SCIENTIFIC AND TECHNICAL AEROSPACE REPORTS
A Biweekly Publication of the National Aeronautics and Space Administration
VOLUME 44, ISSUE 14 - JULY 18, 2006
32 COMMUNICATIONS AND RADAR
Includes radar; radio, wire, and optical communications; land and global communications; communications theory.
For related information see also 04 Aircraft Communications and Navigation; and 17 Space Communications, Spacecraft Communications, Command and Tracking; for search and rescue, see 03 Air Transportation and Safety; and 16 Space Transportation and Safety.
20060019329 Lawrence Livermore National Lab., Livermore, CA USA
Integration Window Position Estimation in TR Receivers
Nekoogar, F.; Dowla, F.; Spiridon, A.; Mar. 21, 2005; 12 pp.; In English Report No.(s): DE2006-862387; UCRL-CONF-210686; No Copyright; Avail.: Department of Energy Information Bridge
Transmitted-reference (TR) receivers avoid the stringent synchronization requirements that exist in conventional pulse detection schemes. However, the performance of such receivers is highly sensitive to precise timing acquisition and tracking as well as the length of their integration window. This window in TR receivers defines the limits of the finite integrator prior to the final decision making block. In this paper, we propose a novel technique that allows us to extract the timing information of the integration window very accurately in UWB-TR receivers in the presence of channel noise. The principles of the method are presented and the BER performance of a modified UWB-TR receiver is investigated by computer simulation. Our studies show that the proposed estimation technique adds value to the conventional TR receiver structure with modest increase in compleaxity. NTIS
Receivers; Time Measurement; Target Acquisition; Channel Noise
20060019786 Congressional Budget Office, Washington, DC USA
CBO Testimony: The Army's Future Combat Systems Program
Gilmore, J M; Apr 4, 2006; 23 pp.; In English; Original contains color illustrations Report No.(s): AD-A446820; No Copyright; Avail.: CASI: A03, Hardcopy
CBO's analysis of the FCS program and potential alternatives supports the following observations: B The FCS program must surmount substantial technical and funding challenges if it is to develop and initially field all of the individual FCS components as currently scheduled by December 2014. B According to the Army's estimates, total annual costs to purchase the various FCS components could approach $10 billion. However, if such costs grew as those of similar programs have in the past, annual costs could reach $16 billion. B Moreover, if the Army fields FCS vehicles according to its current schedule, more than $2 billion of additional funding could be needed annually from 2010 through 2016 with lesser amounts required thereafter to maintain and upgrade the Army s inventory of aging ground combat systems. B Although one of the main purposes of the FCS program is to speed the movement of Army combat units overseas, replacing the current fleet of armored vehicles with FCS vehicles will not significantly reduce deployment times. Alternatives to the currently planned FCSprogram that would eliminate all or part of the program s ground vehicles while retaining its communications equipment and, in some cases, its sensors would reduce the program s annual costs to about $6 billion to $7 billion. Under such alternatives, the Army would incorporate some of those technologies into its current armored vehicles and upgrade those vehicles at the same time, thereby increasing their capabilities and extending their useful lives. However, if it did so, the Army would forgo the potential benefits of the capabilities it now seeks in the FCS program. DTIC
Combat; Communication Equipment; Military Operations; Military Personnel
20060019793 Air Force Inst. of Tech., Wright-Patterson AFB, OH USA
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Evaluating the Correlation Characteristics of Arbitrary AM and FM Radio Signals for the Purpose of Navigation
Kim, Bryan S; Mar 2006; 104 pp.; In English Report No.(s): AD-A446837; AFIT/GE/ENG/06-28; No Copyright; Avail.: CASI: A06, Hardcopy
The Global Positioning System (GPS) provides position estimates on the Earth at anytime, anywhere and in any weather. However, to provide robust positioning, GPS requires an unobstructed path to satellite signals. As such, GPS performance generally degrades or becomes non-existent in environments such as large urban areas. This research investigates and analyzes the correlation characteristics of arbitrary AM and FM radio signals for the purpose of navigation. Simulations are conducted with different combinations of correlation methods ('fixed' or 'varying'), modulation types (AM or FM), and signal types (song or voice). Out of the eight different variations considered, only two provided promising results for the purpose of navigation. Both the FM voice and FM song signals exhibit distinct autocorrelation peaks (i.e., 5.0 dB peak-to-sidelob ratios) using the 'fixed' reference correlation method. However, results for both FM signal types revealed limited potential for navigation when using the 'varying' reference correlation method. All the AM signals considered yielded relatively limited potential for navigation using either correlation method. DTIC
Correlation; Navigation; Radio Signals
20060019797 Federal Armed Forces Univ., Hamburg, Germany
Estimating Demand Elasticities for Mobile Telecommunications in Austria
