ppxscal/embedding_network huggingface dataset:
Low complexity distributed STBCs with unitary relay matrices for any number of relays
Authors: G. Susinder Rajan, B. Sundar Rajan
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 1 (2009)

Jing and Hassibi introduced a distributed space time block coding scheme for symbol synchronous, coherent, amplify and forward relay networks with half duplex constrained relay nodes. In this two phase transmission scheme, the source transmits a vector of complex symbols to the relays during the first phase and each relay applies a pre-assigned unitary transformation to the received vector or its conjugate before transmitting it to the destination during the second phase. The destination then perceives a certain structured distributed space time block code (DSTBC) whose maximum likelihood (ML) decoding complexity in general, is very high. In this paper, explicit constructions of minimum delay, full diversity, four group ML decodable DSTBCs with unitary relay matrices are provided for even number of relay nodes. Prior constructions of DSTBCs with the same features were either limited to power of two number of relay nodes or had non-unitary relay matrices which leads to large peak to average power ratio of the relay's transmitted signals. For the case of odd number of relays, constructions of minimum delay, full diversity, two group ML decodable DSTBCs are given.
An e-customer behavior model with online analytical mining for internet marketing planning
Authors: Irene S. Y. Kwan, Joseph Fong, H. K. Wong
Venue: Decision Support Systems (2005)

In the digital market, attracting sufficient online traffic in a business to customer Web site is vital to an online business's success. The changing patterns of Internet surfer access to e-commerce sites pose challenges for the Internet marketing teams of online companies. For e-business to grow, a system must be devised to provide customers' preferred traversal patterns from product awareness and exploration to purchase commitment. Such knowledge can be discovered by synthesizing a large volume of Web access data through information compression to produce a view of the frequent access patterns of e-customers. This paper develops constructs for measuring the online movement of e-customers, and uses a mental cognitive model to identify the four important dimensions of e-customer behavior, abstract their behavioral changes by developing a three-phase e-customer behavioral graph, and tests the instrument via a prototype that uses an online analytical mining (OLAM) methodology. The knowledge discovered is expected to foster the development of a marketing plan for B2C Web sites. A prototype with an empirical Web server log file is used to verify the feasibility of the methodology.
On the integration and convergence of IN and IP mobile service infrastructures
Authors: Miguel Gómez, Emilio J. Torres, Javier Chamorro, Tomás Hernández, Eduardo Méndez
Venue: Proceedings of the 16th international conference on Telecommunications (2009)

Due to business requirements and the historical network evolution process, service infrastructures owned by most mobile operators present high degrees of heterogeneity and isolation, thus compromising their scalability and hindering the inclusion of new services. This paper presents a mobile service platform architecture that, based on the integration and convergence features facilitated by the adoption of JAIN SLEE carrier-grade middleware, enables operators to gradually evolve their Infrastructures towards a homogeneous and flexible service provisioning environment for IN, IT and IMS services. In addition, the validation trials of the proposed solution undertaken in the service infrastructure of a mobile operator are described, along with the performance results achieved on such tests.
A subsequence-histogram method for generic vocabulary recognition over deletion channels
Authors: Majid Fozunbal
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4 (2009)

We consider the problem of recognizing a vocabulary-a collection of words (sequences) over a finite alphabet-from a potential subsequence of one of its words. We assume the given subsequence is received through a deletion channel as a result of transmission of a random word from one of the two generic underlying vocabularies. An exact maximum a posterior (MAP) solution for this problem counts the number of ways a given subsequence can be derived from particular subsets of candidate vocabularies, requiring exponential time or space. We present a polynomial approximation algorithm for this problem. The algorithm makes no prior assumption about the rules and patterns governing the structure of vocabularies. Instead, through off-line processing of vocabularies, it extracts data regarding regularity patterns in the subsequences of each vocabulary. In the recognition phase, the algorithm just uses this data, called subsequence-histogram, to decide in favor of one of the vocabularies. We provide examples to demonstrate the performance of the algorithm and show that it can achieve the same performance as MAP in some situations. Potential applications include bioinformatics, storage systems, and search engines.
Joint channel width adaptation, topology control, and routing for multi-radio multi-channel wireless mesh networks
Authors: Li Li, Chunyuan Zhang
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

