OFDMA系统中支持混合业务的跨层资源分配算法

针对正交频分多址接入系统（OFDMA）下行链路资源分配问题,提出一种支持混合业务的跨层子载波-功率-比特联合分配算法.引入平均时延控制因子和丢包率控制因子作为时延敏感（DS）业务服务质量（平均时延和丢包率）的控制参数;每分配1个子载波后立即对该子载波所属用户进行一次最优的子载波功率和比特分配,该联合分配方案可最大化系统功率效率.仿真结果表明：该算法既可同时保证不同类型DS业务的服务质量,又可提高时延不敏感（NDS）业务的平均吞吐量并保证用户间的公平性.通过调整2个控制因子不仅能满足不同DS用户的服务质量要求,还可在DS用户服务质量和NDS用户的吞吐量间达到不同的折衷,以满足各种系统设计要求.

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 packetloss 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.