我们证明了对于广义高斯线性估计问题,确定性参数的HCRLB与CRLB重合,因此它是一个渐近紧界。此外,我们证明了ML/MAP估计器[Van Trees and Bell, 2007]对于非贝叶斯参数是渐近有效的,同时提供了贝叶斯参数的最优估计。通过一个信号处理实例对结果进行了验证。结果表明,当某些先验知识仅在参数子集上可用时,混合估计可以提高光谱分辨率。
{"title":"The hybrid Cramér-Rao bound and the generalized Gaussian linear estimation problem","authors":"Y. Noam, H. Messer","doi":"10.1109/SAM.2008.4606898","DOIUrl":"https://doi.org/10.1109/SAM.2008.4606898","url":null,"abstract":"This paper explores the hybrid Cramer-Rao lower-bound (HCRLB) for a Gaussian generalized linear estimation problem in which some of the unknown parameters are deterministic while the other are random. In general, the HCRLB on the non-Bayesian parameters is not asymptotically tight. However, we show that for the generalized Gaussian linear estimation problem, the HCRLB of the deterministic parameters coincides with the CRLB, so it is an asymptotically tight bound. In addition, we show that the ML/MAP estimator [Van Trees and Bell, 2007] is asymptotically efficient for the non-Bayesian parameters while providing optimal estimate of the Bayesian parameters. The results are demonstrated on a signal processing example. It is shown the Hybrid estimation can increase spectral resolution if some prior knowledge is available only on a subset of the parameters.","PeriodicalId":422747,"journal":{"name":"2008 5th IEEE Sensor Array and Multichannel Signal Processing Workshop","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115985366","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 : 2008-07-21DOI: 10.1109/SAM.2008.4606876
S. Nai, W. Ser, Z. L. Yu
Adaptive beamformers can degrade drastically in practice because they are highly sensitive to mismatches between the exploited assumptions and the actual characteristics of the sensor array, environment and sources. At low snapshots, the sidelobes can get very high due to errors in the array covariance matrix. This degrades the signal-to-interference-plus-noise-ratio (SINR). Recently, a robust adaptive beamformer based on worst-case optimization (RAB-WC), has reformulated beamforming as a second-order cone programming (SOCP) problem. It exhibits adaptive interference-rejection capability and robustness against large steering direction errors. However, the sidelobes in RAB-WC are indirectly controlled by a regularization factor and it is not clear how the factor value should be selected. In this paper, we propose a new framework based on the use of a set of beampattern shaping constraints. With this framework, the beamformer possesses not only adaptive interference-rejection capability and robustness against large steering direction errors, but also direct sidelobe control simultaneously. Unlike other state-of-the-art robust adaptive beamformers, the proposed beamformer is robust against moving interferences too. The proposed framework is generic and many beamformers can be derived to tackle specific problems.
{"title":"Robust adaptive beamformers: A beampattern shaping approach","authors":"S. Nai, W. Ser, Z. L. Yu","doi":"10.1109/SAM.2008.4606876","DOIUrl":"https://doi.org/10.1109/SAM.2008.4606876","url":null,"abstract":"Adaptive beamformers can degrade drastically in practice because they are highly sensitive to mismatches between the exploited assumptions and the actual characteristics of the sensor array, environment and sources. At low snapshots, the sidelobes can get very high due to errors in the array covariance matrix. This degrades the signal-to-interference-plus-noise-ratio (SINR). Recently, a robust adaptive beamformer based on worst-case optimization (RAB-WC), has reformulated beamforming as a second-order cone programming (SOCP) problem. It exhibits adaptive interference-rejection capability and robustness against large steering direction errors. However, the sidelobes in RAB-WC are indirectly controlled by a regularization factor and it is not clear how the factor value should be selected. In this paper, we propose a new framework based on the use of a set of beampattern shaping constraints. With this framework, the beamformer possesses not only adaptive interference-rejection capability and robustness against large steering direction errors, but also direct sidelobe control simultaneously. Unlike other state-of-the-art robust adaptive beamformers, the proposed beamformer is robust against moving interferences too. The proposed framework is generic and many beamformers can be derived to tackle specific problems.","PeriodicalId":422747,"journal":{"name":"2008 5th IEEE Sensor Array and Multichannel Signal Processing Workshop","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121712434","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 : 2008-07-21DOI: 10.1109/SAM.2008.4606913
P. Hashemzadeh, T. Rylander, M. Viberg
We estimate the radius of a perfect electric conductor (PEC) half-sphere placed on a ground plane, given six bi-conical antennas that suffer from manufacturing errors. The results are complemented by an analytical model of the sensor system and the scatterer. The analytical model includes the front-end electronics in combination with the antenna radiation impedance and the radiation field function.
