activity
20242026
collaborators

6 papers

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

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…

eess.SP2025

Maximizing Spectrum Efficiency of Data-Carrying Reference Signals via Bayesian Optimization

Taiki Kato, Hiroki Iimori, Chandan Pradhan +2

Data-carrying reference signals are a type of reference signal (RS) constructed on the Grassmann manifold, which allows for simultaneous data transmission and channel estimation to…

eess.SP2025

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.SP2024

Covert Communications Without Pre-Sharing of Side Information and Channel Estimation Over Quasi-Static Fading Channels

Hiroki Fukada, Hiroki Iimori, Chandan Pradhan +2

We propose a new covert communication scheme that operates without pre-sharing side information and channel estimation, utilizing a Gaussian-distributed Grassmann constellation for…