Rethinking Next-Generation Signal Waveform: Integration of Orthogonality and Non-Orthogonality

TL;DR

This paper proposes integrating orthogonal and non-orthogonal waveforms, specifically SC-OFDM and SC-NOFS, to develop sustainable, high-performance physical layer options for 6G communications, emphasizing spectral efficiency and low latency.

Contribution

It introduces a balanced approach combining orthogonal and non-orthogonal waveforms, highlighting SC-NOFS(2D) as a versatile candidate for future 6G applications.

Findings

SC-NOFS(2D) offers improved spectral efficiency.

Enhanced resilience to delay-Doppler effects.

Suitable for high data rate, low-latency, and high mobility scenarios.

Abstract

As 6G communications advance, the demand for new services and capabilities, as defined by the international telecommunication union (ITU), is increasing. A crucial aspect of 6G advancement lies in the development of signal waveforms that can meet these demands while maintaining compatibility with existing standards. This paper explores sustainable physical layer waveform options, focusing on a balanced approach that integrates non-orthogonality with orthogonality to achieve both backward compatibility and forward innovation. Specifically, we investigate two key signal formats: single-carrier orthogonal frequency division multiplexing (SC-OFDM) (1D,2D) and single-carrier non-orthogonal frequency shaping (SC-NOFS)(1D,2D). Both can use 1D frequency and 2D time-frequency precoding, offering enhanced frequency and time diversity, simplified processing, and resilience to delay-Doppler effects. SC-NOFS(2D) further introduces advantages such as improved spectral efficiency and reduced latency, making it a strong candidate for future 6G applications. The comparative analysis highlights that SC-NOFS(2D) provides a broader range of capabilities, particularly those requiring high data rate, high mobility, low-latency communication, sustainability, and interoperability, positioning it as a versatile solution for next-generation 6G communication.