Research On Probe Optimization Methods Based On Terminal MIMO OTA Test System

In order to meet the demand for high data rates and low latency in mobile communication services,Fifth Generation(5G)networks have been deployed in many countries.At the same time,how to evaluate the performance of 5G terminals has also attracted widespread attention.Since the 5G terminal antenna module uses packaged antenna technology,over-the-air(OTA)testing has become the only viable solution to evaluate the performance of 5G terminals.Among the various MultiInput Multi-Output(MIMO)OTA test methods,the multi-probe anechoic chamber(MPAC)has been recognized by the standards organization as the benchmark method for 5G MIMO OTA testing because it can accurately reproduce any propagation channels and support beamforming testing,but the system cost caused by too many hardware resources such as probes required has also become an urgent problem to be solved.This thesis mainly focuses on MIMO OTA testing of 5G terminals based on MPAC method.Since the 5G terminal will be equipped with antenna systems in low frequency and millimeter wave bands,the effective probe optimization scheme is investigated in two scenarios to reduce the cost of testing.Firstly,in order to solve the problem of cost waste caused by a large number of probes idle in the 5G low frequency two-dimensional MPAC,a cuckoo optimization method based on the sectorized MPAC configuration is proposed.This sectorized configuration concentrates the probe in the direction of the incoming signal,which greatly improves the accuracy of spatial correlation reproduction.On this basis,in order to further reduce the cost of the system,the cuckoo search algorithm is introduced to optimize the probe position selection process.Simulation results show that the proposed flexible sectorized MPAC configuration not only has better channel reproduction performance,but also has higher channel reconstruction efficiency.Secondly,aiming at the challenges brought by the proliferation of probes and the change of the evaluation index of channel reconfiguration to the test accuracy and test cost in the 5G millimeter wave frequency three-dimensional MPAC,a joint optimization method of probe weights and positions is proposed.Compared with the previous method of determining the probe power weight based on spatial correlation,the probe weight optimization method based on beamforming power pattern proposed in this thesis can further improve the accuracy of channel reproduction.On this basis,the Archimedes algorithm is used to optimize the probe position,so as to realize the joint optimization of probe weight and position.Simulation results show that Archimedes algorithm has good convergence speed and optimization performance,and the joint optimization method can minimize the number of probes required under the premise of ensuring the accuracy of channel reconstruction,so as to achieve the purpose of reducing system cost.