879 resultados para Secure Wireless Communications
Resumo:
The recent advances in urban wireless communications and protocols that spurred the development of city-wide wireless infrastructure motivated this research, since in many cases, construction sites are not conveniently located for wired connectivity. Large scale transportation projects for example, such as new highways, railroad tracks and the networks of utilities (power-lines, phone lines, mobile towers, etc) that usually follow them are constructed in areas where wired infrastructure for data exchange is often expensive and time-consuming to deploy. The communication difficulties that can be encountered in such construction sites can be addressed with a wireless communications link between the construction site and the decision-making office. This paper presents a case study on long-range, wireless communications suitable for data exchange between construction sites and engineering headquarters. The purpose of this study was to define the requirements for a reliable wireless communications model where common types of electronic construction data will be exchanged in a fast and efficient manner, and construction site personnel will be able to interact and share knowledge, information and electronic resources with the office staff.
Resumo:
A second harmonic suppression scheme allowing RoF links to support communications and passive UHF RFID is reviewed. Using RoF distributed antenna system techniques, the coverage and location accuracy of passive UHF RFID are significantly improved.
Resumo:
An error-free free space communication link with 3 angular coverage and 1.25GHz modulation bandwidth is demonstrated by beam steering an ultra high modulation efficiency bright tapered laser diode using a Liquid Crystal Spatial Light Modulator. © OSA 2012.
Resumo:
This article reviews an important class of MIMO wireless communications, known collectively as turbo-MIMO systems. A distinctive property of turbo-MIMO wireless communication systems is that they can attain a channel capacity close to the Shannon limit and do so in a computationally manageable manner. The article focuses attention on a subclass of turbo-MIMO systems that use space-time coding based on bit-interleaved coded modulation. Different computationally manageable decoding (detection) strategies are briefly discussed. The article also includes computer experiments that are intended to improve the understanding of specific issues involved in the design of turbo-MIMO systems.