Advancing High-Speed Transmissions over OCDMA Networks by Employing an Intelligently Structured Receiver for Noise Mitigation

Abstract

We propose an intelligently structured receiver to achieve high-speed transmissions over optical code-division multiple access (OCDMA) networks. Employing spectral-amplitude coding (SAC) reduces multiuser interference (MUI) in OCDMA, but the network bit-rate is limited by phase-induced intensity noise (PIIN) coming from the incoherency of light sources. To mitigate PIIN, the receiver performs interference estimations and regenerations through consecutive stages. The MUI is removed by subtracting the estimated interference term from the received multiplexed signals. For PIIN variance, it is both dependent on and positively related to user number and bit-rate. Reducing the number of interference users allows the network to support transmissions with a higher speed under a given noise level. The proposed scheme has the advantages of all-optical signal processing and a compact structure. Additionally, the function of noise suppression is rarely studied in the existing MUI elimination schemes, such as serial interference cancellation (SIC) and parallel interference cancellation (PIC). The simulation results show the proposed receiver achieves significant increment in bit-rate than the conventional balanced detector in SAC–OCDMA networks.

Decoding and measurement of frequency‐hopping spread spectrum signals using an adaptive algorithm‐based compressive sensing

“…DS-CDMA is much more popular than FH-CDMA commercially. 25,26 A major advantage of frequency hopping is that it can be implemented over a much larger frequency band than it is possible to implement DS spreading, and the band can be noncontiguous. Another major advantage is that frequency hopping provides resistance to multiple-access interference while not requiring power control to prevent near-far problems.…”

“…In fact, SS or CDMA has only two forms, DS‐CDMA and FH‐CDMA. DS‐CDMA is much more popular than FH‐CDMA commercially 25,26 . A major advantage of frequency hopping is that it can be implemented over a much larger frequency band than it is possible to implement DS spreading, and the band can be noncontiguous.…”

Bipolar Optical Code Division Multiple Access Techniques Using a Dual Electro-Optical Modulator Implemented in Free-Space Optics Communications

“…Some studies have reported a novel multiplex technique, namely optical code division multiple access (OCDMA) [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. OCDMA employs CDMA techniques in optical fiber communication environments.…”

“…Because phase shifts must be identified on a coder spectral response, their entire structure is relatively complex. To improve system performance, some researchers have proposed an intelligently structured receiver to suppress noise effects and a semiconductor optical amplifier (SOA) to mitigate temperature variation effects on links [ 16 , 17 ]. In 2018, Yen et al presented Walsh–Hadamard-code-based OCDMA techniques with moderate security for applications in WOC environments [ 18 ].…”

Multiple-Code Technique for Multi-Rate Transmissions in Optical Packet Switching Networks Based on OCDMA Labels

“…Optical code-division multiple access (OCDMA), providing high speed and security communications in access networks, has the potential to support all-optical processing [9][10][11]. The obtained label numbers in OCDMA are more flexible than the ones in wavelength-division multiplexing (WDM), and recent literature has demonstrated that OCDMA is compatible with the labeling scheme in OPS [9][10][11][12]. Converting packet labels into optical codes can be categorized into two methods, the explicit and implicit labels, according to the packet structure [12].…”