MILCOM 2008 - 2008 IEEE Military Communications Conference最新文献

{"title":"Blind separation of weak signals in non-isotropic spatio-temporal colored noise with possibly critically loaded uncalibrated arrays","authors":"E. Beadle, J. F. Dishman","doi":"10.1109/MILCOM.2008.4753290","DOIUrl":"https://doi.org/10.1109/MILCOM.2008.4753290","url":null,"abstract":"A blind source separation (BSS) algorithm optimal in output signal-to-interference (SIR) for critically loaded arrays operating at possibly negative SNIR is proposed. The proposed technique uses generalized eigen-decomposition (i.e. spectral estimation) of a first-order matrix pencil of spatial fourth-order cumulant matrices of novel definition. The algorithm has demonstrated insensitivity to non-isotropic spatially and/or temporally correlated noise without the need for whitening processes. To illustrate the potential effectiveness of the proposed approach examples are provided involving narrowband statistically independent co-channel signal mixtures of analog and digital modulations with received SNIR < 0 dB, with noise environment and sensing array manifold completely unknown.","PeriodicalId":434891,"journal":{"name":"MILCOM 2008 - 2008 IEEE Military Communications Conference","volume":"884 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131645416","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":"Effect of security architecture on cross-layer signaling in network centric systems","authors":"Junghoon Lee, G. Elmasry, M. Jain","doi":"10.1109/MILCOM.2008.4753363","DOIUrl":"https://doi.org/10.1109/MILCOM.2008.4753363","url":null,"abstract":"Cross-layer signaling has shown promising results in helping to increase the performance of tactical MANET networks. However, most cross-layer signaling studies do not consider how security architecture can affect cross-layer signaling techniques. In this paper, we present how the partition of a tactical network into a cipher text side and a plain text side can result in a partition of cross-layer signaling. We also present a technique that relies on explicit congestion notification (ECN) to bridge the gap created by this partition. We will support this discussion with some simulation results.","PeriodicalId":434891,"journal":{"name":"MILCOM 2008 - 2008 IEEE Military Communications Conference","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131669675","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":"Reed Solomon coded M-ary hyper phase-shift keying","authors":"James Caldwell, C. Robertson","doi":"10.1109/MILCOM.2008.4753300","DOIUrl":"https://doi.org/10.1109/MILCOM.2008.4753300","url":null,"abstract":"Non-binary forward error correction (FEC) coding in conjunction with M-ary hyper phase-shift keying (MHPSK) is considered in order to improve the robustness of a satellite communications uplink. MHPSK is a spectrally efficient modulation technique that uses four orthonormal basis functions to increase the distance between different symbols in the signal space. Spectral efficiency and probability of bit error are two key figures of merit used to evaluate digital modulation techniques. The use of four orthonormal basis functions provides an advantage over traditional modulation techniques such as M-ary phase-shift keying (MPSK) and M-ary quadrature amplitude keying (MQAM) that only possess two degrees of freedom. MHPSK offers an improvement in bit error performance over other spectrally efficient modulation techniques for the same average energy per bit-to-noise power spectral density ratio and similar spectral efficiency. As a result, MHPSK offers a novel way to improve both throughput and reduce power requirements using easy to generate waveforms. In this paper, Reed Solomon coded symbols are assumed to be transmitted with MHPSK. MHPSK, MPSK, and MQAM are compared in terms of probability of bit error and bandwidth efficiency, where the number of bits per coded symbol are typically designed to match the number of bits per channel symbol.","PeriodicalId":434891,"journal":{"name":"MILCOM 2008 - 2008 IEEE Military Communications Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129275018","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":"Cross layer optimization in assured connectivity tactical mesh networks","authors":"J. Madsen, D. Tebben, A. Dwivedi, P. Harshavardhana, W. Turner","doi":"10.1109/MILCOM.2008.4753390","DOIUrl":"https://doi.org/10.1109/MILCOM.2008.4753390","url":null,"abstract":"Dynamic topology control schemes have been discussed earlier for continuously optimizing tactical mesh topologies to maximize the network connectivity. A dynamic optimization of the physical layer topology, however, is treated by layers-1 and 2 as a disruption and usually triggers re-computation of end-to-end paths. Higher layer routing algorithms may not always determine the same path as intended by the optimized physical layer causing conflicts and contention. In this paper we examine the response of higher layers to tactical physical layer topology changes and study the impact of cross layer optimization on the network performance. In particular, the paper describes the network and application performance improvement by an assured connectivity physical layer algorithm named DAPR with and without layer-2 (Ethernet) optimization.","PeriodicalId":434891,"journal":{"name":"MILCOM 2008 - 2008 IEEE Military Communications Conference","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125492358","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":"Dielectric