The Research On Multiple Antenna Techniques In LTE System

In order to meet with the requirement of high data rate and high capacity in futurewireless communication system,3GPP started the LTE which merged the mobilecommunication technology and the broadband wireless access technology. Themultiple-input and multiple-output technology is a key standard, which can improve thespectrum utilization, reduce the transmission power, improve the transmissionefficiency and greatly increase the capacity of the entire system.This paper focuses on the LTE multiple antenna techniques, and obtains thefeatures of each technology through the simulation. It will introduce the basicbackground knowledge firstly, such as the requirement of LTE, the system architecture,the multiple access methods and the frame structure. Then this paper will focus on theLTE multiple antenna techniques, including transmit diversity, spatial multiplexing andbeamforming technology. Transmit diversity includes space-time coding, cyclic delaydiversity and antenna switched technology. Spatial multiplexing using the weakcorrelation of spatial channel can transmit different data in different channel, and eachspatial channel is independent with others, so that the peak data rate is greatly increased.Beamforming technology requires a smaller spacing between the antenna array, in orderto make the main lobe align the desired direction of arrival, and also make the zero lobealign the direction of interference, so increasing the system capacity and the systemcoverage. But these three technologies have different needs of spatial channel and havetheir own characteristics in application scenarios. The beamforming technology andtransmit diversity are applied under the low SNR conditions, while the spatialmultiplexing is applied under the high SNR conditions to increase the data rate.