基于艾森斯坦整数的粒子群优化SCMA码本

Particle swarm optimization SCMA codebook based on Eisenstein integers

稀疏码多址(SCMA)是一种码域的非正交多址(NOMA)方案,可以实现未来的大规模机器型通信网络,而码本的设计对于SCMA系统至关重要。该文在艾森斯坦整数的基础上,按照不同角度将选取的艾森斯坦整数分为三组,在这三组中选择两组艾森斯坦整数作为母星座。根据同一资源块被多个用户占用,且占用的用户的功率之和为定值,随机分配用户的功率从而构造功率不平衡的码本,以最大化最小欧氏距离为目标函数,相关参数作为变量,最后利用粒子群算法求出最优解。通过数值仿真结果表明,与已有的码本相比,该文提出的码本在高斯信道下的误码率(BER)更小,性能更优。

Sparse code multiple access(SCMA)is a non-orthogonal code domain multiple access(NOMA)scheme,which can realize the future large-scale machine communication network,and code book design is very important for SCMA sys-tem.Based on Eisenstein integers,this paper divides them into three groups according to different angles,choosing two gro-ups of Eisenstein integers as the parent constellation.According to the fact that the same resource block is occupied by mul-tiple users,and the sum of the occupied users'power is a fixed value,the power of the users is randomly allocated to construct the unbalanced codebook.The maximum minimum Euclidean distance is taken as the objective function,and the relevant parameters are taken as variables.Finally,the optimal solution is obtained by using particle swarm optimization algorithm.Numerical simulation results show that compared with existing codebooks,the proposed codebook has lower bit error rate and better performance in Gaussian channel.