Pub Date : 2004-10-20DOI: 10.1109/ISIT.2004.1365181
C. Fragouli, E. Soljanin
A subtree decomposition method for network coding is proposed in this paper. This approach enables derivation of tight bounds on the network code alphabet size, makes connections with convolutional codes transparent, allows specification of coding operations at network nodes without the knowledge of the overall network topology, and facilitates design of codes which can easily accommodate future changes in the network, such as addition of receivers and loss of links.
{"title":"Subtree decomposition for network coding","authors":"C. Fragouli, E. Soljanin","doi":"10.1109/ISIT.2004.1365181","DOIUrl":"https://doi.org/10.1109/ISIT.2004.1365181","url":null,"abstract":"A subtree decomposition method for network coding is proposed in this paper. This approach enables derivation of tight bounds on the network code alphabet size, makes connections with convolutional codes transparent, allows specification of coding operations at network nodes without the knowledge of the overall network topology, and facilitates design of codes which can easily accommodate future changes in the network, such as addition of receivers and loss of links.","PeriodicalId":269907,"journal":{"name":"International Symposium onInformation Theory, 2004. ISIT 2004. Proceedings.","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114692851","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 : 2004-10-20DOI: 10.1109/ISIT.2004.1365554
Z. Luo, Jinjun Xiao
We consider the decentralized estimation of a noise-corrupted deterministic parameter by a bandwidth constrained sensor network with a fusion center. We construct a decentralized estimation scheme (DES) where each sensor compresses its observation to a small number of bits with length proportional to the logarithm of its local Signal to Noise Ratio (SNR). The resulting compressed bits from different sensors are then collected and combined by the fusion center to estimate the unknown parameter. The proposed DES is universal in the sense that the local sensor compression schemes and final fusion function are independent of noise pdf. We show that its mean squared error is within a constant factor to that achieved by the classical centralized best linear unbiased estimator (BLUE).
{"title":"Decentralized estimation in an inhomogeneous environment","authors":"Z. Luo, Jinjun Xiao","doi":"10.1109/ISIT.2004.1365554","DOIUrl":"https://doi.org/10.1109/ISIT.2004.1365554","url":null,"abstract":"We consider the decentralized estimation of a noise-corrupted deterministic parameter by a bandwidth constrained sensor network with a fusion center. We construct a decentralized estimation scheme (DES) where each sensor compresses its observation to a small number of bits with length proportional to the logarithm of its local Signal to Noise Ratio (SNR). The resulting compressed bits from different sensors are then collected and combined by the fusion center to estimate the unknown parameter. The proposed DES is universal in the sense that the local sensor compression schemes and final fusion function are independent of noise pdf. We show that its mean squared error is within a constant factor to that achieved by the classical centralized best linear unbiased estimator (BLUE).","PeriodicalId":269907,"journal":{"name":"International Symposium onInformation Theory, 2004. ISIT 2004. Proceedings.","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126677758","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 : 2004-10-20DOI: 10.1109/ISIT.2004.1365286
J. Chamberland, V. Veeravalli
A binary decentralized detection problem in which sensor nodes provide partial information about their environment to a fusion center is studied. The nodes have access to conditionally independent observations and transmit a summary of their own data over wireless channels. Upon reception of the information, the fusion center attempts to accurately reconstruct the state of nature. The communication link between each node and the fusion center is modeled as a fading channel corrupted by additive noise. Channel state information is available at the fusion center and at the sensor nodes. Large deviation theory is used to show that having identical sensor nodes is asymptotically optimal. Algorithms in which each sensor node selects a signaling/coding schemes based on the quality of its channel are studied.
