학술논문
Superanalysis for MIMO Interference Channels
Document Type
Dissertation/ Thesis
Author
Source
Subject
Language
English
Abstract
The cochannel interference is one of inevitable deleterious component in design and analysis of a wireless network. The use of multiple antennas at both transmitting and receiving nodes is promising technique to suppress and/or alleviate the effect of cochannel interference on the capacity. In this thesis, we assess the effects of both antenna correlation and cochannel interference on the ergodic capacity of multiple-input multiple-output (MIMO) interference channels with covariance feedback. In particular, we consider a general family of spatial fading correlation model---called unitary-independent-unitary---which encompasses most of zero-mean channels with arbitrary fading profiles including the popular separable correlation channel models. We first investigate the optimal structure of input covariance matrix which is maximizing the mutual information and is connected with the necessary and sufficient conditions as a generalization of the noise-limited case, which are attested by a simple iterative algorithm. Using the Berezin's supermathematics that treats both commuting and Grassmann anticommuting variables on the same footing, we analyze the average minimum mean-square error and the signal-to-interference-plus-noise ratio of the parallel spatial streams in the correlated Rayleigh-faded MIMO channels with separable correlations. In the asymptotic regimes---large numbers of antennas and/or extreme signal-to-noise ratio (SNR) regimes---we investigate the asymptotic capacity-achieving input covariance and show that this power allocation problem can be simplified drastically. Finally, using the theory of large random matrix, we derive the asymptotic ergodic capacity per receive antenna, and examine the first order behavior of the spectral efficiency as the numbers of antennas tend to infinity again in both low- and high-SNR regimes. Together with the powerful supermathematical framework, our results in this thesis are general enough to accurately assess the effects of spatial correlation and interference power heterogeneity.