具有时延QoS保证的OFDM中继系统子载波配对与功率分配算法

摘要

In this paper, the subcairier pairing and power allocation algorithm for OFDM decode-and-forward (DF) relay systems with direct link is investigated. The goal is to maximize the system throughput while meeting the delay QoS requirements of transmission services. Firstly, by integrating the effective capacity model, the subcarrier pairing and power allocation problem is formulated as a mixed integer programming problem. Then, the problem is transformed into a continuous relaxed convex problem. By using the convex optimization thecsy, the optimal solution of the primal problem is obtained, and an alternative algorithm to achieve jointly optimal subcarrier pairing and power allocation is proposed.The derived analytical and simulation results show that both the optimal subcarrier pairing and power allocation depend on not only the channel quality of the subcarriers but also the delay QoS requirements of the service. Compared with the existing algorithms,our proposed algorithm achieves the highest effective capacity.%本文研究具有直接通信链路的OFDM解码转发(Decode-and-Forward,DF)中继系统的子载波配对与功率分配算法,目标是在满足业务时延QoS要求的前提下最大化系统容量.利用有效容量模型,首先把OFDM DF中继系统的子载波配对与功率分配问题形成为混合整数规划问题,然后把其转化为连续松弛凸规划问题,利用凸优化方法得到原问题的最优解,从而提出了一种联合最优的子载波配对与功率分配迭代算法.理论推导结果和仿真结果表明,最优子载波配对与功率分配不仅取决于子载波的信道增益,还取决于业务的时延QoS要求.与已有算法相比,本文算法获得的有效容量最大.