{"title":"Analysis of 3-D shape estimation using bistatic multi-channel radar systems","authors":"P. Hashemzadeh, T. Rylander, M. Viberg","doi":"10.1109/SAM.2008.4606913","DOIUrl":"https://doi.org/10.1109/SAM.2008.4606913","url":null,"abstract":"We estimate the radius of a perfect electric conductor (PEC) half-sphere placed on a ground plane, given six bi-conical antennas that suffer from manufacturing errors. The results are complemented by an analytical model of the sensor system and the scatterer. The analytical model includes the front-end electronics in combination with the antenna radiation impedance and the radiation field function.","PeriodicalId":422747,"journal":{"name":"2008 5th IEEE Sensor Array and Multichannel Signal Processing Workshop","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116839093","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 : 2008-07-21DOI: 10.1109/SAM.2008.4606839
J. Choi, R. Drost, A. Singer, J. Preisig
In this paper, an iterative multi-channel equalization and decoding technique is introduced to improve system performance in underwater acoustic communications. The turbo principle is applied to the existing canonical receiver structure including fractionally spaced decision feedback equalization with phase synchronization. The performance of multi-channel equalization and adaptive weight update algorithms are aided by soft information delivered from the channel decoder. The complexity of the proposed scheme is shown to be reasonable for highly reverberant underwater channels since it has linear complexity by the use of the least mean square (LMS) algorithm. Experimental results for data transmission at 41.67 k symbol/s with a carrier frequency of 100 kHz demonstrate the feasibility of the proposed algorithm.
{"title":"Iterative multi-channel equalization and decoding for high frequency underwater acoustic communications","authors":"J. Choi, R. Drost, A. Singer, J. Preisig","doi":"10.1109/SAM.2008.4606839","DOIUrl":"https://doi.org/10.1109/SAM.2008.4606839","url":null,"abstract":"In this paper, an iterative multi-channel equalization and decoding technique is introduced to improve system performance in underwater acoustic communications. The turbo principle is applied to the existing canonical receiver structure including fractionally spaced decision feedback equalization with phase synchronization. The performance of multi-channel equalization and adaptive weight update algorithms are aided by soft information delivered from the channel decoder. The complexity of the proposed scheme is shown to be reasonable for highly reverberant underwater channels since it has linear complexity by the use of the least mean square (LMS) algorithm. Experimental results for data transmission at 41.67 k symbol/s with a carrier frequency of 100 kHz demonstrate the feasibility of the proposed algorithm.","PeriodicalId":422747,"journal":{"name":"2008 5th IEEE Sensor Array and Multichannel Signal Processing Workshop","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117179601","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 : 2008-07-21DOI: 10.1109/SAM.2008.4606816
K.T. Phany, S. Vorobyov, N. Sidiropoulos, C. Tellambura
Secondary spectrum usage has the potential to considerably increase spectrum utilization. In this paper, quality-of-service (QoS)-aware spectrum underlay is considered. A multi-antenna access point transmits common information to a set of secondary receivers, by means of appropriate beamforming; the objective is to maximize the multicast beamforming rate (or, equivalently, minimize the signal to noise ratio) for the secondary receivers, while explicitly limiting interference to primary receivers. The formulation incorporates the pragmatic case of inaccurate channel state information (CSI) for both primary and secondary users. Simulation examples illustrate the effectiveness of the proposed approach.
