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As the world becomes increasingly dependent on dynamic and up-to-the-moment information, we recognize that broadband networks must be able to convey this information timely and wirelessly, to and from users in motion. Varieties of 802.11 compliant equipment and other types of broadband wireless equipment have been proposed for, and in some areas, being used to meet this need. There have been questions...
Determining an optimal position of an antenna on a platform is not always intuitive. This paper examines the implementation of a genetic algorithm (GA) within XFdtd, a finite difference time domain (FDTD) solver, for its effectiveness in determining an optimal antenna position when compared to a brute force method. XFdtd uses the FDTD method to solve general electromagnetic problems. Built into XFdtd...
In this paper, we present a single-carrier (SC) waveform with smart antenna and frequency domain equalization (FDE) technologies to effectively combat both urban multipath and radio interference. It is designed to be power efficient, spectrally efficient, high quality, and capable of operating at vehicular speeds with long range. It can work on a small form factor device to support transport of streaming...
The paper introduces a new concept of groupwise generalized selection combining (GGSC), denoted by GGSC(n, m, L) , in which there are n groups of generalized selection combining GSC(m, L) where the largest m (in SNR) elements are selected from L independent elements. The paper proves that GGSC(n, m, L) has the same diversity order (DO) as that of MRC with nL elements, denoted by MRC(nL) and GSC(nm,...
Active topology management in the future airborne networks (AN) can provide improved overall network throughput, efficiency, and scalability and is critical due to the high degree of platform dynamics involved. The RF links that form an airborne network must be established and reconfigured rapidly in response to aircraft joining and leaving the network, aircraft changing flight paths, and to changes...
Multiple antenna systems have been shown to provide significant performance improvements for network nodes; however, the vast majority of nodes in military networks will be limited to single channel devices due to mobility (size and power) and ease of use considerations. In this paper we apply a new joint synchronization-pilot sequence (JSPS) optimization design technique to multiple transmitter OFDM...
Modern industrial textile materials are composed of mechanically strong fibers that find their applications in integrated antennas within soldier's garment and armors in ballistic protection as well. This paper will cover electromagnetic characterization of such textile materials for SoftWear antenna substrate. Dielectric permittivity and loss tangent are analyzed and measured in varying relative...
This paper proposes a statistical approach to off-axis EIRP masks, in order to accommodate satellite communications on the move (SOTM) terminals. A ??statistical mask?? provides a reference EIRP Spectral Density (ESD) limitation, which can be exceeded with a specified maximum probability. Statistical masks and their implementation approaches are discussed in detail. Simulations are provided to show...
We present here an exploration of enabling MIMO spatial multiplexing in a long range LOS point-to-multipoint link such as might be found in a ground-to-air sensor network backhaul or LOS cellular configuration. The paper focuses on the capacity between a single multi-antenna sensor and an airborne multi-antenna transceiver, facilitated by an airborne single-antenna repeater. The multi-point aspect...
A handheld software defined tactical VHF/UHF radio used for AM/FM/PM line of sight communications is transformed into a single sideband HF band radio for HF 2G and 3G ALE networking. Military radio convergence presents real challenges to aggregation of widely variant narrowband waveforms. This paper discusses the hardware adaptations that allow a handheld VHF/UHF radio to act as the core radio of...
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