Pub Date : 2017-02-12DOI: 10.1109/ITA.2017.8023478
Kai Wan, Daniela Tuninetti, P. Piantanida
This paper proposes a novel achievable scheme for the index problem and applies it to the caching problem. Index coding and caching are noiseless broadcast channel problems where receivers have message side information. In the index coding problem the side information sets are fixed, while in the caching problem the side information sets correspond the cache contents, which are under the control of the system designer. The proposed index coding scheme, based on distributed source coding and non-unique decoding, is shown to strictly enlarge the rate region achievable by composite coding. The novel index coding scheme applied to the caching problem is then shown to match an outer bound (previously proposed by the authors and also based on known results for the index coding problem) under the assumption of uncoded cache placement/prefetching.
{"title":"A novel index coding scheme and its application to coded caching","authors":"Kai Wan, Daniela Tuninetti, P. Piantanida","doi":"10.1109/ITA.2017.8023478","DOIUrl":"https://doi.org/10.1109/ITA.2017.8023478","url":null,"abstract":"This paper proposes a novel achievable scheme for the index problem and applies it to the caching problem. Index coding and caching are noiseless broadcast channel problems where receivers have message side information. In the index coding problem the side information sets are fixed, while in the caching problem the side information sets correspond the cache contents, which are under the control of the system designer. The proposed index coding scheme, based on distributed source coding and non-unique decoding, is shown to strictly enlarge the rate region achievable by composite coding. The novel index coding scheme applied to the caching problem is then shown to match an outer bound (previously proposed by the authors and also based on known results for the index coding problem) under the assumption of uncoded cache placement/prefetching.","PeriodicalId":305510,"journal":{"name":"2017 Information Theory and Applications Workshop (ITA)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127970568","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 : 2017-02-10DOI: 10.1109/ITA.2017.8023446
Bharath Shamasundar, S. Jacob, Sandeep Bhat, A. Chockalingam
In index modulation schemes, information bits are conveyed through indexing of transmission entities such as antennas, subcarriers, times slots, precoders, subarrays, and radio frequency (RF) mirrors. Index modulation schemes are attractive for their advantages such as good performance, high rates, and hardware simplicity. This paper focuses on index modulation schemes in which multiple transmission entities, namely, antennas, time slots, and RF mirrors, are indexed simultaneously. Recognizing that such multidimensional index modulation schemes encourage sparsity in their transmit signal vectors, we propose efficient signal detection schemes that use compressive sensing based reconstruction algorithms. Results show that, for a given rate, improved performance is achieved when the number of indexed transmission entities is increased. We also explore indexing opportunities in load modulation, which is a modulation scheme that offers power efficiency and reduced RF hardware complexity advantages in multiantenna systems. Results show that indexing space and time in load modulated multiantenna systems can achieve improved performance.
{"title":"Multidimensional index modulation in wireless communications","authors":"Bharath Shamasundar, S. Jacob, Sandeep Bhat, A. Chockalingam","doi":"10.1109/ITA.2017.8023446","DOIUrl":"https://doi.org/10.1109/ITA.2017.8023446","url":null,"abstract":"In index modulation schemes, information bits are conveyed through indexing of transmission entities such as antennas, subcarriers, times slots, precoders, subarrays, and radio frequency (RF) mirrors. Index modulation schemes are attractive for their advantages such as good performance, high rates, and hardware simplicity. This paper focuses on index modulation schemes in which multiple transmission entities, namely, antennas, time slots, and RF mirrors, are indexed simultaneously. Recognizing that such multidimensional index modulation schemes encourage sparsity in their transmit signal vectors, we propose efficient signal detection schemes that use compressive sensing based reconstruction algorithms. Results show that, for a given rate, improved performance is achieved when the number of indexed transmission entities is increased. We also explore indexing opportunities in load modulation, which is a modulation scheme that offers power efficiency and reduced RF hardware complexity advantages in multiantenna systems. Results show that indexing space and time in load modulated multiantenna systems can achieve improved performance.","PeriodicalId":305510,"journal":{"name":"2017 Information Theory and Applications Workshop (ITA)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133268405","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 : 2017-02-01DOI: 10.1109/ITA.2017.8023470
Bicheng Ying, K. Yuan, Stefan Vlaski, A. H. Sayed
In empirical risk optimization, it has been observed that gradient descent implementations that rely on random reshuffling of the data achieve better performance than implementations that rely on sampling the data randomly and independently of each other. Recent works have pursued justifications for this behavior by examining the convergence rate of the learning process under diminishing step-sizes. Some of these justifications rely on loose bounds, or their conclusions are dependent on the sample size which is problematic for large datasets. This work focuses on constant step-size adaptation, where the agent is continuously learning. In this case, convergence is only guaranteed to a small neighborhood of the optimizer albeit at a linear rate. The analysis establishes analytically that random reshuffling outperforms independent sampling by showing that the iterate at the end of each run approaches a smaller neighborhood of size O(μ2) around the minimizer rather than O(μ). Simulation results illustrate the theoretical findings.
