Non-stationary multi-ring channel model for massive MIMO systems

This paper proposes a novel non-stationary multi-ring channel model for massive multiple-input multiple-output (MIMO) systems. As the dimension of the antenna arrays comes to be huge in massive MIMO systems, farfield assumption used in conventional MIMO channel models is not considered in the proposed model. Thus, the spherical wavefront assumption and a birth-death process to model non-stationary properties on both time and array axes are adopted to the proposed model. In addition, the multi-ring geometry relationships which are relative to the delays of multipath components (MPCs) are assumed to mimic the distribution of the clusters in massive MIMO channels. The numerical results, such as received power levels over the array, antenna correlation and eigenvalue distributions show that the proposed channel model captures specific characteristics of the massive MIMO channel comparing with the measurements.