Spatial Correlation Matrices
Under the Kronecker model, the spatial correlation depends directly on the eigenvalue distributions of the correlation matrices and . Each eigenvector represents a spatial direction of the channel and its corresponding eigenvalue describes the average channel/signal gain in this direction. For the transmit-side matrix it describes the average gain in a spatial transmit direction, while it describes a spatial receive direction for .
High spatial correlation is represented by large eigenvalue spread in or, meaning that some spatial directions are statistically stronger than others.
Low spatial correlation is represented by small eigenvalue spread in or, meaning that almost the same signal gain can be expected from all spatial directions.
Read more about this topic: Spatial Correlation, Mathematical Description