A wireless communication method of a first device, includes: receiving, from a second device through a channel having a bandwidth of 20 megahertz (MHz), a physical layer protocol data unit (PPDU), based on a non-orthogonal frequency-division multiple access (non-OFDMA); based on values of a plurality of fields being related to resource allocation of the channel and included in a signal field of a preamble included in the PPDU, identifying whether a multi-resource unit (MRU) to replace a resource unit (RU) including a 242-tone is allocated to the first device; and based on a result of the identifying, decoding a payload included in the PPDU.