A Novel One-tap Equalizer for Zero-Padded AFDM System over Doubly Selective Channels

Fuente: arXiv
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Main Authors: Zhang, Chenyang, Shafie, Akram, Shen, Cheng, Mishra, Deepak, Yuan, Jinhong
Format: Preprint
Published: 2026
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author Zhang, Chenyang
Shafie, Akram
Shen, Cheng
Mishra, Deepak
Yuan, Jinhong
author_facet Zhang, Chenyang
Shafie, Akram
Shen, Cheng
Mishra, Deepak
Yuan, Jinhong
contents Recently, affine frequency division multiplexing (AFDM) has gained traction as a robust solution for doubly selective channels. In this paper, we present a novel low-complexity one-tap equalizer for zero-padded AFDM (ZP-AFDM) systems. We first select the AFDM parameters, $c_1$ and $c_2$, such that $c_1$ has a relatively high value, and $c_2$ depends on $c_1$, which simplifies the affine domain input-output relation (IOR). This selection also demonstrates that a phase term that varies slowly along the affine domain is experienced by all affine domain symbols and this variation is significantly slower compared to that experienced by the time domain symbols over doubly selective channels. To simplify the equalization, we then introduce zero padding to the transmitted affine domain symbols and reconstruction operation on the received affine domain symbols. By doing so, we convert the effective affine domain IOR of our ZP-AFDM system to be characterized using approximately circular convolution. Next, we transform the resulting affine domain symbols into a new domain called the frequency-of-affine (FoA) domain. We propose our one-tap equalizer in this FoA domain to efficiently recover the transmitted symbols. Numerical results demonstrate the effectiveness of our proposed one-tap equalizer, particularly when $c_1$ is high, without compromising performance robustness.
format Preprint
id arxiv_https___arxiv_org_abs_2603_02703
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle A Novel One-tap Equalizer for Zero-Padded AFDM System over Doubly Selective Channels
Zhang, Chenyang
Shafie, Akram
Shen, Cheng
Mishra, Deepak
Yuan, Jinhong
Signal Processing
Recently, affine frequency division multiplexing (AFDM) has gained traction as a robust solution for doubly selective channels. In this paper, we present a novel low-complexity one-tap equalizer for zero-padded AFDM (ZP-AFDM) systems. We first select the AFDM parameters, $c_1$ and $c_2$, such that $c_1$ has a relatively high value, and $c_2$ depends on $c_1$, which simplifies the affine domain input-output relation (IOR). This selection also demonstrates that a phase term that varies slowly along the affine domain is experienced by all affine domain symbols and this variation is significantly slower compared to that experienced by the time domain symbols over doubly selective channels. To simplify the equalization, we then introduce zero padding to the transmitted affine domain symbols and reconstruction operation on the received affine domain symbols. By doing so, we convert the effective affine domain IOR of our ZP-AFDM system to be characterized using approximately circular convolution. Next, we transform the resulting affine domain symbols into a new domain called the frequency-of-affine (FoA) domain. We propose our one-tap equalizer in this FoA domain to efficiently recover the transmitted symbols. Numerical results demonstrate the effectiveness of our proposed one-tap equalizer, particularly when $c_1$ is high, without compromising performance robustness.
title A Novel One-tap Equalizer for Zero-Padded AFDM System over Doubly Selective Channels
topic Signal Processing
url https://arxiv.org/abs/2603.02703