Research On Beamforming Based Multi-Antenna Technique In LTE+System

Long Term Evolution (LTE) is the main mobile communication standard for next generation, and the standardization work is taken charge by 3GPP. Currently, the major research issues include enhanced MIMO technique, which can improve the system performance dramatically. Especially in time division duplex (TDD) mode, utilizing channel reciprocity, the downlink channel information can be acquired through uplink channel estimation and the extra signaling overhead for channel feedback is saved. Thus, it is fit for the system which is equipped with multiple antennas. Beamforming technique is selected as an important MIMO configuration for its excellent performance in TDD mode. In this dissertation, the downlink enhanced beamforming technique in LTE system and the corresponding design of channel quality information (CQI) feedback regime is studied. Through the system level simulation, this paper gives the improved results brought by improved technique and the corresponding performance analysis.The simulation environment of MIMO-OFDM system is different with other systems. According to its own characteristic, this paper designs a simulator structure which is quite fit for MIMO-OFDM system. The modularization make the simulator have better scalability and higher efficiency. Therefore, the simulator can advantage the future theoretical study and simulation validation.Through the study of the traditional beamforming algorithm and CQI feedback regime, this paper proposes a novel adaptive beamforming technique which is based on the stream from singular value decomposition. Simulation result shows, when the fairness for users is promised and the user satisfaction degree is maximized, this algorithm can acquire better system performance than traditional method which uses the same resource scheduling algorithm.