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Owing to the extensive use of commercial wide-band SATCOM systems by the Department Of Navy (DON) and the Department of Defense (DOD) in general, designers and operators of such systems need to investigate and analyze the performance of a broad range of deployment options with respect to communications requirements under a given warfighting scenario, and show the effects of these alternatives on these...
This paper considers a synchronous DS-CDMA system where channel state information at the base station is acquired via uplink training and channel feedback is used to provide the terminals with the optimal uplink signatures. We examine the tradeoffs involved in the proportioning of a resource block between training, data, and feedback symbols, with linear (matched filter and minimum mean-square error)...
Management of the devices in a Wideband SATCOM enterprise Earth terminal facility (ETF) is currently fragmented among multiple systems, and some of these legacy systems provide only limited functionality. This paper describes the architecture of a consolidated system to manage the elements of an ETF. Such a system can offer a number of benefits. First, the ETF management system can provide a consolidated,...
Communication systems must maintain tight timing synchronization between the transmitter and receiver. Systems typically pull-in timing from a large timing offset and then track timing once it has been sufficiently pulled in. When timing errors are large, additional reference symbols are needed to pull-in time. In some frequency hopping systems, the time pull-in step must be repeated for every hop...
Multicasting can be an useful service in wireless mesh networks (WMNs), which have gained significant acceptance in recent years due to their potentials of providing a low-cost wireless backhaul service to mobile clients. Many applications in WMNs require efficient and reliable multicast communication, i.e., with high delivery ratio but with less overhead, among a group of recipients. However, in...
This paper proposes a low-complexity equalizer for orthogonal frequency division multiplexing (OFDM) systems under time-varying frequency-selective fading environments. The equalization uses suboptimum maximum likelihood sequence estimation (MLSE) in cooperation with semi-blind linear prediction (SBLP) in the estimation of the channel frequency responses. When the number of pilot subcarriers is far...
Recent advances in component technology now make it possible to exploit of the ultraviolet (UV) spectrum for short range, medium bandwidth, low probability of intercept (LPI) communications. BAE Systems will report on analysis of hardware and phenomenology for the near term application of solar blind ultraviolet non line-of-sight communications (SB UV NLOS Comm). Communications in the presence of...
In our previous work, we have shown that hybrid ARQ (HARQ) can be used to achieve secret communication over a fast fading channel. This is a physical-layer technique that can be used in conjunction with conventional cryptography to provide further protection from an eavesdropper. The key to our previous work was to use reliability-based HARQ to improve the decoder performance at the desired user much...
The wideband global SATCOM (WGS) system is currently operational in the Pacific Ocean using WGS1 (175E). GBS traffic is supported in that theater today using the digital video broadcast by satellite (DVB-S) and operates using terminals originally designed for operation using the UHF follow-on satellite (UFO8). These terminals can now operate over WGS1 and UFO8. GBS is planned to migrate to the joint...
Relay network is proposed as a means of improving the error performance and energy efficiency of the wireless networks. Inspired by the battery power efficiency (BPE) analysis in Duan et al. (2009), relay selection from the battery energy efficiency perspective turns out to be an interesting topic. Under the general network setup which integrates typical transmission and reception modules, we adopt...
Future satellite-based packet networks (FSPN) will utilize a request/grant MAC protocol referred to as demand assigned multiple access (DAMA) for uplink allocations. DAMA is conceptually similar to bandwidth-on-demand (BoD) protocols used in terrestrial networks, such as 802.16 and DOCSIS, which flexibly share total bandwidth according to actual loads and usage policies. However, unique characteristics...
The performance of an oversampled multiband wideband digital receiver is presented in this paper. Unlike previous works that assume a single channel receiver and a conventional analog-to-digital converter (ADC), where the quantization error is modeled as an additive uniform random noise, this paper includes the effects of an oversampled sigma-delta (??-??) ADC with noise shaping and an automatic gain...
In this paper, we propose a novel approach, which is termed heterogeneous intelligent filtering (HIF), for intelligent control and application data filtering in multi-domain heterogeneous networks. HIF creates intelligent gateways to rapidly and autonomously adapt the flow of information content to the changing mission needs and network characteristics. HIF employs a MANET management protocol (termed...
This paper investigates the issue of resource allocation in multicarrier wireless networks, where users have a choice between multiple service providers. We investigate the feasibility of modeling the allocation problem as a probabilistic voting game. In other words, competing transmitters are modeled as candidates in an election, while the receivers form the electorate. The specific example analyzed...
In cryptographically-partitioned networks, data within a packet can be used by routers in the plain-text enclaves to make quality of service (QoS) and precedence and preemption (P&P) decisions in regards to forwarding the packet and allocating resources for flows. However, while in a cipher-text shared transit network, the packet is encrypted and is opaque to routers in the transit network and...
This research advances Cyber Situation Management by proposing methods for automated mapping of Cyber Assets to Missions and Users (Camus). To enable accurate and efficient cyber incident mission impact assessment, a Camus ontology that defines entities, relationships and attributes (ERAs) associated with them has been drafted. Methods for fusing data from multiple data sources have been developed...
This paper addresses the use of Resource ReSerVation Protocol-Aggregate (RSVP-AGG) at the tactical edge of the Air Force's Airborne Network (AN). Since the AN tactical edge can have different types of stub-networks accessing the AN (i.e., non-IP based legacy networks like Link 16, DiffServ based networks and IntServ based net-works), RSVP-AGG offers a common access approach regardless of the differences...
This work proposes a method for localizing a single near-field source using a moving array. Using a phase correction factor calculated from two sequences of selected data snapshots, we extend the array aperture and compute the initial estimates of the source's bearing and range from the extended data sets. With the initial estimates of bearing and range we construct a phase difference factor to modify...
The mobile user objective system (MUOS) is a geo-satellite communications system derived from the terrestrial cellular WCDMA air interface. WCDMA power control with the long geo-satellite round trip time presents substantial challenges. This paper describes the Point-to-Point power control system with simulation results using time-varying channel models specified by the MUOS program office.
In this paper we formulate OFDM signals based on explicit pulse shaping filtering. A rectangular pulse in time domain for shaping filtering is most often used, but it has SNR loss compared to a shaping filter with a brick-wall frequency domain filter since in practice both require guard time or guard band. Our formulation of OFDM signal based purely on shaping filter may provide a common platform,...
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