智能反射面辅助毫米波NOMA系统的资源分配联合设计方案

Joint design scheme of resource allocation for intelligent reflecting surface assisted millimeter wave NOMA system

为了进一步提高智能反射面(IRS)辅助毫米波非正交多址接入系统的频谱效率,研究了用户分簇、串行干扰消除(SIC)解码顺序、发射功率分配、模拟波束选择和IRS相移的联合设计方案。在发射功率约束、SIC解码速率约束、波束选择约束、SIC解码顺序约束、用户速率约束和IRS相移约束下,最大化系统和速率。由于离散变量、组合变量以及连续变量在目标函数和约束条件中耦合,所提优化问题难以用传统的优化方法求解。为了求解该问题,首先通过查询表将SIC解码顺序变量这一组合变量转化为二进制离散变量,然后基于混合鲸鱼优化算法解耦离散变量和连续变量,并基于罚函数法对优化约束建模,将非凸优化问题转换为启发式问题进行迭代求解。仿真结果验证了所提方案的有效性。

In order to further improve the spectral efficiency of intelligent reflecting surface(IRS)-assisted millimeter wave non-orthogonal multiple access(NOMA) system, a joint design scheme of user clustering, successive interference cancellation(SIC) decoding order, transmit power allocation, analog beam selection and IRS phase shifting was investigated, under the transmit power constraint, SIC decoding rate constraint, beam selection constraint, SIC decoding order constraint, user rate constraint, and IRS phase shift constraint, aiming at maximizing system sum rate. Because of the coupling of discrete variables, combinatorial variables and continuous variables in objective function and constraints, the formulated optimization problem was difficult to solve by traditional optimization methods. To solve it,first the SIC decoding sequence variables were transformed into binary discrete variables through a query table, then the discrete variables and continuous variables were decoupled based on the hybrid whale optimization algorithm, and delt with the optimization constraints based on the penalty function method, and the non-convex optimization problem was transformed into a heuristic problem for iterative solution. Simulation results verify the effectiveness of the proposed scheme.