Rotatable antennas improve signal rates by adjusting orientation dynamically
Achievable Rate Region Characterization of Rotatable Antenna-assisted Interference Channel
Information Theory
Summary
Wireless devices often struggle when signals from multiple transmitters interfere with each other, making communication slower. This paper studies how antennas that can physically rotate help improve communication by aiming their signals more precisely. The authors found ways to adjust both the antenna direction and signal patterns to reduce interference and boost signal strength. They showed that even simple signal techniques work well when combined with smart antenna rotation. This approach can make wireless networks faster and simpler.
What this means in practice
- •For wireless network engineers: Design wireless systems that dynamically rotate antennas to reduce interference and improve data rates in multi-user environments.
- •For satellite communication teams: Implement rotatable antennas on satellites to better control signal direction, enhancing link quality amid crowded frequency bands.
Authors
Junran Pei, Guangji Chen, Qingqing Wu, Qiaoyan Peng, Wei Cai
Abstract
This paper characterizes the achievable rate region of a rotatable antenna (RA)-assisted multiple-input single-output (MISO) interference channel. We exploit the additional spatial degrees of freedom (DoFs) offered by the dynamic orientation of RAs to simultaneously enhance the desired signal and suppress interference, thereby significantly enlarging the achievable rate region of the interference network. To this end, we invoke the rate-profile technique to formulate a sum-rate maximization problem for jointly optimizing the transmit beamforming and the array rotation, subject to the practical mechanical constraints of the RAs. For the special case of a two-receiver scenario, we introduce the concept of subspace correlation coefficient to derive closed-form solutions for the optimal RA rotation angles and transmit beamforming vectors. Inspired by the insights obtained in the two-receiver special case, we propose an efficient two-step optimization framework to obtain a high-quality solution for the general multi-receiver case. In particular, the array rotation angle of each transmitter is optimized to minimize the leakage interference to non-associated receivers. With the optimized array rotation angles, the optimal transmit beamforming is obtained by invoking the second order cone programming based approach. Numerical results demonstrate that the proposed solution achieves near-optimal performance and that integrating RAs effectively simplifies transceiver designs by enabling simple maximum ratio transmission (MRT) beamforming with negligible performance loss.