Capacity bounds for Gaussian vector broadcast channels
Sriram Vishwanath, Gerhard G. Kramer, Shlomo Shitz Shamai, Syed A. Jafar, A. Goldsmith · DIMACS series in discrete mathematics and theoretical computer science · 2003
Abstract. An outer bound on the capacity region of broadcast channels is presented called the degraded, same marginals (DSM) bound. This bound in-cludes and improves on Sato's sum-rate bound. The DSM bound is applied to Gaussian vector broadcast channels, and it is found that the Gel'fand/Pinsker/Costa dirty-paper coding technique achieves all points inside the bound if only Gauss-ian code books are permitted. This result suggests that dirty paper coding gives the capacity region of Gaussian vector broadcast channels, but the opti-mality of Gaussian code books remains to be veried. 1.