{"title":"On the performance of random reshuffling in stochastic learning","authors":"Bicheng Ying, K. Yuan, Stefan Vlaski, A. H. Sayed","doi":"10.1109/ITA.2017.8023470","DOIUrl":"https://doi.org/10.1109/ITA.2017.8023470","url":null,"abstract":"In empirical risk optimization, it has been observed that gradient descent implementations that rely on random reshuffling of the data achieve better performance than implementations that rely on sampling the data randomly and independently of each other. Recent works have pursued justifications for this behavior by examining the convergence rate of the learning process under diminishing step-sizes. Some of these justifications rely on loose bounds, or their conclusions are dependent on the sample size which is problematic for large datasets. This work focuses on constant step-size adaptation, where the agent is continuously learning. In this case, convergence is only guaranteed to a small neighborhood of the optimizer albeit at a linear rate. The analysis establishes analytically that random reshuffling outperforms independent sampling by showing that the iterate at the end of each run approaches a smaller neighborhood of size O(μ2) around the minimizer rather than O(μ). Simulation results illustrate the theoretical findings.","PeriodicalId":305510,"journal":{"name":"2017 Information Theory and Applications Workshop (ITA)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126625270","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 : 2017-02-01DOI: 10.1109/ITA.2017.8023455
Anxiao Jiang, Pulakesh Upadhyaya, E. Haratsch, Jehoshua Bruck
For the storage of big data, there are significant challenges with its long-term reliability. This paper studies how to use the natural redundancy in data for error correction, and how to combine it with error-correcting codes to effectively improve data reliability. It explores several aspects of natural redundancy, including the discovery of natural redundancy in compressed data, the efficient decoding of codes with random structures, the capacity of error-correcting codes that contain natural redundancy, and the time-complexity tradeoff between source coding and channel coding.
{"title":"Correcting errors by natural redundancy","authors":"Anxiao Jiang, Pulakesh Upadhyaya, E. Haratsch, Jehoshua Bruck","doi":"10.1109/ITA.2017.8023455","DOIUrl":"https://doi.org/10.1109/ITA.2017.8023455","url":null,"abstract":"For the storage of big data, there are significant challenges with its long-term reliability. This paper studies how to use the natural redundancy in data for error correction, and how to combine it with error-correcting codes to effectively improve data reliability. It explores several aspects of natural redundancy, including the discovery of natural redundancy in compressed data, the efficient decoding of codes with random structures, the capacity of error-correcting codes that contain natural redundancy, and the time-complexity tradeoff between source coding and channel coding.","PeriodicalId":305510,"journal":{"name":"2017 Information Theory and Applications Workshop (ITA)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123394822","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 : 2017-02-01DOI: 10.1109/ITA.2017.8023443
E. Biglieri, E. Viterbo
We collect some observations on line coding schemes obtained from a subset of a Permutation Modulation signal set. In particular, we discuss design techniques and develop a tool for performance analysis.
{"title":"Line coding for differential vector signaling","authors":"E. Biglieri, E. Viterbo","doi":"10.1109/ITA.2017.8023443","DOIUrl":"https://doi.org/10.1109/ITA.2017.8023443","url":null,"abstract":"We collect some observations on line coding schemes obtained from a subset of a Permutation Modulation signal set. In particular, we discuss design techniques and develop a tool for performance analysis.","PeriodicalId":305510,"journal":{"name":"2017 Information Theory and Applications Workshop (ITA)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124157705","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 : 2017-02-01DOI: 10.1109/ITA.2017.8023475
Wassim Tabikh, D. Slock, Y. Yuan-Wu
We consider the Multi-Input Single Output (MISO) Interfering Broadcast Channel (IBC), in other words the multi-user (MU) multi-cell half duplex downlink in a cellular or heterogeneous network, aided by a full duplex MIMO relay. The Degrees of Freedom (DoF) are analyzed for joint coordinated beamforming by the base stations and interference neutralization by the relay. Also Weighted Sum Rate Maximization at finite SNR is developed. The main concern however for interference neutralization is channel state information (CSI) at the relay, which does not observe the direct user links. Various solutions are explored.
