Reconfigurable photonics-based millimeter wave signal aggregation for non-orthogonal multiple access.

Area of Science:

• Optical communications
• Signal processing
• Millimeter wave technology

Background:

• Current optical-to-electrical signal aggregation methods face limitations in flexibility and efficiency.
• Millimeter wave (MMW) communication demands higher data rates and spectral efficiency.

Purpose of the Study:

• To propose and demonstrate a reconfigurable optical-to-electrical signal aggregation system.
• To achieve efficient aggregation of multiple optical signals into advanced modulation formats for MMW carriers.
• To investigate the system's reconfigurability and performance under various conditions.

Main Methods:

• Utilizing optical signal processing and photo-mixing technology for signal aggregation.
• Employing an optimized heterodyne beating process through a single photodiode.
• Demonstrating reconfigurability by aggregating Binary Phase-Shift Keying (BPSK) and Quadrature Phase-Shift Keying (QPSK) signals into various MMW formats like QPSK and 16-Quadrature Amplitude Modulation (16-QAM).
• Investigating the impact of laser phase noise and implementing electrical de-aggregation using successive interference cancellation.

Main Results:

• Successfully aggregated two QPSK signals into a single 16-QAM signal on a 28-GHz MMW carrier.
• Demonstrated reconfigurability by mapping BPSK signals into MMW QPSK or Pulse Amplitude Modulation (PAM) signals.
• Achieved aggregation of 16-QAM into 256-QAM and three QPSK signals into 64-QAM.
• Experimental validation confirmed numerical simulations, showing successful aggregation and transmission over fiber and wireless channels.

Conclusions:

• The proposed system offers a flexible and efficient solution for optical-to-electrical signal aggregation.
• The technology enables the creation of higher-order modulation formats for MMW communication.
• The system's performance is robust, with successful de-aggregation and evaluation using standard metrics.