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This paper details a compact, reconfigurable channel emulator (CRCE) specifically designed to create severe, multipath fading channels. The CRCE is a chamber that, unlike anechoic or reverberation chambers, provides non-uniform fading profiles for wireless devices placed within. In particular, the contribution of this work is that the CRCE is capable of creating not only Ricean and Rayleigh fading...
Motivated by the use of wireless sensors aboard aircraft, this work provides a method to delineate large- and small-scale propagation characteristics using data collected over space, polarization, and frequency. Empirical results from a transport helicopter are presented to illustrate the technique. Of particular note, the instance of multipath fading more severe than Rayleigh was found to be greater...
This work demonstrates the use of wireless sensor nodes to monitor time- and frequency-selective channel fading in the 2.4 GHz ISM band. Four distinct channel conditions are considered: (1) a static node experiencing little to no fade, (2) a static node experiencing severe, frequency-selective fading, (3) a static node, in a dynamic environment and (4) a moving node in a highly multipath environment...
This demonstration presents the results of a study addressing an issue that has constrained the effectiveness of wireless sensor network deployments to date, namely, connectivity. A physically compact, diversity antenna has been developed that is low in complexity and therefore suitably controlled using resource-limited wireless sensor hardware. Herein, this prototype antenna is demonstrated utilizing...
Recently, measured channel responses for wireless links in airframes, busses and helicopter environments have demonstrated that frequency-selective fading can be more severe than predicted by the Rayleigh channel model. The work herein investigates simple diversity methods as a means to mitigate such fading which is referred to as exhibiting hyper-Rayleigh behavior. In particular, the work presents...
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