In this paper, we propose a symbol-level precoding (SLP) design that aims to minimize the weighted mean square error between the received signal and the constellation point located in the constructive interference region (CIR). Unlike most existing SLP schemes that rely on channel state information (CSI) only, the proposed scheme exploits both CSI and the distribution information of the noise to achieve improved performance. We firstly propose a simple generic description of CIR that facilitates the subsequent SLP design. Such an objective can further be formulated as a nonnegative least squares (NNLS) problem, which can be solved efficiently by the active-set algorithm. Furthermore, the weighted minimum mean square error (WMMSE) precoding and the existing SLP can be easily verified as special cases of the proposed scheme. Finally, simulation results show that the proposed precoding outperforms the state-of-the-art SLP schemes in full signal-to-noise ratio ranges in both uncoded and coded systems without additional complexity over conventional SLP.
翻译:在本文件中,我们提议了一个符号级预编码(SLP)设计,目的是尽量减少收到信号与位于建设性干扰区(CIR)的星座点之间的加权平均正方差。与大多数仅依赖频道状态信息(CSI)的现有SLP计划不同,拟议的计划利用CSI和噪音的分布信息来提高性能。我们首先提议一个简单的CIR通用描述,为随后的SLP设计提供便利。这个目标可以进一步表述为非负最小方(NNNLS)问题,通过主动设定算法可以有效解决。此外,加权最小平均方差(WMMSE)预编码和现有的SLP可以很容易地作为拟议计划的特殊案例加以核实。最后,模拟结果表明,拟议的预编码在未编码和编码的常规 SLP 上不增加复杂性的完全信号-神经比率范围内,超越最先进的SLP计划。