面向MIMO系统的通用随机预编码框架
A Universal Random Precoding Framework for MIMO Systems
AI总结：
针对MIMO系统易受选择性衰落的问题，提出通用随机预编码框架，设计低复杂度实现方式与最优跨域检测器，仿真表明该框架性能接近RM且复杂度低、频谱效率灵活。
AI中文摘要：
当前无线系统通过对角化或稀疏化信道矩阵来对抗符号间干扰（ISI），但仍易受选择性衰落影响。为解决该问题，本文提出一种基于普适性类的通用随机预编码（RP）传输框架，RP利用随机变换从统计上利用所有子信道，构建属于普适性类的等效信道，从而在保持与现有波形后向兼容性的同时提升分集增益。低复杂度实现方式包括随机置换快速变换（FT-RP）和交织块稀疏快速变换（IBSFT-RP）。本文为RP系统设计了跨域OAMP/MAMP（CD-OAMP/MAMP）检测器，根据状态演化（SE），该检测器是副本最大后验（MAP）最优的。针对MIMO系统的仿真结果表明，采用CD-OAMP/MAMP的RP可实现接近RM的性能，且复杂度低得多，还具备灵活压缩比以提升频谱效率的额外优势。
英文摘要：
Current wireless systems combat inter-symbol interference (ISI) by diagonalizing or sparsifying the channel matrix, yet they remain vulnerable to selective fading. To address this, we propose a universal random precoding (RP) transmission framework based on the universality class. RP leverages random transforms to statistically exploit all subchannels and construct an equivalent channel belonging to the universality class, thereby enhancing diversity gain while maintaining backward compatibility with existing waveforms. Low-complexity implementations include the randomly permuted fast transform (FT-RP) and the interleaved block-sparse fast transform (IBSFT-RP). A cross-domain OAMP/MAMP (CD-OAMP/MAMP) detector is designed for RP systems, which is replica maximum \textit{a posteriori} (MAP)-optimal according to state evolution (SE). Simulation results on MIMO systems demonstrate that RP with CD-OAMP/MAMP achieves near-RM performance with much lower complexity, with additional benefits of flexible compression ratios for spectral efficiency.
