oDQPSK: Optical Differential Quadrature Phase Shift Keying

What does oDQPSK mean? The above is one of oDQPSK meanings. It may have other definitions. Please refer to the end of this passage.

oDQPSK: Optical Differential Quadrature Phase Shift Keying

Definition in English: Optical Differential Quadrature Phase Shift Keying