Capacity limitation is one of the fundamental issues in wireless mesh networks. The aggregate capacity can be increased by equipping each mesh router with multiple radios tuned into distinct frequency channels. However, most past research efforts that attempt to exploit multiple channels assume orthogonal channels of fixed pre-determined width, which prohibits the further effective use of spectrum resource. In this paper, we use mathematical programming to address how to optimally adapt channel width to make full use of the spectrum resource. We formulate the channel width adaptation, topology control and routing as a joint mixed 0-1 integer linear optimization problem. Simulation results show that our algorithm can significantly improve spectrum use efficiency and network performance.
On application of nonparametric regression estimation to options pricing
Authors: Michael Kohler, Adam Krzyzak, Harro Walk
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

We consider American options also called Bermudan options in discrete time. We use the dual approach to derive upper bounds on the price of such options using only a reduced number of nested Monte Carlo steps. The key idea is to use nonparametric regression to estimate continuation values and all other required conditional expectations and to combine the resulting estimate with another estimate computed by using only a reduced number of nested Monte Carlo steps. The mean value of the resulting estimate is an upper bound on the option price. One can show that the estimates of the option prices are universally consistent, i.e., they converge to the true price regardless of the structure of the continuation values. The finite sample behavior is validated by experiments on simulated data.
Hyper-trim shrinkage for denoising of ECG signal
Authors: S. Poornachandra, N. Kumaravel
Venue: Digital Signal Processing (2005)

We introduce a new shrinkage scheme, hyper-trim that generalizes hard and soft shrinkage proposed by Donoho and Johnstone (1994). The new adaptive denoising method presented is based on Stein's unbiased risk estimation (SURE) and on a new class of shrinkage function. The proposed new class of shrinkage function has continuous derivative. The shrinkage function is simulated and tested with ECG signals added with standard Gaussian noise using MATLAB. This method gives better mean square error (MSE) performance over conventional wavelet shrinkage methodologies.
Linear compressive networks
Authors: Naveen Goela, Michael Gastpar
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 1 (2009)

A linear compressive network (LCN) is defined as a graph of sensors in which each encoding sensor compresses incoming jointly Gaussian random signals and transmits (potentially) low-dimensional linear projections to neighbors over a noisy uncoded channel. Each sensor has a maximum power to allocate over signal subspaces. The networks of focus are acyclic, directed graphs with multiple sources and multiple destinations. LCN pathways lead to decoding leaf nodes that estimate linear functions of the original high dimensional sources by minimizing a mean squared error (MSE) distortion cost function. An iterative optimization of local compressive matrices for all graph nodes is developed using an optimal quadratically constrained quadratic program (QCQP) step. The performance of the optimization is marked by power-compression-distortion spectra, with converse bounds based on cut-set arguments. Exampies include single layer and multi-layer (e.g. p-layer tree cascades, butterfly) networks. The LCN is a generalization of the Karhunen-Loève Transform to noisy multi-layer networks, and extends previous approaches for point-to-point and distributed compression-estimation of Gaussian signals. The framework relates to network coding in the noiseless case, and uncoded transmission in the noisy case.
Active measurement of routing table in Kad
Authors: Jie Yu, Zhoujun Li
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

As the first DHT implemented in real applications and involving millions of simultaneous users, all aspects of Kad must be analyzed and measured carefully. This paper focuses on measuring the routing table of Kad in eMule/aMule. We present and analyze the availability and stability of routing table by crawling actively. We find the phenomenon of ID repetition in Kad that many peers use a same ID simultaneously, which will decrease the performance of routing and then reduce the availability of routing table. The connection availability of global routing table is relatively low, the average of which is about 64.9%. Connection availability influences the efficiency of searching and routing in Kad network directly.
Quantitative analysis of Wi-Fi in the presence of interferers
Authors: Ying Bing Yap, Li Li, Bingjian Zhang, Kunal Rele
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

Wireless Fidelity (Wi-Fi) based networks operate in the unlicensed 2.4GHz ISM band. This "unlicensed" band is crowded by other wireless devices like baby monitors, Bluetooth based devices, and cordless phones. Microwave Ovens (MWO) are particularly popular unintentional transmitters that also operate in this band. This paper discusses a research focused on quantitatively analyzing the effects of various interferers on Wi-Fi based on metrics such as average data rates, number of packets transmitted, total power, retry rate and CRC error rate. This analysis will be a key element in designing and comparing various interference mitigation mechanisms in Wi-Fi and implementing restrictions on proprietary devices.
Leap-of-faith security is enough for IP mobility
Authors: Miika Komu, Janne Lindqvist
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

