Diversity-Multiplexing Tradeoff in Rank-De fi cient and Spatially Correlated MIMO Channels

In this paper, we first generalize a recent work of Zheng and Tse on diversity-multiplexing tradeoff (DMT) for some rank-deficient channels (poor scattering). We show that rank deficiency lowers DMT curves from that of i.i.d. Rayleigh fading channels. We show an interesting observation that suggests a fractional diversity gain may be possible at integer multiplexing gains. As the scattering becomes rich, the DMT approaches that of the i.i.d. Rayleigh fading channels. We next focus on spatially correlated multiple-input multipleoutput (MIMO) channels. We show that spatial correlation does not change the DMT but still degrades the outage performance and analyze such a degradation at high SNR.