In this paper, we investigate the construction of a transmit signal for a base station with a massive number of antenna arrays under the cost-effective 1-bit digital-to-analog converters. Due to the coarse nonlinear property, conventional precoding methods could not yield an attractive performance with a severe error-floor problem. Moreover, finding an optimal transmit signal is computationally implausible because of its combinatorial nature. Thus, it is still an open problem to construct a 1-bit transmit signal efficiently. As an extension of our earlier work, we propose an efficient method to construct an 1-bit transmit-signal under quadrature-amplitude-modulation constellations. Toward this, we first derive the so-called feasibility condition which ensures that every user's noiseless observation belongs to a desired decision region, and then transform it as linear constraints. Taking into account the robustness to an additive noise, the proposed construction method is formulated as a well-defined mixed-integer-linear-programming problem. Based on this, we develop a low-complexity algorithm to solve it (equivalently, to generate a 1-bit transmit signal). Via simulations, we verify the superiority of the proposed method in terms of a computational complexity and detection performance.
翻译:在本文中, 我们调查一个基站的传输信号的构造。 基站上有大量的天线阵列, 在成本效率为1比位的数字到模拟转换器下。 由于粗略的非线性属性, 常规的预编码方法无法产生有吸引力的性能, 并存在严重的错误层问题。 此外, 找到一个最佳的传输信号是计算不可信的, 因为它的组合性质。 因此, 高效地构建一个 1比的传输信号仍然是一个未解决的问题 。 作为我们早期工作的延伸, 我们提出了一个高效的方法, 以构建一个1比特的在象形放大调控下的一个信号信号。 为此, 我们首先得出所谓的可行性条件, 以确保每个用户的无噪音观察都属于一个理想的决策区域, 然后将它转换成线性限制 。 考虑到对添加噪音的坚固性, 拟议的施工方法是精心定义的混合内线性传输信号。 作为我们早期工作的延伸, 我们为此开发了一种低兼容性算法, 来解决它( 等等量性, 和我们模拟的信号的检测方法) 。