A Block Circulant Embedding Method for Simulation of Stationary Gaussian   Random Fields on Block-regular Grids
  We propose a new method for sampling from stationary Gaussian random field on a grid which is not regular but has a regular block structure which is often the case in applications. The introduced block circulant embedding method (BCEM) can outperform the classical circulant embedding method (CEM) which requires a regularization of the irregular grid before its application. Comparison of BCEM vs CEM is performed on some typical model problems. 
M. Park and M.V. Tretyakov
stat.CO math.NA