On MIMO phase noise channels at high SNR

International audienceWe consider the point-to-point multi-input-multiple-output (MIMO) channel with phase uncertainty (MIMO phase noise channel) at high SNR. With phase noise on the individual paths of the channel (model A), we show that the multiplexing gain is 1 2 , which implies that the capacity does not scale with the channel dimension at high SNR. With phase noise at both the input and output of the channel (model B), the multiplexing gain is upper-bounded by 1 2 min{nt, (nr − 2) + + 1}, and lower-bounded by 1 2 min{nt, nr+1 2 }, where nt and nr are the number of transmit and receive antennas, respectively. The multiplexing gain is enhanced to 1 2 min{nt, nr} without receive phase noise, and to 1 2 min{2nt − 1, nr} without transmit phase noise. Our main results rely on the derivation of non-trivial upper and lower bounds on the capacity of such channels