Nonlinear precoding and pulse shaping are jointly considered in multi-user massive multiple-input multiple-output (MIMO) systems with low-resolution D/A-converters (DACs) in terms of algorithmic approach as well as large system performance. Two design criteria are investigated: the mean square error (MSE) with active constellation extension (ACE) and the symbol error rate (SER). Both formulations are solved based on a modified version of the generalized approximate message passing (GAMP) algorithm. Furthermore, theoretical performance results are derived based on the state evolution analysis of the GAMP algorithm. The MSE based technique is extended to jointly perform over-the-air (OTA) spectral shaping and precoding for frequency-selective channels, in which the spectral performance is characterized at the transmitter and at the receiver. Simulation and analytical results demonstrate that the MSE based approach yields the same performance as the SER based formulation in terms of uncoded SER. The analytical results provide good performance predictions up to medium SNR. Substantial improvements in detection, as well as spectral performance, are obtained from the proposed combined pulse shaping and precoding approach compared to standard linear methods.
翻译:非线性预编码和脉冲成型在多用户大规模多投入多输出(MIMO)系统(MIMO)中共同考虑,在算法方法以及大型系统性能方面,采用低分辨率D/A-交换器(DACs),采用低分辨率D/A-converers(DACs)系统(DACs),采用两种设计标准:中平方差(MSE),使用主动星座扩展和符号误差率(SER)。这两种配方都是根据通用近似电流传递(GAMP)算法的修改版本解决的。此外,理论性能结果是根据GAMP算法的州性演变分析得出的。基于MSE的技术扩展至联合进行超空(OTA)光谱成型和频率选择性信道预编码,在发报器和接收器中标明光谱性能特征。模拟和分析结果显示,基于MESE的方法在未编码的SER制式上产生与SER的类似性能。分析结果向中SNR提供良好的性能预测。基于探测和光谱性能的改进,以及光谱性性能表现取自拟议的混合脉冲成前标准方法。