TY - GEN
T1 - On 2×2 MIMO Gaussian Channels with a Small Discrete-Time Peak-Power Constraint
AU - Dytso, Alex
AU - Barletta, Luca
AU - Kramer, Gerhard
N1 - Publisher Copyright:
© 2024 IEEE.
PY - 2024
Y1 - 2024
N2 - A multi-input multi-output (MIMO) Gaussian chan-nel with two transmit antennas and two receive antennas is studied that is subject to an input peak-power constraint. The ca-pacity and the capacity-achieving input distribution are unknown in general. The problem is shown to be equivalent to a channel with an identity matrix but where the input lies inside and on an ellipse with principal axis length rp and minor axis length rm. If rp≤√2, then the capacity-achieving input has support on the ellipse. A sufficient condition is derived under which a two-point distribution is optimal. Finally, if rm < rp≤√2, then the capacity-achieving distribution is discrete.
AB - A multi-input multi-output (MIMO) Gaussian chan-nel with two transmit antennas and two receive antennas is studied that is subject to an input peak-power constraint. The ca-pacity and the capacity-achieving input distribution are unknown in general. The problem is shown to be equivalent to a channel with an identity matrix but where the input lies inside and on an ellipse with principal axis length rp and minor axis length rm. If rp≤√2, then the capacity-achieving input has support on the ellipse. A sufficient condition is derived under which a two-point distribution is optimal. Finally, if rm < rp≤√2, then the capacity-achieving distribution is discrete.
UR - http://www.scopus.com/inward/record.url?scp=85202815468&partnerID=8YFLogxK
U2 - 10.1109/ISIT57864.2024.10619699
DO - 10.1109/ISIT57864.2024.10619699
M3 - Conference contribution
AN - SCOPUS:85202815468
T3 - IEEE International Symposium on Information Theory - Proceedings
SP - 2365
EP - 2370
BT - 2024 IEEE International Symposium on Information Theory, ISIT 2024 - Proceedings
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2024 IEEE International Symposium on Information Theory, ISIT 2024
Y2 - 7 July 2024 through 12 July 2024
ER -