Diversity spectra of dense antenna arrays

We analyse the spatial diversity of dense antenna arrays in the plane and show how it can be characterised by the eigenvalue spectrum of the spatial autocorrelation kernel. We show how this diversity spectrum can be calculated for any spatial fading statistics represented by the power azimuth spectrum (PAS). Numerically calculated diversity spectra provide estimates of the possible diversity gains of the system and help to optimise the geometry of an antenna array.