Time-Frequency Warped Waveforms for Well-Contained Massive Machine Type Communications

TL;DR

This paper introduces a novel time-frequency warped waveform with asymmetric pulses for improved containment and robustness in massive machine-type communications and IoT, outperforming traditional OFDM schemes.

Contribution

It proposes a new waveform design using time-frequency warping and asymmetric pulses to enhance signal containment and performance in mMTC and IoT applications.

Findings

Better containment in time and frequency domains.

Improved performance over ZT-DFT-s-OFDM and CP-DFT-s-OFDM.

Effective control of waveform occupancy with warping functions.

Abstract

This paper proposes a novel time-frequency warped waveform for short symbols, massive machine-type communication (mMTC), and internet of things (IoT) applications. The waveform is composed of asymmetric raised cosine (RC) pulses to increase the signal containment in time and frequency domains. The waveform has low power tails in the time domain, hence better performance in the presence of delay spread and time offsets. The time-axis warping unitary transform is applied to control the waveform occupancy in time-frequency space and to compensate for the usage of high roll-off factor pulses at the symbol edges. The paper explains a step-by-step analysis for determining the roll-off factors profile and the warping functions. Gains are presented over the conventional Zero-tail Discrete Fourier Transform-spread-Orthogonal Frequency Division Multiplexing (ZT-DFT-s-OFDM), and Cyclic prefix (CP) DFT-s-OFDM schemes in the simulations section.