Modified constellation reshaping method for PAPR reduction of PDM CO-OFDM based on a SLM algorithm

Area of Science:

• Optical Communications
• Signal Processing

Background:

• Polarization Division Multiplexing (PDM) and Coherent Optical Orthogonal Frequency Division Multiplexing (CO-OFDM) are advanced techniques in optical communication systems.
• Peak-to-Average Power Ratio (PAPR) reduction is crucial for improving the efficiency and performance of these systems.
• The Selective Mapping (SLM) method is a common technique for PAPR reduction, but often requires side information.

Purpose of the Study:

• To propose a modified constellation reshaping method for PAPR reduction in PDM-CO-OFDM systems.
• To enhance the SLM method by incorporating modified Quadrature Amplitude Modulation (M-QAM) constellations.
• To eliminate the need for transmitting additional side information at the receiver.

Main Methods:

• A modified Quadrature Amplitude Modulation (M-QAM) constellation is generated with the same minimum distance as conventional QAM (C-QAM).
• The modified SLM (M-SLM) method combines M-QAM constellations with the traditional SLM technique.
• At the receiver, mean square errors are calculated between received data constellations and rotated M-QAM constellations to identify the optimal phase rotation factor.

Main Results:

• The proposed M-SLM method effectively reduces PAPR in PDM-CO-OFDM systems.
• The method achieves nearly the same PAPR reduction performance as the traditional SLM method.
• Bit error rate (BER) performance is comparable to the traditional SLM method.
• Crucially, the proposed method does not require the transmission of additional side information.

Conclusions:

• The modified constellation reshaping method offers an effective PAPR reduction strategy for PDM-CO-OFDM systems.
• The M-SLM approach provides a practical solution by eliminating the need for side information, simplifying receiver design.
• This technique maintains high performance in terms of PAPR reduction and BER, making it suitable for advanced optical communication systems.