针对加性高斯白噪声信道下的多用户非正交多脉冲调制系统,提出了基于QR分解的非相干判决反馈多用户检测器。该检测器通过QR分解矩阵变换,利用功率较强用户的判决信息来进行干扰抵消,可以有效消除用户间的多址干扰。而在各用户内,针对多脉冲调制技术,提出了一种线性解相关运算来进行非相干检测。同时,考虑解相关运算中矩阵求逆的复杂度比较高,进一步提出了一种软干扰抵消检测器。仿真结果表明所提的两种多用户检测算法可以有效消除非正交调制所造成的多址干扰,极大地提高功率较弱用户的性能,并且所提软干扰抵消检测器通过避免矩阵求逆降低了计算复杂度,同时检测性能没有损失。
Noncoherent decision feedback multiuser detector based on QR decomposition for muhiuser nonorthogonal multi- pulse modulation over the additive white Gaussian noise channel is proposed. Based on QR decomposition matrix transformation, the proposed detector can effectively eliminate the multiple access interference by utilizing the decisions of Stronger users. In each user, a linear decorrelating algorithm is proposed for noncoherent detection because of the multiple modulation technology. In addition, a soft interference cancellation detector is proposed to avoid the complexity of matrix inversion of decorrelating algorithm. Simulation results show that the proposed two multiuser detection algorithms can effectively eliminate the multiple access interference caused by nonorthogonal modulation, significantly improve the performance of the weak users. And the soft interference cancellation detector reduces the computational complexity by avoiding matrix inversion, while detecting performance without loss.