Rate region boundary of the SISO Z-interference channel with improper signaling

TitleRate region boundary of the SISO Z-interference channel with improper signaling
Publication TypeJournal Article
Year of Publication2017
AuthorsC. Lameiro, I. Santamaría, and P. J. Schreier
JournalIEEE Transactions on Communications
ISSN0090-6778
AbstractThis paper provides a complete characterization of the boundary of an achievable rate region, called the Pareto boundary, of the single-antenna Z interference channel (Z-IC), when interference is treated as noise and users transmit complex Gaussian signals that are allowed to be improper. By considering the augmented complex formulation, we derive a necessary and sufficient condition for improper signaling to be optimal. This condition is stated as a threshold on the interference channel coefficient, which is a function of the interfered user rate and which allows insightful interpretations into the behavior of the achievable rates in terms of the circularity coefficient (i.e., degree of impropriety). Furthermore, the optimal circularity coefficient is provided in closed form. The simplicity of the obtained characterization permits interesting insights into when and how improper signaling outperforms proper signaling in the singleantenna Z-IC. We also provide an in-depth discussion on the optimal strategies and the properties of the Pareto boundary.
DOI10.1109/TCOMM.2016.2641948