Time-spreading and wavelength-group-hopping codes implemented over fiber-to-the-home networks

Exploiting the inherent cyclic and periodic free-spectral-range (FSR) properties of arrayed-waveguide-grating (AWG) routers, the time-spreading and free-spectral-range (FSR) group hopping code, which embedded maximum length sequence (i.e., called TS/GH embedded M-sequence code) is configured over fiber-to-the-home (FTTH) network. In this study, the proposed codeword, which integrated time and spectral (wavelength) domain, is constructed as the same prime code sequence and therefore is referred as two-dimension (2-D) optical codes. Importantly, for the proposed broadband light source (BLS), the total number of available wavelengths is partitioned into the different groups G based on the M-sequence code length. Every group is referred as hopping pattern and characterized by the FSR interval of AWG router. To improve the prime-hop code (PHC) and modified prime-hop code (MPHC) of 2-D OCDMA system with cascading one additional AWG router, the cardinality of proposed scheme is significantly increased by the factor of 15 times under the optimum arrangement for group hopping number of G=7. Moreover, the correlation property and bit error rate (BER) of proposed scheme is evaluated and the result reveals that the BER of proposed scheme is better than MPHC and PHC.