Branch-and-Bound Approach to OFDMA Radio Resource Allocation

Radio resource allocation (RRA) problems in orthogonal frequency division multiple access (OFDMA) systems are studied in this paper. By assuming perfect channel estimation for all users, fast branch-and-bound (BnB) based optimal and suboptimal algorithms are proposed to solve the RRA problems in OFDMA systems. As demonstrated by simulation results, the proposed optimal algorithm offers the same performance as that achieved by using exhaustive full-search algorithm, but the computational complexity involved is significantly reduced relative to the full-search algorithm. The proposed suboptimal algorithm offers near- optimal performance whereas the associated computational complexity is much lower than that associated with the proposed optimal algorithm.