Severely Fading MIMO Channels: Models and Mutual Information

Abstract

Abstract-In most wireless communications research, the channel models considered experience less severe fading than the classic Rayleigh fading case. In this work, however, we investigate MIMO channels where the fading is more severe. In these environments, we show that the coefficient of variation of the channel amplitudes is a good predictor of the link mutual information, for a variety of models. We propose a novel channel model for severely fading channels based on the complex multivariate t distribution. For this model, we are able to compute exact results for the ergodic mutual information and approximations to the outage probabilities for the mutual information. Applications of this work include wireless sensors, RF tagging, land-mobile, indoor-mobile, ground-penetrating radar, and ionospheric radio links. Finally, we point out that the methodology can also be extended to evaluate the mutual information of a cellular MIMO link and the performance of various MIMO receivers in a cellular scenario. In these cellular applications, the channel itself is not severely fading but the multivariate t distribution can be applied to model the effects of inter-cell interference.

A Power Scaling Analysis of Norm-Based Antenna Selection Techniques

“…There is considerable support for the accuracy of this approach in the literature [14], [15], [16], [17]. Analytical work in this area includes [14], [15], [17] and simulation evidence is given in [16].…”

“…In a similar vein, expansions derived in [17] employ only the first few moments of the channel coefficients. Lastly, in [16] simulations over a wide range of isotropic non-Gaussian channels showed that for fixed values of the second order statistics, the ergodic capacity is highly insensitive to the exact distribution unless the channel exhibits very severe fading.…”

Capacity-based Link Design of MIMO Radio Systems

“…In mobile communication systems, received signal vector of the single-user MIMO link y can be modeled by [7] [8] y…”

The impact of spatial correlation on the statistical properties of the capacity of nakagami-m channels with MRC and EGC

“…The ADF T C (r) of the channel capacity C(t) can be obtained using T C (r) = F C (r)/N C (r) [31], where F C (r) and N C (r) are given by (14) and (16), respectively.…”

“…Numerous papers have been published so far dealing with the performance and the capacity analysis of wireless communication systems employing diversity combining techniques in Rayleigh and Rice channels (e.g., [6,11,12]). However, in recent years the Nakagamim channel model [13] has gained considerable attention due to its good fitness to experimental data and mathematically tractable form [14,15]. Moreover, the Nakagami-m channel model can be used to study scenarios where the fading is more (or less) severe than the Rayleigh fading.…”