PHOTONIC CDMA BY COHERENT MATCHED FILTERING USING TIME-ADDRESSED CODING IN OPTICAL LADDER NETWORKS

We investigate a photonic CDMA system based on coherent matched filter ing in ladder networks, employing both time-spreading and selective in terference to discriminate wanted from unwanted signals. A theory is p resented for time-resolved pulses which takes account of arbitrary sou rce coherence. We examine the key issues of optical source requirement s and phase and polarization control of en/decoder networks, and demon strate key concepts experimentally. The crosstalk-limited signal-to-no ise ratio is shown to be much higher than previous, purely incoherent systems. CDMA systems using coherent matched filtering therefore offer renewed promise for practical high capacity, multigigabit/s, multiuse r networks.