George Levin

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—Diversity-multiplexing tradeoff (DMT) was characterized asymptotically (SNR-> infinity) for i.i.d. Rayleigh fading channel by Zheng and Tse [1]. The SNR-asymptotic DMT overestimates the finite-SNR one [2]. This paper outlines a number of additional limitations and difficulties of the DMT framework and discusses their implications. Using the recent results(More)
Various normalizations of the MIMO channel matrix are discussed from a physical perspective. It is demonstrated that the physics of antenna arrays and propagation channel should be taken into account when normalization is chosen, so that SNR has proper meaning, the conclusions are physical and correspond to realistic systems. The antenna array geometry and(More)
—An information-theoretic analysis of a multi-keyhole channel, which includes a number of statistically independent keyholes with possibly different correlation matrices, is given. When the number of keyholes or/and the number of Tx/Rx antennas is large, there is an equivalent Rayleigh-fading channel such that the outage capacities of both channels are(More)
—Diversity multiplexing tradeoff (DMT) in MIMO relay channels, where the transmitter and receiver are equipped with multiple antennas and the relay with a single one, is derived for a broad class of fading distributions, including, as special cases, non-identical, spatially correlated, and non-zero mean channels. It is shown that the DMT does not depend on(More)
—An extension of the popular diversity-multiplexing tradeoff framework to the low-SNR (or wideband) regime is proposed. The concept of diversity gain is shown to be redundant in this regime since the outage probability is SNR-independent and depends on the multiplexing gain and the channel power gain statistics only. The outage probability under the DMT(More)
— Diversity–multiplexing tradeoff (DMT) presents a compact framework to compare various MIMO systems and channels in terms of the two main advantages they provide (i.e. high data rate and/or low error rate). This tradeoff was characterized asymptotically (SNR-> infinity) for i.i.d. Rayleigh fading channel by Zheng and Tse [1]. The asymptotic DMT(More)
— A stronger and general sufficient condition for the asymptotic normality of MIMO channel eigenvalues and its capacity is given. Physical interpretation of this condition is discussed. Simple alternative conditions, which do not require eigenvalue decomposition, are proposed. It is demonstrated that some popular correlation matrix models satisfy these(More)
—Fading MIMO relay channels are studied analytically , when the source and destination are equipped with multiple antennas and the relays have a single one. Compact closed-form expressions are obtained for the outage probability under i.i.d. and correlated Rayleigh-fading links. Low-outage approximations are derived, which reveal a number of insights,(More)
– This paper provides a partial answer to the question: "what is the best angular density of multipath in MIMO channels?" using the size-asymptotic theory of Toeplitz matrices for uniform 2-D and 3-D antenna arrays. A Kronecker-type approximation of the array correlation structure is proposed and used to find the angular densities that completely eliminate(More)
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