{"title":"Adaptive signaling schemes for detection in wireless sensor networks","authors":"J. Chamberland, V. Veeravalli","doi":"10.1109/ISIT.2004.1365286","DOIUrl":"https://doi.org/10.1109/ISIT.2004.1365286","url":null,"abstract":"A binary decentralized detection problem in which sensor nodes provide partial information about their environment to a fusion center is studied. The nodes have access to conditionally independent observations and transmit a summary of their own data over wireless channels. Upon reception of the information, the fusion center attempts to accurately reconstruct the state of nature. The communication link between each node and the fusion center is modeled as a fading channel corrupted by additive noise. Channel state information is available at the fusion center and at the sensor nodes. Large deviation theory is used to show that having identical sensor nodes is asymptotically optimal. Algorithms in which each sensor node selects a signaling/coding schemes based on the quality of its channel are studied.","PeriodicalId":269907,"journal":{"name":"International Symposium onInformation Theory, 2004. ISIT 2004. Proceedings.","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128330899","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 : 2004-10-20DOI: 10.1109/ISIT.2004.1365307
I. Marić, R. Yates
For reliable and unreliable forwarding in a parallel-relay network that allows orthogonal transmissions, we maximize the achievable rate under the total power constraint over all nodes. In such a network, the energy cost per information bit [S. Verdu, 1990] during the reliable forwarding is minimized in the wideband regime. For the wideband decode-and-forward (DF) strategy, we show that the optimum parallel-relay solution is to send the data through one relay that is in the "best" position. On the other hand, as observed in [B.E. Schein, 2001], the benefit of unreliable amplify-and-forward (AF) strategy diminishes in the wideband regime. We characterize the optimum bandwidth for AF and show that transmitting in the optimum bandwidth allows the network to operate in the linear regime where the achieved rate increases linearly with transmit power. We identify the best subset of AF relay nodes and characterize the optimum power allocation per dimension among relays.
{"title":"Forwarding strategies for Gaussian parallel-relay networks","authors":"I. Marić, R. Yates","doi":"10.1109/ISIT.2004.1365307","DOIUrl":"https://doi.org/10.1109/ISIT.2004.1365307","url":null,"abstract":"For reliable and unreliable forwarding in a parallel-relay network that allows orthogonal transmissions, we maximize the achievable rate under the total power constraint over all nodes. In such a network, the energy cost per information bit [S. Verdu, 1990] during the reliable forwarding is minimized in the wideband regime. For the wideband decode-and-forward (DF) strategy, we show that the optimum parallel-relay solution is to send the data through one relay that is in the \"best\" position. On the other hand, as observed in [B.E. Schein, 2001], the benefit of unreliable amplify-and-forward (AF) strategy diminishes in the wideband regime. We characterize the optimum bandwidth for AF and show that transmitting in the optimum bandwidth allows the network to operate in the linear regime where the achieved rate increases linearly with transmit power. We identify the best subset of AF relay nodes and characterize the optimum power allocation per dimension among relays.","PeriodicalId":269907,"journal":{"name":"International Symposium onInformation Theory, 2004. ISIT 2004. Proceedings.","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126509980","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 : 2004-10-20DOI: 10.1109/ISIT.2004.1365446
Hsiao-feng Lu, P. V. Kumar
This paper presents an optimal construction of space-time codes over multiple fading blocks and over a variety of constellations including PAM, QAM and 2/sup K/-ary PSK. The constructions can be used for any numbers of transmit antennas and for any desirable transmit diversity gain.
{"title":"Optimal constructions of space-time codes over multiple fading blocks","authors":"Hsiao-feng Lu, P. V. Kumar","doi":"10.1109/ISIT.2004.1365446","DOIUrl":"https://doi.org/10.1109/ISIT.2004.1365446","url":null,"abstract":"This paper presents an optimal construction of space-time codes over multiple fading blocks and over a variety of constellations including PAM, QAM and 2/sup K/-ary PSK. The constructions can be used for any numbers of transmit antennas and for any desirable transmit diversity gain.","PeriodicalId":269907,"journal":{"name":"International Symposium onInformation Theory, 2004. ISIT 2004. Proceedings.","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116813024","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 : 2004-10-20DOI: 10.1109/ISIT.2004.1365284
P. Gupta, Y. Sankarasubramaniam, A. Stolyar
A class of distributed scheduling algorithms, Regulated Contention Medium Access Control (RCMAC), which provides dynamic prioritized access to users for service differentiation, is considered in this paper. In addition to WLANs, the basic concepts of RCMAC have applications in multihop cellular and ad hoc networks and emerging sensor networks. Furthermore, by regulating multiuser contention, RCMAC achieves higher throughput when traffic is bursty. In this paper, differential function with two special cases like weight proportional and old base regulation is presented. Arrivals at each user are bursty, generated using standard two-state Markov model and the multiplicative increase/decrease rule are employed.
