Research into Multiple Element Antennas to Enhance Performance of Wireless Communication Systems

The paper concentrates on two specific areas of applications of multiple element antennas (MEAs) to enhance performance of wireless communication systems. The first area concerns multiple input multiple output (MIMO) systems, in which MEA are used both at the transmitter (TX) and receiver (RX) to increase the communication transmission rate or enhance the received signal quality via diversity. The other area encompasses wideband smart antennas (MISO/SIMO systems) where MEAs are used only either at the transmitter or receiver sites. With respect to MIMO, suitable signal propagation models are developed, which in an approximate or exact manner take into account interactions between antenna elements and scattering objects. In parallel to the theoretical models, two types of experimental facilities for MIMO testing, a simple transmit/receive diversity testbed and a full MIMO testbed, are described. The last part of the paper describes smart antennas, which use the concept of full spatial signal processing to obtain beam forming over a wide frequency band.