Patent ID: 8917998
Filing Date: 2014-12-23
Classification: H04B,H04J

Abstract:
1. A method implemented in a transmission apparatus used in an optical fiber communications system for a polarization switched differential quaternary phase-shift keying (DQPSK) signal, the method comprising: splitting data into two or more data streams; inputting said two or more data streams to 1-bit DQPSK precoders to perform 1-bit DQPSK precoding; multiplexing inphase outputs of the 1-bit DQPSK precoders to generate a first output; and multiplexing quadrature outputs of the 1-bit DQPSK precoders to generate a second output, wherein an operation speed of the 1-bit DQPSK precoders is set to half of a total data rate to perform differential encoding of the two of more data streams, wherein the first and second outputs output output where xn and yn represent nth data from odd and even channels, and each output has at least part of two independent data streams x and y and when performing 2-bit differential detection (x