基于QoS要求的全双工中继多载波安全系统的功率分配研究

摘要

针对采用非理想干扰消除的全双工中继的多载波安全通信系统,借助安全有效容量引入时延服务质量(Quality-of-Service,QoS)限制,该文提出一种满足统计时延QoS要求的功率分配策略.在对中继干扰功率和总功率进行限制的条件下,考虑统计时延QoS要求,以最大化系统的安全有效容量为目标,建立优化问题,研究系统的功率分配策略.进一步,通过泰勒近似方法,简化原凸优化问题,并基于拉格朗日对偶方法和卡罗需-库恩-塔克(Karush-Kuhn-Tucker,KKT)条件,采用子梯度迭代法得到最优解并进行仿真验证.仿真结果表明,提出的最优功率分配策略可以获得最大的安全有效容量,同时可以满足时延QoS要求.%For a multicarrier full-duplex-relay secure communication system with imperfect loop-interference cancelations, an optimal power allocation strategy with the statistical delay Quality-of-Service (QoS) guarantees is proposed, by using the delay QoS constraint with the concept of the secure effective capacity. Considering the statistical delay QoS guarantees and aiming to maximize the secure effective capacity, an optimization problem is formulated with the constraints of powers of both the whole system and the loop-interference of full-duplex relay. Then, in order to study the power allocation strategy, the original optimization problem is simplified by Taylor approximation and the problem is solved based on Lagrangian dual method and Karush-Kuhn-Tucker conditions. Therefore, the optimal solution is obtained by the sub-gradient iterative algorithm and simulation results are presented. The results show that the proposed optimal power allocation strategy can not only get the largest secure effective capacity but also satisfy the upper layer delay QoS requirement.