8 papers
On Optimal Strategies for Joint Reciprocity Calibration in Distributed MIMO
Kohei Ueda, Anubhab Chowdhury, Koji Ishibashi +1
This paper investigates the impact of reciprocity calibration errors on the downlink spectral efficiency (SE) of multi-user large antenna systems. Specifically, we consider two cal…
Repeater-Assisted Massive MIMO Downlink Performance with Calibration Errors
Kohei Ueda, Anubhab Chowdhury, Koji Ishibashi +1
Reciprocity-based downlink beamforming is imperative for a scalable time-division duplex massive multiple-input multiple-output~(MIMO) deployment. Specifically, for a dual-antenna…
Expectation Propagation-Based Signal Detection for Highly Correlated MIMO Systems
Kabuto Arai, Takumi Yoshida, Takumi Takahashi +1
Large-scale multiple-input-multiple-output (MIMO) systems typically operate in dense array deployments with limited scattering environments, leading to highly correlated and ill-co…
Joint Pilot Allocation and Sequence Design for MIMO-OFDM Systems With Channel Sparsity
Kabuto Arai, Koji Ishibashi, Hiroki Iimori +3
This paper proposes a joint optimization of pilot subcarrier allocation and non-orthogonal sequence for multiple-input-multiple-output (MIMO)-orthogonal frequency-division multiple…
Joint Channel and Data Estimation for Multiuser Extremely Large-Scale MIMO Systems
Kabuto Arai, Koji Ishibashi, Hiroki Iimori +2
This paper proposes a joint channel and data estimation (JCDE) algorithm for uplink multiuser extremely large-scale multiple-input-multiple-output (XL-MIMO) systems. The initial ch…
Channel Estimation for Hybrid MIMO Systems With Array Model Errors and Beam Squint Effects
Kabuto Arai, Koji Ishibashi
This paper proposes a channel estimation method for hybrid wideband multiple-input-multiple-output (MIMO) systems in high-frequency bands, including millimeter-wave (mmWave) and su…