82 research outputs found

    IA-OPD : an optimized orthogonal pulse design scheme for waveform division multiple access UWB systems

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    A new design scheme of orthogonal pulses is proposed for waveform division multiple access ultra-wideband (WDMA-UWB) systems. In order to achieve WDMA and to improve user capacity, the proposed method, termed as interference alignment based orthogonal pulse design (IA-OPD), employs combined orthogonal wavelet functions in the pulse design. The combination coefficients are optimized by using interference alignment. Due to the reciprocity between transmitted and local template signals, the iterative process based on maximum signal to interference plus noise ratio (Max-SINR) criterion can be used to solve the optimization problem in interference alignment. Numerical results demonstrate that the optimized orthogonal pulses provide excellent performances in terms of multiple access interference (MAI) suppression, user capacity and near-far resistance without using any multiuser detection (MUD) techniques. Thus, the IA-OPD scheme can be used to efficiently design a large number of orthogonal pulses for multiuser WDMA-UWB systems with low computational complexity and simple transceiver structure

    A COMPREHENSIVE REVIEW OF INTERNET OF THINGS WAVEFORMS FOR A DOD LOW EARTH ORBIT CUBESAT MESH NETWORK

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    The Department of Defense (DOD) requires the military to provide command and control during missions in locations where terrestrial communications infrastructure is unreliable or unavailable, which results in a high reliance on satellite communications (SATCOM). This is problematic because they use and consume more digital data in the operational environment. The DOD has several forms of data capable of meeting Internet of Things (IoT) transmission parameters that could be diversified onto an IoT network. This research assesses the potential for an IoT satellite constellation in Low Earth Orbit to provide an alternative, space-based communication platform to military units while offering increased overall SATCOM capacity and resiliency. This research explores alternative IoT waveforms and compatible transceivers in place of LoRaWAN for the NPS CENETIX Ortbial-1 CubeSat. The study uses a descriptive comparative research approach to simultaneously assess several variables. Five alternative waveforms—Sigfox, NB-IoT, LTE-M, Wi-sun, and Ingenu—are evaluated. NB-IoT, LTE-M, and Ingenu meet the threshold to be feasible alternatives to replace the LoRaWAN waveform in the Orbital-1 CubeSat. Six potential IoT transceivers are assessed as replacements. Two transceivers for the NB-IoT and LTE-M IoT waveforms and one transceiver from U-blox for the Ingenu waveform are assessed as compliant.Lieutenant, United States NavyApproved for public release. Distribution is unlimited

    A New RF Satellite Link Analyzing and Antenna Effect on Satellite Communication

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    Satellite communications (SatComs) recently, have admitted as a new technological advances that attracted and raised special investment and ventures. Space communication technology has found many application areas from costly, one-of-a-sort structures, to utilize again of technology on sequential tasks, to the progress of canonical protocols accepted by space agencies of lots of countries. Satellite communication has accepted as one of the important technologies for 5G backhauling, particularly on bandwidth request increased in 5G mobile broad band (eMBB) applications. This paper presents the efficiency of the satellite communication system using 16 QAM digital modulation technique for the X band. This digital modulation method presents high data rate in transmission without raising the bandwidth compared with other digital modulation methods. Applications are realized in Matlab environment and obtained conclusions are discussed such as power spectrum diagrams, constellation schemas and BER ratio for several bands such as 4, 8, 12, 16 GHz

    USING COMMERCIAL 5G AND LEO TECHNOLOGIES TO ENHANCE NAVY-ARMY SENSOR-TO-SHOOTER NETWORKS

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    The emerging commercial technologies of 5G and low Earth orbit (LEO) satellite communications have the capability to provide links that send large amounts of data with low latency. As the DOD continues to explore how to best leverage these technologies, it is important to develop potential use cases within the military. This thesis describes a sensor-to-shooter operational scenario and the network transport links currently in use to move data from a Navy sensor to an Army shooter. The current sensor-to-shooter network transport links are then compared to the emerging commercial alternatives of 5G and LEO satellite communications in the categories of throughput, latency and range. This analysis demonstrates the comparative advantages and disadvantages of both 5G and LEO technologies over current links.Captain, United States ArmyLieutenant, United States NavyApproved for public release. Distribution is unlimited
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