arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2003.10676eess.SPcs.ITmath.IT
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MU-MISO网络中用于和速率优化的鲁棒波束形成设计

Robust Beamforming Design for Sum Secrecy Rate Optimization in MU-MISO Networks

Pu Zhao, Meng Zhang, Hui Yu, Hanwen Luo, Wen Chen

摘要:

本文研究了多用户下行链路网络的波束赋形设计问题,假设基站已知不完全的信道状态信息。在这种情况下,基站配备有多个天线,并且每个用户被特定的窃听者窃听,其中每个用户或窃听者配备有一个天线。假设基站采用具有对总发射功率的给定要求的发射波束成形。其目标是最大化网络的总保密率。由于信道的不确定性,很难精确计算系统的总保密率。因此,考虑了和保密率下界的最大值。和保密率下限的优化仍然使得所考虑的波束形成设计问题难以处理。为了解决这个问题,提出了一种波束形成设计方案,通过采用基于泰勒展开的半定松弛和一阶逼近技术,将原问题转化为凸逼近问题。此外,在基站能够抵消窃听者的速率的情况下,提出了一种基于迫零的波束形成方法,该方法具有低复杂度的优点。当基站不具备这种能力时,可以采用用户选择算法。仿真结果表明,前一种方法的性能优于后一种方法,这主要得益于其波束形成方向的优化能力,且均优于基于信噪比的算法。

英文摘要:

This paper studies the beamforming design problem of a multi-user downlink network, assuming imperfect channel state information known to the base station. In this scenario, the base station is equipped with multiple antennas, and each user is wiretapped by a specific eavesdropper where each user or eavesdropper is equipped with one antenna. It is supposed that the base station employs transmit beamforming with a given requirement on sum transmitting power. The objective is to maximize the sum secrecy rate of the network. Due to the uncertainty of the channel, it is difficult to calculate the exact sum secrecy rate of the system. Thus, the maximum of lower bound of sum secrecy rate is considered. The optimization of the lower bound of sum secrecy rate still makes the considered beamforming design problem difficult to handle. To solve this problem, a beamforming design scheme is proposed to transform the original problem into a convex approximation problem, by employing semidefinite relaxation and first-order approximation technique based on Taylor expansion. Besides, with the advantage of low complexity, a zero-forcing based beamforming method is presented in the case that base station is able to nullify the eavesdroppers' rate. When the base station doesn't have the ability, user selection algorithm would be in use. Numerical results show that the former strategy achieves better performance than the latter one, which is mainly due to the ability of optimizing beamforming direction, and both outperform the signal-to-leakage-and-noise ratio based algorithm.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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