Cross-layer resource allocation algorithm to support hybrid traffics for OFDMA system

For the issue of resource allocation in downlink orthogonal frequency division multiple access (OFDMA) system, a cross-layer resource allocation algorithm for joint subcarrier, power and bit allocation to support hybrid traffics was proposed. Average delay control factor and packet-loss rate control factor were introduced as control parameters for quality of service (average delay and packet-loss rate) of delay-sensitive (DS) traffics. By the joint allocation scheme which optimized a user's power and bit allocation immediately after the user had been allocated a subcarrier, system power efficiency was maximized. Simulation results show that the proposed algorithm not only can guarantee quality of service (QoS) of different DS traffics simultaneously but also can improve average throughput of non-delay-sensitive (NDS) traffics and ensure the fairness between users. By adjusting two control factors, the proposed algorithm not only can meet different QoS requirements of DS users also can achieve different trade-offs between DS users' QoS and average throughput of NDS users so as to satisfy different system design requirements.