Host mobility presents a challenge for security protocols. For example, many proposals exist for integrating IPsec to Mobile IP. However, the existing approaches are cumbersome to configure and contain many round trips for security and mobility updates. The Host Identity Protocol (HIP) is being developed in the IETF to provide secure host mobility and multihoming. The default way to operate the protocol is that the connection initiator knows the peer's public key or a hash of the public key. This requires either infrastructure support or preconfiguration which introduces difficulties for deploying the protocol. In this paper, we present an implementation and evaluation of HIP that creates leap-of-faith security associations. The implemented approach establishes end-to-end security without requiring any new infrastructure to be deployed. We argue that since worldwide PKI is nowhere near, and seems to nearly impossible to deploy in practice, leap-of-faith security is enough for Internet access and mobility. In our view, the deployment of opportunistic HIP even makes the deployment of DNSSEC unnecessary for most applications.
The Gelfand-Pinsker channel: strong converse and upper bound for the reliability function
Authors: Himanshu Tyagi, Prakash Narayan
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

We consider a Gelfand-Pinsker discrete memoryless channel (DMC) model and provide a strong converse for its capacity. The strong converse is then used to obtain an upper bound on the reliability function. Instrumental in our proofs is a new technical lemma which provides an upper bound for the rate of codes with codewords that are conditionally typical over large message dependent subsets of a typical set of state sequences. This technical result is a nonstraightforward analog of a known result for a DMC without states that provides an upper bound on the rate of a good code with codewords of a fixed type (to be found in, for instance, the Csiszár-Körner book).
Home appliance control using heterogeneous sensor networks
Authors: Yuichiro Kato, Takahiro Ito, Hideki Kamiya, Masatoshi Ogura, Hiroshi Mineno, Norihiro Ishikawa, Tadanori Mizuno
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

The design and implementation of home appliance control based on information from sensors is presented. In a ubiquitous networking society, there are a lot of devices connected to a network. However, many kinds of networks coexist, and they use different communication protocols. Therefore, a technology to integrate different networks is necessary to provide flexible services, which can control various devices connected to different networks where different protocols are used. At the same time, the technology of sensor networks is important in such a society. Sensors also use different protocols. Therefore, using sensing data from different kinds of sensor networks is difficult. To collect and process information from various kinds of sensors, we designed and implemented a Sensor Gateway. To control home appliances, protocols defined by the Peer-to-Peer Universal Computing Consortium are used in our system.
On the tightness of Marton's regions for semi-additive broadcast channels
Authors: Eli Haim, Ram Zamir
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4 (2009)

We study cost constrained side-information channels, where the cost function depends on a state which is known only to the encoder. In the additive noise case, we bound the capacity loss due to not knowing the cost state at the decoder and show that it is small under various assumptions, and goes to zero in the limit of weak noise. This model plays an important role in the (non-degraded) broadcast channel. In the semi-additive noise case, we bound the gap between the best known single letter achievable region and the true capacity region, using tools developed for the first problem. In the limit of weak noise, we show that the bounds coincide, thus we get the complete characterization of the capacity region.
On the degrees-of-freedom of the K -user Gaussian interference channel
Authors: Raul Etkin, Erik Ordentlich
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

The degrees-of-freedom of a K-user Gaussian interference channel (GIFC) has been defined to be the multiple of (1/2) log2 P at which the maximum sum of achievable rates grows with increasing P. In this paper, we establish that the degrees-of-freedom of three or more user, real, scalar GIFCs, viewed as a function of the channel coefficients, is discontinuous at points where all of the coefficients are non-zero rational numbers. More specifically, for all K > 2, we find a class of K-user GIFCs that is dense in the GIFC parameter space for which K/2 degrees-of-freedom are exactly achievable, and we show that the degrees-of-freedom for any GIFC with non-zero rational coefficients is strictly smaller than K/2. These results are proved using new connections with number theory and additive combinatorics.
The maximum likelihood probability of skewed patterns
Authors: Alan Orlitsky, Shengjun Pan
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 2 (2009)

A pattern is skewed if, as in 11123, one of its symbols repeats and the others appear once. We show that the pattern-maximum-likelihood distribution of essentially all skewed patterns consists of one discrete element whose probability is the fraction of times the repeated symbol appears in the pattern.
Towards a resilience benchmarking for home gateways
Authors: S. Ramanathan, C. Lac
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

