Robust Improper Signaling for Two-user SISO Interference Channels
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.
Cite
@article{arxiv.1901.05760,
title = {Robust Improper Signaling for Two-user SISO Interference Channels},
author = {Mohammad Soleymani and Christian Lameiro and Ignacio Santamaria and Peter J. Schreier},
journal= {arXiv preprint arXiv:1901.05760},
year = {2019}
}
Comments
IEEE Transactions on Communications (accepted)