The Ray Inversion Method to Obtain Regional Multipath Channels From Finite Impulse Responses

With the development and application of fifth-generation mobile communication technologies, cutting-edge techniques, including multiple-input multiple-output and beamforming, have come to the forefront. However, the performance gain of these techniques is in the trade of deep understanding of regional multipath channel. To obtain the channel impulse response (CIR) of a given area will typically require pointwise scanning in both channel measurements or ray tracing (RT)-based modeling method. In this letter, we propose the ray inversion (RI) method. The RI method aims to obtain the region channel response (RCR) with only a limited number of observed CIR and avoid the involvement of surrounding environment information. The method classifies of observed propagation paths first and then inverts the ray transmission process to identify the locations of the secondary wave sources and obtain the local regional response. The method significantly enhances the efficiency of obtaining RCR. An iterative fission method has been further designed to guarantee both the efficiency and accuracy. The utilization of this technology can assist the RT method in achieving rapid acquisition of RCR. The RI method is based on geometric inversion, making it applicable to different frequencies. Compared to the traditional point-by-point scanning RT method, the computation speed in an open scene is increased by 15 times, and in a closed scene by four times when the receiving antenna spacing of RCR is 1 m. The RI method provides an innovative perspective for the research and application of next-generation wireless communication.