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arXiv · 2408.05988

Eigenvalue Based Active User Enumeration for Grant-Free Access Under Carrier Frequency Offsets

Takanori Hara
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Abstract

This paper investigates a grant-free non-orthogonal multiple access (GF-NOMA) system in the presence of carrier frequency offsets. We propose two schemes for enumerating active users in such a GF-NOMA system, which is equivalent to estimating the sparsity level. Both schemes utilize a short common pilot and the eigenvalues of the sample covariance matrix of the received signal. The two schemes differ in their treatment of noise variance: one exploits known variance information, while the other is designed to function without this knowledge. Simulation results demonstrate the effectiveness of the proposed schemes in terms of the normalized root-mean-squared error.

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Takanori Hara. 2024-08-12. Eigenvalue Based Active User Enumeration for Grant-Free Access Under Carrier Frequency Offsets. https://arxiv.org/abs/2408.05988

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