Research On MIMO Detection Algorithm Based On Neighborhood Search

Multiple input multiple output(MIMO)technology is widely used in wireless communication systems because it does not increase bandwidth and increases data transmission speed.Based on MIMO technology,large-scale MIMO technology can increase the data transmission speed by tens or even hundreds of times by increasing the number of antennas.With the increasing number of antennas,the common detection algorithms in MIMO systems are limited by the complexity and detection performance,which is difficult to be directly applied to large-scale MIMO systems.Based on this background,this paper focuses on the large-scale MIMO detection of the Likelihood Ascend Search(LAS)algorithm and the Layered Tabu Search(LTS)algorithm and proposes two improved algorithms.In this paper,the factors that affect the complexity of the algorithm are taken as the starting point.Firstly,LAS algorithm is analyzed.Aiming at the problem that LAS algorithm needs a lot of operations to continuously execute ML cost function,a Constellation Constraints LAS(CC-LAS)algorithm is proposed.The algorithm determines the reliability of each signal in the solution vector by CC structure,and removes the neighbor vector of the reliable signal in the neighborhood space,so as to reduce the computational complexity of LAS algorithm.Then,Reactive Tabu Search(RTS)algorithm and LTS algorithm for high-order modulation mode are analyzed.Aiming at the problem of high complexity of LTS algorithm,this paper proposes a Constellation Constraints Constellation Constraints Successive Interference Cancellation-LTS(CC-SIC-LTS)algorithm,CC-SIC-LTS algorithm uses SIC algorithm to eliminate the reliable signals in the solution vector determined by CC structure and the related interference corresponding to the reliable signals,and only executes RTS algorithm on the remaining unreliable signals in the solution vector,so as to effectively reduce the overall algorithm complexity.The results show that CC-LAS algorithm and CC-SIC-LTS algorithm have similar detection performance with the original algorithm,and reduce the computational complexity of the original algorithm effectively.