Pub Date : 2009-03-18DOI: 10.1109/CISS.2009.5054841
Hyosung Kim, Jitendra Tugnait
We present an adaptive soft-input soft-output (SISO) turbo equalization receiver for doubly-selective channels. The proposed receiver exploits the complex exponential basis expansion model (CE-BEM) for the overall channel variations, and an autoregressive (AR) model for the BEM coefficients. We extend an existing turbo equalization approach based on symbol-wise AR modeling of channels to channels based on BEMs. Simulation examples and an EXIT chart analysis demonstrate that our CE-BEM-based approach outperforms the existing symbol-wise AR model-based turbo equalizer.
{"title":"Iterative (Turbo) equalization for doubly-selective channels using exponential basis expansion models","authors":"Hyosung Kim, Jitendra Tugnait","doi":"10.1109/CISS.2009.5054841","DOIUrl":"https://doi.org/10.1109/CISS.2009.5054841","url":null,"abstract":"We present an adaptive soft-input soft-output (SISO) turbo equalization receiver for doubly-selective channels. The proposed receiver exploits the complex exponential basis expansion model (CE-BEM) for the overall channel variations, and an autoregressive (AR) model for the BEM coefficients. We extend an existing turbo equalization approach based on symbol-wise AR modeling of channels to channels based on BEMs. Simulation examples and an EXIT chart analysis demonstrate that our CE-BEM-based approach outperforms the existing symbol-wise AR model-based turbo equalizer.","PeriodicalId":433796,"journal":{"name":"2009 43rd Annual Conference on Information Sciences and Systems","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115911610","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 : 2009-03-18DOI: 10.1109/CISS.2009.5054711
M. Charafeddine, A. Paulraj
Treating the interference as noise, the paper studies the first derivative of the frontiers which trace the achievable rates region of the 2-user interference channel. The achievable rates region in this case was found to be the convex hull of the union of two regions, each is bounded by a log-defined line. Those log-defined lines are characterized by holding one of the transmitters at full power, while the other transmitter sweeps its full power range [1]. Maximizing the sum rates for the 2-user interference channel translates to the study of the first intersection point with lines of slope -1 approaching the rates region from positive infinity. The paper achieves the same result reported in [2], that the maximum sum rates solution is one of three points: one user transmitting with full power while the other user is silent, or both users transmitting at full power simultaneously. The result in [2] is achieved through analysis of the objective function, while the solution presented herein follows from analyzing the first derivative of the rates region frontiers.
{"title":"Maximum sum rates via analysis of 2-user interference channel achievable rates region","authors":"M. Charafeddine, A. Paulraj","doi":"10.1109/CISS.2009.5054711","DOIUrl":"https://doi.org/10.1109/CISS.2009.5054711","url":null,"abstract":"Treating the interference as noise, the paper studies the first derivative of the frontiers which trace the achievable rates region of the 2-user interference channel. The achievable rates region in this case was found to be the convex hull of the union of two regions, each is bounded by a log-defined line. Those log-defined lines are characterized by holding one of the transmitters at full power, while the other transmitter sweeps its full power range [1]. Maximizing the sum rates for the 2-user interference channel translates to the study of the first intersection point with lines of slope -1 approaching the rates region from positive infinity. The paper achieves the same result reported in [2], that the maximum sum rates solution is one of three points: one user transmitting with full power while the other user is silent, or both users transmitting at full power simultaneously. The result in [2] is achieved through analysis of the objective function, while the solution presented herein follows from analyzing the first derivative of the rates region frontiers.","PeriodicalId":433796,"journal":{"name":"2009 43rd Annual Conference on Information Sciences and Systems","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120874364","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 : 2009-03-18DOI: 10.1109/CISS.2009.5054777
Yi Cao, Biao Chen
This paper considers the so-called cognitive Z channel, where two users transmit two independent messages to their respective receivers through a Z interference channel. User 1 (primary user) interferes with receiver 2 while user 2 (secondary user) does not interfere with receiver 1. In addition, user 2 overhears the transmission of user 1 through a noisy channel, hence the term ‘cognitive’. Capacity bounds for such channel in different parameter regimes are obtained and the impact of such causal cognition is carefully studied. In particular, depending on the channel parameters, the cognitive link may not be useful in terms of the capacity region. Numerical examples are also given.
