Instantaneous Mutual Information and Eigen-Channels in MIMO Mobile Rayleigh Fading

• Published in: IEEE transactions on information theory Vol. 58; no. 1; pp. 353 - 368
• Main Authors: Shuangquan Wang, Abdi, A.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.01.2012; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Accuracy; Applied sciences; Approximation; Approximation methods; Autocorrelation function; average fade/outage duration; Channels; Computer simulation; Correlation; Correlation analysis; correlation coefficient; Correlation coefficients; eigen-channels; Eigenvalues and eigenfunctions; Exact sciences and technology; Fading; Information theory; Information, signal and communications theory; instantaneous mutual information; Joints; level crossing rate; Mathematical analysis; MIMO; Monte Carlo methods; Monte Carlo simulation; multiple-input multiple-output (MIMO); Scattering; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transmission and modulation (techniques and equipments); Fading channels; Correlation coefficient; Autocorrelation function; MIMO system; Monte Carlo method; Second order; average fade/outage duration; Outage; Rayleigh channels; Order statistic; instantaneous mutual information; multiple-input multiple-output (MIMO); Time variation; Average fade duration; Statistical method; Accuracy; Level crossing rate; Analytical method; Numerical simulation; Metric; Rayleigh fading; eigen-channels; Mutual information; Large scale system
• ISSN: 0018-9448; 1557-9654
• DOI: 10.1109/TIT.2011.2171519

In this paper, we study two important metrics in multiple-input multiple-output (MIMO) time-varying Rayleigh flat fading channels. One is the eigen-channel, and the other is the instantaneous mutual information (IMI). Their second-order statistics, such as the correlation coefficient, level crossing rate (LCR), and average fade/outage duration, are investigated, assuming a general nonisotropic scattering environment. Exact closed-form expressions are derived and Monte Carlo simulations are provided to verify the accuracy of the analytical results. For the eigen-channels, we found they tend to be spatio-temporally uncorrelated in large MIMO systems. For the IMI, the results show that its correlation coefficient can be well approximated by the squared amplitude of the correlation coefficient of the channel, under certain conditions. Moreover, we also found the LCR of IMI is much more sensitive to the scattering environment than that of each eigen-channel.