A New Family of Optical Code Sequences for Spectral-Amplitude-Coding Optical CDMA Systems

TLDR

DW codes have a fixed weight of two, while the modified double‑weight (MDW) family allows variable weights greater than two. The authors propose a new spectral‑amplitude‑coding optical CDMA code structure based on double‑weight code families. Using a mapping technique, the authors generate codes with larger weights that exist for every natural number n and exhibit ideal cross‑correlation properties. The MDW code demonstrates significantly better performance than Hadamard and modified frequency‑hopping codes in theory and simulation.

Abstract

A new code structure for spectral-amplitude-coding optical code-division multiple-access system based on double-weight (DW) code families is proposed. The DW code has a fixed weight of two. By using a mapping technique, codes that have a larger number of weights can be developed. Modified double-weight (MDW) code is a DW code family variation that has variable weights of greater than two. The newly proposed code possesses ideal cross-correlation properties and exists for every natural number n. Based on theoretical analysis and simulation, MDW code is shown here to provide a much better performance compared to Hadamard and modified frequency-hopping codes.