Photonic Architectures for Performing Perfect Shuffle on a Time-Division Multiplexed Signal

Abstract

Systems which permute the time-slots within a frame, called time-slot interchangers, are used in digital communications to map an incoming transmission associated with the i-th time-slot to an outgoing message for a receiver associated with the j-th time-slot. In a time-multiplexed optical computer environment, a time-slot interchanger corresponds to a multiprocessor interconnection network in a spatially parallel multiprocessor system. This work attempts to perform permutation among time-slots by deriving a time-domain version of the spatial shuffle-exchange network. In so doing, a new and a powerful structure called serial array architecture has been developed which has demonstrated very high potential for substantial hardware reduction. The shuffle permutation is the more interesting part of the stage and is the topic of this work. Detailed analysis and theory of time-slot interchange with specific reference to performing perfect shuffle has been developed. Different parameters for measurement based on time-slot shift have been presented and used in analysing the interchange problem and studying the power and limitation of a 2x2 photonic directional coupler. Three important classes of architectures using directional couplers have been presented for performing perfect shuffle on odd and even-sized frames of different lengths. Finally the basic relationship between ternary base and the 2x2 switch used in the feedback mode has been brought out and used to develop minimum switch architectures for perfect shuffle.© (1990) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.