@article {547,
	title = {Robust Improper Signaling for Two-user SISO Interference Channels},
	journal = {IEEE Transactions on Communications},
	volume = {67},
	year = {2019},
	month = {July},
	pages = {4709-4723},
	abstract = {It has been shown that improper Gaussian signaling (IGS) can improve the performance of wireless interference limited systems when perfect channel state information (CSI) is available. In this paper, we investigate the robustness of IGS against imperfect CSI on the transmitter side in a two-user single-input single-output (SISO) interference channel (IC) as well as in a SISO Z-IC, when interference is treated as noise. We assume that the true channel coefficients belong to a known region around the channel estimates, which we call the uncertainty region. Following a worst-case robustness approach, we study the rate-region boundary of the IC for the worst channel in the uncertainty region. For the two-user IC, we derive a robust design in closed-form, which is independent of the phase of the channels by allowing only one of the users to transmit IGS. For the Z-IC, we provide a closed-form design for the transmission parameters by considering an enlarged uncertainty region and allowing both users to employ IGS. In both cases, the IGS-based designs are ensured to perform no worse than proper Gaussian signaling. Furthermore, we show, through numerical examples, that the proposed robust designs significantly outperform non-robust solutions.},
	keywords = {Achievable rate region, imperfect CSI, improper Gaussian signaling, two-user interference channel, worst-case robustness.},
	doi = {10.1109/TCOMM.2019.2910549},
	author = {Mohammad Soleymani and Lameiro, Christian and Santamar{\'\i}a, Ignacio and Schreier, Peter J.}
}
