The invention discloses a modular XL-
MIMO near-field beam training method, which belongs to the technical field of XL-
MIMO beam training, and comprises the following steps: activating antennas of a head module and a
tail module in an array to carry out far-field
beam scanning, determining a
code word index with the maximum beam
gain of the head module and the
tail module, estimating the
code word index with the maximum beam
gain of the whole array, and taking the
code word index with the maximum beam
gain as a center, the method comprises the following steps: selecting a plurality of candidate angles, carrying out non-uniform
distance sampling by adopting a polar domain
codebook, generating candidate sampling points, distributing each candidate sampling point to a collaborative module for training, determining the energy of each candidate sampling point, further determining an optimal polar domain near-field codeword index, and completing modular XL-
MIMO near-field beam training. The method not only can effectively reduce the training overhead, but also can maximize the accuracy of beam gain and angle
estimation under the condition of
limited resources.