A Channel Capacity Calculation Method for Two-Dimensional Antenna Arrays Without Receivers

Estimating channel capacity is challenging for advanced communication systems with unconventional excitation sources such as information metamaterials and Moire metasurfaces, where traditional methods relying on transmitters and receivers become impractical. To address this challenge, this paper proposes a novel method for calculating the channel capacity of two-dimensional (2D) antenna arrays, which is based on the electric fields generated by the sources, eliminating the need for port-based measurements. Besides, the correlation matrix can be obtained to achieve a more accurate evaluation of capacity limits. The proposed methodology overcomes the limitations of traditional techniques, providing a robust solution for those scenarios where port definitions are infeasible. It is particularly applicable to metasurface-based communication systems, near-field systems, and complex environments. By establishing the theoretical upper bounds of the channel capacity, this work demonstrates a significant potential in advanced communication system design and performance optimization.