breakdown of Electromagnetic Metamaterials in the mean-field approximation","authors":"J. Boksiner, Timothy Bocskor","doi":"10.1109/MILCOM.2008.4753043","DOIUrl":"https://doi.org/10.1109/MILCOM.2008.4753043","url":null,"abstract":"Electromagnetic Metamaterials (MTMs) are artificial materials with novel electromagnetic properties not available in nature. MTMs typically consist of a homogeneous host material containing appropriately configured embedded compact inclusions. MTMs have the potential to enable significant improvement on performance of low-profile (i.e. microstrip) and conformal antennas, including reduction of antenna size and antenna coupling. One key limitation for MTM implementation is the possibility of dielectric breakdown from electrical stresses such as high ambient electric fields arising from the transmitter itself, lightning and atmospheric charges, precipitation static (p-static), and electrostatic discharge (ESD). In this paper we investigate dielectric breakdown in the mean- field approximation. Dielectric breakdown is deemed to occur if the electric potential across an insulator exceeds a certain critical value, causing the insulator to become conductive and leading to failure of the insulator. Embedded conductive structures, such as those comprising MTMs, cause electric field enhancement near the metallic inclusion lowering the electric strength. We calculate the detailed electric field distribution within the MTM and compare the peak values to a critical breakdown field. Using the mean-field theory, we replace each inclusion by an equivalent dipole. The effect of remaining dipoles is taken into account by an effective field. The polarizability is determined by a self-consistent solution for the effective field. We determine the detailed field in the vicinity of the inclusion by summing the effective field and the local field due to the inclusion. We find that the presence of inclusions reduces the electric strength of the MTM in comparison to the electric strength of the pure host material. For a dilute MTM, the reduction depends mainly on the geometry of the inclusion. The reduction depends weakly on the concentration of the inclusions and is independent of the permittivity of the host material. The reduction may be significant even for very dilute MTMs and needs to be taken into account in practical applications. This work is an initial stage in CERDEC's effort to evaluate limitations to MTM parameters given the presence of intrinsic or environmental electromagnetic fields.","PeriodicalId":434891,"journal":{"name":"MILCOM 2008 - 2008 IEEE Military Communications Conference","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126846038","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":"Electronics Prognostics Reference Architecture","authors":"N. Almonte, D. Cook, J. Devereaux, M. Henry, T. Higgins, G. Roth","doi":"10.1109/MILCOM.2008.4753129","DOIUrl":"https://doi.org/10.1109/MILCOM.2008.4753129","url":null,"abstract":"Electronics prognostics can be defined as the prediction of the Remaining Useful Life (RUL) of electronic components before a failure occurs. This field, while immature, is increasingly important to Raytheonpsilas customers. Raytheon must develop a common and synergistic strategy to address new prognostic requirements. For this reason, Raytheon established a Prognostics and Health Management (PHM) (formerly known as Health Management System) Technology Information Group (TIG) to coordinate these efforts. The PHM TIG identified the need for an Electronics Prognostics Reference Architecture (ePRA) to use in proposals and during the evaluation of new systems with prognostics requirements. With that need in mind the authors of this paper employed the Raytheon Enterprise Architecture Process1 (REAP) to create an ePRA. A list of ldquomust haverdquo requirements for the ePRA were derived that enable its use across many Raytheon projects. Additionally, a list of quality attributes was created for the ePRA. Together these requirements and attributes led to the creation of supporting Department of Defense Architecture Framework2 (DoDAF) views. While there are numerous evolutionary concerns in the area of electronics prognostics, compliance with and the evolution of this ePRA will position Raytheon well to rapidly respond to its customerspsila growing prognostics requirements. The evolution of prognostic systems will fortify Raytheonpsilas customer focus by supplementing highly reliable products with RUL predictions. This will allow for ldquojust in timerdquo replacement of components, improvement within the logistics chain, and a reduction of down-time for the user in an increasingly mobile battlespace. The ePRA developed in this paper will guide the implementation and incorporation of electronics prognostics into Raytheonpsilas products.","PeriodicalId":434891,"journal":{"name":"MILCOM 2008 - 2008 IEEE Military Communications Conference","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126341507","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":"Compact UUV antenna assembly for reliable communications","authors":"R. Waterhouse, D. Novak","doi":"10.1109/MILCOM.2008.4753040","DOIUrl":"https://doi.org/10.1109/MILCOM.2008.4753040","url":null,"abstract":"We present a compact antenna assembly for UUVs (unmanned undersea vehicles) that supports UHF line of sight (LOS), DAMA (demand assigned multiple access) and MUOS (mobile user objective system) SATCOM communications. We have incorporated new size reduction and performance enhancing techniques to create one wideband, small volume antenna assembly that can be mounted directly to the UUV mast. The antenna achieves an electromagnetic performance that enables an efficient solution to be realized for UUV RF communications without the need for expensive antenna beam steering electronics. A proof of concept version of the compact mast mount antenna assembly with form factor suitable for integration on a 21\" UUV, has been prototyped and tested.","PeriodicalId":434891,"journal":{"name":"MILCOM 2008 - 2008 IEEE Military Communications Conference","volume":"634 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122949494","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":"A practical routing strategy in Delay Tolerant Networks using multiple pigeons","authors":"Hui Guo, Jiang Li, Y. Qian, Ye Tian","doi":"10.1109/MILCOM.2008.4753116","DOIUrl":"https://doi.org/10.1109/MILCOM.2008.4753116","url":null,"abstract":"The development of delay tolerant networks (DTN) has attracted significant attention in the networking research community. In this paper, we investigate a new type of delay tolerant network - homing pigeon based DTN (HoP-DTN) system. In HoP-DTN, each node owns multiple dedicated messengers (called pigeons), and each pigeon will take a round trip starting from its home, through the destination nodes and then return home, disseminating the messages on its way. The proposed scheme is a practical and effective way to overcome end-to-end disconnection in DTN. We obtain the average message delay of the scheme through theoretical analysis. The analytical model is validated by simulations. We also study the effects of several key parameters on system performance.","PeriodicalId":434891,"journal":{"name":"MILCOM 2008 - 2008 IEEE Military Communications Conference","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122223587","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":"Combined approach to tactical situations analysis","authors":"V. Popovich, A. Prokaev, O. V. Smirnova, F. Galiano","doi":"10.1109/MILCOM.2008.4753518","DOIUrl":"https://doi.org/10.1109/MILCOM.2008.4753518","url":null,"abstract":"Analysis of available sources reveals that situation awareness (SAW) for various objectives is realized through different approaches and techniques. Situation awareness is the perception of the elements in the environment within a volume of time and space, the comprehension of their meaning, and the projection of their status in the near future. The research done showed that results received in the field of artificial intelligence could be used to elaborate real SAW work algorithms. The most developed fields here are artificial neural networks (ANN) and genetic algorithms (GA). New progress and research in informatics, based on information processing implementing protein molecules' immune networks, processing principles appeared under the term of \"immunocomputing\" (IC). However, precision of situation recognition when using IC method directly depends on the training sample volume and quality, as it happens when using any other pattern recognition method. And yet during analysis it is possible that training data volume could be evidently insufficient for the correct situation recognition. In that case Aggregated Indices Method (AIM) could be used for the situation analysis. In the context of this method it is assumed that the experts assess the factors defining the tactical situation. In the method's framework any process of alternatives' preference estimation by an aggregated preference index may be put into terminological shape of correspondent objects quality estimation by an aggregated quality index. In this paper the combined approach to the tactical situation analysis is offered. The mentioned methods application in the uniform situation analysis system with the purpose of the recognition reliability rate increase is examined.","PeriodicalId":434891,"journal":{"name":"MILCOM 2008 - 2008 IEEE Military Communications Conference","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126763263","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":"Energy efficient scheduling in networks with correlated data","authors":"R. Cristescu","doi":"10.1109/MILCOM.2008.4753356","DOIUrl":"https://doi.org/10.1109/MILCOM.2008.4753356","url":null,"abstract":"We consider a network of nodes measuring a correlated data field, and in which information measured by the nodes needs to reach a central location where the field is reconstructed. We consider the situation where, in order to save energy, the nodes employ a random ON/OFF schedule of being active. We analyze the tradeoff between the distortion of reconstruction of the field, given by the number of nodes not covered by active nodes, and the energy cost for gathering the data, given by the shortest path tree on the graph formed by the active nodes. This scenario is relevant in the design of energy efficient scheduling for sensor networks measuring correlated data. We show that in general there is an optimal probability defining the schedule which minimizes a cost function which considers jointly the distortion and the energy cost.","PeriodicalId":434891,"journal":{"name":"MILCOM 2008 - 2008 IEEE Military Communications Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115934539","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}