{"title":"Relay aided coordinated beamforming and interference neutralization","authors":"Wassim Tabikh, D. Slock, Y. Yuan-Wu","doi":"10.1109/ITA.2017.8023475","DOIUrl":"https://doi.org/10.1109/ITA.2017.8023475","url":null,"abstract":"We consider the Multi-Input Single Output (MISO) Interfering Broadcast Channel (IBC), in other words the multi-user (MU) multi-cell half duplex downlink in a cellular or heterogeneous network, aided by a full duplex MIMO relay. The Degrees of Freedom (DoF) are analyzed for joint coordinated beamforming by the base stations and interference neutralization by the relay. Also Weighted Sum Rate Maximization at finite SNR is developed. The main concern however for interference neutralization is channel state information (CSI) at the relay, which does not observe the direct user links. Various solutions are explored.","PeriodicalId":305510,"journal":{"name":"2017 Information Theory and Applications Workshop (ITA)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131788998","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 : 2017-02-01DOI: 10.1109/ITA.2017.8023473
Hang Wu, Cong Shen, Shengbo Chen
We study the scheduling problem of an asymmetric queueing system in the presence of heavy-tailed interference. The system consists of two parallel queues, competing for one server. One of the queues experiences heavy-tailed OFF periods during the ON/OFF renewal channel process, caused by a heavy-tailed interference to its service link, while the other experiences light-tailed interference. We analyze the throughput characteristic and the expected queue length performance under the priority and max-weight scheduling policies. We show that the expected queue length of the heavy queue cannot be maintained finite even under the most favorable priority policy. The finiteness of the light queue's expected queue length, however, can be guaranteed with service priority, but the system is no longer throughput optimal. We further show that the max-weight scheduling policy does not provide any benefit to the light queue in terms of the steady-state queue length behavior, though the system is always throughput optimal.
{"title":"On scheduling policies in the presence of heavy-tailed interference","authors":"Hang Wu, Cong Shen, Shengbo Chen","doi":"10.1109/ITA.2017.8023473","DOIUrl":"https://doi.org/10.1109/ITA.2017.8023473","url":null,"abstract":"We study the scheduling problem of an asymmetric queueing system in the presence of heavy-tailed interference. The system consists of two parallel queues, competing for one server. One of the queues experiences heavy-tailed OFF periods during the ON/OFF renewal channel process, caused by a heavy-tailed interference to its service link, while the other experiences light-tailed interference. We analyze the throughput characteristic and the expected queue length performance under the priority and max-weight scheduling policies. We show that the expected queue length of the heavy queue cannot be maintained finite even under the most favorable priority policy. The finiteness of the light queue's expected queue length, however, can be guaranteed with service priority, but the system is no longer throughput optimal. We further show that the max-weight scheduling policy does not provide any benefit to the light queue in terms of the steady-state queue length behavior, though the system is always throughput optimal.","PeriodicalId":305510,"journal":{"name":"2017 Information Theory and Applications Workshop (ITA)","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131102882","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 : 2017-02-01DOI: 10.1109/ITA.2017.8023442
Juane Li, Keke Liu, Shu Lin, K. Abdel-Ghaffar
This paper presents a special type of LDPC codes constructed based on the conventional parity-check matrices of Reed-Solomon (RS) codes. LDPC codes of this type are referred to as globally coupled RS-LDPC codes. These codes are designed for correcting random errors, random short phased bursts of erasures and long bursts of erasures. The Tanner graph of a globally coupled RS-LDPC is composed of a number of disjoint copies of the Tanner graph of a local RS-LDPC code which are connected together by a group of overall check-nodes (CNs), called global CNs. A globally coupled RS-LDPC code can be decoded with a two-phase local/global iterative scheme which allows correction of local random errors and phased bursts of erasures in the local phase and global random errors and a single long burst of erasures in the global phase.
