TY - GEN
T1 - A general outer bound for MISO broadcast channel with heterogeneous CSIT
AU - Lashgari, Sina
AU - Tandon, Ravi
AU - Avestimehr, A. Salman
N1 - Publisher Copyright:
© 2015 IEEE.
PY - 2015/9/28
Y1 - 2015/9/28
N2 - We study the impact of heterogeneity of channel-state-information available at the transmitters (CSIT) on the capacity of broadcast channels with a multiple-antenna transmitter and k single-antenna receivers (MISO BC). In particular, we consider the k-user MISO BC, where the CSIT with respect to each receiver can be either instantaneous/perfect (P), delayed (D), or not available (N); and we study the impact of this heterogeneity of CSIT on the degrees-of-freedom (DoF) of such network. We develop a general outer bound on the DoF region of k-user MISO BC for all possible heterogeneous CSIT configurations, assuming linear encoding strategies at the transmitter. The outer bound leads to an approximate linear sum-DoF characterization to within 0.5 for a broad range of CSIT configurations. It also leads to an exact characterization of linear sum-DoF for some specific CSIT configurations. Our proof of the outer bound relies on the development of a novel lemma, called Interference Decomposition Bound, which lower bounds the interference dimension at a receiver which supplies delayed CSIT based on the average dimension of constituents of that interference, thereby decomposing it into its components.
AB - We study the impact of heterogeneity of channel-state-information available at the transmitters (CSIT) on the capacity of broadcast channels with a multiple-antenna transmitter and k single-antenna receivers (MISO BC). In particular, we consider the k-user MISO BC, where the CSIT with respect to each receiver can be either instantaneous/perfect (P), delayed (D), or not available (N); and we study the impact of this heterogeneity of CSIT on the degrees-of-freedom (DoF) of such network. We develop a general outer bound on the DoF region of k-user MISO BC for all possible heterogeneous CSIT configurations, assuming linear encoding strategies at the transmitter. The outer bound leads to an approximate linear sum-DoF characterization to within 0.5 for a broad range of CSIT configurations. It also leads to an exact characterization of linear sum-DoF for some specific CSIT configurations. Our proof of the outer bound relies on the development of a novel lemma, called Interference Decomposition Bound, which lower bounds the interference dimension at a receiver which supplies delayed CSIT based on the average dimension of constituents of that interference, thereby decomposing it into its components.
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U2 - 10.1109/ISIT.2015.7282485
DO - 10.1109/ISIT.2015.7282485
M3 - Conference contribution
AN - SCOPUS:84969772275
T3 - IEEE International Symposium on Information Theory - Proceedings
SP - 401
EP - 405
BT - Proceedings - 2015 IEEE International Symposium on Information Theory, ISIT 2015
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - IEEE International Symposium on Information Theory, ISIT 2015
Y2 - 14 June 2015 through 19 June 2015
ER -