Subcarrier and bit allocation strategies for OFDMA based wireless ad hoc networks

Orthogonal frequency division multiple access (OFDMA) is an emerging multiple access technology. We consider OFDMA in the context of fixed wireless ad hoc networks. We address the problem of assigning subcarriers and bits to point-to-point wireless links in the presence of cochannel interference and Rayleigh fading. The objective is to minimize the total transmitted power over the entire network while satisfying the data rate requirement of each link. We formulate this problem as a constrained optimization problem and present a heuristic algorithm. The simulation results show that our algorithm results in an efficient assignment of subcarriers and transmitter power levels in terms of the energy required for transmitting each bit of information.