Variable cross-correlation code construction for spectral amplitude coding optical CDMA networks

Optik ◽  
2012 ◽  
Vol 123 (11) ◽  
pp. 956-963 ◽  
Author(s):  
Hilal A. Fadhil ◽  
Syed A. Aljunid ◽  
Hassan Y. Ahmed ◽  
Hamza M.R. AlKhafaji
Keyword(s):  
Cross Correlation ◽  
Optical Cdma ◽  
Spectral Amplitude ◽  
Variable Cross ◽  
Code Construction ◽  
Cdma Networks ◽  
Spectral Amplitude Coding

scholarly journals Noncoherent Spectral Optical CDMA System Using 1D Active Weight Two-Code Keying Codes

2016 ◽  
Vol 2016 ◽  
pp. 1-9
Author(s):  
Bih-Chyun Yeh
Keyword(s):  
Cross Correlation ◽  
Transfer Functions ◽  
Block Design ◽  
Optical Network ◽  
Optical Cdma ◽  
Spectral Amplitude ◽  
Source Power ◽  
New Family ◽  
Spectral Amplitude Coding ◽  
Code Division Multiple

We propose a new family of one-dimensional (1D) active weight two-code keying (TCK) in spectral amplitude coding (SAC) optical code division multiple access (OCDMA) networks. We use encoding and decoding transfer functions to operate the 1D active weight TCK. The proposed structure includes an optical line terminal (OLT) and optical network units (ONUs) to produce the encoding and decoding codes of the proposed OLT and ONUs, respectively. The proposed ONU uses the modified cross-correlation to remove interferences from other simultaneous users, that is, the multiuser interference (MUI). When the phase-induced intensity noise (PIIN) is the most important noise, the modified cross-correlation suppresses the PIIN. In the numerical results, we find that the bit error rate (BER) for the proposed system using the 1D active weight TCK codes outperforms that for two other systems using the 1D M-Seq codes and 1D balanced incomplete block design (BIBD) codes. The effective source power for the proposed system can achieve −10 dBm, which has less power than that for the other systems.

A Study of Bipolar Walsh-Hadamard Coding Method in Optical CDMA Networks

2013 ◽  
Vol 284-287 ◽  
pp. 2667-2671
Author(s):  
Chih Ta Yen ◽  
Wen Bin Chen
Keyword(s):  
Multiple Access ◽  
Multiple Access Interference ◽  
Optical Filters ◽  
Optical Cdma ◽  
Spectral Amplitude ◽  
Eye Diagram ◽  
Cdma Networks ◽  
Coding Method ◽  
Simulation Results ◽  
Spectral Amplitude Coding

This study analyzes and calculates unipolar and bipolar coded configurations of spectral-amplitude-coding optical division multiple access (SAC-OCDMA) systems by using analytic and simulated methods. The important feature of the SAC-OCDMA systems is that multiple access interference (MAI) can be eliminated by code sequences of a fixed in-phase cross-correlation value. This property can be effectively canceled by multiple access interference by using balance detection schemes. This study uses Walsh-Hadamard codes as signature codes for the unipolar and bipolar schemes. The coder and decoder structures are based on optical filters of fiber Bragg gratings (FBGs). The simulation results of unipolar/bipolar coding structures are first presented by commercial simulation obtained using OptiSystem software. The simulation results show that the bit error rate (BER) through use of the bipolar coding method is superior to the unipolar scheme, especially when the received effect power is large. The eye diagram also shows that the bipolar encoding structure exhibits a wider opening than the unipolar encoding structure.

New design of Zero Cross Correlation Codes for Spectral Amplitude Coding in OCDMA systems

2011 ◽  
Author(s):  
C. B. M. Rashidi ◽  
S. A. Aljunid ◽  
F. Ghani ◽  
M. S. Anuar ◽  
H. Al-Khafaji ◽  
...  
Keyword(s):  
Cross Correlation ◽  
Spectral Amplitude ◽  
Spectral Amplitude Coding
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