{"title":"Spectrum sharing in wireless networks: A QOS-aware secondary multicast approach with worst user performance optimization","authors":"K.T. Phany, S. Vorobyov, N. Sidiropoulos, C. Tellambura","doi":"10.1109/SAM.2008.4606816","DOIUrl":"https://doi.org/10.1109/SAM.2008.4606816","url":null,"abstract":"Secondary spectrum usage has the potential to considerably increase spectrum utilization. In this paper, quality-of-service (QoS)-aware spectrum underlay is considered. A multi-antenna access point transmits common information to a set of secondary receivers, by means of appropriate beamforming; the objective is to maximize the multicast beamforming rate (or, equivalently, minimize the signal to noise ratio) for the secondary receivers, while explicitly limiting interference to primary receivers. The formulation incorporates the pragmatic case of inaccurate channel state information (CSI) for both primary and secondary users. Simulation examples illustrate the effectiveness of the proposed approach.","PeriodicalId":422747,"journal":{"name":"2008 5th IEEE Sensor Array and Multichannel Signal Processing Workshop","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128565438","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 : 2008-07-21DOI: 10.1109/SAM.2008.4606900
F. Rubio, X. Mestre
In this paper, we propose an estimator of the eigenspectrum of the array observation covariance matrix that builds upon the well-known power method and is consistent for an arbitrarily large array dimension. Traditional estimators based on the eigendecomposition of the sample covariance matrix are known to be consistent provided that the number of observations grow to infinity with respect to any other dimension in the signal model. On the contrary, in order to avoid the loss in the estimation accuracy associated with practical finite sample-size situations, a generalization of the conventional implementation is derived that proves to be a very good approximation for a sample-size and an array dimension that are comparatively large. The proposed solution is applied to the construction of a subspace-based extension of the Capon source power estimator. For our purposes, we resort to the theory of the spectral analysis of large dimensional random matrices, or random matrix theory. As it is shown via numerical simulations, the new estimator turns out to allow for a significantly improved estimation accuracy in practical finite sample-support scenarios.
{"title":"On the estimation of the covariance eigenspectrum of array sample observations","authors":"F. Rubio, X. Mestre","doi":"10.1109/SAM.2008.4606900","DOIUrl":"https://doi.org/10.1109/SAM.2008.4606900","url":null,"abstract":"In this paper, we propose an estimator of the eigenspectrum of the array observation covariance matrix that builds upon the well-known power method and is consistent for an arbitrarily large array dimension. Traditional estimators based on the eigendecomposition of the sample covariance matrix are known to be consistent provided that the number of observations grow to infinity with respect to any other dimension in the signal model. On the contrary, in order to avoid the loss in the estimation accuracy associated with practical finite sample-size situations, a generalization of the conventional implementation is derived that proves to be a very good approximation for a sample-size and an array dimension that are comparatively large. The proposed solution is applied to the construction of a subspace-based extension of the Capon source power estimator. For our purposes, we resort to the theory of the spectral analysis of large dimensional random matrices, or random matrix theory. As it is shown via numerical simulations, the new estimator turns out to allow for a significantly improved estimation accuracy in practical finite sample-support scenarios.","PeriodicalId":422747,"journal":{"name":"2008 5th IEEE Sensor Array and Multichannel Signal Processing Workshop","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127843160","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 : 2008-07-21DOI: 10.1109/SAM.2008.4606826
M. Schoor, Bin Yang
Calibration of an antenna array is very important for high-resolution direction-of-arrival (DOA) estimation. In this paper, we study this issue for an automotive frequency modulated continuous wave (FMCW) radar whose low-cost dielectric lens antenna causes, in addition to the coupling between sensor elements and gain or phase mismatch, direction-dependent perturbations to the sensor response. We apply both global and local calibration methods and compare their performance.
{"title":"Local and global calibration for high-resolution doa estimation in automotive radar","authors":"M. Schoor, Bin Yang","doi":"10.1109/SAM.2008.4606826","DOIUrl":"https://doi.org/10.1109/SAM.2008.4606826","url":null,"abstract":"Calibration of an antenna array is very important for high-resolution direction-of-arrival (DOA) estimation. In this paper, we study this issue for an automotive frequency modulated continuous wave (FMCW) radar whose low-cost dielectric lens antenna causes, in addition to the coupling between sensor elements and gain or phase mismatch, direction-dependent perturbations to the sensor response. We apply both global and local calibration methods and compare their performance.","PeriodicalId":422747,"journal":{"name":"2008 5th IEEE Sensor Array and Multichannel Signal Processing Workshop","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121429752","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 : 2008-07-21DOI: 10.1109/SAM.2008.4606827
U. Nickel
Higher Order Statistics (HOS) have been proposed to achieve improvements over second order statistics array processing for various applications. We investigate the potential for angle estimation and source resolution with a very small planar array with 3 elements. We use the MUSIC method as generic DOA estimator. Using standard array theory we evaluate conditions under which an improvement in resolution can be obtained. A critical feature is the higher sensitivity of HOS methods to sources of unequal power. In this case standard MUSIC can perform better. A parallel complementary use of both methods is therefore recommended.
