The concept of continuous-aperture multiple-input multiple-output (CAP-MIMO) technology has been proposed recently, which aims at achieving high spectrum efficiency by deploying extremely dense antennas or even continuous antennas in a given aperture. The fundamental question of CAP-MIMO is whether it can achieve much better performance than the traditional discrete MIMO system. In this paper, to model the CAP-MIMO, we use self-adjoint operators to depict the structural characteristics of the continuous random electromagnetic fields from physical laws. Then, we propose a non-asymptotic performance comparison scheme between continuous and discrete MIMO systems based on the analysis of mutual information. We show the consistency of the proposed scheme by proving that the mutual information between discretized transceivers converges to that between continuous transceivers. Numerical analysis verifies the theoretical results, and suggests that the mutual information obtained from the discrete MIMO with widely adopted half-wavelength spaced antennas almost achieves the mutual information obtained from CAP-MIMO.
翻译:最近提出了连续孔径多投入多输出技术(CAP-MIMO)概念,目的是通过在特定孔径上部署极为密集的天线,甚至连续天线,实现高频谱效率;CAP-MOIMO的根本问题是,它能否比传统的离散的MIMO系统取得更好的性能;在本文中,为了模拟CAP-MIMO,我们使用自联操作员从物理法中描绘连续随机电磁场的结构特征;然后,我们根据对相互信息的分析,提议对连续和离散的MIMO系统进行非简易性能性能比较计划;我们通过证明离散的收发器之间的相互信息与连续的收发器之间的相互信息汇合,表明拟议的计划的一致性;数字分析验证了理论结果,并表明,从离散的MIMIMO和广泛采用的半波长空天线所获得的相互信息几乎达到了从CAP-MIMO获得的相互信息。