Cell signal processing circuit and optical switch apparatus using the

Abstract

A cell signal processing circuit is provided which is capable of precisely extracting a timing signal and a cell synchronizing signal. The cell signal processing circuit is principally composed of a signal adder circuit for adding a dummy signal comprising bit signals in a direct current balanced state to an end portion of respective inputted time series cell signals, and a separator circuit for separating and outputting the time series cell signals. Each dummy signal being composed of the same number of bits '0' and '1' is added to input signals in the form of time series cells such that signal cells are exchanged at a time of a bit '0' in the dummy signal. An optical switch apparatus using the cell signal processing circuit as an optical switch array is also provided which includes a photoelectric converter for converting the time series optical cell signal to an electric signal, a clock recovery circuit for extracting a clock signal from an output from the photoelectric converter, a cell synchronization circuit for extracting a cell synchronizing signal from the output from the photoelectric converter, and a decision circuit for deciding between signals in the output from the photoelectric converter by the use of the clock signal. The optical switch apparatus of the invention is simple and is not influenced by data loss and jitter.