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- Hult, Tommy, et al.
(författare)
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Active Suppression of Electromagnetic Fields Using a MIMO Antenna System
- 2003
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Konferensbidrag (refereegranskat)abstract
- Active suppression of noise and vibrations is a well established field of research with many applications in acoustic and mechanical industries. In this paper we test some of these active control methods in order to assess their validity and performance when applied to electromagnetic fields. The application that we evaluated is a model of a mobile telephone equipped with one ordinary transmitting antenna and two actuator-antennas which purpose is to cancel out the electromagnetic field at a specific point in space (e.g. at your head).
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| 2. |
- Nordebo, Sven, et al.
(författare)
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A Semi-definite Programming Approach to Spatial Decorrelation of Independently Polarized Signals
- 2007
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Ingår i: Wireless Communications & Mobile Computing. - : Wiley. - 1530-8669 .- 1530-8677. ; 7:1, s. 91-101
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Tidskriftsartikel (refereegranskat)abstract
- A MIMO channel spatial decorrelation scheme based on semi-definite programming is introduced. As a particular application example, the paper addresses the potential gain of using multiple antennas and MIMO-OFDM techniques in order to increase the bandwidth efficiency in satellite communication systems. In particular, we consider the increase in channel capacity that is possible by exploiting satellite and polarization diversity. A fundamental case is studied with three satellite branches, and where each transmit/receive antenna unit consists of six elemental electric and magnetic dipoles yielding six distinguishable parallel polarization channels per frequency. The numerical examples show that capacity increases linearly on a logarithmic signal-to-noise ratio scale where the constant of proportionality is the number of active parallel channels. In this respect, the simultaneous use of triple electric and triple magnetic dipoles has the potential to triple the capacity of an antenna system based on antenna units of single dipoles. Copyright (c) 2006 John Wiley & Sons, Ltd.
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