New photonic asynchronous-transfer-mode switch with optical signal processing and code-division multiple access

摘要

We present the design of new photonic asynchronous-transfer-mode (ATM) switches that use optical code-division multiple access (CDMA) and strict optical orthogonal codes (OOCs). All the peaks of cross-correlation functions and all the sidelobes of any autocorrelation functions for a strict OOC are always limited to be a unit pulse-amplitude (i.e., 1 in the normalized case) for incoherent optical processing, regardless of whether an aperiodic or a periodic pulse sequence is input to optical CDMA decoders. Since the coding and correlation of strict OOCs are performed in the optical domain by using optical delay lines, the processing speed of the proposed photonic ATM switch can be very high. This, in turn, can support real-time broadband communications. Owing to the correlation characteristics of strict OOCs, the proposed ATM switch can flexibly handle both equal-rate and variable-rate/ multirate communication services without violating the cross-correlation and autocorrelation constraints of 1 and with no change of optical CDMA encoders and decoders. This, in turn, can substantially improve the switch flexibility without increasing system complexity. # 1998 Society of Photo-Optical Instrumentation Engineers. S0091-3286(98)00412-7 Subject terms: photonic switch; optical fiber communications; optical signal processing; code-division multiple access. Paper FIB-04 received May 20, 1998; accepted for publication May 22, 1998.