A. R. Arief

Enhanced performance of new family Modified Double Weight codes spectral amplitude coding optical CDMA system network

A new family of spectral/spatial spectral amplitude-coding (SAC) optical code division multiple access (OCDMA) scheme using Modified Double Weight (MDW) code is developed. The new codes are derived from Modified Double Weight codes with good cross correlation. This proposed system can suppress the phase-induced intensity noise (PIIN) by using multiuser interference (MUI) cancellation property. The proposed 2-D OCDMA MDW can offer a much larger capacity compare to the 1-D OCDMA MDW Code.

Performance analysis of 2-D Extended-EDW Code for optical CDMA system

Two-dimensional Optical Code Division Multiple Access (2-D OCDMA) has gained great interest among researchers in optical communication systems. This work is aimed to present an alternative way of formulating the spectral/spatial incoherent two-dimensional Extended Enhanced Double Weight (2-D Extended-EDW) code. This code is proposed to suppress the phase induced intensity noise (PIIN) by using multiple access interference (MAI) cancellation property. The numerical analysis shows that 2-D EDW code has a better performance, in terms of bit error rate (BER) and the cardinality compared with one-dimensional Enhanced Double Weight (1-D EDW) code. In comparison with different combinations of spatial and spectral code length for 2-D Extended-EDW code, we found that by increasing the number of time chip, it significantly enhances the performance of the system.

Phase-induced intensity noise suppression wavelength-time modified double weight codes optical code division multiple access systems

The wavelength-time modified double weight (MDW) optical division multiple access (OCDMA) scheme to reduce multiple access interference (MAI) and compensate bit error rate (BER) and phase-induced intensity noise (PIIN) in incoherent OCDMA systems is proposed. The analysis permits thorough understanding of PIIN, shot and thermal noises effect on 2-Dimensional (2-D) MDW OCDMA system performance. PIIN is the dominant noise factor in the OCDMA time-spreading scheme. The 2-D MDW code shows better tolerance to PIIN in comparison to others with enhanced system performance. We prove by numerical analysis that the PIIN is maximally suppressed by the proposed code through minimizing property of cross-correlation in comparison to the 2-D PDC and 2-D MQC OCDMA code.

Modeling and simulation of variable weight zero cross correlation code in optical access network

In this paper, we demonstrate a novel architecture of variable weight Zero Cross Correlation code in the family of Spectral Amplitude Coding(SAC) Optical Code Division Multiple Access (OCDMA) to be utilized in the triple play services of OCDMA applications based on the end users demand and requirements. This is achieved by adapting multiple weights of Zero Cross Correlation (ZCC) code onto one system to accommodate different Quality of Service (QoS) requirements. The results are characterized by bit error rate (BER) and eye pattern simulated using OptiSystem software. Results proved a successful transmission of this scheme over 20km distance thus offering flexibility of independent QoS. It is also revealed that the performance is always better for users with larger number of code weight compared to those assigned with smaller code weight.

LED spectrum slicing for ZCC SAC-OCDMA coding system

In this paper we propose a Zero Cross-correlation (ZCC) code in Optical Code Division Multiple Access (OCDMA) CDMA system based on amplitude spectral encoding of low-cost broadband sources such as Light Emitting Diode (LED). We also study how the sliced spectrum of LED can be used as a cost-effective light source in ZCC code. Our system requires only standard optical elements and simple direct-detection receivers. We show that for number of weight = 4, up to 100 users can transmit asynchronously with an average bit error rate equal to 10−9. This ZCC code also demonstrates that BER of 10−9 can be achieved within the minimum received power of −25.5 dBm.

The Evolution of Double Weight Codes Family in Spectral Amplitude Coding OCDMA

This paper presents the review of Double Weight (DW) codes family from perspective of codes evolution since beginning until now. First generation focuses on one-dimensional (1D) code which spreading has been carried out in time. Later, the second generation was introduced known as two-dimensional (2D) code where the encoding of data bit has spread in both wavelength and time domain. Codes construction and variety of detection techniques scheme used in DW codes family are also discussed. In this paper we focus on structure of among DW codes family as all the design of code sequence aim to eliminate Multiple Access Interference (MAI). Previous papers of DW codes family show a good quality of transmission and satisfactory the standard quality of Bit Error Rate (BER) above 10−9.

An optimal cardinality of wavelength/time incoherent OCDMA system using 2-D hybrid FCC-MDW code

A 2-Dimensional (2-D) Wavelength/Time (W/T) scheme is proposed for spectral amplitude coding OCDMA network system. The new hybrid codes are utilizing Flexible Cross Correlation (FCC) and Modified Double Weight (MDW) codes which both codes have good correlation properties and capable to suppress multiple access interference (MAI). From the numerical calculation, it has been shown that this new hybrid code effectively suppresses the phase Induced Intensity Noise (PIIN) and eliminates MAI. Furthermore, the cardinality of this proposed code accommodates 150% and 275% improvement compared to 2-D PD code and 2-D M-Matrices code respectively at the BER=10-9. As a result, the performance of the system can be improved as well as support much more simultaneous users compared to Perfect Difference (PD) and M-matrices codes.

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

A new design code structure for Spectral Amplitude Coding with zero cross- correlation in Optical Code Division Multiple Access (OCDMA) has been proposed in this paper. The proposed code called Modified Zero Cross Correlation Code (MZCC). MZCC code provides much easier code construction, given any number of users K and weights to have minimum code length. MZCC code will be demonstrated using OptiSys 6.0. The results indicated that MZCC code is truly performs better in term of noise performance compared with existing Optical CDMA codes.

Noise mitigation for OCDMA system with wavelength/time 2D hybrid code

The benefits of employing 2-Dimensional (2D) Wave-length/Time (W/T) Hybrid code to mitigate the optical noise in spectral amplitude coding OCDMA networks system is in-vestigated. This analysis allows us to identify the influences of optical noise such as PIIN noise, shot noise and thermal noise in the system performance by using 2D Hybrid FCC-MDW code. The mathematical calculation reveals this new code effectively mitigates the Phase Induced Intensity Noise (PIIN) and eliminates Multiple Access Interference (MAI). As a result, the performance of the system can be improved as well as support much more simultaneous users compared to 2D Perfect Difference (PD) and 2D M-matrices codes.

Enhanced cardinality and effective transmitted power of 2-D extended-EDW OCDMA code

Various two-dimensional (2-D) OCDMA codes have been introduced in recent years due to their capabilities in enhancing cardinality, suppressing phase induced intensity noise (PIIN) and eliminates multiple access interference (MAI). This paper presents our new proposal of 2-D spectral/spatial Extended Enhanced Double Weight (2-D Extended-EDW) code. This code is designed to enhance cardinality and effective transmitted power. In other word, it effectively reduces noise and increasing simultaneous users. From our numerical analysis, we found that 2-D Extended-EDW code has a significantly better performance, in terms of the cardinality and effective transmitted power when compared with 2-D M-Matrices code.