arXiv subjects

Chuangye Shan

Publications and source records attributed to Chuangye Shan.

4 recordsLinked to original sources

arXiv2026

Flexible Coupler Antenna Enhanced Wireless Communication: Modeling and Coupler Position Optimization

This paper proposes a novel flexible coupler antenna (FCA) that translates passive coupling elements around a fixed-position active antenna to reshape the induced currents on the passive elements for radiation. A new form of mechanical beamforming is achieved by moving only the passive coupling elements while keeping the active antenna stationary. The proposed design significantly reduces the antenna and radio-frequency (RF) chain costs of conventional active array beamforming with low mechanical control complexity and energy consumption. For the purpose of exposition, we consider a point-to-point communication system with one FCA at the transmitter and one fixed antenna at the receiver. Specifically, based on multi-port circuit theory, we establish both the line-of-sight (LoS) and multipath channel models and derive the mechanical beamforming weights of the passive couplers as functions of their positions. Then, we formulate a new problem to maximize the received signal-to-noise ratio (SNR) by optimizing the positions of passive couplers at the transmitter, subject to coupler movement and transmit power constraints. Solving the resulting problem is inherently difficult because coupled channel and mechanical beamforming create non-linearity in the objective function.To tackle this problem, we propose an efficient block-coordinate conditional gradient method to search for the best positions of all passive couplers by sequentially optimizing the position of each coupler with those of the other couplers fixed in an iterative manner.Simulation results demonstrate that the proposed system significantly outperforms benchmark schemes in terms of achievable rate, but with significantly reduced active antennas and RF chains.

cs.IT↗

arXiv2026

Rotatable Coupler Antenna Enhanced Wireless Network: Modeling and Coupler Rotation Optimization

Flexible coupler antenna systems have recently received significant research interest due to their capability to intelligently reconfigure wireless channels by controlling coupler positions and/or rotations and dynamically exploiting mutual coupling. In this paper, we investigate a new type of flexible coupler antenna, termed rotatable coupler antenna (RCA), for enabling spectrum and energy efficient wireless communication cost-effectively. Specifically, an RCA consists of one fixed active antenna and multiple low-cost passive couplers, each of which can independently rotate in three-dimensional (3D) space, so as to collaboratively achieve mechanical beamforming without requiring additional radio-frequency (RF) chains for the couplers. We study an RCA-enhanced point-to-point communication system, where one RCA is deployed at the transmitter to serve a single user equipped with a fixed antenna. Based on multi-port circuit theory, we establish the channel model and characterize the mutual coupling coefficients as a function of coupler rotations. We formulate a new problem to maximize the received signal-to-noise ratio (SNR) at the user by optimizing the 3D rotations of all couplers, subject to practical coupler rotation constraints. To tackle this nonconvex problem, we develop a spherical-cap conditional-gradient-based algorithm with cross-entropy-method initialization. Simulation results demonstrate that the proposed RCA system can significantly improve communication performance in comparison with benchmark schemes, while requiring substantially fewer active antennas and RF chains.

cs.IT↗

arXiv2026

Reconfigurable Coupler Antenna for Wireless Networks

The reconfigurable coupler antenna (RCA), also called the flexible coupler antenna (FCA), is a new technique that aims to improve the performance of wireless communication networks by reconfiguring the positions and rotations of low-cost couplers around fixed-position active antennas to harness mutual coupling. Specifically, different couplers can independently adjust their positions and/or rotations at the transceiver to reshape the induced currents on the couplers for radiation, thereby collaboratively achieving mechanical beamforming for directional signal enhancement or nulling. The position and/or rotation reconfiguration of passive couplers provides a new and cost-effective means of enhancing wireless communication performance, while significantly reducing the antenna and radio-frequency (RF) chain costs of conventional active arrays. The compact and low form-factor structure of the RCA makes it particularly appealing for devices with stringent size, weight, and power (SWAP) constraints. In this article, we provide an overview of RCA to reveal its promising capabilities in wireless networks, including its system modeling, practical implementation, and competitive advantages over existing techniques. We present a variety of RCA-enabled performance enhancements in terms of mechanical beamforming gain, path-loss reduction, fading mitigation, spatial multiplexing gain, interference suppression, and geometric gain. Furthermore, we elaborate on the design challenges of RCA as well as promising solutions, and discuss the key applications of RCA in wireless networks. Finally, numerical results are presented to verify the substantial capacity gains enabled by RCA-aided transmission in wireless networks.

cs.IT↗

arXiv2026

Coupler Position Optimization and Channel Estimation for Flexible Coupler Antenna Aided Multiuser Communication

In this paper, we propose a distributed flexible coupler antenna (FCA) array to enhance communication performance with low hardware cost. At each FCA, there is one fixed-position active antenna and multiple passive couplers that can move within a designated region around the active antenna. Moreover, each FCA is equipped with a local processing unit (LPU). All LPUs exchange signals with a central processing unit (CPU) for joint signal processing. We study an FCA-aided multiuser multiple-input multiple-output (MIMO) system, where an FCA array base station (BS) is deployed to enhance the downlink communication between the BS and multiple single-antenna users. We formulate optimization problems to maximize the achievable sum rate of users by jointly optimizing the coupler positions and digital beamforming, subject to movement constraints on the coupler positions and the transmit power constraint. To address the resulting nonconvex optimization problem, the digital beamforming is expressed as a function of the FCA position vectors, which are then optimized using the proposed distributed coupler position optimization algorithm. Considering a structured time domain pattern of pilots and coupler positions, pilot-assisted centralized and distributed channel estimation algorithms are designed under the FCA array architecture. Simulation results demonstrate that the distributed FCA array achieves substantial rate gains over conventional benchmarks in multiuser systems without moving active antennas, and approaches the performance of fully active arrays while significantly reducing hardware cost and power consumption. Moreover, the proposed channel estimation algorithms outperform the benchmark schemes in terms of both pilot overhead and channel reconstruction accuracy.

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