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.

翻译：本文将多用户预编码问题作为无线MIMO系统的一个非碳化优化问题来研究。 在我们的工作中,我们将目标光谱效率功能与一个新的更简单的计算功能相近。 然后,我们将预编码问题降低到一个不受限制的优化任务,使用特殊的差别预测方法,并通过Qasi-Newton L-BFGS迭接程序加以解决,以获得能力。我们正在用Quadriga(用于产生现实无线电频道脉冲反应的开放源软件)来测试几种设想方案中的拟议方法。我们的方法显示,在合理的计算时间里,比超常方法有单一的改进。拟议的L-BFGS优化计划在这方面是新颖的,对标准方法有很大的优势。