Pub Date : 2008-08-15DOI: 10.1109/ITA.2008.4601029
B. Vellambi, F. Fekri
In this paper, we study the effect of finite buffer sizes on the (unicast) throughput in directed acyclic wired erasure networks. First, we motivate the problem by presenting the underlying idea of throughput estimation in wireline networks. We observe that the problem of exact throughput estimation for wireline networks is equivalent to the calculation of steady state probabilities for a regular, ergodic Markov chain. We extend the ideas of rate loss and information leakage due to buffer overflow (i.e., discarding of packets) at nodes to general wired acyclic packet networks. We then use the estimates of the loss in rate at various nodes to derive simple and easily estimable bounds on the maximum achievable rate of information transmission during unicast sessions in such networks.
{"title":"On the throughput of acyclic wired packet networks with finite buffers","authors":"B. Vellambi, F. Fekri","doi":"10.1109/ITA.2008.4601029","DOIUrl":"https://doi.org/10.1109/ITA.2008.4601029","url":null,"abstract":"In this paper, we study the effect of finite buffer sizes on the (unicast) throughput in directed acyclic wired erasure networks. First, we motivate the problem by presenting the underlying idea of throughput estimation in wireline networks. We observe that the problem of exact throughput estimation for wireline networks is equivalent to the calculation of steady state probabilities for a regular, ergodic Markov chain. We extend the ideas of rate loss and information leakage due to buffer overflow (i.e., discarding of packets) at nodes to general wired acyclic packet networks. We then use the estimates of the loss in rate at various nodes to derive simple and easily estimable bounds on the maximum achievable rate of information transmission during unicast sessions in such networks.","PeriodicalId":345196,"journal":{"name":"2008 Information Theory and Applications Workshop","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114918227","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 : 2008-08-15DOI: 10.1109/ITA.2008.4601089
E. Yang, Dake He
In near lossless source coding with decoder only side information, i.e., Slepian-Wolf coding (with one encoder), a source X with finite alphabet X is first encoded, and then later decoded subject to a small error probability with the help of side information Y with finite alphabet Y available only to the decoder. The classical result by Slepian and Wolf shows that the minimum average compression rate achievable asymptotically subject to a small error probability constraint for a memoryless pair (X , Y) is given by the conditional entropy H(X|Y). In this paper, we look beyond conditional entropy and investigate the tradeoff between compression rate and decoding error spectrum in Slepian-Wolf coding when the decoding error probability goes to zero exponentially fast. It is shown that when the decoding error probability goes to zero at the speed of 2-deltan, where delta is a positive constant and n denotes the source sequences' length, the minimum average compression rate achievable asymptotically is strictly greater than H(X|Y) regardless of how small delta is. More specifically, the minimum average compression rate achievable asymptotically is lower bounded by a quantity called the intrinsic conditional entropy Hin(X|Y, delta), which is strictly greater than H(X|Y), and is also asymptotically achievable for small delta.
{"title":"Near lossless source coding with side information at the decoder: Beyond conditional entropy","authors":"E. Yang, Dake He","doi":"10.1109/ITA.2008.4601089","DOIUrl":"https://doi.org/10.1109/ITA.2008.4601089","url":null,"abstract":"In near lossless source coding with decoder only side information, i.e., Slepian-Wolf coding (with one encoder), a source X with finite alphabet X is first encoded, and then later decoded subject to a small error probability with the help of side information Y with finite alphabet Y available only to the decoder. The classical result by Slepian and Wolf shows that the minimum average compression rate achievable asymptotically subject to a small error probability constraint for a memoryless pair (X , Y) is given by the conditional entropy H(X|Y). In this paper, we look beyond conditional entropy and investigate the tradeoff between compression rate and decoding error spectrum in Slepian-Wolf coding when the decoding error probability goes to zero exponentially fast. It is shown that when the decoding error probability goes to zero at the speed of 2-deltan, where delta is a positive constant and n denotes the source sequences' length, the minimum average compression rate achievable asymptotically is strictly greater than H(X|Y) regardless of how small delta is. More specifically, the minimum average compression rate achievable asymptotically is lower bounded by a quantity called the intrinsic conditional entropy Hin(X|Y, delta), which is strictly greater than H(X|Y), and is also asymptotically achievable for small delta.","PeriodicalId":345196,"journal":{"name":"2008 Information Theory and Applications Workshop","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115027771","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 : 2008-08-15DOI: 10.1109/ITA.2008.4601038
B. Hochwald, H. Artés
Recent work on wireless beamforming has focused on multi-user diversity effects, where terminals are chosen opportunistically based on their responses to test beams. Orthogonality between the test beams is typically chosen to aid subsequent interference-free transmission to the corresponding terminals. However, much of this work assumes that: (i) the pool of terminals on a given frequency-band is large enough that a subset of terminals can be found whose spatial signatures match the test beams; (ii) the responses to the test beams of the entire pool are known to the basestation; (iii) beamforming considerations can drive traffic scheduling and resource allocation. These conditions are not always met. Rather, we examine orthogonalizing a given set of beams for terminals that are chosen randomly or according to other resource considerations. Our orthogonalization is chosen to maximize the beamforming gain to the desired terminals, with the intent that other terminals may then ldquoeavesdroprdquo on the beamformed signals, knowing that the beams are orthogonal. These orthogonal beams can be used for training channel state information even if the actual beams are not known. We distinguish between frequency-division duplex and time-division duplex systems and show that there are training advantages for each.
