Dual Optimal Resource Allocation for Heterogeneous Transmission in OFDMA Systems

This paper is concerned with dynamic resource allocation for heterogeneous downlink in orthogonal frequency division multiple access (OFDMA) systems. First, this paper formulates the resource allocation problem when one terminal may demand both non-real time (or best effort) transmission and real time transmission over the downlink simultaneously. We consider the constraint on the total transmission power of the base station for both types of services and the constraint on the rate requirement of each terminal for a real time transmission. To solve this problem, an efficient instantaneous per-symbol method with dual optimality is proposed based on the convex optimization framework. Compared to the exhaustive search, simulations show that the performance degradation of our method is limited to 0.002% of the optimal solution, when an OFDMA system consists of more than 16 subcarriers. Therefore, this paper illustrates that it is not computationally prohibitive to optimally solve the resource allocation problem for heterogeneous transmission over OFDMA downlink.