26 citations · 43 across the 8 of their papers we have counts for
9 papers
A New Noncoherent Gaussian Signaling Scheme for Low Probability of Detection Communications
Yuma Katsuki, Giuseppe Thadeu Freitas de Abreu, Koji Ishibashi +1
We propose a novel, Gaussian signaling mechanism for low probability of detection (LPD) communication systems with either single or multiple antennas. The new scheme is designed to…
Noncoherent Massive MIMO with Embedded One-Way Function Physical Layer Security
Yuma Katsuki, Giuseppe Thadeu Freitas de Abreu, Koji Ishibashi +1
We propose a novel physical layer security scheme that exploits an optimization method as a one-way function. The proposed scheme builds on nonsquare differential multiple-input mu…
Grant-Free Access via Bilinear Inference for Cell-Free MIMO with Low-Coherent Pilots
Hiroki Iimori, Takumi Takahashi, Koji Ishibashi +2
We propose a novel joint activity, channel, and data estimation (JACDE) scheme for cell-free multiple-input multiple-output (MIMO) systems compliant with fifth-generation (5G) new…
Full-Duplex MIMO Systems with Hardware Limitations and Imperfect Channel Estimation
Hiroki Iimori, Giuseppe Thadeu Freitas de Abreu, Koji Ishibashi
We consider a bidirectional in-band full-duplex (FD) multiple-input multiple-output (MIMO) system subject to imperfect channel state information (CSI), hardware distortion, and lim…
Discrete-Aware Matrix Completion via Proximal Gradient
Hiroki Iimori, Giuseppe Thadeu Freitas de Abreu, Omid Taghizadeh +1
We present a novel algorithm for the completion of low-rank matrices whose entries are limited to a finite discrete alphabet. The proposed method is based on the recently-emerged p…
Fractional Programming for Robust TX BF Design in Multi-User/Single-Carrier PD-NOMA
Hiroki Iimori, Giuseppe Abreu, Koji Ishibashi
We present a new Beamforming-based (BB) Multiple-Input Single-Output (MISO)-Non-orthogonal Multiple Access (NOMA) scheme for Power Domain NOMA (PD-NOMA), in which the total transmi…
Repeat-Accumulate Signal Codes
Manato Takai, Koji Ishibashi
State-constrained signal codes directly encode modulation signals using signal processing filters, the coefficients of which are constrained over the rings of formal power series.…
Optimized Frameless ALOHA for Cooperative Base Stations with Overlapped Coverage Areas
Shun Ogata, Koji Ishibashi, Giuseppe Abreu
Herein, we consider the problem of cooperative multi-access in the presence of overlapped coverage areas. Assuming a frameless ALOHA transmission scheme, we derive exact analytical…
Wireless Power Transfer for Distributed Estimation in Sensor Networks
Vien V. Mai, Won-Yong Shin, Koji Ishibashi
This paper studies power allocation for distributed estimation of an unknown scalar random source in sensor networks with a multiple-antenna fusion center (FC), where wireless sens…