Power Domain Sparse Dimensional Constellation Multiple Access (PD-SDCMA) for Enabled Flexible PONs

TL;DR

This paper introduces PD-SDCMA, a novel multiple access scheme for fiber optic PONs that improves capacity and reduces interference, supporting higher modulation and more users for next-generation high-speed networks.

Contribution

The paper proposes PD-SDCMA, a new high-dimensional sparse constellation scheme that enhances spectral efficiency and user capacity in PONs, compatible with existing OFDM systems.

Findings

Supports more users than PD-NOMA and 3D-NOMA

Reduces bit error rate in 25 km fiber systems

Enables high spectral efficiency and flexibility

Abstract

With the commercial deployment of 5G and the in-depth research of 6G, the demand for high-speed data services in the next-generation fiber optic access systems is growing increasingly. Passive optical networks (PONs) have become a research hotspot due to their characteristics of low loss, high bandwidth, and low cost. However, the traditional orthogonal multiple access (OMA-PON) has difficulty meeting the requirements of the next-generation PON for high spectral efficiency and flexibility. In this paper, a novel transmission technology, namely power-domain sparse dimension constellation multiple access (PD-SDCMA), is proposed for the first time. Through the signal space dimension selection strategy (S2D-strategy) in the high-dimensional signal space, the low-dimensional constellation is sparsely superimposed into the high-dimensional space, thereby reducing multi-user interference and enhancing the system capacity. PD-SDCMA supports higher-order modulation formats and more access groups, and is also compatible with the existing orthogonal frequency division multiplexing (OFDM) architecture. The simulation results show that in a 25 km single-mode fiber system, compared with PD-NOMA and 3D-NOMA, PD-SDCMA can support more users and significantly reduce BER. This technology provides an efficient and low-cost solution for the evolution of Flexible PONs.