Talks and Poster Presentations (with Proceedings-Entry):
W. Yang, G. Durisi, E. Riegler:
"Unitary isotropically distributed inputs are not capacity-achieving for large-MIMO fading channels";
Talk: IEEE International Symposium on Information Theory (ISIT),
Cambridge, MA;
07-01-2012
- 07-06-2012; in: "2012 IEEE International Symposium on Information Theory Proceedings",
(2012),
5 pages.
English abstract:
We analyze the capacity of Rayleigh block-fading multiple-input multiple-output (MIMO) channels in the noncoherent setting and prove that unitary space-time modulation (USTM) is not capacity-achieving when the total number of antennas exceeds the coherence time of the fading channel. This situation is relevant for MIMO systems with large antenna arrays (large-MIMO systems). Our result settles a conjecture by Zheng & Tse (2002) in the affirmative. The capacity-achieving input signal, which we refer to as Beta-variate space-time modulation (BSTM), turns out to be the product of a unitary isotropically distributed random matrix, and a diagonal matrix whose nonzero entries are distributed as the square-root of the eigenvalues of a Beta-distributed random matrix of appropriate size. Numerical results illustrate that using BSTM instead of USTM in large-MIMO systems yields a rate gain as large as 13% for SNR values of practical interest.
German abstract:
We analyze the capacity of Rayleigh block-fading multiple-input multiple-output (MIMO) channels in the noncoherent setting and prove that unitary space-time modulation (USTM) is not capacity-achieving when the total number of antennas exceeds the coherence time of the fading channel. This situation is relevant for MIMO systems with large antenna arrays (large-MIMO systems). Our result settles a conjecture by Zheng & Tse (2002) in the affirmative. The capacity-achieving input signal, which we refer to as Beta-variate space-time modulation (BSTM), turns out to be the product of a unitary isotropically distributed random matrix, and a diagonal matrix whose nonzero entries are distributed as the square-root of the eigenvalues of a Beta-distributed random matrix of appropriate size. Numerical results illustrate that using BSTM instead of USTM in large-MIMO systems yields a rate gain as large as 13% for SNR values of practical interest.
Keywords:
Capacity, Noncoherent, MIMO
"Official" electronic version of the publication (accessed through its Digital Object Identifier - DOI)
http://dx.doi.org/10.1109/ISIT.2012.6283571
Related Projects:
Project Head Erwin Herbert Riegler:
Nicht kohärente Übertragungsverfahren für Zeit-Frequenz selektive Mobilfunkkanäle
Created from the Publication Database of the Vienna University of Technology.