针对准静态环境下物理层密钥随机性差且易受窃听的问题，文章提出了一种基于预编码和协作矩阵的密钥生成方案（PCM-SKG）。该方案通过对信道状态信息进行奇异值分解（SVD）获得预编码矩阵P，然后对预编码信道信息进行正交三角（QR）分解得到协作矩阵U，最后利用复合信道信息（HPU）量化密钥。仿真结果表明，PCM-SKG方案的近似密钥熵比传统方案提高近三倍，滑动平均步骤使密钥一致性提高约8dB。在MMSE估计中，该方案在15dB时的密钥错配率接近于10-4，通信误码率也更接近于系统效果最优值。PCM-SKG方案复杂度低且交互信息少，无需额外信道和设备传输信息，结合预编码矩阵和协作矩阵的多样性，实现密钥生成的随机源与信道相关且可变。

To address the issue of low randomness and vulnerability to eavesdropping in physical layer keys under quasi-static environments, this paper presents a key generation scheme based on precoding and cooperation matrix (PCM-SKG). The scheme uses singular value decomposition (SVD) to obtain the precoding matrix P from the channel state information. It then performs QR decomposition on the precoded channel information to get the cooperative matrix U. Finally, the composite channel information (HPU) is utilized to quantify the secret key. Simulation results show that the approximate key entropy of the PCM-SKG scheme increases nearly three times compared to traditional schemes, while the sliding average step improves key consistency by about 8dB. In MMSE estimation, the scheme achieves a key mismatch rate close to 10-4 at 15dB, with the communication error rate approaching optimal system performance. The PCM-SKG scheme features low complexity and minimal interactive information, requiring no additional channels or devices for information transmission. By leveraging the diversity of the precoding and cooperative matrices, it generates random sources for key generation that are channel-dependent and variable.