Multidimensional QPSK symbol modulation scheme based on random sequence extraction for D-band photonics-aided...

Area of Science:

• Optical communication
• Digital signal processing
• Wireless communication systems

Background:

• Traditional quadrature phase shift keying (QPSK) signals have limitations in probabilistic shaping.
• Existing probabilistic shaping (PS) and geometric shaping (GS) methods require modifications to digital signal processing (DSP) architecture.

Purpose of the Study:

• To propose a novel multidimensional (MD) QPSK modulation and demodulation scheme using random sequence extraction.
• To overcome the limitations of traditional QPSK in probabilistic shaping without altering DSP architecture.
• To enable flexible adjustment of source entropy (SE).

Main Methods:

• Developed a QPSK symbol modulation and demodulation scheme based on random sequence extraction.
• Integrated sequence modulation and demodulation modules into the system.
• Conducted experimental verification in a 50 m, 150 GHz photonics-aided wireless communication system.

Main Results:

• The proposed random sequence extraction QPSK (SE-QPSK) scheme achieved a maximum optical power gain of 0.7 dB.
• The scheme operates effectively under the same net data rate as traditional methods.
• Source entropy (SE) was demonstrated to be flexibly adjustable.

Conclusions:

• The SE-QPSK scheme effectively enhances system performance in photonics-aided wireless communication.
• This approach offers a promising alternative for future wireless communication systems.
• The method avoids complex modifications to existing DSP architectures, simplifying implementation.