Patent ID: 7840143
Filing Date: 2010-11-23
Classification: H04B,H04L

Abstract:
1. An apparatus for demodulating an optical Differential Phase-Shift Keying (DPSK) signal, comprising: a self-homodyne receiver for receiving the optical signal; a converter for converting the optical signal received by the self-homodyne receiver into a representative electrical signal; and a processor that processes the representative electrical signal using decision feedback multi-symbol detection in order to obtain a decision variable that indicates a differential phase-shift in the optical signal, the decision feedback multi-symbol detection utilized by the processor being implemented according to the following equation: wherein the complex number u(t) is representative of the electrical signal converted by the converter, the real number w is a weighting factor, the complex number exp[−jc(n−1)] is representative of the estimated phase of the previous data symbol and the complex number x(t) is the decision variable.