Research On Channel Reconstruction Method For Dual Chamber OTA Radiated Testing

With the deployment of the fifth generation(5G)mobile communication system,the industry is facing new challenges in testing communication equipment.One of the challenges is the integration of the antenna and radio frequency unit without accessible ports between them,whether it is a base station or a terminal device.Therefore,the over-the-air(OTA)testing proposed by relevant academic researchers has become the preferred testing method.OTA testing typically involves radio frequency testing and performance testing.The multi-probe anechoic chamber method is a popular performance testing method,which reconstructs the real channel environment in an anechoic chamber.As wireless communication has developed,both ends of the communication equipment have integrated radio frequency(RF)and antenna.To accommodate this structure,the dual anechoic chamber setup based on the multi-probe anechoic chamber method has been proposed in existing literature.This method uses a test structure of two anechoic chambers and a channel emulator,which not only satisfies the test requirements for reconstructing the real channel environment but also completely simulates the 5G communication link,accurately reconstructing the channel environment from the sending end to the receiving end.Although the dual anechoic chamber setup has its advantages over the single anechoic chamber setup,there are still some urgent problems that need to be addressed.Firstly,the current anechoic chamber setup lacks a suitable probe configuration algorithm.Due to its unique test structure,the Multi-shot algorithm is no longer suitable for selecting probe positions.Secondly,the channel emulator is a valuable resource,yet the existing methods show that the utilization rate of the channel emulator is very low.To achieve the goal of this graduation project,there are two main areas that need to be addressed:improving the algorithm in the dual anechoic chamber setup and reducing the cost of the channel emulator.Firstly,a multi-objective particle swarm algorithm based on feedback and prediction is proposed to configure the probe.The objective function of channel reconstruction is re-examined from the perspective of dual anechoic chamber setup,and it is found to be a multi-objective non-deterministic polynomial(NP)problem.To transform this problem into a solvable form,the equal area sampling method is used.This approach leads to the multiobjective particle swarm optimization algorithm being more suitable for the dual anechoic chamber setup and having better performance through feedback and prediction,resulting in the joint optimization of probe configuration.Secondly,the utilization rate of the channel emulator in the dual anechoic chamber setup is improved by designing a channel emulator that takes advantage of the particularity of the dual anechoic chamber setup and combines the internal structure of the emulator.The single-connected channel emulator structure is adopted to achieve this.Finally,the simulation results demonstrate that the proposed method significantly improves the channel reconstruction accuracy of the dual anechoic chamber setup and greatly reduces the construction cost with the same resources.