AFDM: A Full Diversity Next Generation Waveform for High Mobility Communications

Bemani, Ali; Ksairi, Nassar; Kountouris, Marios

doi:10.1109/iccworkshops50388.2021.9473655

Cited by 27 publications

(15 citation statements)

References 12 publications

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“…Their difference lies in the fact that, in contrast to OCDM, where chirps have a fixed slope, AFDM allows for adaptation of the chirp slope to the channel profile by optimizing 𝑐 1 and 𝑐 2 . This enables AFDM to extract full diversity of linear time-variant channels, outperforming OCDM and having the same performance as OTFS, but with lower implementation complexity [26]. Due to its similarity with OCDM, it is straightforward to conclude that AFDM has the same characteristics in terms of PAPR, full-duplex and ADC bandwidth, as well as the same necessity for research in MIMO, channel estimation and multi-user multiplexing aspects.…”

Section: Full Integrationmentioning

confidence: 95%

“…c) AFDM: AFDM, which was recently proposed by [26], is based on a discretization of the generalized Fresnel transform and has an almost identical structure to OCDM. Their difference lies in the fact that, in contrast to OCDM, where chirps have a fixed slope, AFDM allows for adaptation of the chirp slope to the channel profile by optimizing 𝑐 1 and 𝑐 2 .…”

Section: Full Integrationmentioning

confidence: 99%

“…6 we plot the uncoded bit error rates (BERs) vs. signal- to-noise ratio (SNR) performance of OCDM and AFDM for frequency selective, time selective and time-frequency selective channels. Following [26], we consider the channel to have paths with delays that are integer multiples of the sampling period and Doppler shifts that are integer multiples of the subcarrier spacing. The different paths have independent and identically distributed (iid) Rayleigh fading with variance 1/𝑃, where 𝑃 is the number of paths.…”

Section: Full Integrationmentioning

confidence: 99%

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Towards Integrated Sensing and Communications for 6G

Wang¹,

Kakkavas²,

Gong³

et al. 2022

Preprint

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For the next generation of mobile communications systems, the integration of sensing and communications promises benefits in terms of spectrum utilization, cost, latency, area and weight. In this paper, we categorize and summarize the key features and technical considerations for different integration approaches and discuss related waveform design issues for a future sixth generation (6G) system. We provide results on new candidate waveforms for monostatic sensing and finally highlight important open issues and directions that deserve future in-depth research.

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Section: Full Integrationmentioning

confidence: 95%

Section: Full Integrationmentioning

confidence: 99%

Section: Full Integrationmentioning

confidence: 99%

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Towards Integrated Sensing and Communications for 6G

Wang¹,

Kakkavas²,

Gong³

et al. 2022

Preprint

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“…k /d as the estimate of x k (which would have amounted to using the MRC criterion), we define the symbol estimate as 1) .…”

Section: Low-complexity Weighted Mrc-based Dfe Detectionmentioning

confidence: 99%

“…N. Ksairi is with the Mathematical and Algorithmic Sciences Lab, Huawei France R&D, Paris, France. Email: nassar.ksairi@huawei.com Part of the results appear in [1] and [2].…”

Section: Introductionmentioning

confidence: 99%

Affine Frequency Division Multiplexing for Next-Generation Wireless Networks

Bemani

Cuozzo

Ksairi

et al. 2021

2021 17th International Symposium on Wireless Communication Systems (ISWCS)

Self Cite

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Affine Frequency Division Multiplexing (AFDM), a new chirp-based multicarrier waveform for high mobility communications, is introduced here. AFDM is based on discrete affine Fourier transform (DAFT), a generalization of discrete Fourier transform, which is characterized by two parameters that can be adapted to better cope with doubly dispersive channels. First, we derive the explicit input-output relation in the DAFT domain showing the effect of AFDM parameters in the input-output relation.Second, we show how the DAFT parameters underlying AFDM have to be set so that the resulting DAFT domain impulse response conveys a full delay-Doppler representation of the channel. Then, we show analytically that AFDM can achieve full diversity in doubly dispersive channels, where full diversity refers to the number of multipath components separable in either the delay or the Doppler domain, due to its full delay-Doppler representation. Furthermore, we present a low complexity detection method taking advantage of zero-padding. We also propose an embedded pilot-aided channel estimation scheme for AFDM, in which both channel estimation and data detection are performed within the same AFDM frame. Finally, simulations corroborate the validity of our analytical results and show the significant performance gains of AFDM over state-of-the-art multicarrier schemes in high mobility scenarios.

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