In this paper, we propose a multiple-input multipleoutput (MIMO) transmission strategy that is closer to the Shannon limit than the existing strategies. Different from most existing strategies which only consider uniformly distributed discrete input signals, we present a unified framework to optimize the MIMO precoder and the discrete input signal distribution jointly. First, a general model of MIMO transmission under discrete input signals and its equivalent formulation are established. Next, in order to maximize the mutual information between the input and output signals, we provide an algorithm that jointly optimizes the precoder and the input distribution. Finally, we compare our strategy with other existing strategies in the simulation. Numerical results indicate that our strategy narrows the gap between the mutual information and Shannon limit, and shows a lower frame error rate in simulation.

翻译：在本文中,我们提出了一个与香农极限相近的多投入多输出传输战略(MIIMO)战略。与大多数仅考虑统一分布的离散输入信号的现有战略不同,我们提出了一个统一框架,以优化IMO预编码器和离散输入信号联合分布。首先,建立了离散输入信号下IMO传输的一般模型及其等效配方。接下来,为了最大限度地增加输入和输出信号之间的相互信息,我们提供了一种计算法,以共同优化预编码器和输入分布。最后,我们将我们的战略与模拟中的其他现有战略进行比较。数字结果表明,我们的战略缩小了相互信息与香农极限之间的差距,并显示了模拟中较低的框架错误率。