{"title":"Resolution enhancement by HOS for small planar arrays","authors":"U. Nickel","doi":"10.1109/SAM.2008.4606827","DOIUrl":"https://doi.org/10.1109/SAM.2008.4606827","url":null,"abstract":"Higher Order Statistics (HOS) have been proposed to achieve improvements over second order statistics array processing for various applications. We investigate the potential for angle estimation and source resolution with a very small planar array with 3 elements. We use the MUSIC method as generic DOA estimator. Using standard array theory we evaluate conditions under which an improvement in resolution can be obtained. A critical feature is the higher sensitivity of HOS methods to sources of unequal power. In this case standard MUSIC can perform better. A parallel complementary use of both methods is therefore recommended.","PeriodicalId":422747,"journal":{"name":"2008 5th IEEE Sensor Array and Multichannel Signal Processing Workshop","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116491431","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 : 2008-07-21DOI: 10.1109/SAM.2008.4606882
Lei Yu, W. Liu, R. Langley
A novel adaptive beamforming method is proposed without the knowledge of the direction of arrival of the signal of interest. It is a combination of the traditional beamspace processing method and a recently proposed technique called ldquodomain weighted principal component analysis (DW-PCA)rdquo and can be applied to the case where the signal of interest is stronger than the interfering signals in both single-path and multi-path environments. Its effectiveness is verified by simulation results.
{"title":"Beamspace adaptive beamforming based on principle component analysis","authors":"Lei Yu, W. Liu, R. Langley","doi":"10.1109/SAM.2008.4606882","DOIUrl":"https://doi.org/10.1109/SAM.2008.4606882","url":null,"abstract":"A novel adaptive beamforming method is proposed without the knowledge of the direction of arrival of the signal of interest. It is a combination of the traditional beamspace processing method and a recently proposed technique called ldquodomain weighted principal component analysis (DW-PCA)rdquo and can be applied to the case where the signal of interest is stronger than the interfering signals in both single-path and multi-path environments. Its effectiveness is verified by simulation results.","PeriodicalId":422747,"journal":{"name":"2008 5th IEEE Sensor Array and Multichannel Signal Processing Workshop","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116521919","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 : 2008-07-21DOI: 10.1109/SAM.2008.4606848
Yimin D. Zhang, Xin Li, E. Monnerie, G. Pritchard, R. S. Cardozo
As utilities convert from manual meter reading to automated systems, a new set of operation challenges arise in the day-to-day operation of the metering system. One of the most significant problems occurs when a meter is installed, but the physical location of the meter has not been properly recorded by the utilitiespsila system of record. This condition is commonly referred to as an ldquoorphanrdquo meter. Current methods of locating orphan meters are manual and time intensive. This paper presents a new method for electronically locating orphan meters. The technique leverages spatio-temporal correlations between the reference meters and the orphan meter. Additional information, such as the received signal power, is also used to provide more robust location estimation performance. Ray-tracing simulation and field measurement results have shown promising localization results of the orphan meters.
{"title":"Localization of orphan utility meters based on spatio-temporal signature information","authors":"Yimin D. Zhang, Xin Li, E. Monnerie, G. Pritchard, R. S. Cardozo","doi":"10.1109/SAM.2008.4606848","DOIUrl":"https://doi.org/10.1109/SAM.2008.4606848","url":null,"abstract":"As utilities convert from manual meter reading to automated systems, a new set of operation challenges arise in the day-to-day operation of the metering system. One of the most significant problems occurs when a meter is installed, but the physical location of the meter has not been properly recorded by the utilitiespsila system of record. This condition is commonly referred to as an ldquoorphanrdquo meter. Current methods of locating orphan meters are manual and time intensive. This paper presents a new method for electronically locating orphan meters. The technique leverages spatio-temporal correlations between the reference meters and the orphan meter. Additional information, such as the received signal power, is also used to provide more robust location estimation performance. Ray-tracing simulation and field measurement results have shown promising localization results of the orphan meters.","PeriodicalId":422747,"journal":{"name":"2008 5th IEEE Sensor Array and Multichannel Signal Processing Workshop","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134623396","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}