{"title":"Distributed scheduling in wireless data networks with service differentiation","authors":"P. Gupta, Y. Sankarasubramaniam, A. Stolyar","doi":"10.1109/ISIT.2004.1365284","DOIUrl":"https://doi.org/10.1109/ISIT.2004.1365284","url":null,"abstract":"A class of distributed scheduling algorithms, Regulated Contention Medium Access Control (RCMAC), which provides dynamic prioritized access to users for service differentiation, is considered in this paper. In addition to WLANs, the basic concepts of RCMAC have applications in multihop cellular and ad hoc networks and emerging sensor networks. Furthermore, by regulating multiuser contention, RCMAC achieves higher throughput when traffic is bursty. In this paper, differential function with two special cases like weight proportional and old base regulation is presented. Arrivals at each user are bursty, generated using standard two-state Markov model and the multiplicative increase/decrease rule are employed.","PeriodicalId":269907,"journal":{"name":"International Symposium onInformation Theory, 2004. ISIT 2004. Proceedings.","volume":"134 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124885616","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 : 2004-10-20DOI: 10.1109/ISIT.2004.1365136
Hsiao-feng Lu, P. V. Kumar
In this paper, a systematic method for constructing space-time block codes that are optimal in terms of achieving the rate-diversity tradeoff over a large variety of signal constellations whose sizes are power of a prime p is presented. The resulting signal constellation includes the p/sup K/-ary PAM, QAM, and PSK signallings as special cases. The construction is a generalization of the unified construction proposed by the authors earlier. It consists of a generalized unified mapper and a class of maximal, rank-d, p-codes over F/sub p/. The generalized unified construction can also be applied to build optimal space-time block and trellis codes.
{"title":"Generalized unified construction of space-time codes with optimal rate-diversity tradeoff","authors":"Hsiao-feng Lu, P. V. Kumar","doi":"10.1109/ISIT.2004.1365136","DOIUrl":"https://doi.org/10.1109/ISIT.2004.1365136","url":null,"abstract":"In this paper, a systematic method for constructing space-time block codes that are optimal in terms of achieving the rate-diversity tradeoff over a large variety of signal constellations whose sizes are power of a prime p is presented. The resulting signal constellation includes the p/sup K/-ary PAM, QAM, and PSK signallings as special cases. The construction is a generalization of the unified construction proposed by the authors earlier. It consists of a generalized unified mapper and a class of maximal, rank-d, p-codes over F/sub p/. The generalized unified construction can also be applied to build optimal space-time block and trellis codes.","PeriodicalId":269907,"journal":{"name":"International Symposium onInformation Theory, 2004. ISIT 2004. Proceedings.","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127112528","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 : 2004-10-20DOI: 10.1109/ISIT.2004.1365341
A. Orlitsky, Sajama, N. Santhanam, K. Viswanathan, Junan Zhang
We consider the problem of modeling a distribution whose alphabet size is large relative to the amount of observed data. It is well known that conventional maximum-likelihood estimates do not perform well in that regime. Instead, we find the distribution maximizing the probability of the data's pattern. We derive an efficient algorithm for approximating this distribution. Simulations show that the computed distribution models the data well and yields general estimators that evaluate various data attributes as well as specific estimators designed especially for these tasks
{"title":"Algorithms for modeling distributions over large alphabets","authors":"A. Orlitsky, Sajama, N. Santhanam, K. Viswanathan, Junan Zhang","doi":"10.1109/ISIT.2004.1365341","DOIUrl":"https://doi.org/10.1109/ISIT.2004.1365341","url":null,"abstract":"We consider the problem of modeling a distribution whose alphabet size is large relative to the amount of observed data. It is well known that conventional maximum-likelihood estimates do not perform well in that regime. Instead, we find the distribution maximizing the probability of the data's pattern. We derive an efficient algorithm for approximating this distribution. Simulations show that the computed distribution models the data well and yields general estimators that evaluate various data attributes as well as specific estimators designed especially for these tasks","PeriodicalId":269907,"journal":{"name":"International Symposium onInformation Theory, 2004. ISIT 2004. Proceedings.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129746264","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 : 2004-10-20DOI: 10.1109/ISIT.2004.1365439
M. Yuksel, E. Erkip
We consider a wireless system consisting of one source, one destination and M relays. Assuming path loss and Rayleigh fading, we use the cutset upper bound to show that no matter where the relays are located, the maximum diversity one can obtain is M+1. However, one can achieve a higher diversity gain, namely /spl lfloor/(M+2/2)/sup 2//spl rfloor/, if /spl lfloor/M/2/spl rfloor/ of the relays are clustered with the source and /spl lceil/M/2/spl rceil/ with the destination. This result utilizes the observation that if two wireless nodes are very close, Rayleigh assumption breaks and the proper channel model is additive white Gaussian noise (AWGN). Hence to realize a virtual multiinput multioutput (MIMO) system, clustering is essential.
