A Unified Framework for Ambiguity Function Shaping and PAPR Control in AFDM Systems

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Meng, Lingsheng, Guan, Yong Liang, Liu, Zilong, Luo, Yirui, Fan, Pingzhi
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911621176098816
author Meng, Lingsheng
Guan, Yong Liang
Liu, Zilong
Luo, Yirui
Fan, Pingzhi
author_facet Meng, Lingsheng
Guan, Yong Liang
Liu, Zilong
Luo, Yirui
Fan, Pingzhi
contents Affine frequency division multiplexing (AFDM) has emerged as a promising integrated sensing and communication (ISAC) waveform due to its intrinsic chirp signalling nature. Nevertheless, practical AFDM-based ISAC still faces two key obstacles, namely, high ambiguity function (AF) sidelobes and high peak-to-average power ratio (PAPR). By leveraging the reserved chirp-subcarrier (RCS) symbols, we develop a unified AFDM waveform design framework for AF shaping and/or PAPR control. The proposed framework supports three modes: AF shaping via weighted integrated sidelobe level (ISL) minimization, PAPR minimization, and joint AF shaping and PAPR control under a prescribed PAPR constraint. To solve the formulated nonconvex problem and to accommodate the discrete-phase constraints on the optionally optimized pre-chirp parameters, a joint ISL-PAPR-discrete-phase majorization-minimization (JIPD-MM) algorithm is developed. Simulation results verify the effectiveness of the proposed framework under all three design modes. The joint mode further demonstrates that the prescribed PAPR constraint can be effectively satisfied while still achieving meaningful ISL reduction. These gains are also reflected in improved weak-target detectability under multitarget scenarios and lower bit error rate (BER) under power-amplifier (PA) nonlinearity.
format Preprint
id arxiv_https___arxiv_org_abs_2604_22198
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle A Unified Framework for Ambiguity Function Shaping and PAPR Control in AFDM Systems
Meng, Lingsheng
Guan, Yong Liang
Liu, Zilong
Luo, Yirui
Fan, Pingzhi
Signal Processing
Affine frequency division multiplexing (AFDM) has emerged as a promising integrated sensing and communication (ISAC) waveform due to its intrinsic chirp signalling nature. Nevertheless, practical AFDM-based ISAC still faces two key obstacles, namely, high ambiguity function (AF) sidelobes and high peak-to-average power ratio (PAPR). By leveraging the reserved chirp-subcarrier (RCS) symbols, we develop a unified AFDM waveform design framework for AF shaping and/or PAPR control. The proposed framework supports three modes: AF shaping via weighted integrated sidelobe level (ISL) minimization, PAPR minimization, and joint AF shaping and PAPR control under a prescribed PAPR constraint. To solve the formulated nonconvex problem and to accommodate the discrete-phase constraints on the optionally optimized pre-chirp parameters, a joint ISL-PAPR-discrete-phase majorization-minimization (JIPD-MM) algorithm is developed. Simulation results verify the effectiveness of the proposed framework under all three design modes. The joint mode further demonstrates that the prescribed PAPR constraint can be effectively satisfied while still achieving meaningful ISL reduction. These gains are also reflected in improved weak-target detectability under multitarget scenarios and lower bit error rate (BER) under power-amplifier (PA) nonlinearity.
title A Unified Framework for Ambiguity Function Shaping and PAPR Control in AFDM Systems
topic Signal Processing
url https://arxiv.org/abs/2604.22198