{"title":"On channel capacity of communication via antenna arrays with receiver noise matching","authors":"R. Müller, B. Godana, M. A. Sedaghat, J. Huber","doi":"10.1109/ITW.2012.6404701","DOIUrl":"https://doi.org/10.1109/ITW.2012.6404701","url":null,"abstract":"We consider the total capacity of a Gaussian multiple-access MIMO channel with a linear array of R receive antennas and T distributed transmit antennas. If the spatial distribution of transmit antennas weighed by their path loss and marginalized to a sphere around the receive array is proportional to the ratio of receive antenna directivity to transmit antenna directivity, the capacity is shown to approach Rlog(1 + SNR) as T → ∞, irrespective of the inter-element distance at the receiver.We further show that the capacity for other distributions of transmit antennas can be even greater, as the inter-element distance approaches zero.","PeriodicalId":325771,"journal":{"name":"2012 IEEE Information Theory Workshop","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125746595","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}
{"title":"Optimal reliability over a class of binary-input channels with feedback","authors":"Mohammad Naghshvar, M. Wigger, T. Javidi","doi":"10.1109/ITW.2012.6404700","DOIUrl":"https://doi.org/10.1109/ITW.2012.6404700","url":null,"abstract":"This paper considers the problem of variable-length coding over a binary-input channel with noiseless feedback. A deterministic sequential coding scheme is proposed and shown to attain the optimal error exponent for any binary-input channel whose capacity is achieved by the uniform input distribution. The proposed scheme is deterministic and has only one phase of operation, in contrast to all previous coding schemes that achieve the optimal error exponent.","PeriodicalId":325771,"journal":{"name":"2012 IEEE Information Theory Workshop","volume":"509 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115891004","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}
{"title":"Network coding with computation alignment","authors":"Naveen Goela, Changho Suh, M. Gastpar","doi":"10.1109/ITW.2012.6404725","DOIUrl":"https://doi.org/10.1109/ITW.2012.6404725","url":null,"abstract":"Determining the capacity of multi-receiver networks with arbitrary message demands is an open problem in the network coding literature. In this paper, we consider a multi-source, multi-receiver symmetric deterministic network model parameterized by channel coefficients (inspired by wireless network flow) in which the receivers compute a sum of the symbols generated at the sources. Scalar and vector linear coding strategies are analyzed. It is shown that computation alignment over finite field vector spaces is necessary to achieve the computation capacities in the network. To aid in the construction of coding strategies, network equivalence theorems are established for the decomposition of deterministic models into elementary sub-networks. The linear coding capacity for computation is characterized for all channel parameters considered in the model for a countably infinite class of networks. The constructive coding schemes introduced herein for a specific class of networks provide an optimistic viewpoint for the application of structured codes in network communication.","PeriodicalId":325771,"journal":{"name":"2012 IEEE Information Theory Workshop","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132008394","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}
{"title":"Characterizing the entropy function region via extreme rays","authors":"Qi Chen, R. Yeung","doi":"10.1109/ITW.2012.6404674","DOIUrl":"https://doi.org/10.1109/ITW.2012.6404674","url":null,"abstract":"Contrary to the traditional method of information inequalities, in this paper, the entropy function region Γ<sub>n</sub>* and its closure ̅Γ<sub>n</sub>* are characterized via extreme rays of its outer bound polymatroidal region Γ<sub>n</sub>. The characterization of Γ<sub>3</sub>* and the tightness of Γ<sub>n</sub> as an outer bound on ̅Γ<sub>n</sub>* are studied.","PeriodicalId":325771,"journal":{"name":"2012 IEEE Information Theory Workshop","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131855842","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}
{"title":"On the role of deterministic models in K × K × K wireless networks","authors":"Ilan Shomorony, A. Avestimehr","doi":"10.1109/ITW.2012.6404749","DOIUrl":"https://doi.org/10.1109/ITW.2012.6404749","url":null,"abstract":"This paper establishes a connection between the capacity region of the K × K × K wireless network under the AWGN channel model and under a truncated deterministic channel model, which allows any outer bound on the capacity region of the truncated network to be translated into an outer bound on the capacity region of the AWGN network. The result is obtained through the utilization of a recent worst-case noise theorem [1], which shows that perturbing the noise distribution in AWGN networks only increases the capacity region.","PeriodicalId":325771,"journal":{"name":"2012 IEEE Information Theory Workshop","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115590214","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}
{"title":"An information-theoretic protocol compiler","authors":"A. Sahai","doi":"10.1109/ITW.2012.6404657","DOIUrl":"https://doi.org/10.1109/ITW.2012.6404657","url":null,"abstract":"One of the most fundamental goals in cryptography is to design protocols that remain secure when adversarial participants can engage in arbitrary malicious behavior. In 1986, Goldreich, Micali, and Wigderson presented a powerful paradigm for designing such protocols: their approach reduced the task of designing secure protocols to designing protocols that only guarantee security against “honest-but-curious” participants. By making use of zero-knowledge proofs, the GMW paradigm enforces honest behavior without compromising secrecy. Over the past two decades, this approach has been the dominant paradigm for cryptographic protocol design, based on zero-knowledge protocols based on computational hardness assumptions. In this work, we describe a new general paradigm/protocol