{"title":"Diversity gains and clustering in wireless relaying","authors":"M. Yuksel, E. Erkip","doi":"10.1109/ISIT.2004.1365439","DOIUrl":"https://doi.org/10.1109/ISIT.2004.1365439","url":null,"abstract":"We consider a wireless system consisting of one source, one destination and M relays. Assuming path loss and Rayleigh fading, we use the cutset upper bound to show that no matter where the relays are located, the maximum diversity one can obtain is M+1. However, one can achieve a higher diversity gain, namely /spl lfloor/(M+2/2)/sup 2//spl rfloor/, if /spl lfloor/M/2/spl rfloor/ of the relays are clustered with the source and /spl lceil/M/2/spl rceil/ with the destination. This result utilizes the observation that if two wireless nodes are very close, Rayleigh assumption breaks and the proper channel model is additive white Gaussian noise (AWGN). Hence to realize a virtual multiinput multioutput (MIMO) system, clustering is essential.","PeriodicalId":269907,"journal":{"name":"International Symposium onInformation Theory, 2004. ISIT 2004. Proceedings.","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125338263","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 : 2004-10-20DOI: 10.1109/ISIT.2004.1365462
Jae-Hyun Park, Jaeyoon Lee, Sang-Won Lee, Songnam Hong, Dong-joon Shin
The block coding scheme for OFDM, which is combining Golay complementary sequence with Reed-Muller code (GCRM) that limits PAPR up to 3 dB with error-correcting capability, has been introduced recently [J. A. Davis et al. (1999)]. However, the coding gain of GCRM cannot overcome ICI caused by frequency error in OFDM. In this paper, a new combined scheme of ICI self-cancellation [Y. Zhao et al. (2001)] [Y. Fu et al. (2002)] and GCRM code is proposed. This scheme is analyzed to show that it limits PAPR up to 6 dB and can compensate the nonlinear distortion by TWTA. It is also verified that for the low back-off value of TWTA, our scheme shows better performance than GCRM.
OFDM的分组编码方案结合了Golay互补序列和Reed-Muller码(GCRM),将PAPR限制在3db以内,并具有纠错能力,最近被引入[J]。A. Davis et al.(1999)。然而,GCRM的编码增益无法克服OFDM中频率误差带来的ICI。本文提出了一种新的ICI自抵消组合格式[Y。赵等(2001)[j]。Fu et al.(2002)],并提出了GCRM代码。分析结果表明,该方案可将PAPR限制在6 dB以内,并可通过TWTA补偿非线性失真。验证了由于TWTA的回退值较低,我们的方案比GCRM具有更好的性能。
{"title":"ICI self cancellation - Golay complementary Reed-Muller code scheme for OFDM systems","authors":"Jae-Hyun Park, Jaeyoon Lee, Sang-Won Lee, Songnam Hong, Dong-joon Shin","doi":"10.1109/ISIT.2004.1365462","DOIUrl":"https://doi.org/10.1109/ISIT.2004.1365462","url":null,"abstract":"The block coding scheme for OFDM, which is combining Golay complementary sequence with Reed-Muller code (GCRM) that limits PAPR up to 3 dB with error-correcting capability, has been introduced recently [J. A. Davis et al. (1999)]. However, the coding gain of GCRM cannot overcome ICI caused by frequency error in OFDM. In this paper, a new combined scheme of ICI self-cancellation [Y. Zhao et al. (2001)] [Y. Fu et al. (2002)] and GCRM code is proposed. This scheme is analyzed to show that it limits PAPR up to 6 dB and can compensate the nonlinear distortion by TWTA. It is also verified that for the low back-off value of TWTA, our scheme shows better performance than GCRM.","PeriodicalId":269907,"journal":{"name":"International Symposium onInformation Theory, 2004. ISIT 2004. Proceedings.","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117038106","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}