6 papers
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…
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…
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…
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…
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…
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…