不完全SIC下CR-NOMA系统的功率分配算法

Power Allocation Algorithm of CR-NOMA System Under Imperfect SIC

在不完全连续干扰消除(SIC)条件下,对认知无线电-非正交多址混合系统中的次用户总传输速率进行研究,提出一种基于参数变换和KKT条件的功率分配算法。采用非正交多址方式使次用户接入授权信道,在主次用户服务质量、最大发射功率等约束条件下,通过参数变换对原约束条件进行改写设计新的优化问题,并利用KKT条件求解最优功率分配因子进而实现系统中次用户总传输速率的最大化。仿真结果表明,与CNPA算法和等功率分配算法相比,该算法可明显提高系统中次用户的总传输速率,并且对于不完全SIC具有更强的承受能力。

This paper presents a study on the total transmission rate of secondary users in a Cognitive Radio(CR)NonOrthogonal Multiple Access(NOMA)hybrid system under imperfect Successive Interference Cancellation(SIC).On this basis,a power allocation algorithm based on parameter transformation and KKT conditions is proposed.In this system,the secondary users use NOMA to access the authorized channel.Considering the constraints of the primary and secondary users’Quality of Service(QoS)and maximum transmission power,the original constraint conditions are rewritten by using the parameter transformation method to construct a new optimization problem.The optimal power allocation factor is solved by using KKT conditions in order to maximize the total transmission rate of secondary users in the system.Simulation results show that compared with the CNPA algorithm and the equal power allocation algorithm,this algorithm can significantly improve the total transmission rate of secondary users in the system,and has a better tolerance for imperfect SIC.