180 citations · 719 across the 46 of their papers we have counts for
15 papers · 1 filter
Multiuser Detection by MAP Estimation with Sum-of-Absolute-Values Relaxation
Hampei Sasahara, Kazunori Hayashi, Masaaki Nagahara
In this article, we consider multiuser detection that copes with multiple access interference caused in star-topology machine-to-machine (M2M) communications. We assume that the tr…
Symbol Detection for Frame-Based Faster-than-Nyquist Signaling via Sum-of-Absolute-Values Optimization
Hampei Sasahara, Kazunori Hayashi, Masaaki Nagahara
In this letter, we propose a new symbol detection method for faster-than-Nyquist signaling (FTNS) systems. Based on frame theory, we formulate a symbol detection problem as a under…
Discrete Signal Reconstruction by Sum of Absolute Values
Masaaki Nagahara
In this letter, we consider a problem of reconstructing an unknown discrete signal taking values in a finite alphabet from incomplete linear measurements. The difficulty of this pr…
Communication Performance Analysis of Sampled-Data H-infinity Optimal Coupling Wave Canceler
Hampei Sasahara, Masaaki Nagahara, Kazunori Hayashi +1
In this manuscript, we propose a design method of digital filters which cancel coupling waves generated in single-frequency full-duplex wireless relay stations by using the sampled…
L1 Control Theoretic Smoothing Splines
Masaaki Nagahara, Clyde F. Martin
In this paper, we propose control theoretic smoothing splines with L1 optimality for reducing the number of parameters that describes the fitted curve as well as removing outlier d…
FIR Digital Filter Design by Sampled-Data H-infinity Discretization
Masaaki Nagahara, Yutaka Yamamoto
FIR (finite impulse response) digital filter design is a fundamental problem in signal processing. In particular, FIR approximation of analog filters (or systems) is ubiquitous not…
Multirate Digital Signal Processing via Sampled-Data H-infinity Optimization
Masaaki Nagahara
In this thesis, we present a new method for designing multirate signal processing and digital communication systems via sampled-data H-infinity control theory. The difference betwe…
YY Filter - A Paradigm of Digital Signal Processing
Masaaki Nagahara
YY filter, named after the founder Prof. Yutaka Yamamoto, is a digital filter designed by sampled-data control theory, which can optimize the analog performance of the signal proce…
Active Noise Control with Sampled-Data Filtered-x Adaptive Algorithm
Masaaki Nagahara, Ken-ichi Hamaguchi, Yutaka Yamamoto
Analysis and design of filtered-x adaptive algorithms are conventionally done by assuming that the transfer function in the secondary path is a discrete-time system. However, in re…
H-infinity Design of Periodically Nonuniform Interpolation and Decimation for Non-Band-Limited Signals
Masaaki Nagahara, Masaki Ogura, Yutaka Yamamoto
In this paper, we consider signal interpolation of discrete-time signals which are decimated nonuniformly. A conventional interpolation method is based on the sampling theorem, and…
H-infinity Optimal Approximation for Causal Spline Interpolation
Masaaki Nagahara, Yutaka Yamamoto
In this paper, we give a causal solution to the problem of spline interpolation using H-infinity optimal approximation. Generally speaking, spline interpolation requires filtering…
Signal Reconstruction via H-infinity Sampled-Data Control Theory: Beyond the Shannon Paradigm
Yutaka Yamamoto, Masaaki Nagahara, Pramod P. Khargonekar
This paper presents a new method for signal reconstruction by leveraging sampled-data control theory. We formulate the signal reconstruction problem in terms of an analog performan…
Min-Max Design of FIR Digital Filters by Semidefinite Programming
Masaaki Nagahara
In this article we consider two problems: FIR (Finite Impulse Response) approximation of IIR (Infinite Impulse Response) filters and inverse FIR filtering of FIR or IIR filters. By…
H-Infinity-Optimal Fractional Delay Filters
Masaaki Nagahara, Yutaka Yamamoto
Fractional delay filters are digital filters to delay discrete-time signals by a fraction of the sampling period. Since the delay is fractional, the intersample behavior of the ori…
Frequency Domain Min-Max Optimization of Noise-Shaping Delta-Sigma Modulators
Masaaki Nagahara, Yutaka Yamamoto
This paper proposes a min-max design of noise-shaping delta-sigma modulators. We first characterize the all stabilizing loop-filters for a linearized modulator model. By this chara…