Low SNR Capacity of Jointly-Correlated MIMO Channels

This paper researches the capacity of multiple-input multiple-output (MIMO) channels jointly-correlated spatially on both sides in the low signal-to-noise (SNR) regime. We shall derive two key low SNR metrics: the minimum required E_b/N₀ and the wideband slope, assuming two types of channel state information (CSI) at the transmitter. We obtain closed-from solutions of these low SNR parameters for Gaussian MIMO channels, which embrace many existing results in the literature as special cases. Monte-Carlo simulations are performed to validate our analytical results.