The paper studies the multi-user precoding problem as a non-convex optimization problem for wireless MIMO systems. In our work, we approximate the target Spectral Efficiency function with a novel computationally simpler function. Then, we reduce the precoding problem to an unconstrained optimization task using a special differential projection method and solve it by the Quasi-Newton L-BFGS iterative procedure to achieve gains in capacity. We are testing the proposed approach in several scenarios generated using Quadriga -- open-source software for generating realistic radio channel impulse response. Our method shows monotonic improvement over heuristic methods with reasonable computation time. The proposed L-BFGS optimization scheme is novel in this area and shows a significant advantage over the standard approaches.

中文翻译：

---

使用优化方法在大规模 MIMO 中寻找更好的预编码

本文将多用户预编码问题作为无线MIMO系统的非凸优化问题进行研究。在我们的工作中，我们用一个新的计算更简单的函数来近似目标频谱效率函数。然后，我们使用特殊的差分投影方法将预编码问题简化为无约束优化任务，并通过拟牛顿 L-BFGS 迭代程序解决该问题，以实现容量增益。我们正在使用 Quadriga 生成的几种场景中测试所提出的方法 - 用于生成真实无线电信道脉冲响应的开源软件。我们的方法以合理的计算时间显示出对启发式方法的单调改进。所提出的 L-BFGS 优化方案在该领域是新颖的，并且显示出优于标准方法的显着优势。