Uplink RSMA for Pinching-Antenna Systems Enhances Two-user Indoor Communications and Mitigates Path Loss

Next-generation wireless networks require adaptable systems capable of meeting increasing demands for reliable, high-capacity communication, and researchers are actively seeking ways to overcome the limitations of conventional antenna technology. Apostolos A. Tegos, Yue Xiao, Sotiris A. Tegos, and colleagues from Aristotle University of Thessaloniki, along with collaborators, present a novel approach utilising ‘pinching-antenna systems’ which dynamically activate antennas to create stronger, more direct connections, particularly within indoor environments. This work investigates a two-user network employing rate-splitting multiple access, demonstrating that this method significantly improves resilience and outperforms existing non-orthogonal multiple access schemes in pinching-antenna systems. The team derives new mathematical formulas to predict system reliability, validating their approach and paving the way for more robust and efficient wireless networks.

This allows for precise control over radiation patterns, polarization, and other parameters, offering a way to achieve dynamic beamforming, spatial multiplexing, and improved signal quality without relying on multiple antenna elements or complex circuitry. Furthermore, the research extends to physical layer security techniques and integration with technologies like orthogonal frequency-division multiplexing (OFDM) and integrated sensing and communication. Future research directions include addressing practical implementation challenges, such as mechanical reliability, actuation control, and integration with radio frequency circuitry. Scientists also propose developing more realistic channel models, integrating machine learning techniques for optimization, and exploring energy harvesting to power the antenna mechanisms. Researchers engineered a system comprising an access point and two pinching antennas, strategically positioned opposite their corresponding users to simplify the signal path and maximize received power. This configuration mitigates the impact of path loss, a common limitation in wireless networks. The core of the research involved deriving closed-form expressions for outage probability, a critical metric for assessing the reliability of wireless links.

Scientists meticulously modeled the wireless channel between each antenna and user, accounting for distance, wavelength, and path loss using a detailed mathematical formulation. The team’s approach avoids approximations commonly used in similar studies, providing highly accurate theoretical insights into system performance. These systems utilize dielectric waveguides deployed within a room, enabling activation of antennas at any point along the waveguide and minimizing the distance between transmitter and receiver. These expressions offer valuable insights into optimizing system design and performance. The findings contribute to a growing body of knowledge surrounding reconfigurable intelligent surfaces and movable antenna technologies, offering a pathway towards more reliable and high-capacity wireless networks for future applications.