Title :
On the role of the input power constraint in the beamforming optimality range in TIMO channels
Author :
Al-Ahmadi, Saad ; Yanikomeroglu, Halim
Author_Institution :
Syst. & Comput. Eng, Carleton Univ., Ottawa, ON
Abstract :
In this paper, the effect of the input power constraint on the beamforming optimality range in Gaussian two-input multiple-output (TIMO) channels is explored. The obtained results, using standard Lagrangian formulation, determine explicitly the range of the input SNR for which rank-1 signaling (beamforming) is optimal in TIMO channels for both the common power constraint and the individual power constraint cases. Moreover, the obtained results are extended to random TIMO channels, with channel state information at the receiver only, using the Jensen´s upper bound on the mutual information.
Keywords :
Gaussian channels; MIMO communication; array signal processing; covariance matrices; Gaussian two-input multiple-output channels; Jensen upper bound; MIMO channels; TIMO channels; beamforming optimality range; channel state information; covariance matrix; input power constraint; standard Lagrangian formulation; Array signal processing; Channel capacity; Channel state information; Constraint theory; Covariance matrix; Hydrogen; Lagrangian functions; MIMO; Mutual information; Upper bound; MIMO channels; beamforming; common power constraint; individual power constraints; input covariance matrix; mutual information;
Conference_Titel :
Information Theory, 2009. CWIT 2009. 11th Canadian Workshop on
Conference_Location :
Ottawa, ON
Print_ISBN :
978-1-4244-3400-8
Electronic_ISBN :
978-1-4244-3401-5
DOI :
10.1109/CWIT.2009.5069521