A Home Gateway (HG) connects the residential network to ISPs for offering services like Internet access, VoIP, IPTV, etc. Its sensitivity to faults and the increasing failure challenges are often perceived by users, giving rise to a lack of trustworthiness in the HG. In order to tackle this kind of problem, a provider needs to improve the HG's resilience, and also to assess the dependability and security of the manufacturer's prototypes through benchmark. This paper 1 describes a resilience benchmarking procedure for HGs: starting from test and field failure data, we analyzed the effective metrics for measuring and assessing the various HG responses under different situations with respect to the resilience properties, i.e., availability, reliability, security, etc. It is done by covering the largest possible range of faults (accidental disturbances, environmental perturbations, etc.), and selecting some subset of each class to analyze the HG behaviour, thus resulting in its robustness assessment. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
EPC UHF RFID reader: mobile phone integration and services
Authors: Jari T. Savolainen, Harri Hirvola, Sassan Iraji
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

Electrical identifiers are rushing to overtake and replace traditional identification methods, like barcodes. Advantages of these new technologies are bigger data capacity and rate, more reliable reading and no need for line of sight. NFC tags are widely used already for example in libraries, but the representative of newer technology in UHF frequency band, EPC, is just around the corner. In this paper, we present the integration of EPC RFID reader to the mobile phone, as a functional cover. Furthermore, we propose ways to provide services to the user who reads EPC tags.
New group shuffled BP decoding algorithms for LDPC codes
Authors: Chi-Yuan Chang, Yu-Liang Chen, Chang-Ming Lee, Yu T. Su
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 3 (2009)

Implementing a belief propagation (BP) based LDPC decoder requires high degrees of parallelism using many component soft-in soft-output (SISO) decoding units to perform message passing from variable nodes to check nodes or vice versa. An obvious complexity-reduction solution is to serialize the decoding process, i.e., dividing a decoding iteration into several serial sub-iterations in which a sub-iteration performs only part of the complete parallel message-passing operation. The group horizontal shuffled BP (GHSBP) and vertical shuffled BP (GVSBP) algorithms respectively partition the check and variable nodes of the code graph into groups to perform group-by-group message-passing decoding. This paper proposes new techniques to improve three key elements of a GHSBP decoding algorithm, namely, the grouping method, the decoding schedule and the log-likelihood updating formulae. The (check nodes) grouping method and decoding schedule optimize certain design criterion. The new normalized min-sum updating formula with a self-adjustable correction (scaling) factor offers better nonlinear approximation. Numerical performance of new GHSBP algorithms that include part or all three new techniques indicate that the combination of the proposed grouping and decoding schedule yields a faster convergence rate and our modified min-sum algorithm gives performance superior to that of the conventional min-sum and normalized min-sum algorithm and is very close to that of the sum-product algorithm.
LR-aided MMSE lattice decoding is DMT optimal for all approximately universal codes
Authors: Joakim Jaldén, Petros Elia
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 2 (2009)

Currently for the nT × nR MIMO channel, any explicitly constructed space-time (ST) designs that achieve optimality with respect to the diversity multiplexing tradeoff (DMT) are known to do so only when decoded using maximum likelihood (ML) decoding, which may incur prohibitive decoding complexity. In this paper we prove that MMSE regularized lattice decoding, as well as the computationally efficient lattice reduction (LR) aided MMSE decoder, allows for efficient and DMT optimal decoding of any approximately universal lattice-based code. The result identifies for the first time an explicitly constructed encoder and a computationally efficient decoder that achieve DMT optimality for all multiplexing gains and all channel dimensions. The results hold irrespective of the fading statistics.
Short baseline propagation characteristics of determinstic wireless fingerprinting systems for localisation
Authors: Andrew G. Dempster, Binghao Li, Ishrat Quader
Venue: Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference (2009)

Fingerprinting is a technique that records vectors of received power from several transmitters, and later matches these to a new measurement to position the new user. This paper examines data from locations at very short ranges from each other in order to observe the nature of the relationship between short-range fingerprints. We find that even at short distances, variation due to fading dominates and a suitable signal model has yet to be produced. We also conclude that fingerprints should be averaged over a range near the point of interest.
What is the value of joint processing of pilots and data in block-fading channels?
Authors: Nihar Jindal, Angel Lozano, Thomas L. Marzetta
Venue: Proceedings of the 2009 IEEE international conference on Symposium on Information Theory - Volume 4 (2009)

The spectral efficiency achievable with joint processing of pilot and data symbol observations is compared with that achievable through the conventional (separate) approach of first estimating the channel on the basis of the pilot symbols alone, and subsequently detecting the data symbols. Studied on the basis of a mutual information lower bound, joint processing is found to provide a nonnegligible advantage relative to separate processing, particularly for fast fading. It is shown that, regardless of the fading rate, only a very small number of pilot symbols (at most one per transmit antenna and per channel coherence interval) should be transmitted if joint processing is allowed.