| With the development of wireless communication technology,wireless communication network is becoming more and more complex,and a large number of interference seriously restricts the performance of the network.In order to solve this problem,a new interference management technology represented by interference alignment has appeared.Interference alignment aligns the interference signals from different users into smaller interference subspace through precoding and interference cancellation between transmitter and receiver,which improves the system capacity.Compared with the traditional interference cancellation technology,interference alignment has obvious advantages in performance.However,in practical applications,the performance of interference alignment will be affected under the condition of imperfect channel state information.There are also various problems in the interference alignment algorithm itself that need further research.The contents of this paper are as follows:1.Several common network models in multi-user MIMO system are introduced,and then linear interference alignment algorithm,progressive interference alignment algorithm and distributed iterative interference alignment algorithm are introduced,including minimum mean square error algorithm,minimum interference leakage algorithm and maximum signal interference noise ratio algorithm.The minimum interference leakage algorithm and maximum signal interference noise ratio algorithm are simulated True analysis.2.Under the condition of imperfect channel state information,the performance impact of distributed iterative interference alignment algorithm is analyzed,and the optimized algorithms of minimum interference leakage and maximum signal interference to noise ratio are simulated and analyzed.3.Considering single cell multi-user MIMO scenario,based on GMD decomposition interference alignment algorithm,this paper proposes a GMD decomposition interference alignment algorithm under imperfect channel state information.Firstly,the channel matrix is decomposed by GMD to obtain the equivalent channel matrix,and then the imperfect channel is replaced by MMSE interference alignment algorithm.The precoding matrix and interference suppression are derived to minimize the error term Matrix.Compared with the traditional GMD algorithm,the proposed algorithm has a lower efficiency than the traditional algorithm in the case of different SNR. |