{"title":"Orthogonalizing a random set of beams","authors":"B. Hochwald, H. Artés","doi":"10.1109/ITA.2008.4601038","DOIUrl":"https://doi.org/10.1109/ITA.2008.4601038","url":null,"abstract":"Recent work on wireless beamforming has focused on multi-user diversity effects, where terminals are chosen opportunistically based on their responses to test beams. Orthogonality between the test beams is typically chosen to aid subsequent interference-free transmission to the corresponding terminals. However, much of this work assumes that: (i) the pool of terminals on a given frequency-band is large enough that a subset of terminals can be found whose spatial signatures match the test beams; (ii) the responses to the test beams of the entire pool are known to the basestation; (iii) beamforming considerations can drive traffic scheduling and resource allocation. These conditions are not always met. Rather, we examine orthogonalizing a given set of beams for terminals that are chosen randomly or according to other resource considerations. Our orthogonalization is chosen to maximize the beamforming gain to the desired terminals, with the intent that other terminals may then ldquoeavesdroprdquo on the beamformed signals, knowing that the beams are orthogonal. These orthogonal beams can be used for training channel state information even if the actual beams are not known. We distinguish between frequency-division duplex and time-division duplex systems and show that there are training advantages for each.","PeriodicalId":345196,"journal":{"name":"2008 Information Theory and Applications Workshop","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127655981","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 : 2008-08-15DOI: 10.1109/ITA.2008.4601036
Baback Moghaddam, Amit Gruber, Yair Weiss, S. Avidan
We extend the l0-norm ldquosubspectralrdquo algorithms developed for sparse-LDA (Moghaddam, 2006) and sparse-PCA (Moghaddam, 2006) to more general quadratic costs such as MSE in linear (or kernel) regression. The resulting ldquosparse least squaresrdquo (SLS) problem is also NP-hard, by way of its equivalence to a rank-1 sparse eigenvalue problem. Specifically, for minimizing general quadratic cost functions we use a highly-efficient method for direct eigenvalue computation based on partitioned matrix inverse techniques that leads to times103 speed-ups over standard eigenvalue decomposition. This increased efficiency mitigates the O(n4) complexity that limited the previous algorithmspsila utility for high-dimensional problems. Moreover, the new computation prioritizes the role of the less-myopic backward elimination stage which becomes even more efficient than forward selection. Similarly, branch-and-bound search for exact sparse least squares (ESLS) also benefits from partitioned matrix techniques. Our greedy sparse least squares (GSLS) algorithm generalizes Natarajanpsilas algorithm (Natarajan, 1995) also known as order-recursive matching pursuit (ORMP). Specifically, the forward pass of GSLS is exactly equivalent to ORMP but is more efficient, and by including the backward pass, which only doubles the computation, we can achieve a lower MSE than ORMP. In experimental comparisons with LARS (Efron, 2004), forward-GSLS is shown to be not only more efficient and accurate but more flexible in terms of choice of regularization.
