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Spectral Amplitude Coding Optical Code Division Multiple Access (SAC–OCDMA) is an auspicious advancement in an asynchronous environments. In this paper, we have presented an effective Enhanced Quantum Logic Gate (EQLG) code for SAC–OCDMA to improve the code construction, cross-correlation and minimize the noises. The EQLG code contains unitary matrices with minimum overlaps in code spectral wavelengths of various clients. This drops the Multiple Access Interference (MAI) and furthermore EQLG code, provides high data-rate transmission in networks. The development of the proposed EQLG code is depicted in following strides as; at first build a matrix utilizing the estimation of the weight value and the number of subscribers. Based upon that, the number of rows and columns are located in the matrix. Second, each diagonal sequences are computed by using the QLG method. The execution of the recommended EQLG code will be analysed with existing SAC–OCDMA systems in response to Bit Error Rate (BER). The simulations of encoding with 10–60 users with 622 Mb/s data transmission at a BER of 10−9 have been successfully achieved. [ABSTRACT FROM AUTHOR]

We present a comparative analysis of performance characteristics of the optical code-division multiple-access systems, which are based on spectralamplitude coding (SAC) and are implemented using eight different one-dimensional optical codes and a multi-array laser. We try to find the best code for the SAC systems by taking into consideration such parameters as system requirements for the number of users, the data rate and the type of network suitable for a particular code. Our simulations reveal that the capacity of the SAC systems can be improved when those systems are implemented with a laser rather than incoherent light source. Moreover, we demonstrate that the laser-based SAC system performs well in terms of high data rates, which is followed by improved bit error rates occurring with increasing number of users. As a trade-off among different performance characteristics, different optical codes under analysis can be applied for different specific communication systems. The suggested codes support the maximal data rates up to 12 Gbps for approximately 50 users. The maximal fibre length that supports error-free transmission is equal to 70 km. [ABSTRACT FROM AUTHOR]

In this paper, we present a new algorithm to generate two-dimensional (2D) permutation vectors' (PV) code for incoherent optical code division multiple access (OCDMA) system to suppress multiple access interference (MAI) and system complexity. The proposed code design approach is based on wavelength-hopping time-spreading (WHTS) technique for code generation. All possible combinations of PV code sets were attained by employing all permutations of the vectors with repetition of each vector weight (W) times. Further, 2D-PV code set was constructed by combining two code sequences of the 1D-PV code. The transmitter-receiver architecture of 2D-PV code-based WHTS OCDMA system is presented. Results indicated that the 2D-PV code provides increased cardinality by eliminating phase-induced intensity noise (PIIN) effects and multiple user data can be transmitted with minimum likelihood of interference. Simulation results validated the proposed system for an agreeable bit error rate (BER) of 10−9. [ABSTRACT FROM AUTHOR]