Method of optical data transmission using polarization division multiplexing and QPSK

摘要

Proposed is a method of optical data transmission. The method comprises different steps. At least one stream of data bits is received. Sets of data bits are mapped onto successive logical states. The logical states correspond to respective sets of two initial QPSK symbols chosen according to a QPSK mapping and according to a set partitioning rule. The logical states are differentially encoded according to a differential encoding rule. For the differentially encoded logical states respective sets of two resulting QPSK symbols are derived according to the QPSK mapping and according to the set partitioning rule. The encoded sets of two QPSK symbols are transmitted using polarization division multiplexing. The differential encoding rule results in a differential encoding of one of the initial QPSK symbols but not the other of the initial QPSK symbols.

主权项

1. Method of optical data transmission,
comprising:
receiving at least one stream of data bits,mapping sets of said data bits onto successive logical states, wherein said logical states correspond to respective initial sets of two initial quadrature phase shift keying (QPSK) symbols chosen according to a QPSK mapping and according to a set partitioning rule,differentially encoding said logical states according to a differential encoding rule,deriving for said differentially encoded logical states respective sets of two resulting QPSK symbols according to said QPSK mapping and according to said set partitioning rule, andtransmitting said encoded sets of two QPSK symbols using polarization division multiplexing (PDM), wherein said differential encoding rule causes a differential encoding of an initial set of QPSK symbols such that a first initial QPSK symbol of said initial set is differentially encoded but not the other initial QPSK symbol of said initial set.