Research On The Key Technologies Of Downlink MIMO Enhan-cement For TD-LTE

TD-LTE is a system of time division duplex mode in the LTE, which is the follow-upevolution technology and standard of TD-SCDMA researched and designed by ourselves.Multi-antenna technology is one of the key technologies of TD-LTE system, which includestransmit diversity, space division multiplexing and beamforming. Because of the growingdata services and emerging new services, multi-day technology needs to be enhanced. Thus,the double-stream and multi-stream beamforming technology was introduced in the3GPP R9,R10to achieve effective combination of beamforming and space division multiplexing toprovide higher data rates and reliability of wireless transmission in the radio link.Firstly, through in-depth analysis of multi-antenna key technology (nine kinds ofdelivery mode) and signal processing of TD-LTE system downlink physical layer,a TD-LTEdownlink system simulation platform based on Matlab environment is built.The platformfocuses on increasing TU channel models and designing double beamforming mode.Secondly, a variety of beamforming approaches are elaborated in TD-LTE system,especially the double beamforming mode. And theoretically in-depth study that a singledouble beamforming under different conditions will show different transmission properties(single double adaptive problems) is done;Thirdly, because the UE antenna spacing and size determine the existence ofperformance bottlenecks in the SU-MIMO double beamforming (higher antenna correlationof UE side), the double-beam Fuxin MU-MIMO mode is introduced and MU-MIMO pairingalgorithm performance becomes the key of wireless link transmission performance under thetransmit mode. In order to solve higher matching algorithm complexity of existing problems,we propose a fast matching method based on code comparison.Finally, bit error rate and block error rate performance of SU-MIMO double beamforming under different deployment scenarios are studied and analyzed, a single doublebeamforming switching threshold is determined and the adaptive throughput is got bysimulation platform. Such a conclusion is drawn that users could switch adaptively to theappropriate mode to achieve better transmission efficiency in different scenarios. In addition,the results validate effectiveness of the MU-MIMO pairing algorithm which is referred in thearticle through the simulation of different matching algorithms.