Multi-User Visible Light Communication Broadcast Channels With Zero-Forcing Precoding
Multi-User Visible Light Communication Broadcast Channels With Zero-Forcing Precoding
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DOI：
10.1109/tcomm.2017.2691710
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发表时间：
2017-06-01
影响因子：
8.3
通讯作者：
Pham, Anh T.
中科院分区：
文献类型：
--
作者：
Pham, Thanh V.;Hoa Le-Minh;Pham, Anh T.
本文研究了多用户多输入单输出可见光通信（VLC）广播信道的迫零（ZF）预编码设计。在此类广播系统中，主要的挑战性问题源于非协调用户之间存在的多用户干扰（MUI）。为了完全抑制MUI，采用了最初为射频(RF)通信设计的ZF预编码。与 RF 信号不同，VLC 信号本质上是非负的，并且线性范围有限，这导致输入数据信号的幅度受到限制。与平均功率约束不同，获得幅度受限信道的准确容量更加麻烦。在本文中，我们首先研究幅度受限高斯信道容量的下限和上限，这在高信噪比情况下尤其严格。基于导出的边界，最大最小公平性和率以及最大和率问题的最优波束形成器设计被表述为凸优化问题，然后可以通过使用标准优化包来有效地解决。
This paper studies zero-forcing (ZF) precoding designs for multi-user multiple-input single-output visible light communication (VLC) broadcast channels. In such broadcast systems, the main challenging issue arises from the presence of multi-user interference (MUI) among non-coordinated users. In order to completely suppress the MUI, ZF precoding, which is originally designed for radio frequency (RF) communications, is adopted. Different from RF counterpart, VLC signal is inherently non-negative and has a limited linear range, which leads to an amplitude constraint on the input data signal. Unlike the average power constraint, obtaining the exact capacity for an amplitude-constrained channel is more cumbersome. In this paper, we first investigate lower and upper bounds on the capacity of an amplitude-constrained Gaussian channel, which are especially tight in the high signal-to-noise regime. Based on the derived bounds, optimal beamformer designs for the max-min fairness sum-rate and the maximum sum-rate problems are formulated as convex optimization problems, which then can be efficiently solved by using standard optimization packages.