Dewenter, Ralf; Haucap, Justus; Dec 2004; 27 pp.; In English Report No.(s): AD-A446842; No Copyright; Avail.: CASI: A03, Hardcopy
This paper analyzes price elasticities in the Austrian market for mobile telecommunications services using data on firm-specific data on different tariffs. Both static and dynamic panel data analyses were used to estimate short- and long-run price elasticities and the impact of networks' subscriber bases on the demand for mobile calls. The results indicate that the demand for mobile telecommunications services in Austria is relatively elastic when compared to other countries. From a competition policy perspective, these results imply that policy makers in Austria have to be less concerned about collusion between mobile operators than in other countries. This result is consistent with more qualitative comparative studies that have demonstrated the high degree of competition in the Austrian mobile telecommunications sector. Given the regulatory framework that is in place in Austria (e.g., involving the regulation of termination fees and mobile number portability), the authors do not see any obvious reason for any further regulatory intervention or supervision at this point. The intense competition between mobile operators not only makes collusion relatively unlikely, but it also benefits consumers. DTIC
Austria; Econometrics; Elastic Properties; Estimates; Estimating; Telecommunication
20060020152 Istituto Superiore di Sanita, Rome, Italy
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II Processo di Comunicazione Istituzionale Attraverso Technologies Web. II Caso Del Sito 3.0 Dell'Istituto Superiore di Sanita (Web Technologies for Institutional Communication Process Istituto Superiore di Sanita's 3.0 Website)
Faralli, C.; Ferrari, M.; Guderzo, S.; Deodati, S.; Bertini, P.; January 2005; 110 pp.; In Italian Report No.(s): PB2006-109212; ISTISAN-05/44; Copyright; Avail.: National Technical Information Service (NTIS)
An institutional web site design cannot leave out of consideration the conformity with specific regulations and is job which involves different and specialized professionalities. Concepts as accessibility and usability must be held into consideration, not neglecting the vital cycle analysis of the contents and as these must be carried towards the web site visitors. The discussion involves the editorial coordination that must guarantee to the user that the entire site is benefited in the same way, with the same clarity and a coherent language, as the contents are produced from various structures. There are detailed instruments and strategies that have brought to the publication of release 3.0 of the Istituto Superiore di Sanita site and it comes back a panoramic on the method with which it has been managed this new project, since the dynamism is a continuous necessity and one of the foundations of the web communication. NTIS
Interprocessor Communication; Websites
20060020161 Newcastle-upon-Tyne Univ., Newcastle, UK
Framework for the Rigorous Implementation of Security Protocols
Robinson, P.; Cook, N.; Shivastava, S.; Dec. 2005; 30 pp.; In English Report No.(s): PB2006-109192; CS-TR-937; Copyright; Avail.: National Technical Information Service (NTIS)
The correct implementation of security protocols is a challenging task. Like any software, to gain high confidence in a given implementation, ideally one requires both: (i) a formal specification that has been subjected to verification; and (ii) tool support to generate an implementation from the verified specification. The former area has attracted considerable attention for security protocols, and significant advances have been made. In the latter area, the state of the art has not progressed beyond simple security protocols with a small number of steps. This paper presents an improved approach to protocol implementation. Starting with a formal protocol specification, a rigorous process with considerable tool support leads to the deployment of implementations in a flexible middleware framework for their execution. To illustrate the approach, the paper describes the implementation of a deterministic, fair non-repudiation protocol. Such protocols are quite complex, as they require both sub-protocols and trusted third party involvement in order to guarantee fairness. Therefore, it is reasonable to assume that we can extend the approach to a wide range of less complex, deterministic security protocols. NTIS
Computer Information Security; Protocol (Computers); Security
20060020182 Swedish Defence Research Establishment, Linkoeping, Sweden
Specification-Based Intrusion Detection Combined with Cryptography Methods for Mobile Ad Hoc Networks (Policy-Baserad Intrangsdetektering foer Mobila Ad Hoc-Naet)
Hansson, E.; Groenkvist, J.; Persson, K.; Nordqvist, D.; Dec. 2005; 34 pp.; In English Report No.(s): PB2006-112070; FOI-R-1867-SE; Copyright; Avail.: National Technical Information Service (NTIS)
New challenges within the area of security have arisen due to a relatively new paradigm called mobile ad hoc networks. A mobile ad hoc network consists of wireless nodes that build a radio network without any pre-existing infrastructure or centralized servers. However, these networks have inherent vulnerabilities that make them susceptible to malicious attacks such as denial of service and propagation of incorrect routing information. Current security solutions for tactical radio networks, which mainly are based on cryptography, are not sufficient. We need to search for new solutions in order to obtain an acceptable level of security for tactical mobile ad hoc networks. In this report, we examine the vulnerabilities of mobile and hoc networks and argue that both cryptography solutions and intrusion detection must be included in mobile ad hoc networks. NTIS
