对于MIMO的研究(几篇信道容量的文章)

Patricia

【文件名】:06524@52RD_s link with isotropically random Rician fading.rar
【格　式】:rar
【大　小】:158K
【简　介】:Abstract—We analyze the capacity of a multiple-antenna wireless link with antennas at the transmitter and antennas at the receiver
in a Rician fading channel when the channel is unknown at both the
transmitter and the receiver. The Rician model is a nonstandard model
with a Rayleigh component and an isotropically random rank-one
specular component. The Rayleigh and specular components remain
constant for symbol periods, after which they change to completely
independent realizations, and so on. To maximize mutual information over
the joint density of complex transmitted signals it is sufficient to maximize over a joint density of min real transmitted signal magnitudes. The capacity-achieving signal matrix is equal to the product of two independent matrices, a isotropically random unitary matrix and a real nonnegative diagonal matrix. If ,
optimum signaling uses only out of the transmit antennas. We derive a novel lower bound on capacity which enables us to compute achievable rate regions for many cases. This lower bound is also valid for the case of purely Rayleigh-fading channels, where it has not been feasible,in general, to compute capacity, or mutual information. Our numerical results also indicate that the Rayleigh model is surprisingly robust: under our Rician model, up to half of the received energy can arrive via the specular component without significant reduction in capacity compared with the purely Rayleigh case.
the case of high SNR with no channel knowledge.In all the works mentioned above the attention has been limited to a Rayleigh-fading channel. Farrokhi et al. [2] considered a channel with a specular component, where the receiver knows the channel.Sengupta and Mitra [9] had, however, considered a Rician channel with coherence interval T = 1. In [6], the authors consider a Rician
fading model similar to the one presented in this correspondence.
They derive a nontrivial upper bound on capacity for the special case
of M = N = T = 1.In this correspondence, we analyze a mobile wireless link with a line-of-sight component (specular component) and a diffuse component
(Rayleigh component) both changing over time. Traditionally, in
a Rician model, the fading coefficients are modeled as Gaussian with
nonzero mean. We depart from the traditional model in the sense that
we model the mean (specular component) as time-varying and stochastic.
This permits a straightforward application of the notion of
ergodic capacity. The specular component is a rank-one isotropically
【目　录】:
I. INTRODUCTION
II. SIGNAL MODEL
III. PROPERTIES OF CAPACITY-ACHIEVING SIGNALS
IV. CAPACITY UPPER AND LOWER BOUNDS
V. NUMERICAL RESULTS
VI. DISCUSSION
VII. CONCLUSION