一种面向WHT-NOMA的LC-MMSE-SIC检测算法

LC-MMSE-SIC detection algorithm for WHT-NOMA

非正交多址接入(Non-Orthogonal Multiple Access,NOMA)在功率域中将多个用户信号叠加编码在一个发送信号中,这虽然增大了系统的容量与吞吐量,但在接收端造成更多的干扰。为了进一步提高接收机性能,文中将沃尔什-哈达玛变换(Walsh-Hadamard Transformation,WHT)与传统的NOMA技术结合。同时为了降低接收端串行干扰消除技术(Successive Interference Cancellation,SIC)的计算复杂度,将大信道矩阵分解为空心矩阵与对角矩阵的和,再利用诺伊曼级数近似将信道矩阵的直接求逆运算转化为对角矩阵求逆运算的乘积之和,有效地降低计算复杂度。仿真结果表明,WHT-NOMA系统的误比特率优于传统的NOMA系统,同时文中所提出的低复杂度的SIC算法的性能是与最小均方误差SIC算法相接近的。

Non-orthogonal multiple access(NOMA)encodes multiple user signals in a single transmission signal in the power domain,increasing the capacity and the throughput of the system,but causing more interference at the receiver.To further improve the performance of the receiver,this paper combines the Walsh-Hadamard transformation(WHT)with the traditional NOMA technology.Meanwhile,to reduce the computational complexity of the receiver’s successive interference cancellation(SIC),a large channel matrix is decomposed into the sum of the hollow matrix and the diagonal matrix,and then the direct inverse operation of the channel matrix is transformed into the sum of the product of the inverse operation of the diagonal matrix by the Neumann series approximation,thus reducing the computational complexity.Simulation results show that the bit error rate of WHT-NOMA system is better than that of traditional NOMA system,and the performance of the low-complexity SIC algorithm is close to that of the minimum mean square error SIC algorithm.