MIMO TRANSMISSION USING PARASITIC ARRAY ANTENNA-thesis
Multiple-Input-Multiple-Output (MIMO) transmission is one of the promising antenna technologies used for wireless communication. When the transceiver uses more than one antenna, the antennas must be placed at least half of the carrier wavelength apart, in order to transmit/receive uncorrelated signals. As a result size and cost sensitive devices like mobile terminals cannot facilitate MIMO transmission. Parasitic antenna on the other hand, uses only one active RF front end along with two or more parasitic elements which can be placed much closer resulting in a compact design. The parasitic elements can be electronically switched to form different antenna beams for the active RF feed, in each symbol period. Both theory and computer simulations have shown that, these different beams can be used to have MIMO transmission with traditional uniform linear array (ULA) antennas placed at the receiver. This work involves configuring and customizing a classical MIMO testbed to use a 3-element electronically steerable parasitic array radiator (ESPAR) at the transmitter and traditional two ULA of antennas at the receiver, using BPSK modulation. Vertical Bell labs Layered Space Time (V-BLAST) architecture was used together with zero forcing equalizer at the receiver, to verify over-the-air MIMO transmission using the parasitic antenna.
Mobile communication is well popular among the world in day to day life. With the ever increasing sophisticated mobile applications, the requirement of having high data rate communication is a challenge. There are several technologies which caters this requirement such as W-CDMA, and WiMax. Multiple-input-multiple-output (MIMO) transmission is one of the promising antenna technologies used for wireless communications. Through spatial multiplexing, MIMO achieves high capacities. The only limitation is that, the transmitting and receiving antennas should be placed at least half the wave length of the carrier signal in order to transmit or receive uncorrelated signals. Apart from that, each of transmit or receive antenna requires a separate circuit which means, higher the no of antennas used higher the cost.