This invention provides a UPA near-field channel
estimation method based on two-dimensional block sparsity, comprising: representing the UPA near-field channel matrix as the sum of the outer products of the
horizontal and vertical ULA near-field steering vectors; constructing improved DFT dictionaries in the
horizontal and vertical directions respectively; representing the channel matrix as a total
coefficient matrix under these dictionaries, which presents a two-dimensional block
sparse structure determined by the
outer product of the
horizontal and vertical block sparse representation vectors, thereby transforming channel
estimation into a two-dimensional block sparse
signal recovery problem; and solving the problem using the 2D-PCSBL
algorithm, in which the accuracy parameter of each
sparse coefficient in the prior distribution is determined by the weighted sum of its own
hyperparameter and the hyperparameters of its two-dimensional neighbors, to capture the sparse
coupling characteristics of the UPA near-field channel in the horizontal and
vertical dimensions. This invention achieves high-precision channel
estimation with fewer pilots and a lower
signal-to-
noise ratio, and its computational complexity is comparable to that of the one-dimensional block sparse method.