Sequence-Based OOK for Orthogonal Multiplexing of Wake-up Radio Signals and OFDM Waveforms

TL;DR

This paper introduces a novel frequency domain sequence-based OOK method for orthogonal multiplexing of wake-up signals and OFDM waveforms, enhancing receiver performance and interference management in fading channels.

Contribution

It extends the CAN algorithm to generate OOK waveforms with Manchester coding for improved orthogonal multiplexing in wake-up radios.

Findings

Improved WURx performance by controlling frequency domain energy distribution.

Reduction of interference-floor at the OFDM receiver.

Demonstrated superiority over state-of-the-art approaches.

Abstract

In this study, we propose an approach to constructing on-off keying (OOK) symbols for wake-up radios (WURs) by using sequences in the frequency domain. The proposed method enables orthogonal multiplexing of wake-up signals (WUSs) and orthogonal frequency division multiplexing (OFDM) waveforms. We optimize the sequences with a tractable algorithm by considering the reliability of WUSs in fading channels. The proposed algorithm relies on an alternating minimization technique, i.e. cyclic algorithm-new (CAN), which was originally proposed for obtaining a unimodular sequence with good aperiodic correlation properties. In this study, we extend CAN to generate OOK waveforms with Manchester coding. We demonstrate the performance of four optimized sequences and compare with state-of-the-art approaches. We show that the proposed scheme improves the wake-up radio receiver (WURx) performance by controlling the energy distribution in frequency domain while removing the interference-floor at the OFDM receiver.