Sub-channels in cells of an Orthogonal Frequency Division Multiple Access (OFDMA) network are formed based on random permutations of a set of subcarrier indices. The random permutations are performed for each cell of the network using a pseudo-random number generator (PRNG) and a shuffle technique. Different initial states of the PRNG are used to generate the random permutation of the subcarrier indices for each cell. In an embodiment, sub-carriers represented by a contiguous group of indices in the random permutation obtained for a cell are assigned to form a sub-channel. Interference diversity for the OFDMA network is thereby improved.