Soft-Partition Environment Division Multiple Access via Movable-Signals and Pinching Antennas

Abstract

Environment division multiple access (EDMA) provides a propagation-centric multiple-access framework for pinching-antenna systems (PASS) by using segmented waveguides and line-of-sight (LoS) blockage to partition the service area and reduce inter-region interference. Recent PASS–movable-signal (MS) studies further suggest that carrier-domain actuation can reshape delay-dependent channel responses. Motivated by these developments, this paper studies segmented PASS–MS–EDMA under explicit LoS+NLoS propagation. Unlike earlier PASS–MS works that optimize a generic user-channel matrix for fairness, reliability, beamforming, or sensing, the present work focuses on the EDMA-specific region-to-region coupling matrix induced by one segment, one feed/RF chain, one active pinching point, and one scheduled user per region. We adopt a guided-delay plus radiated LoS/NLoS delay-superposition channel model and show that each diagonal and off-diagonal coupling entry becomes a finite trigonometric polynomial of the common carrier. This yields a soft-partition interpretation of NLoS EDMA: PASS shapes a diagonally favored coupling structure, while MS searches the carrier domain for operating points that reduce cross-region leakage more than they perturb desired in-region links. We identify the delay-visibility boundary under which MS is ineffective, characterize the diagonal/off-diagonal carrier-sensitivity asymmetry, and derive leakage valleys and critical carriers from off-diagonal delay differences. Building on these insights, we develop a two-timescale solver with an inner scalar-link power update and an outer PASS–MS update using adaptive soft-partition certification, critical-carrier refinement, and segment-wise proximal geometry ascent. Numerical results validate the proposed theory under both favorable and weak-asymmetry regimes and show consistent weighted-sum-rate gains over LoS-only EDMA, fixed-carrier NLoS EDMA, and grid-based carrier-search baselines.