Research On Scheduling Algorithms In MIMO System

MIMO and OFDMA have been the key technologies of the fourth generation communication system (4G) because of its high capacity, high spectral efficiency. This paper mainly studies the scheduling algorithm. The algorithm is to choose the reasonable resource allocation method in the process of time, frequency, power, and buffer sharing between multiple users. It can achieve multi-objective optimal use of resources. This article discusses the scheduling algorithm in two directions:LTE uplink frequency hopping,diversity/multiplexing switching algorithm.The article studies two types of LTE uplink frequency hopping and several configuration modes. It then describes several common diversity and multiplexing techniques,and their characteristics. It also analyzes Adaptive hybrid space-time code technology and diversity multiplexing switch technology the switch algorithm of diversity and multiplexing under a fixed transmission rate environment. The last part presents a improved switch algorithm of diversity and multiplexing.in Adaptive hybrid space-time code technology, A part of transmit antennas ale used to transmit the Alamouti STBC and the others to transmit the Perfect STBC. Meanwhile, according to the feedback from the receiver, this scheme adaptively adjusts the allocation of transmit antennas to adapt to the change of the channel.In switching technology of diversity and multiplexing, Under a fixed transmission rate environment,according to the feedback from the receiver, this scheme selects the better one between Alamouti STBC and Vblast. Vblast layered space-time code is no diversity gain,so we propose a improved switching scheme with perfect space-time block codes instead of Vblast. Perfect space-time block codes with full diversity gain and rate,can improve reliability without decreasing spectrum efficiency. Through the simulation, the system can get better ber performance.