New code assignment strategy for optical communication link using multi-rate MC-DS-CDMA in Time-Frequency-Wavelength (TFW) domain spreading

This paper presents a code assignment scheme for the optical communication link using a combination of orthogonal wavelength division multiplexing and the spreading of Multi-Carrier Direct Sequence Code Division Multiple Access (MC-DS-CDMA) with time-frequency-wavelength (TFW) domain spreading. The proposed strategies of code assignment avoid the interference by using of entire three dimensions (3D) tree structure of time, frequency and wavelength. The paper proposes two new code placement strategies for new code requested based on the wavelength of the optical communication link. The proposed strategies can effectively reduce the multiple access interference (MAI) and support a lot of users in the optical communication link with high performance of call blocking. The proposed scheme has been numerically simulated to confirm that our proposed scheme results actually improve the code blocking probability with efficient utilization.