{"title":"Sparse regression as a sparse eigenvalue problem","authors":"Baback Moghaddam, Amit Gruber, Yair Weiss, S. Avidan","doi":"10.1109/ITA.2008.4601036","DOIUrl":"https://doi.org/10.1109/ITA.2008.4601036","url":null,"abstract":"We extend the l0-norm ldquosubspectralrdquo algorithms developed for sparse-LDA (Moghaddam, 2006) and sparse-PCA (Moghaddam, 2006) to more general quadratic costs such as MSE in linear (or kernel) regression. The resulting ldquosparse least squaresrdquo (SLS) problem is also NP-hard, by way of its equivalence to a rank-1 sparse eigenvalue problem. Specifically, for minimizing general quadratic cost functions we use a highly-efficient method for direct eigenvalue computation based on partitioned matrix inverse techniques that leads to times103 speed-ups over standard eigenvalue decomposition. This increased efficiency mitigates the O(n4) complexity that limited the previous algorithmspsila utility for high-dimensional problems. Moreover, the new computation prioritizes the role of the less-myopic backward elimination stage which becomes even more efficient than forward selection. Similarly, branch-and-bound search for exact sparse least squares (ESLS) also benefits from partitioned matrix techniques. Our greedy sparse least squares (GSLS) algorithm generalizes Natarajanpsilas algorithm (Natarajan, 1995) also known as order-recursive matching pursuit (ORMP). Specifically, the forward pass of GSLS is exactly equivalent to ORMP but is more efficient, and by including the backward pass, which only doubles the computation, we can achieve a lower MSE than ORMP. In experimental comparisons with LARS (Efron, 2004), forward-GSLS is shown to be not only more efficient and accurate but more flexible in terms of choice of regularization.","PeriodicalId":345196,"journal":{"name":"2008 Information Theory and Applications Workshop","volume":"1993 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131008244","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 : 2008-08-15DOI: 10.1109/ITA.2008.4601031
H. Seferoglu, A. Lakshmikantha, A. Ganesh, P. Key
In this paper, we propose new dynamic decentralized multi-channel multiple access (MAC) protocols and study their performance. Our protocols build on slotted Aloha, but extend it in several ways to improve flow completion time and throughput, as follows: (i) channels are assigned to flows rather than packets to eliminate per packet collisions, thus the total number of collisions is reduced, and (ii) each flow owns or drops channels dynamically considering successful transmissions, thus the number of owned channels adapts to varying traffic. We present an analysis of the stability region and of flow completion times, for our algorithms, and show that one of them can achieve close to 100% throughput if flow sizes are large. We demonstrate by extensive simulations that, compared to current multi-channel MAC protocols, our algorithms improve flow completion time and throughput in wireless local area and mesh networks.
{"title":"Dynamic decentralized multi-channel MAC protocols","authors":"H. Seferoglu, A. Lakshmikantha, A. Ganesh, P. Key","doi":"10.1109/ITA.2008.4601031","DOIUrl":"https://doi.org/10.1109/ITA.2008.4601031","url":null,"abstract":"In this paper, we propose new dynamic decentralized multi-channel multiple access (MAC) protocols and study their performance. Our protocols build on slotted Aloha, but extend it in several ways to improve flow completion time and throughput, as follows: (i) channels are assigned to flows rather than packets to eliminate per packet collisions, thus the total number of collisions is reduced, and (ii) each flow owns or drops channels dynamically considering successful transmissions, thus the number of owned channels adapts to varying traffic. We present an analysis of the stability region and of flow completion times, for our algorithms, and show that one of them can achieve close to 100% throughput if flow sizes are large. We demonstrate by extensive simulations that, compared to current multi-channel MAC protocols, our algorithms improve flow completion time and throughput in wireless local area and mesh networks.","PeriodicalId":345196,"journal":{"name":"2008 Information Theory and Applications Workshop","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130991022","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 : 2008-08-15DOI: 10.1109/ITA.2008.4601030
M. Franceschini, R. Pighi, G. Ferrari, R. Raheli
In this paper, we investigate the relation between the quadrature amplitude modulation (QAM) input information rates (IRs) of multi-carrier (MC) and single carrier (SC) systems transmitted over inter-symbol interference (ISI) channels with additive white Gaussian noise (AWGN). In particular, considering uniform power spectrum transmission, we conjecture that, for a given channel impulse response, the IR corresponding to an SC input distribution is higher than that corresponding to an MC input distribution. We give an intuitive justification of our conjecture and confirm it, by means of numerical results, considering two sets of randomly generated channels.
