Research Briefing
cs.IT 2605.29824v1 worth_reading

On the Effect of Pulse Shaping Filters in Zak-OTFS Waveform for Radar Sensing

Abhishek Bairwa, Ananthanarayanan Chockalingam

Published 2026-05-28 12:05:53 相关性 1.0000 价值 0.7600 cs.IT eess.SP
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摘要

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In radar sensing, the self-ambiguity function of the probing waveform plays a crucial role in the resolvability and detection of multiple targets. In the recent Zak-OTFS based radar literature, Gaussian pulse shaping filter has been considered, and it has been shown to offer better range/velocity estimation performance compared to the traditional chirp waveform in scenes with multiple targets. While the self-ambiguity function with Gaussian filter has very low side lobes, its main lobe is wide which compromises resolvability and performance. Motivated by this, we seek filters with better ambiguity characteristics. Specifically, we explore two other known filters, namely, sinc and Gaussian-sinc (GS) filters, and demonstrate that these filters offer better performance compared to Gaussian filter under different scenarios and receiver processing. Towards demonstrating this, we derive closed-form expressions for the self-ambiguity functions of Zak-OTFS waveform with sinc and GS filters. The ambiguity functions of sinc and GS filtered waveforms have narrow main lobes, resulting in better resolvability in scenes with densely populated targets for the basic peak-detection based receiver. The ambiguity function of Gaussian filtered waveform has very low sidelobes, resulting in better performance in sparsely populated scenes. When a receiver with inter-target interference mitigation is used, the sinc and GS filters perform better in both dense and sparsely populated scenes compared to Gaussian filter.

相关性判断

high
相关方向
wireless_communications radar_sensing otfs signal_processing
判断依据

Directly about Zak-OTFS waveform design, ambiguity functions, and radar sensing performance, which is adjacent to communications and signal processing with clear technical relevance.

价值判断

High relevance to cs.IT signal processing through Zak-OTFS radar waveform design and delay-Doppler ambiguity analysis. Structure evidence indicates concrete technical contributions: closed-form ambiguity functions, receiver-dependent comparisons, and dense/sparse multi-target simulations. Practical value is clear for OTFS/radar sensing readers, but the contribution appears focused on comparing known filters rather than introducing a broad new framework.

核心问题与主要方法

核心问题

How DD-domain pulse shaping affects Zak-OTFS radar self-ambiguity and multi-target sensing performance

场景：Zak-OTFS radar sensing in the delay-Doppler domain, comparing sinc, Gaussian, and Gaussian-sinc pulse shaping under dense and sparse multi-target scenes

主要方法

Zak-OTFS probing waveform is modeled as a DD-domain pulse shaped by a separable transmit filter and mapped to time using the inverse Zak transform. The paper evaluates sensing quality through the self-ambiguity function, emphasizing the unavoidable ambiguity volume and its redistribution across main lobe and sidelobes. Closed-form self-ambiguity derivations use the Zak-OTFS framework, twisted convolution, Parseval-type manipulations, and error-function expressions for Gaussian/GS cases. Performance interpretation is receiver-dependent: basic peak detection benefits from narrow main lobes in dense scenes and low sidelobes in sparse scenes; ITI mitigation reconstructs and subtracts target contributions from the cross-ambiguity function. The radar receiver samples cross-ambiguity on an oversampled DD grid and relies on crystallization conditions to separate true target peaks from DD aliases.

关键贡献与后续阅读

关键贡献

Provides an ambiguity-function-centered comparison of sinc, Gaussian, and Gaussian-sinc DD pulse shaping for Zak-OTFS radar sensing. Derives or reports closed-form self-ambiguity expressions for the compared filters, with detailed payload support for new Gaussian and GS expressions and reproduced sinc expression from prior literature. Quantifies main-lobe/sidelobe tradeoffs using main-lobe width, PSLR, and ISLR, showing Gaussian has much wider main lobe but very low sidelobes while sinc/GS have narrow main lobes with higher sidelobes. Connects ambiguity-shape metrics to multi-target sensing behavior in dense and sparse scenes using ROC and RMS range/velocity estimation results. Introduces and evaluates an inter-target interference mitigation receiver based on estimating, reconstructing, and subtracting target contributions in the cross-ambiguity domain.

研究启发

The payload contains an inconsistency: some text says new closed-form expressions are for sinc and GS, while the detailed contribution section says Gaussian and GS with sinc reproduced from prior work. Which claim is correct in the final PDF? How sensitive are the dense/sparse conclusions to target power distribution, number of targets, oversampling factors, and DD window margins? Does the ITI mitigation receiver remain robust when first-target delay/Doppler/fade estimates are biased or when targets overlap strongly in both delay and Doppler? Are there communication-side tradeoffs for sinc and GS filters in an ISAC setting, beyond the radar sensing metrics reported here?

限制与不确定性

Novelty may be incremental because sinc and Gaussian-sinc are known filters and evidence is limited to the provided analysis. Performance conclusions may depend strongly on the chosen scenes, receiver assumptions, and interference mitigation method. No independent validation beyond the supplied structure analysis was used.

原文信息

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参考文献 29
最近更新 2026-05-30 13:21
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Abstract

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On the Effect of Pulse Shaping Filters in Zak-OTFS Waveform for Radar Sensing

In radar sensing, the self-ambiguity function of the probing waveform plays a crucial role in the resolvability and detection of multiple targets. A desired distribution of the ambiguity volume (volume under squared self-ambiguity function) for good sensing performance is characterized by 1) narrow main lobe, 2) low peak sidelobe ratio, and 3) low integrated sidelobe ratio. With Zak-OTFS waveform, this volume distribution is achieved by choosing appropriate delay-Doppler (DD) pulse shaping filter. In the recent Zak-OTFS based radar literature, Gaussian pulse shaping filter has been considered, and it has been shown to offer better range/velocity estimation performance compared to the traditional chirp waveform in scenes with multiple targets. While the self-ambiguity function with Gaussian filter has very low side lobes, its main lobe is wide which compromises resolvability and performance. Motivated by this, we seek filters with better ambiguity characteristics. Specifically, in this paper, we explore two other known filters, namely, sinc and
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