On the low SNR capacity of MIMO fading channels with imperfect channel state information

Abstract
The capacity of multiple-input multiple-output (MIMO) Rayleigh fading channels with full knowledge of channel state information (CSI) at both the transmitter and the receiver (CSI-TR) has been shown recently to scale at low signal-to-noise ratio (SNR) essentially as SNR log(1/SNR), independently of the number of transmit and receive antennas. In this paper, we investigate the ergodic capacity of MIMO Rayleigh fading channel with estimated channel state information at the transmitter (CSI-T) and possibly imperfect channel state information at the receiver (CSI-R). Our framework can be seen as a generalization of previous works as it can capture the perfect CSI-TR as a special case when the estimation error variance goes to zero. In this paper, we mainly focus on the low SNR regime, and we show that the capacity scales as (1-α) SNR log(1/SNR), where α is the estimation error variance. This characterization shows the loss of performance due to error estimation over the perfect channel state information at both the transmitter and the receiver. As a by-product of our new analysis, we show that our framework can be also extended to characterize the capacity of MIMO Rician fading channels at low SNR with possibly imperfect CSI-T and CSI-R. © 1972-2012 IEEE.

Citation
Benkhelifa, F., Tall, A., Rezki, Z., & Alouini, M.-S. (2014). On the Low SNR Capacity of MIMO Fading Channels With Imperfect Channel State Information. IEEE Transactions on Communications, 62(6), 1921–1930. doi:10.1109/tcomm.2014.2321375

Acknowledgements
This paper was funded by a grant from the office of competitive research funding of KAUST, Saudi Arabia. The associate editor coordinating the review of this paper and approving it for publication was T. Q. S. Quek.

Publisher
Institute of Electrical and Electronics Engineers (IEEE)

Journal
IEEE Transactions on Communications

DOI
10.1109/TCOMM.2014.2321375

Permanent link to this record