Optimal reuse factor and resource allocation for downlink OFDMA with multicell interference

In this paper we investigate the issue of power control and subcarrier assignment in an OFDMA downlink system impaired by multicell interference. As done in Wimax, we assume that a certain part of the available bandwidth is likely to be reused by different base stations (and is thus subject to multicell interference) and that an other part of the bandwidth is used by one base station only (and is thus ldquoprotectedrdquo from multicell interference). Questions are: (i) how many subcarriers should be assigned to a given user in the interference bandwidth, and how many in the protected bandwidth ? (ii) What power should be allocated to a given user in each of these bands ? (iii) What is the optimal frequency reuse factor ?