Secure DoF of MIMO Rayleigh block fading wiretap channels with No CSI anywhere
Journal
2014 IEEE International Conference on Communications, ICC 2014
Pages
1959-1964
Date Issued
2014
Author(s)
Abstract
We consider the block Rayleigh fading multiple-input multiple-output (MIMO) wiretap channel with no prior channel state information (CSI) available at any of the terminals. The channel gains remain constant in a coherence time of T symbols, and then change to another independent realization. The transmitter, the legitimate receiver and the eavesdropper have nt, nr and ne antennas, respectively. We determine the exact secure degrees of freedom (s.d.o.f.) of this system when T ≥ 2 min(nt, n r). We show that, in this case, the s.d.o.f. is exactly (min(n t, nr) - ne)+(T - min(nt, nr))/T. The first term can be interpreted as the eavesdropper with ne antennas taking away ne antennas from both the transmitter and the legitimate receiver. The second term can be interpreted as a fraction of s.d.o.f. being lost due to the lack of CSI at the legitimate receiver. In particular, the fraction loss, min(nt, nr)/T, can be interpreted as the fraction of channel uses dedicated to training the legitimate receiver for it to learn its own CSI. We prove that this s.d.o.f. can be achieved by employing a constant norm channel input, which can be viewed as a generalization of discrete signalling to multiple dimensions. © 2014 IEEE.
SDGs
Other Subjects
Antennas; MIMO systems; Rayleigh fading; Transmitters; Block fading; Channel gains; Channel inputs; Coherence time; Multiple dimensions; Rayleigh; Wire-tap channels; Channel state information
Type
conference paper