A jamming-resilient sparse delay-Doppler NOMA scheme with randomized active sets, unitary precoding justified by Marchenko-Pastur conditioning, and Merkle-Hellman superincreasing power allocation achieves no jammer-induced BER floor and exact ML-equivalent SIC performance.
Zak-OTFS based Multiuser Uplink in Doubly-Spread Channels
2 Pith papers cite this work. Polarity classification is still indexing.
abstract
Wireless users with different characteristics will be expected to share spectrum in next generation communication networks. One of the great strengths of wireless networks based on Orthogonal Frequency Division Multiplexing (OFDM) is the ease with which different non-overlapping time-frequency (TF) resources can be allocated to different users by simply shifting each user's signal in time and frequency. However, a significant weaknesses of OFDM is the inflexibility of sub-carrier spacing. Since OFDM does not allow users to have different sub-carrier spacing, a single user subject to inter-carrier interference causes carrier spacing to increase for all users. Zak-OTFS is an alternative delay-Doppler (DD) domain modulation scheme, where, in contrast to OFDM, the Input-Output (I/O) relation is predictable. We match the strength of OFDM by designing a novel DD domain method of shaping the transmitted Zak-OTFS pulse on the uplink that enables flexible non-overlapping TF resource allocation. The base station (BS) receives a superposition of uplink signals and applies individual matched filters to obtain the data specific to individual users. We develop theoretical measures of interference between users, and present numerical simulations for a vehicular channel model representative of next generation propagation environments. We demonstrate single-user performance in a multiuser Zak-OTFS uplink system without needing to provision guard bands between TF resources allocated to different users. These performance results demonstrate that the benefits of a predictable Zak-OTFS waveform can be realized within an architecture for uplink communication.
years
2026 2representative citing papers
TF-shift multiuser Zak-OTFS with heterogeneous frames and superimposed ZC spread-pilots yields near-single-user IOR estimation and filter-dependent spectral-efficiency gains over embedded pilots.
citing papers explorer
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Jamming-Resilient Sparse Delay-Doppler NOMA: Unitary Precoding, Randomized Active Sets, and Superincreasing Power Allocation
A jamming-resilient sparse delay-Doppler NOMA scheme with randomized active sets, unitary precoding justified by Marchenko-Pastur conditioning, and Merkle-Hellman superincreasing power allocation achieves no jammer-induced BER floor and exact ML-equivalent SIC performance.
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Multiuser Zak-OTFS on the Uplink with Superimposed Spread-Pilots
TF-shift multiuser Zak-OTFS with heterogeneous frames and superimposed ZC spread-pilots yields near-single-user IOR estimation and filter-dependent spectral-efficiency gains over embedded pilots.