{"title":"On information theoretic aspects of single- and multi-carrier communications","authors":"M. Franceschini, R. Pighi, G. Ferrari, R. Raheli","doi":"10.1109/ITA.2008.4601030","DOIUrl":"https://doi.org/10.1109/ITA.2008.4601030","url":null,"abstract":"In this paper, we investigate the relation between the quadrature amplitude modulation (QAM) input information rates (IRs) of multi-carrier (MC) and single carrier (SC) systems transmitted over inter-symbol interference (ISI) channels with additive white Gaussian noise (AWGN). In particular, considering uniform power spectrum transmission, we conjecture that, for a given channel impulse response, the IR corresponding to an SC input distribution is higher than that corresponding to an MC input distribution. We give an intuitive justification of our conjecture and confirm it, by means of numerical results, considering two sets of randomly generated channels.","PeriodicalId":345196,"journal":{"name":"2008 Information Theory and Applications Workshop","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131927559","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 : 2008-08-15DOI: 10.1109/ITA.2008.4601063
Zheng Wang, H. Sadjadpour, J. Garcia-Luna-Aceves
In this paper, we compute the throughput capacity of random wireless ad hoc networks in which nodes are endowed with multipacket reception (MPR) capabilities. We show that lambda(n) = Theta((R(n))(1-2/alpha)/n1/alpha) bits per second constitutes a tight bound for the throughput capacity of random wireless ad hoc networks using physical model, where alpha > 2 is the path loss parameter in the physical model, n is the total number of nodes in the network, and R(n) is the MPR receiver range. Compared to the original result derived for plain routing by Gupta and Kumar, MPR closes the capacity gap and achieves a capacity gain of at least Theta((log n)alpha-2/2alpha) when R(n) = Theta(radiclog n/n).
{"title":"Closing the capacity gap in wireless ad hoc networks using multi-packet reception","authors":"Zheng Wang, H. Sadjadpour, J. Garcia-Luna-Aceves","doi":"10.1109/ITA.2008.4601063","DOIUrl":"https://doi.org/10.1109/ITA.2008.4601063","url":null,"abstract":"In this paper, we compute the throughput capacity of random wireless ad hoc networks in which nodes are endowed with multipacket reception (MPR) capabilities. We show that lambda(n) = Theta((R(n))(1-2/alpha)/n1/alpha) bits per second constitutes a tight bound for the throughput capacity of random wireless ad hoc networks using physical model, where alpha > 2 is the path loss parameter in the physical model, n is the total number of nodes in the network, and R(n) is the MPR receiver range. Compared to the original result derived for plain routing by Gupta and Kumar, MPR closes the capacity gap and achieves a capacity gain of at least Theta((log n)alpha-2/2alpha) when R(n) = Theta(radiclog n/n).","PeriodicalId":345196,"journal":{"name":"2008 Information Theory and Applications Workshop","volume":"13 13","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132644146","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 : 2008-08-15DOI: 10.1109/ITA.2008.4601017
Y. Bresler
Spectrum-blind sampling (SBS), proposed in the mid-90psilas, is a sensing technique enabling minimum-rate sampling and reconstruction of signals with unknown but sparse spectra. SBS is applicable to continuous or discrete-index signals, finite or infinite length, in one or more dimensions. We revisit SBS and explore its relationship to compressive sensing (CS). On the one hand, recent results in CS provide efficient reconstruction techniques for SBS. On the other hand, SBS provides efficient structured designs for blind, non-adaptive sensing of spectrum-sparse signals with minimal sampling requirements, and formulation leading to reconstruction cost only linear in the amount of data, and robustness against noise.
{"title":"Spectrum-blind sampling and compressive sensing for continuous-index signals","authors":"Y. Bresler","doi":"10.1109/ITA.2008.4601017","DOIUrl":"https://doi.org/10.1109/ITA.2008.4601017","url":null,"abstract":"Spectrum-blind sampling (SBS), proposed in the mid-90psilas, is a sensing technique enabling minimum-rate sampling and reconstruction of signals with unknown but sparse spectra. SBS is applicable to continuous or discrete-index signals, finite or infinite length, in one or more dimensions. We revisit SBS and explore its relationship to compressive sensing (CS). On the one hand, recent results in CS provide efficient reconstruction techniques for SBS. On the other hand, SBS provides efficient structured designs for blind, non-adaptive sensing of spectrum-sparse signals with minimal sampling requirements, and formulation leading to reconstruction cost only linear in the amount of data, and robustness against noise.","PeriodicalId":345196,"journal":{"name":"2008 Information Theory and Applications Workshop","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127928357","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 : 2008-08-15DOI: 10.1109/ITA.2008.4601077
Xiaojun Tang, Ruoheng Liu, P. Spasojevic, H. Poor
In this paper, the hybrid automatic retransmission request (HARQ) coding scheme is revisited for a block-fading wire-tap channel, in which two legitimate users communicate over a block-fading channel in the presence of a passive eavesdropper who intercepts the transmissions through an independent block-fading channel. In this model, the transmitter obtains a 1-bit ACK/NACK feedback from the legitimate receiver via an error-free public channel. Both reliability and confidentiality of secure HARQ protocols are studied by the joint consideration of channel coding, secrecy coding, and retransmission protocols. In particular, the error and secrecy performance of repetition time diversity (RTD) and incremental redundancy (INR) schemes are investigated based on good Wyner code sequences, which ensure that the confidential message is decoded successfully by the legitimate receiver and is kept in total ignorance by the eavesdropper for a given set of channel realizations. This paper first illustrates that there exists a good rate-compatible Wyner code family which ensures a secure INR protocol. Next, two types of outage probabilities, connection outage and secrecy outage probabilities are defined in order to characterize the tradeoff between the reliability of the legitimate communication link and the confidentiality with respect to the eavesdropperpsilas link. For a given connection/secrecy outage probability pair, an achievable throughput of secure HARQ protocols is derived for block-fading channels. Finally, both asymptotic analysis and numerical computations demonstrate the benefits of HARQ protocols to throughput and secrecy.
