Interference Management of OFDMA Uplinks

The next generation of wireless networks will use OFDMA (orthogonal frequency division multiple access) technology in the uplink. In OFDMA, the uplink resources assigned to a user are called tiles each of which consists of a subset of consecutive subcarriers. Since at most one user is assigned to each of these tiles then reverse link transmissions within a sector are orthogonal. However, the transmission is affected by intersector interference since users in adjacent sectors may also have been assigned to the same tile. If those users in the adjacent sectors transmitted with high power then the intersector interference may severely limit the SINR achieved by the user. Therefore user transmission powers must be carefully managed to avoid excessive intersector interference. In this paper we investigate a framework in which each sector periodically broadcasts information on its intersector interference. Each access terminal (AT) then uses this information to adjust its transmission power in order to maintain intersector interferences below some specified threshold. We provide an algorithm for doing this and we show that the algorithm is robust, efficient and fair.