Subcarrier and power allocation for multi-user OFDMA wireless networks under imperfect channel state information

In this study, the authors investigate subcarrier and power allocation for point-to-point data transmission under imperfect channel state information in multi-user orthogonal frequency-division multiple-access (OFDMA) networks. The resource optimisation problem is formulated to handle inter competition (the resource competition among different users) and intra competition (the resource assignment between channel estimation and data transmission for each individual user). The authors employ the non-cooperative game with pricing approach to solve the optimisation problem. By analysing optimal relationship between channel estimation cost and total occupied resource for each user, the twolevel resource competition is simplified to the problem including only inter competition, which is modelled as a noncooperative subcarrier and power allocation game with subcarrier pricing. In this game, the utility function is defined as the number of received data bits per joule of energy, which is associated with the estimate error and cost, the data transmit power and the number of data-subcarriers. The authors prove the existence, uniqueness and Pareto efficiency of Nash equilibrium (NE) for the proposed resource allocation game. Furthermore, a distributed resource allocation algorithm is designed to achieve the NE.