A feasible downlink scheduling algorithm in OFDMA systems with discrete rate constraints

In practical OFDMA systems such as LTE, the deployment of adaptive modulation and coding scheme (AMC) results in only a limited discrete set of rates available to users, which yields restriction in resource allocation policy design to some extent. Although this problem has been investigated in some literatures up to this time, issues about, for instance, feasibility and complexity, which have not been addressed effectively still exist. In this paper, we propose a lightweight suboptimal algorithm for feasible downlink scheduling in multiuser OFDMA systems considering discrete rate constraints. With satisfying different rate requirements of users and meanwhile ensuring sum rate maximization, our proposed algorithm is also demonstrated experimentally by simulation results that it reduces the implementation complexity significantly.