{"title":"The cognitive Z channel","authors":"Yi Cao, Biao Chen","doi":"10.1109/CISS.2009.5054777","DOIUrl":"https://doi.org/10.1109/CISS.2009.5054777","url":null,"abstract":"This paper considers the so-called cognitive Z channel, where two users transmit two independent messages to their respective receivers through a Z interference channel. User 1 (primary user) interferes with receiver 2 while user 2 (secondary user) does not interfere with receiver 1. In addition, user 2 overhears the transmission of user 1 through a noisy channel, hence the term ‘cognitive’. Capacity bounds for such channel in different parameter regimes are obtained and the impact of such causal cognition is carefully studied. In particular, depending on the channel parameters, the cognitive link may not be useful in terms of the capacity region. Numerical examples are also given.","PeriodicalId":433796,"journal":{"name":"2009 43rd Annual Conference on Information Sciences and Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116492945","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 : 2009-03-18DOI: 10.1109/CISS.2009.5054818
A. A. Moghadam, H. Radha
In this paper, we propose a new approach for compressed sensing of integer-valued signals using prime numbers. In particular, we utilize the logarithmic values of prime numbers to construct projection matrices that are capable of significant reductions in the number of observations (m) needed for the recovery of integer-valued signals when compared to leading compressed-sensing methods. At one extreme, and under ideal conditions, the proposed Log of Prime-numbers (LoP) projection enables single-observation compressed sensing, where one sample (m = 1) can be used for the recovery of a sparse signal with N original integer samples. More importantly, we design a practical LoP projection system and a corresponding low-complexity solver that only requires m = k observations, where k is the sparsity of the signal S in some space ?. We compare the performance of the proposed LoP system with popular Basis Pursuit (BP) and Orthogonal Matching Pursuit (OMP) methods, and demonstrate the significant improvements that can be achieved by utilizing LoP projection matrices.
本文提出了一种利用素数对整数值信号进行压缩感知的新方法。特别是，我们利用素数的对数值来构建投影矩阵，与领先的压缩感知方法相比，该矩阵能够显著减少恢复整数值信号所需的观测数(m)。在一个极端和理想的条件下，所提出的Log of Prime-numbers (LoP)投影可以实现单观测压缩感知，其中一个样本(m = 1)可以用于恢复具有N个原始整数样本的稀疏信号。更重要的是，我们设计了一个实用的LoP投影系统和相应的低复杂度求解器，它只需要m = k个观测值，其中k为信号S在某个空间中的稀疏度。我们将所提出的LoP系统的性能与流行的基追踪(BP)和正交匹配追踪(OMP)方法进行了比较，并证明了使用LoP投影矩阵可以实现显著的改进。
{"title":"Practical compressed sensing with log-of-prime projections","authors":"A. A. Moghadam, H. Radha","doi":"10.1109/CISS.2009.5054818","DOIUrl":"https://doi.org/10.1109/CISS.2009.5054818","url":null,"abstract":"In this paper, we propose a new approach for compressed sensing of integer-valued signals using prime numbers. In particular, we utilize the logarithmic values of prime numbers to construct projection matrices that are capable of significant reductions in the number of observations (m) needed for the recovery of integer-valued signals when compared to leading compressed-sensing methods. At one extreme, and under ideal conditions, the proposed Log of Prime-numbers (LoP) projection enables single-observation compressed sensing, where one sample (m = 1) can be used for the recovery of a sparse signal with N original integer samples. More importantly, we design a practical LoP projection system and a corresponding low-complexity solver that only requires m = k observations, where k is the sparsity of the signal S in some space ?. We compare the performance of the proposed LoP system with popular Basis Pursuit (BP) and Orthogonal Matching Pursuit (OMP) methods, and demonstrate the significant improvements that can be achieved by utilizing LoP projection matrices.","PeriodicalId":433796,"journal":{"name":"2009 43rd Annual Conference on Information Sciences and Systems","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127230054","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 : 2009-03-18DOI: 10.1109/CISS.2009.5054736
H. Bagheri, A. Motahari, A. Khandani
We consider a two-user symmetric Gaussian Interference Channel (IC), in which one encoder is connected to the other by a unidirectional orthogonal cooperative link with specific capacity. In this setup, we employ a simplified Han-Kobayashi scheme used in [1], along with cooperative communication. We characterize the generalized degrees of freedom [1] of the channel for interference-limited regimes by comparing the achievable sum-rate with some existing upper bounds and also with a new upper bound, introduced in this paper. In particular, we express the number of degrees of freedom available for communication as a function of the interference-to-noise ratio and the multiplexing gain of the cooperative link. In addition, we give the sum-capacity of the channel for the strong interference regime when the capacity of the cooperative link is large enough in terms of the channel parameters. Finally, we show that for noise-limited regimes, treating interference as noise and not using the cooperative link, offer a sum-rate that is at most one bit less than the sum-capacity of the channel.
