2008 Information Theory and Applications Workshop最新文献_第6页

Near lossless source coding with side information at the decoder: Beyond conditional entropy 在解码器处具有侧信息的近无损源编码:超越条件熵

2008 Information Theory and Applications Workshop Pub Date : 2008-08-15 DOI: 10.1109/ITA.2008.4601089

E. Yang, Dake He

{"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}

引用次数: 2

On the throughput of acyclic wired packet networks with finite buffers 有限缓冲区下无环有线分组网络的吞吐量

2008 Information Theory and Applications Workshop Pub Date : 2008-08-15 DOI: 10.1109/ITA.2008.4601029

B. Vellambi, F. Fekri

引用次数: 5

Orthogonalizing a random set of beams 正交化一组随机的光束

2008 Information Theory and Applications Workshop Pub Date : 2008-08-15 DOI: 10.1109/ITA.2008.4601038

B. Hochwald, H. Artés

{"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}

引用次数: 0

Closing the capacity gap in wireless ad hoc networks using multi-packet reception 利用多包接收缩小无线自组织网络的容量差距

2008 Information Theory and Applications Workshop Pub Date : 2008-08-15 DOI: 10.1109/ITA.2008.4601063

Zheng Wang, H. Sadjadpour, J. Garcia-Luna-Aceves

引用次数: 5

On information theoretic aspects of single- and multi-carrier communications 单载波和多载波通信的信息理论研究

2008 Information Theory and Applications Workshop Pub Date : 2008-08-15 DOI: 10.1109/ITA.2008.4601030

M. Franceschini, R. Pighi, G. Ferrari, R. Raheli

引用次数: 5

Dynamic decentralized multi-channel MAC protocols 动态分散的多通道MAC协议

2008 Information Theory and Applications Workshop Pub Date : 2008-08-15 DOI: 10.1109/ITA.2008.4601031

H. Seferoglu, A. Lakshmikantha, A. Ganesh, P. Key

引用次数: 8

Sparse regression as a sparse eigenvalue problem 稀疏回归作为稀疏特征值问题

2008 Information Theory and Applications Workshop Pub Date : 2008-08-15 DOI: 10.1109/ITA.2008.4601036

Baback Moghaddam, Amit Gruber, Yair Weiss, S. Avidan

{"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}

引用次数: 22

Spectrum-blind sampling and compressive sensing for continuous-index signals 连续指数信号的频谱盲采样和压缩感知

2008 Information Theory and Applications Workshop Pub Date : 2008-08-15 DOI: 10.1109/ITA.2008.4601017

Y. Bresler

引用次数: 97

Coding schemes for confidential communications 保密通信的编码方案

2008 Information Theory and Applications Workshop Pub Date : 2008-08-15 DOI: 10.1109/ITA.2008.4601077

Xiaojun Tang, Ruoheng Liu, P. Spasojevic, H. Poor

{"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}

引用次数: 1

Fast bayesian matching pursuit 快速贝叶斯匹配追踪

2008 Information Theory and Applications Workshop Pub Date : 2008-08-15 DOI: 10.1109/ITA.2008.4601068

P. Schniter, L. Potter, Justin Ziniel

引用次数: 196