Scheduling gain analysis of opportunistic OFDMA and OFDM-TDMA systems

In this paper, the performance of opportunistic scheduling in orthogonal frequency division multiplexing (OFDM) networks is studied. An analytical model is developed to extend the multi-class processor-sharing model in single-carrier networks to multi-carrier OFDM networks, where the total service rate depends on the total number of users. Based on the analytical model, the scheduling gains in both OFDM-TDMA (time division multiple access) and OFDMA (orthogonal frequency division multiple access) networks are evaluated. Different from previous works in this area, we focus on the scheduling performance at the flow level and consider a dynamic network setting with random finite-size service demands. Simulations are performed to verify the analytical results.