{"title":"Generalized degrees of freedom of the symmetric gaussian interference channel with partial unidirectional transmitter cooperation","authors":"H. Bagheri, A. Motahari, A. Khandani","doi":"10.1109/CISS.2009.5054736","DOIUrl":"https://doi.org/10.1109/CISS.2009.5054736","url":null,"abstract":"We consider a two-user symmetric Gaussian Interference Channel (IC), in which one encoder is connected to the other by a unidirectional orthogonal cooperative link with specific capacity. In this setup, we employ a simplified Han-Kobayashi scheme used in [1], along with cooperative communication. We characterize the generalized degrees of freedom [1] of the channel for interference-limited regimes by comparing the achievable sum-rate with some existing upper bounds and also with a new upper bound, introduced in this paper. In particular, we express the number of degrees of freedom available for communication as a function of the interference-to-noise ratio and the multiplexing gain of the cooperative link. In addition, we give the sum-capacity of the channel for the strong interference regime when the capacity of the cooperative link is large enough in terms of the channel parameters. Finally, we show that for noise-limited regimes, treating interference as noise and not using the cooperative link, offer a sum-rate that is at most one bit less than the sum-capacity of the channel.","PeriodicalId":433796,"journal":{"name":"2009 43rd Annual Conference on Information Sciences and Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125797285","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 : 2009-03-18DOI: 10.1109/CISS.2009.5054685
Samuel Cheng
We consider a generalized formulation for Slepian-Wolf coding based on the Wyner syndrome approach and present some preliminary theoretical results. We then describe how the compressed source can be decoded using belief propagation under our formulation. Simulation experiment results are given to show feasibility of the approach.
{"title":"Non-asymmetric Slepian-Wolf decoding using belief propagation","authors":"Samuel Cheng","doi":"10.1109/CISS.2009.5054685","DOIUrl":"https://doi.org/10.1109/CISS.2009.5054685","url":null,"abstract":"We consider a generalized formulation for Slepian-Wolf coding based on the Wyner syndrome approach and present some preliminary theoretical results. We then describe how the compressed source can be decoded using belief propagation under our formulation. Simulation experiment results are given to show feasibility of the approach.","PeriodicalId":433796,"journal":{"name":"2009 43rd Annual Conference on Information Sciences and Systems","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127796300","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 : 2009-03-18DOI: 10.1109/CISS.2009.5054729
Shanshan Zheng, T. Jiang, J. Baras
This paper compares the performance of parametric and non-parametric sequential change detection algorithms for detecting in-band wormholes in wireless ad hoc networks. The algorithms considered are the non-parametric cumulative sum (NP-CUSUM) and the repeated sequential probability ratio test (R-SPRT). Theoretical performance of the two is compared using metrics that take into account the algorithms' repeated nature, and the advantage of the parametric method is illustrated. On the other hand, connections between the parametric and non-parametric methods are made in the proposed worst case adversary model, where the non-parametric method is shown to be more robust to attack strategy changes. Experimental evaluation of wormhole detection schemes based on the two algorithms is presented. This work has implications for both the theoretical understanding and practical design of wormhole detection schemes based on parametric and nonparametric change detection algorithms.
{"title":"Performance comparison of two sequential change detection algorithms on detection of in-band wormholes","authors":"Shanshan Zheng, T. Jiang, J. Baras","doi":"10.1109/CISS.2009.5054729","DOIUrl":"https://doi.org/10.1109/CISS.2009.5054729","url":null,"abstract":"This paper compares the performance of parametric and non-parametric sequential change detection algorithms for detecting in-band wormholes in wireless ad hoc networks. The algorithms considered are the non-parametric cumulative sum (NP-CUSUM) and the repeated sequential probability ratio test (R-SPRT). Theoretical performance of the two is compared using metrics that take into account the algorithms' repeated nature, and the advantage of the parametric method is illustrated. On the other hand, connections between the parametric and non-parametric methods are made in the proposed worst case adversary model, where the non-parametric method is shown to be more robust to attack strategy changes. Experimental evaluation of wormhole detection schemes based on the two algorithms is presented. This work has implications for both the theoretical understanding and practical design of wormhole detection schemes based on parametric and nonparametric change detection algorithms.","PeriodicalId":433796,"journal":{"name":"2009 43rd Annual Conference on Information Sciences and Systems","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127944259","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 : 2009-03-18DOI: 10.1109/CISS.2009.5054741
J. Almodovar, J. Nelson
We consider the estimation of the locations of multiple transmitters based on received signal strength measurements at a network of randomly-placed receivers. We develop a simple and computationally efficient interference subtraction method for estimating the locations of multiple emitters that transmit simultaneously in adjacent coverage areas. The method estimates the location of each emitter independently by computing a low-complexity approximation to the maximum likelihood location estimate. Results reveal that, under constraints on computational complexity, the proposed interference subtraction method outperforms competing schemes in multiple transmitter localization.
