Contribution of New Three-Dimensional Code Based on the VWZCC Code Extension in Eliminating Multiple Access Interference in Optical CDMA Networks

Abstract

In order to solve the problem of one-dimensional code length, two-dimensional code spatial length, phase induced intensity noise PIIN effect, improved system capacity, and increased the number of simultaneous users, a new three-dimensional spectral/time/spatial variable weight zero cross correlation code for non-coherent spectral amplitude coding-optical code division multiple access (3D-VWZCC-SAC-OCDMA) is proposed in this paper. Its construction is based on a one-dimensional (1D) spectral sequence and two-dimensional (2D) temporal/spatial sequences, which are characterized by the property of zero cross correlation ZCC. The simulation results demonstrate that our code proves high immunity against PIIN noise and shot noise, it increases multiplexing ability when the passage is from (1D) and (2D) to (3D) up to 5.112 and 2.248 times, and it saves −7.04 dBm and −5.9 dBm of the receiver power due to simple detection at the receiver; furthermore, the 3D-VWZCC system capacity has outperformed the 3D-PD, 3D-PD/MD and 3D-DCS/MD codes, which reach 3686, 2908, and 3234 times, respectively. Moreover, our code offers better performance, in terms of data rates, with up to 2 Gbps compared to previous codes, which makes the system meet the requirements of optical communication networks. Further, 3D-VWZCC is also simulated in Optisystem software, where our code offers a transmission quality Q reaching 11.56 with a bit error rate BER of 1.99 × 10−31 despite a high number of users.

Massive capacity of novel three‐dimensional OCDMA‐FSO system for next generation of high‐data wireless networks

“…An example of the 3D‐SW code words is shown in Table 2 for ($$$ {K}_1 $$$ = 2, $$$ {K}_2 $$$ = 3,$$$ {K}_3 $$$ = 2), while, Figure 1 shows the graphical depiction of 3D‐SW code. Hence, the three‐dimensional SW code is expressed as follows 2 : $$$$ {B}_{g,h,l}={X}_g^T{Y}_h{Z}_l. $$$$ …”

“…To further clarify the cross‐correlation of 3D‐SW coding feature, the characteristic matrices $$$ {B}^{(d)}={B}^{(0)},{B}^{(1)},\dots {B}^{(7)} $$$ are provided as follows 2 : $$$$ {B}^{(d)}=\left\{\begin{array}{c}{B}^{(0)}={X}^TY\ Z\\ {}{B}^{(1)}={X}^T\overline{Y}\ Z\\ {}\begin{array}{c}{B}^{(2)}={\overline{X}}^TY\ Z\\ {}{B}^{(3)}={\overline{X}}^T\overline{Y}\ Z\end{array}\end{array}\right.\ \left\{\begin{array}{c}{B}^{(4)}={X}^TY\ \overline{Z}\\ {}{B}^{(5)}={X}^T\overline{Y}\ \overline{Z}\\ {}\begin{array}{c}{B}^{(6)}={\overline{X}}^TY\ \overline{Z}\\ {}{B}^{(7)}={\overline{X}}^T\overline{Y}\ \overline{Z}\end{array}\end{array}\right. $$$$ where $$$ {X}^T $$$…”

“…To further clarify the cross-correlation of 3D-SW coding feature, the characteristic matrices B (d) = B (0) , B (1) , … B (7) are provided as follows 2 : (4) (g,h,l) R (5) (g,h,l) R (6) (g,h,l) R (7) (g,h,l)…”

“…The OCDMA system has become a technique attracting most international researchers due to its increased simultaneous transmission ability, high communication security, simple architecture, and good bandwidth exploitation, allowing for the assignment of a unique signature to each user while using the entire system's bandwidth. [1][2][3] Regarding optical codes, there are two types: zero cross-correlation codes (ZCCC) and non-zero cross-correlation codes (N-ZCCC). ZCCCs provide good performance due to the missing inter-user interference, which eliminates phase-induced intensity noise (PIIN) and the influence of multi-user interference (MUI).…”

“…Nowadays, the present development of optical networks involves the need to improve the quality of service (QoS), transmission speed, and optical network simultaneous transmission. The OCDMA system has become a technique attracting most international researchers due to its increased simultaneous transmission ability, high communication security, simple architecture, and good bandwidth exploitation, allowing for the assignment of a unique signature to each user while using the entire system's bandwidth 1–3 …”