compiler for secure protocol design known as the IPS compiler, that departs considerably from the GMW framework, and provides a method for obtaining efficient protocols with information-theoretic security guarantees in settings where appropriate channels exist. This new approach also reduces the task of designing secure protocols to designing protocols that only guarantee security against honest-but-curious participants. However, the new approach avoids the use of zero-knowledge proofs, and instead makes use of multi-party protocols in a much simpler setting - where the majority of participants are completely honest (such multi-party protocols can exist with information-theoretic security guarantees without assuming any special channels). The IPS paradigm yields protocols that rely on Oblivious Transfer channels (OT) as a building block. This offers a number of advantages in generality and efficiency. In contrast to the GMW paradigm, by avoiding the use of zero-knowledge proofs, the IPS paradigm is able to treat all of its building blocks as “black boxes”. This allows improvement over previous results in the area of secure computation. In particular, the IPS compiler yields conceptually simpler and more efficient ways for basing unconditionally secure cryptography on OT and other noisy channels; more efficient protocols for generating a large number of OTs using a small number of OTs; and secure and efficient protocols which only make a blackbox use of cryptographic primitives or underlying algebraic structures in settings where no such protocols were known before.","PeriodicalId":325771,"journal":{"name":"2012 IEEE Information Theory Workshop","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123909673","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}
{"title":"Suppressing pseudocodewords by penalizing the objective of LP decoding","authors":"Xishuo Liu, S. Draper, B. Recht","doi":"10.1109/ITW.2012.6404695","DOIUrl":"https://doi.org/10.1109/ITW.2012.6404695","url":null,"abstract":"In this paper, we present a new class of decoders for low density parity check (LDPC) codes. We are motivated by the observation that the linear programming (LP) decoder has worse error performance than belief propagation (BP) decoders at low SNRs. We base our new decoders on the alternating direction method of multipliers (ADMM) decomposition technique for LP decoding. The ADMM not only efficiently solves the LP decoding problem, but also makes it possible to explore other decoding algorithms. In particular, we add various penalty terms to the linear objective of LP decoding with the goal of suppressing pseudocodewords. Simulation results show that the new decoders achieve much better error performance compared to LP decoder at low SNRs. What is more, similar to the LP decoder, no error floor is observed at high SNRs.","PeriodicalId":325771,"journal":{"name":"2012 IEEE Information Theory Workshop","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114449150","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}
{"title":"Spatially coupled quantum LDPC codes","authors":"I. Andriyanova, D. Maurice, J. Tillich","doi":"10.1109/ITW.2012.6404686","DOIUrl":"https://doi.org/10.1109/ITW.2012.6404686","url":null,"abstract":"We propose here a new construction of spatially coupled quantum LDPC codes using a small amount of entangled qubit pairs shared between the encoder and the decoder which improves quite significantly all other constructions of quantum LDPC codes or turbo-codes with the same rate.","PeriodicalId":325771,"journal":{"name":"2012 IEEE Information Theory Workshop","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114422234","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}
{"title":"Multi-terminal source coding: Zero-rate encoders cannot enlarge the rate region","authors":"B. Vellambi","doi":"10.1109/ITW.2012.6404684","DOIUrl":"https://doi.org/10.1109/ITW.2012.6404684","url":null,"abstract":"This work proves that in the multi-terminal source coding problem, any achievable rate point achievable with asymptotically zero rate on a subset of links can also be achieved without any communication over the same subset of links, or equivalently, when the links in the subset are removed from the network. This work shows that asymptotically zero-rate communication over a subset of links cannot be crucial for the inclusion of a rate point in the rate region in spite of the absence of an explicit characterization of the rate region.","PeriodicalId":325771,"journal":{"name":"2012 IEEE Information Theory Workshop","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121980489","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}
{"title":"Capacity region of two symmetric nearby erasure channels with channel state feedback","authors":"Chih-Chun Wang","doi":"10.1109/ITW.2012.6404691","DOIUrl":"https://doi.org/10.1109/ITW.2012.6404691","url":null,"abstract":"This work considers a commonly encountered wireless transmission scenario: Two nearby 1-hop flows s<sub>1</sub> → d<sub>1</sub> and s<sub>2</sub> → d<sub>2</sub> are within the transmission range of each other. The network nodes thus have to share the time resources, which limits the sum-rate performance. On the other hand, both s<sub>i</sub> and d<sub>i</sub> can (occasionally) overhear the transmission of the other pair (s<sub>j</sub>, d<sub>j</sub>) for all i ≠ j, which opens up the opportunity of using network coding (NC) and ACK/NACK to improve the throughput. The key challenge, however, is that any dedicated communication between s<sub>1</sub> and s<sub>2</sub> also consumes the precious time resources. Hence NC coordination must be achieved through unreliable overhearing. In this work, the above scenario is modeled as four wireless nodes interconnected by broadcast erasure channels with channel state feedback. The corresponding capacity region (R1,R2) is fully characterized for the setting of symmetric, spatially independent erasure channels.","PeriodicalId":325771,"journal":{"name":"2012 IEEE Information Theory Workshop","volume":"113 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125026161","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}