NEW ZERO CROSS CORRELATION CODES BASED ON ZECHMETHOD’S FOR OCDMA SYSTEMS
A new structure code for Spectral Amplitude Coding Optical Code Division Multiple Access (SAC–OCDMA) system with zero cross-correlation (ZCC) is presented in this paper. The principle idea of this method is based on the use of Zech’s logarithms in the construction of the code sequences to ensure orthogonality and compare their performances with previously reported codes. The maximum cross correlation of this code is zero signifying that Multi Access Interference (MAI) and Phase Induced intensity noise (PIIN) effects are completely eliminated thus the system performances are improved. The BER simulation results against the total number of active users show a significant improvement in performance of the proposed code over preceding reported codes. The system can accommodate more than 90 simultaneous users compared to others codes at a bit error rate of 〖10〗^(-9). Furthermore, the construction method offers a good flexibility in the choice of the number of users, the weight and the code length