A time/frequency two-dimensional OCDMA en-/decoding system scheme is presented. The system adopting prime-hop code and fiber Bragg grating (FBG) en-/decoder are experimentally demonstrated. The experimental results show that inputting data at the transmitter can be received accurately at the receiver. It offers a real example for OCDMA technology application in optical communication system.
Two schemes of linear combinatorial code (LCC) coding scheme with different and multiple wavelength bandwidth were proposed using fiber grating cascades in series and parallel, respectively. The system model and probability density function are investigated. Numerical simulation confirmed that bit error ratio (BER) performance largely improved due to that of sub-codeword system. Moreover, the preference of LCC with different wavelength bandwidth is better than that of multiple wavelength bandwidth.
A novel wavelength-time differential code division multiple access system is proposed for multirate transmission. The system model is given and analyzed. Differential detection can be adopted by assigning two orthogonal codes for one user and using these two codes to encode “1” and “0” with different period, respectively. When one-branch and zero-branch are balanced perfectly, the system can reduce the noise of background, thermal, dark current, and multiple access inference. Moreover, by varying the ratio of number of bit ”1” and bit “0” in data steaming, the multirate data stream transmission is achieved.