A method and system for indexing physical channels in an OFDMA system where one OFDM symbol includes a plurality of subcarriers and one TTI includes a plurality of OFDM symbols are provided. A total number of subcarriers per OFDM symbol are divided into N groups. A kth group is selected from the N groups in each OFDM symbol of a TTI, and a physical channel corresponding to a set of subcarriers indexed with predetermined values, included in the kth groups of the TTI is indexed with an ordered pair (N, k).