Phase Rotation Signal Processing for Optical Fiber Energy Waste Reduction

The patent applies preliminary action by performing phase rotation processing on the real-number-type signal before transmission. This pre-processing step creates a complex-number-type signal where both real and imaginary parts are related to the original signal, ensuring that power detection at the receiver does not waste energy on unrelated imaginary components. The phase rotation is performed in advance at the transmitter side, which resolves the energy waste problem without adding complexity to the receiver's detection process.

The patent applies parameter changes by modifying the signal's mathematical parameters through phase rotation. The real-number-type signal is transformed into a complex-number-type signal by changing its representation parameters, specifically creating equal real and imaginary parts through phase rotation. This parameter transformation ensures that both components carry relevant information, reducing energy waste during power detection while the processing complexity remains manageable through standard phase rotation algorithms.

The patent prevents the imaginary part from being unrelated by performing preliminary phase rotation processing. This action is taken at the transmitter before signal transmission, ensuring that the imaginary part is derived from and related to the original real-number-type signal. By taking this preliminary action, the system avoids the energy waste that would occur if the imaginary part were unrelated, while still maintaining relatively simple signal generation through standard phase rotation techniques.