{"title":"Reed-Solomon based globally coupled quasi-cyclic LDPC codes","authors":"Juane Li, Keke Liu, Shu Lin, K. Abdel-Ghaffar","doi":"10.1109/ITA.2017.8023442","DOIUrl":"https://doi.org/10.1109/ITA.2017.8023442","url":null,"abstract":"This paper presents a special type of LDPC codes constructed based on the conventional parity-check matrices of Reed-Solomon (RS) codes. LDPC codes of this type are referred to as globally coupled RS-LDPC codes. These codes are designed for correcting random errors, random short phased bursts of erasures and long bursts of erasures. The Tanner graph of a globally coupled RS-LDPC is composed of a number of disjoint copies of the Tanner graph of a local RS-LDPC code which are connected together by a group of overall check-nodes (CNs), called global CNs. A globally coupled RS-LDPC code can be decoded with a two-phase local/global iterative scheme which allows correction of local random errors and phased bursts of erasures in the local phase and global random errors and a single long burst of erasures in the global phase.","PeriodicalId":305510,"journal":{"name":"2017 Information Theory and Applications Workshop (ITA)","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124391749","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 : 2017-02-01DOI: 10.1109/ITA.2017.8023480
B. Vasic, P. Ivaniš, Srdan Brkic
A new class of bit flipping algorithms for low-density parity-check codes over the binary symmetric channel is proposed. The algorithms employ multiple bits at a variable node to represent its reliability, and multiple bits a check node to capture the sequence of its syndrome values. The check node update function thus requires a simple bit-shift operation, while the variable node updates require a nonlinear Boolean function. This class of multi-bit flipping (MBF) algorithms is enhanced by the probabilistic gradient descent (PGD) algorithm. The gradient descent algorithm minimizes the variable node energy function which, in addition to the classical term which quantifies the discrepancy between the variable estimate and channel value, also involves an additive term defined as a weighted sum of neighboring check node states. Only the variable nodes with the maximal value of energy are eligible for updating, but the updates are not done by default but probabilistically. The resulting probabilistic gradient descent multi-bit flipping PGD-MBF algorithm combined with rewinding improves the codeword probability of error while keeping the complexity lower than that of the state-of-the-art algorithms of comparable throughput.
{"title":"Multi-bit flipping algorithms with probabilistic gradient descent","authors":"B. Vasic, P. Ivaniš, Srdan Brkic","doi":"10.1109/ITA.2017.8023480","DOIUrl":"https://doi.org/10.1109/ITA.2017.8023480","url":null,"abstract":"A new class of bit flipping algorithms for low-density parity-check codes over the binary symmetric channel is proposed. The algorithms employ multiple bits at a variable node to represent its reliability, and multiple bits a check node to capture the sequence of its syndrome values. The check node update function thus requires a simple bit-shift operation, while the variable node updates require a nonlinear Boolean function. This class of multi-bit flipping (MBF) algorithms is enhanced by the probabilistic gradient descent (PGD) algorithm. The gradient descent algorithm minimizes the variable node energy function which, in addition to the classical term which quantifies the discrepancy between the variable estimate and channel value, also involves an additive term defined as a weighted sum of neighboring check node states. Only the variable nodes with the maximal value of energy are eligible for updating, but the updates are not done by default but probabilistically. The resulting probabilistic gradient descent multi-bit flipping PGD-MBF algorithm combined with rewinding improves the codeword probability of error while keeping the complexity lower than that of the state-of-the-art algorithms of comparable throughput.","PeriodicalId":305510,"journal":{"name":"2017 Information Theory and Applications Workshop (ITA)","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124561803","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 : 2017-02-01DOI: 10.1109/ITA.2017.8023476
U. Tamm
Claude Shannon's pioneering paper on computer chess found immediate interest in the journal “Chess Review” whose New York corespondent Edward Lasker was responsible for three articles involving Claude Shannon in 1950, 1951, and 1957, respectively. We shall briefly review these three articles and sketch the further development of computer chess which was essentially based on Shannon's ideas.
{"title":"Claude Shannon in Chess Review","authors":"U. Tamm","doi":"10.1109/ITA.2017.8023476","DOIUrl":"https://doi.org/10.1109/ITA.2017.8023476","url":null,"abstract":"Claude Shannon's pioneering paper on computer chess found immediate interest in the journal “Chess Review” whose New York corespondent Edward Lasker was responsible for three articles involving Claude Shannon in 1950, 1951, and 1957, respectively. We shall briefly review these three articles and sketch the further development of computer chess which was essentially based on Shannon's ideas.","PeriodicalId":305510,"journal":{"name":"2017 Information Theory and Applications Workshop (ITA)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114388563","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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