Communication Networks; Cryptography; Detection; Policies; Warning Systems
20060020682 Northwestern Univ., Evanston, IL USA
Secure Communication Using Mesoscopic Coherent States
Barbosa, Geraldo A; Corndorf, Eric; Kumar, Prem; Yuen, Horace P; Apr 17, 2003; 5 pp.; In English; Original contains color illustrations Contract(s)/Grant(s): F30602-01-2-0528 Report No.(s): AD-A446503; No Copyright; ONLINE: http://hdl.handle.net/100.2/ADA446503; Avail.: CASI: A01, Hardcopy
We demonstrate theoretically and experimentally that secure communication using intermediate energy (mesoscopic) coherent states is possible. Our scheme is different from previous quantum cryptographic schemes in that a short secret key is explicitly used and in which quantum noise hides both the bit and the key. This encryption scheme can be optically amplified. new avenues are open to secure communications at high speeds in fiber-optic or free-space channels. DTIC
Fiber Optics; Communication; Security
20060021043 Hawaii Univ., Honolulu, HI USA
Adaptive M-QAM Modulation for MIMO Systems
Gowrishankar, Ramkumar; Demirkol, Mehmet Fatih; Jan 1, 2005; 5 pp.; In English; Original contains color illustrations Report No.(s): AD-A447442; No Copyright; Avail.: CASI: A01, Hardcopy
Adaptive modulation substantially increases the throughput of a wireless network by adjusting the modulation index to the channel conditions. It was shown that adaptive power and rate M-QAM system can give a power gain of almost 20dB relative to non-adaptive transmission for CDMA systems. A review of adaptive modulation for broadband system was presented. Multiple-input multiple-output (MIMO) links exploit the spatial dimension and antenna arrays at both ends of a link to transmit multiple parallel streams in the same time and frequency channel. The result is an extraordinary bandwidth-efficient approach to wireless communication, especially in rich multi-path environments. V-BLAST is a simple and widely considered architecture for open-loop (OL) MIMO systems. In this paper we propose algorithms for implementing adaptive M-QAM modulation for both OL- and CL-MIMO systems. The goal is to maximize the throughput subject to a target BER constraint. For OL-MIMO the algorithm proposed finds the number of transmit antennas and the modulation index to be used for all streams. For CL-MIMO, we propose a new rate maximization scheme that, on the average, has 20% throughput improvement over OL-MIMO. We also modify the water-filling and MMSE solutions to accommodate adaptive modulation and BER constraints. We use the flat Rayleigh-fading channel model for our simulations, and assume perfect channel estimation. This paper is organized as follows: The OL- and CL-MIMO strategies are discussed in Section II. The adaptive M-QAM scheme is discussed in Section III. In Section IV we introduce our adaptive modulation implementations and propose a new rate maximization scheme for CL-MIMO that takes into account the BER threshold. DTIC
Amplitude Modulation; Communication Networks; MIMO (Control Systems); Quadrature Amplitude Modulation; Wireless Communication
20060021375 Swedish Defence Research Establishment, Linkoeping, Sweden
Free Space Optics Communication for Transmission of Warning and Countermeasure Information Between Ships
Sakari, P.; Pettersson, M.; Sep. 2005; 34 pp.; In Swedish Report No.(s): PB2006-112090; FOI-R-1718-SE; Copyright; Avail.: National Technical Information Service (NTIS)
In the development of warner and countermeasure systems for ships in military units, there is a need of information transmission. This report studies laser communication, also called Free Space Optics (FSO), as an alternative to radio based communication. Communication range of more than 10 km is possible, even if the visibility is moderate. At poorer visibility the range will be reduced. The study shows that high precision pointing and tracking is necessary, but in return covert communication with high bit rates (Gbps) are possible. The potential of high bit rates does not only make traditional warner and countermeasure information transmission possible. It can also be utilized for transmission of large quantities of sensor close data. This will result in new possibilities of distributed sensors and sensor fusion, for instance in getting bearing of other ships. NTIS
Countermeasures; Optical Communication; Space Communication
20060021394 Swedish Defence Research Establishment, Linkoeping, Sweden
Using Variable Data Rate in Mobile Ad Hoc Networks Supporting Delay Sensitive Traffic
Farman, L.; Nilsson, J.; Tronarp, O.; Oct. 2005; 38 pp.; In English Report No.(s): PB2006-112080; FOI-R-1725-SE; Copyright; Avail.: National Technical Information Service (NTIS)
In wireless ad hoc networking efficient resource management is crucial in order to deal with delay sensitive traffic. This paper results from studying such traffic in a mobile scenario and focuses on the gains that can be obtained by variable data rate. We study this from several points of view, the effect of lower data rates, the routing metric, and delayed routing update. The results show that the greatest benefit with adding lower data rate links in the increased connectivity in the network. Lower data rates also give a better support when the routing information in the network is delayed. Further, the choice of routing metric is also important in order to be able to fully utilize a large range of data rates. NTIS
