Channel Capacity of Massive MIMO With Selected Multi-Stream Transmission in Spatially Correlated Fading Environments

Abstract

This study analyzed the channel capacity of multiple-input multiple-output (MIMO) reception by large-scale arrays at both ends in spatially correlated fading environments. The environments considered were Rayleigh fading for representing the non-line-of-sight condition and Nakagami-Rice fading for the line-of-sight condition. The transmission characteristics of massive MIMO were evaluated using the asymptotic eigenvalue distribution of a Wishart matrix composed of the channel matrix. The transmission scheme adopted here was eigen-mode multi-stream transmission that selected L from N streams of N-by-M (M ≥ N) massive MIMO. From the analysis, we determined that the effect of spatial correlation for the case of L/N being less than approximately 20% enhances the channel capacity, unlike spatial diversity operation. In this way, we clarified the effect of spatial correlation on channel capacity of massive MIMO quantitatively through asymptotic eigenvalue analysis.