{"title":"Multiple transmitter localization via interference subtraction","authors":"J. Almodovar, J. Nelson","doi":"10.1109/CISS.2009.5054741","DOIUrl":"https://doi.org/10.1109/CISS.2009.5054741","url":null,"abstract":"We consider the estimation of the locations of multiple transmitters based on received signal strength measurements at a network of randomly-placed receivers. We develop a simple and computationally efficient interference subtraction method for estimating the locations of multiple emitters that transmit simultaneously in adjacent coverage areas. The method estimates the location of each emitter independently by computing a low-complexity approximation to the maximum likelihood location estimate. Results reveal that, under constraints on computational complexity, the proposed interference subtraction method outperforms competing schemes in multiple transmitter localization.","PeriodicalId":433796,"journal":{"name":"2009 43rd Annual Conference on Information Sciences and Systems","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127509417","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 : 2009-03-18DOI: 10.1109/CISS.2009.5054699
Xiantao Sun, L. Cimini, L. Greenstein, D. Chan
An orthogonal frequency division multiplexing (OFDM) system suffers performance degradation when the length of the cyclic prefix (CP) is less than the channel impulse response. The root cause of this degradation is the inter-carrier interference (ICI) and inter-symbol interference (ISI) introduced by the excessive multipath delay. Generally, MIMO beamforming is helpful in mitigating such interference because it can spatially suppress some of the multipath. However, the effectiveness of this suppression is very limited. In this paper, we propose an ICI/ISIaware beamforming algorithm which explicitly takes into account the multipath characteristic of the channel. Optimal steering vectors are derived to maximize the signal-to-interference-plus-noise ratio (SINR). This technique not only achieves the beamforming benefit, but also significantly mitigates the ICI and ISI. We show, via simulations, that the proposed algorithm can dramatically reduce the block error rate, permitting good performance for channel delay profiles that would break conventional links. This is vitally important for the extension of indoor WLAN designs to outdoor uses.
{"title":"ICI/ISI aware beamforming for MIMO-OFDM wireless system","authors":"Xiantao Sun, L. Cimini, L. Greenstein, D. Chan","doi":"10.1109/CISS.2009.5054699","DOIUrl":"https://doi.org/10.1109/CISS.2009.5054699","url":null,"abstract":"An orthogonal frequency division multiplexing (OFDM) system suffers performance degradation when the length of the cyclic prefix (CP) is less than the channel impulse response. The root cause of this degradation is the inter-carrier interference (ICI) and inter-symbol interference (ISI) introduced by the excessive multipath delay. Generally, MIMO beamforming is helpful in mitigating such interference because it can spatially suppress some of the multipath. However, the effectiveness of this suppression is very limited. In this paper, we propose an ICI/ISIaware beamforming algorithm which explicitly takes into account the multipath characteristic of the channel. Optimal steering vectors are derived to maximize the signal-to-interference-plus-noise ratio (SINR). This technique not only achieves the beamforming benefit, but also significantly mitigates the ICI and ISI. We show, via simulations, that the proposed algorithm can dramatically reduce the block error rate, permitting good performance for channel delay profiles that would break conventional links. This is vitally important for the extension of indoor WLAN designs to outdoor uses.","PeriodicalId":433796,"journal":{"name":"2009 43rd Annual Conference on Information Sciences and Systems","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127648137","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 : 2009-03-18DOI: 10.1109/CISS.2009.5054805
Yasuhiro Ito, Kazuki Saruta, Yuki Terata, K. Takeda
Visual category recognition is challenging in computer vision and has several problem. Some of problems on visual category recognition are variance to the object instance position and background clutter. In this paper, we propose method select region of interest(ROI) in training and recognizing automatically. This provide invariance to object instance position and removing background clutter. In training phase, we make object detector to select ROI in recognizing automatically. The object detector is made by training regions of object and non-object, which determine a ROI without user annotation by using class label and some same class image of set of training image set. In this paper, the set of experiments is on the image database. We prove our proposed method can achieve high accuracy and recognize object position in training and recognizing
{"title":"Category classification with ROIs using object detector","authors":"Yasuhiro Ito, Kazuki Saruta, Yuki Terata, K. Takeda","doi":"10.1109/CISS.2009.5054805","DOIUrl":"https://doi.org/10.1109/CISS.2009.5054805","url":null,"abstract":"Visual category recognition is challenging in computer vision and has several problem. Some of problems on visual category recognition are variance to the object instance position and background clutter. In this paper, we propose method select region of interest(ROI) in training and recognizing automatically. This provide invariance to object instance position and removing background clutter. In training phase, we make object detector to select ROI in recognizing automatically. The object detector is made by training regions of object and non-object, which determine a ROI without user annotation by using class label and some same class image of set of training image set. In this paper, the set of experiments is on the image database. We prove our proposed method can achieve high accuracy and recognize object position in training and recognizing","PeriodicalId":433796,"journal":{"name":"2009 43rd Annual Conference on Information Sciences and Systems","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128753736","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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