collaborators

8 papers

eess.SP2026

Quantum-Native Maximum Likelihood Detection in Random Access Channel with Overloaded MIMO

Hyoga Iizumi, Naoki Ishikawa, Shunsuke Uehashi +3

In this paper, we propose a quantum-native formulation of maximum likelihood detection (MLD) for overloaded multiple-input multiple-output (MIMO) systems in a random access channel…

cs.IT2026

Z-Opt: A Near-Optimal Reduced-Complexity Two-Dimensional Grassmannian Constellation

Kotaro Shigenaga, Hiroki Iimori, Yuto Hama +3

Grassmannian constellations are known to achieve the capacity of noncoherent communications over Rayleigh fading channels in the high-SNR regime, yet their efficient construction r…

eess.SP2026

Sparsification of Precoding Codebooks for PAPR Reduction via Grassmannian Representations

Joe Asano, Yuto Hama, Hiroki Iimori +2

In this letter, we propose a sparsification method for precoding codebooks that reduces the peak-to-average power ratio (PAPR) while preserving the achievable rate. By exploiting t…

eess.SP2026

Low-Complexity and Power-Efficient Precoding Codebook Design on Sparse Grassmannian

Joe Asano, Yuto Hama, Hiroki Iimori +3

We propose a sparse Grassmannian design for precoding codebooks. Due to their sparse structure, our proposed codebooks achieve low peak-to-average power ratio (PAPR), low complexit…

eess.SP2026

Superimposed Pilot-Based OTFS: Will It Work?

Yuta Kanazawa, Hiroki Iimori, Chandan Pradhan +2

Orthogonal time frequency space (OTFS) modulation is a promising solution to handle doubly-selective fading, but its channel estimation is a nontrivial task in terms of maximizing…

eess.SP2026

Sparse Grassmannian Design for Noncoherent Codes via Schubert Cell Decomposition

Joe Asano, Yuto Hama, Hiroki Iimori +3

In this paper, we propose a method for designing sparse Grassmannian codes for noncoherent multiple-input multiple-output systems. Conventional pairwise error probability formulati…