Research On Scheduling Algorithms In Multi-User MIMO System

MIMO has been one of the key technologies of the fourth generation communication system (4G) just because of its high capacity, high spectral efficiency and the ability of supporting simultaneous data transmission to multiple users.The thesis focuses on the downlink multi-user MIMO system. In order to overcome the high computing complexity of the existed PUURC algorithm, we propose the greedy proportional fairness scheduling algorithm, which tries to reduce the computing complexity while guarantying the system throughput and user fairness.The essence of the greedy proportional fairness scheduling algorithm is information feedback based on codebook, namely mobile stations calculate SINR values based on the precoding matrix of the codebook and feed back the information to the base stations according to full information feedback and minimum information feedback mechanisms. Then the base stations select the right user/stream based on proportional fairness criterion according to greedy algorithm.Through the theoretical analysis and computer simulation verification, we conclude that the greedy proportional fairness scheduling algorithm can guarantee the fairness between users and has the same feedback information amount with PUURC algorithm and decrease the computing complexity and processing delay in both information feedback modes and satisfy the QoS requirements while scarifying some system throughput. This algorithm is applicable in the actual communication system because of the low complexity and high system throughput.