In the ever-evolving landscape of wireless communication, Orthogonal Time Frequency Space (OTFS) modulation has emerged as a promising technique for enhancing performance in high-Doppler wireless scenarios for both radar and communication waveform designs. One critical issue OTFS faces is high Peak-to-Average Power Ratio (PAPR) due to the presence of inverse-discrete Fourier Transform operations, which can result in inefficient transmission performance and lower the quality of the transmission. In their latest paper, the authors, in the framework of the ENABLE-6G project, introduce a groundbreaking, low-complexity, standard-compliant PAPR reduction scheme specifically designed for OTFS modulation.
Why is OTFS Modulation relevant?
OTFS modulation is gaining traction for its ability to provide robust performance in environments with high mobility and multi-path interference, providing better signal reliability and efficiency, especially in 6G and beyond networks.
One of the main challenges with OTFS modulation is its high PAPR. A high PAPR means that the peaks in the signal are much higher than the average power level, which can lead to inefficiencies and distortions in power amplifiers. Addressing this issue without compromising the system’s complexity and compliance with existing standards is crucial.
The proposed solution
The solution focuses on maintaining system performance while significantly reducing the computational burden associated with PAPR reduction by introducing a novel constrained constellation shaping (CCS) method. It is a metric-based, symbol pre-distortion method tailored for OTFS modulation to minimise PAPR. Key features of the proposed solution by ENABLE-6G include:
- Low complexity: the solution reduces the computational requirements, making it feasible for real-time implementation in 6G networks.
- Standard Compliance: The scheme is designed to be compatible with existing communication standards, ensuring smooth integration and deployment.
- Effective PAPR reduction: the method efficiently lowers the PAPR, improving the overall signal quality and reducing power consumption.
How it Works
The solution proposed by the authors employs a series of optimization techniques to minimize PAPR without requiring complex algorithms or significant changes to the existing infrastructure. By focusing on reducing the peaks in the transmitted signal, RISC-MAP ensures that power amplifiers can operate more efficiently, leading to better performance and lower energy consumption.
As 6G and beyond technologies continue to develop, the ability to manage PAPR effectively will be crucial for achieving the desired performance levels. The solution does not only address this critical issue but does so in a manner that is both practical and scalable.
For more interesting papers and publications, check the results section in the ENABLE-6G website.