{"title":"Coding schemes for confidential communications","authors":"Xiaojun Tang, Ruoheng Liu, P. Spasojevic, H. Poor","doi":"10.1109/ITA.2008.4601077","DOIUrl":"https://doi.org/10.1109/ITA.2008.4601077","url":null,"abstract":"In this paper, the hybrid automatic retransmission request (HARQ) coding scheme is revisited for a block-fading wire-tap channel, in which two legitimate users communicate over a block-fading channel in the presence of a passive eavesdropper who intercepts the transmissions through an independent block-fading channel. In this model, the transmitter obtains a 1-bit ACK/NACK feedback from the legitimate receiver via an error-free public channel. Both reliability and confidentiality of secure HARQ protocols are studied by the joint consideration of channel coding, secrecy coding, and retransmission protocols. In particular, the error and secrecy performance of repetition time diversity (RTD) and incremental redundancy (INR) schemes are investigated based on good Wyner code sequences, which ensure that the confidential message is decoded successfully by the legitimate receiver and is kept in total ignorance by the eavesdropper for a given set of channel realizations. This paper first illustrates that there exists a good rate-compatible Wyner code family which ensures a secure INR protocol. Next, two types of outage probabilities, connection outage and secrecy outage probabilities are defined in order to characterize the tradeoff between the reliability of the legitimate communication link and the confidentiality with respect to the eavesdropperpsilas link. For a given connection/secrecy outage probability pair, an achievable throughput of secure HARQ protocols is derived for block-fading channels. Finally, both asymptotic analysis and numerical computations demonstrate the benefits of HARQ protocols to throughput and secrecy.","PeriodicalId":345196,"journal":{"name":"2008 Information Theory and Applications Workshop","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130548900","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 : 2008-08-15DOI: 10.1109/ITA.2008.4601068
P. Schniter, L. Potter, Justin Ziniel
A low-complexity recursive procedure is presented for minimum mean squared error (MMSE) estimation in linear regression models. A Gaussian mixture is chosen as the prior on the unknown parameter vector. The algorithm returns both an approximate MMSE estimate of the parameter vector and a set of high posterior probability mixing parameters. Emphasis is given to the case of a sparse parameter vector. Numerical simulations demonstrate estimation performance and illustrate the distinctions between MMSE estimation and MAP model selection. The set of high probability mixing parameters not only provides MAP basis selection, but also yields relative probabilities that reveal potential ambiguity in the sparse model.
{"title":"Fast bayesian matching pursuit","authors":"P. Schniter, L. Potter, Justin Ziniel","doi":"10.1109/ITA.2008.4601068","DOIUrl":"https://doi.org/10.1109/ITA.2008.4601068","url":null,"abstract":"A low-complexity recursive procedure is presented for minimum mean squared error (MMSE) estimation in linear regression models. A Gaussian mixture is chosen as the prior on the unknown parameter vector. The algorithm returns both an approximate MMSE estimate of the parameter vector and a set of high posterior probability mixing parameters. Emphasis is given to the case of a sparse parameter vector. Numerical simulations demonstrate estimation performance and illustrate the distinctions between MMSE estimation and MAP model selection. The set of high probability mixing parameters not only provides MAP basis selection, but also yields relative probabilities that reveal potential ambiguity in the sparse model.","PeriodicalId":345196,"journal":{"name":"2008 Information Theory and Applications Workshop","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133569051","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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