Rates (Per Time); Sensitivity; Traffic
20060021505 NASA Johnson Space Center, Houston, TX, USA
Performance Evaluation of a UWB-RFID System for Potential Space Applications
Phan, Chan T.; Arndt, D.; Ngo, P.; Gross, J.; Ni, Jianjun; Rafford, Melinda; [2006]; 18 pp.; In English; AIAA Annual Technical Symposium (ATS) 2006, 19 May 2006, Houston, TX, USA; Original contains color illustrations; No Copyright; Avail.: CASI: A03, Hardcopy
This talk presents a brief overview of the ultra-wideband (UWB) RFID system with emphasis on the performance evaluation of a commercially available UWB-RFID system. There are many RFID systems available today, but many provide just basic identification for auditing and inventory tracking. For applications that require high precision real time tracking, UWB technology has been shown to be a viable solution. The use of extremely short bursts of RF pulses offers high immunity to interference from other RF systems, precise tracking due to sub-nanosecond time resolution, and robust performance in multipath environments. The UWB-RFID system Sapphire DART (Digital Active RFID & Tracking) will be introduced in this talk. Laboratory testing using Sapphire DART is performed to evaluate its capability such as coverage area, accuracy, ease of operation, and robustness. Performance evaluation of this system in an operational environment (a receiving warehouse) for inventory tracking is also conducted. Concepts of using the UWB-RFID technology to track astronauts and assets are being proposed for space exploration. Author
Broadband; Multipath Transmission; Radio Frequencies; Performance Tests; Real Time Operation; Tracking (Position)
20060021515 Swedish Defence Research Establishment, Linkoeping, Sweden
Metodik foer Kommunikationssystemvaerdering: Rapport 1 (Methodology for Communications System Assessment: Report 1)
Asp, B.; Carling, C.; Johansson, B.; Johansson, P.; Dec. 2005; 38 pp.; In Swedish Report No.(s): PB2006-112096; FOI-R-1809-SE; Copyright; Avail.: National Technical Information Service (NTIS)
This document summarizes the first year of activities within the three-year project Communication Assessment, COAT. The report describes the project background, the interpretation of the term assessment made by the project team and the content of the commission. The report not only describes the methodology used in the treatment of the assessment problem but also the development of a rudimentary assessment methodology. A test of this assessment methodology has been performed on a civilian communication system in a military scenario. Furthermore, experiences made during the work are discussed. Finally, the report describes how some of these experiences will influence the forthcoming development of the methodology. The final methodology for assessment must work as a support for a wide range of assessment tasks, from the quick one-man investigation to the long-lasting complex assessment with many experts involved. The proposed methodology draft may to the reader seem to be very complicated and overambitious. This is justified by the fact that during the development, it is necessary to have a detailed roadmap of the process and also a good document structure in order to obtain a well defined test object. The descriptions outlined here area to be treated as the basis for the continued work with the development of a user friendly and straightforward methodology as possible. NTIS
Telecommunication; Methodology
20060021525 Swedish Defence Research Establishment, Linkoeping, Sweden
Vaerdering Avvaegning TK/SAT en Foerstudie (Balanced Assessment of Electronic Warfare and Signature Management Technologies, a Pre-Study)
Klum, P.; Carlsson, P.; Olsson, G.; Nelsson, C.; Johansson, P.; Dec. 2005; 90 pp.; In Swedish Report No.(s): PB2006-112098; FOI-R-1817-SE; Copyright; Avail.: National Technical Information Service (NTIS)
Signature Management Technologies (SMT) and Electronic Warfare (EW) are two important assets in order to increase survivability of platforms and combat units and be able to fulfill a mission objective. This report describes the effort that has been conducted in the pre-study Vardering avvagning TK/SAT, en forstudies. In the pre-study, operational systems, methods and tools for balancing SMT and EW have been studied. In addition software has been developed to demonstrate a balancing method. The purpose of the pre-study has been to lay the foundation for further work in the field of combined and balanced SMT/EW support systems. Balancing these assets may improve survivability and efficiency for platforms and combat units. Arestriction has been made in that only SMT/EW support systems applicable to planning, prior to and during combat missions have been studied. System methods and tools have been compiled in the report, together with acquired experience. One conclusion is that balancing SMT/EW is an exceedingly complex task and that further work has to be conducted. Further work should, for example: be restricted to SMT/EW support during combat missions; be restricted to ground combat operations; select a few promising methods for assessment; develop co-operation with domain experts in the field of SMT, EW, decision support and resource allocation. NTIS
Electronic Warfare; Signatures
Source: NASA
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