An operation method of a first communication node may include: mapping data symbols to be transmitted to a second communication node of the communication system to resources in a first two-dimensional (2D) domain; pre-processing the data symbols mapped to the resources in the first 2D domain to spread the data symbols on resources in a second 2D domain; mapping the pre-processed data symbols to the resources in the second 2D domain; and performing multi-carrier modulation on the data symbols mapped to the resources in the second 2D domain for each of the resources in the second 2D domain.