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We study a distributed algorithm for adjusting beamforming vectors in a peer-to-peer wireless network with multiple-input multiple-output (MIMO) channels. Each transmitter precoding matrix has rank one, and a linear minimum mean squared error (MMSE) filter is applied at each receiver. Our objective is to maximize the total utility summed over all users, where each user's utility is a function of the...
If binary signaling is used in an n-channel OFDM link, the maximum possible bit rate is n bits per OFDM symbol duration. We show a simple scheme based on selective channel use that increases this capacity by nearly 60%. By using only k channels out of the n, we show how to use the choice of the k channels as an additional auxiliary channel. For proper choice of parameters, the information transferred...
Similar to the customer / service provider network model that exists in the Internet today, the Department of Defense's (DoD's) Global Information Grid (GIG) will consist of various customer networks (Army, Navy, etc.) that interconnect over a common core. Customer networks will source and sink IP traffic, and a transit network(s) will provide connectivity between geographically disparate customer...
DoD has defined three levels of data fusion for network centric warfare (NCW). Level 1 data fusion combines data from single or multiple sensors and sources to provide the best estimate of objects and events in the battlespace. Level 2 data fusion focuses on situation assessment. Level 3 data fusion is threat assessment. To facilitate situation assessment, we investigate the problem of jointly classifying...
We study end-to-end delay performance of different routing algorithms in networks with random failures. Specifically, we compare delay performances of differential backlog (DB) and shortest path (SP) routing algorithms and show that DB routing outperforms SP routing in terms of throughput when the network is heavily loaded and/or the failure rate is high while SP routing achieves better delay performance...
In this paper, we propose two modified proportional fair scheduling algorithms for multiuser multicarrier systems. Compared to the existing proportional fair scheduling algorithms, our proposed algorithms are devised to support the delay constraint for the real-time applications as well as to guarantee a certain level of fairness. The simulation results show that the proposed scheduling algorithms...
The emerging technologies of multiple, cooperative unmanned systems have brought in an exciting period of possibilities, possibilities of solving challenging problems in medical, social, engineering, and military communities. The technologies have also introduced a growing number of new challenges such as resource allocation, communication and coordination, establishment of consensus, and control...
The FlexNet-Waveform (FN-WF) is a new, highly-configurable MANET waveform for the international ground-based SDR arena, designed for the new FlexNet-One and FlexNet-Four hardware platforms. To ensure maximum compatibility and interoperability, the FN-WF assumes an IP-based platform with standard COTS protocols on the wired, Ethernet connections, while the wireless links utilize the best practices...
Modern Unmanned Aerial Vehicles (UAVs) have the capability of carrying sensors that produce large amounts of data. A high speed wireless data link is required to transfer this data to other systems for processing. This paper presents an FPGA-based implementation of a high data-rate (350 Mbps) QPSK modulator and demodulator to support a high data rate relay from a UAV to a ground station. By using...
Bluetooth is one of the most widely available wireless technologies with over 2 billion Bluetooth-enabled devices shipped. Used by cell phones, laptops, gaming consoles and many other devices, it is the predominant wireless personal area networking technology. Over the last couple of years, US Government Departments including the Department of Defense (DoD) have begun to embrace Bluetooth due to its...
Communications systems are increasingly reliant on system-on-chip (SoC) solutions. As the complexity and size of SoCs continues to grow, so does the risk of ??Trojan?? attacks, in which an integrated circuit (IC) design is surreptitiously and maliciously altered at some point during the design or manufacturing process. Despite the risks that such an attack entail, relatively little attention has been...
The foray of wireless sensor networks into time-sensitive applications demands support for emergency services with guaranteed quality of service (QoS) bounds. We introduced CP-EDCA, a channel preemptive enhancement to the IEEE 802.11e EDCA standard, for guaranteed emergency medium access in distributed wireless environments. The performance results for emergency traffic depicted 50% uniform decrease...
To support highly flexible network mobility in mobile communication systems, various types of movable network entities, especially mobile base stations (M-BSs), will appear in near future. In this environment, a scanning process to identify the availability of neighbor M-BSs for handoff should be newly designed, because a conventional method does not reflect the motion of base stations. Therefore,...
One of the major QoS goals for future battlefield networks (FBN) is to ensure multi-level precedence and preemption (MLPP). Ensuring MLPP is difficult, partly due to the networking architecture for FBN which consists of wired ??red?? network connected by encrypted wireless ??black?? network. The security requirements for FBN do not allow passing information from black to red networks. So when congestion...
Input to JTRS' future increment products may present an opportunity to address the design and the operational needs for MUOS handheld terminals. In terms of capacity, bit rate, coverage, availability and portability, MUOS handheld terminals provide significantly enhanced warfighter capability over the existing UHF satellite communication (SATCOM). In addition, it fulfills the needs for the hereto...
In this paper, we present an automated region-of-interest-based video coding system for use in ultra-low-bandwidth applications. Region-of-interest (ROI) coding methodology specifies that targets or ROIs be coded at higher fidelity using a greater number of available bits, while the remainder of the scene or background is coded using fewer bits. This allows the target regions within the scene to be...
We consider multi-constrained power, rate and channel allocation crafted for low power consumption, delay tolerant traffic, and under interfering link conditions that may be used in a cognitive radio system. Specifically, an iterative distributed algorithm, based on a sum-power constrained sum-rate maximization with upper (and lower) per user and channel power and rate constraints, as well as upper...
The majority of the routing protocols designed and implemented to date for mobile ad hoc networks (MANET) rely on flooding of route requests for the establishment of routes on demand, flooding of topology information, or the hop-by-hop dissemination of distances or paths for each destination. The signaling overhead incurred with these strategies consumes excessive amounts of the scarce bandwidth available...
Peak-to-average power ratio (PAR) reduction algorithms have been thoroughly studied for single system multicarrier signals that tend to have low power efficiency. However, an emerging application for PAR reduction, namely asynchronous multi-plexed signals, has not been examined. This paper frames the problem arising in modern base stations where multiple frequency-division OFDM waveforms are multiplexed...
The Defense Information Systems Agency (DISA) has been supporting dissemination of airborne sensor Full Motion Video (FMV) since the inception of the Global Broadcast Service (GBS). DISA actively investigates emerging video technologies and participates in DoD and industry conferences related to FMV. In 2006, DISA increased its involvement in FMV dissemination through support to several US Central...
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