이종호 교수

In this paper, we propose an analog self-interference cancelation scheme for full-duplex wireless orthogonal frequency-division multiplexing (OFDM) systems. Since the delay of the echo path is presented as a phase rotation of the baseband transmit signal at each subcarrier, the proposed scheme uses the rotated baseband signals to emulate self-interference signals for analog cancelation. While the conventional analog cancelation schemes are matched only to a single frequency, the proposed scheme

Recently, ferroelectric tunnel junctions (FTJs) have gained extensive attention as possible candidates for emerging memory and synaptic devices for neuromorphic computing. However, the working principles of FTJs remain controversial despite the importance of understanding them. In this study, we demonstrate a comprehensive and accurate analysis of the working principles of a metal-ferroelectric-dielectric-semiconductor stacked FTJ using low-frequency noise (LFN) spectroscopy. In contrast to resi

In this paper, we investigate the effects of charge storage engineering (CSE) on the NO₂ gas sensing properties such as response, recovery, and sensitivity of a FET-type gas sensor with a horizontal floating-gate (FG) having tungsten trioxide (WO₃) as a sensing layer. When the FET transducer is set at an erase state (ΔV_th = -2 V), the holes injected into the FG by Fowler-Nordheim (F-N) tunneling increase the electron concentration at the WO₃-passivatio

A joint channel estimation and phase noise suppression scheme for orthogonal frequency-division multiplexing (OFDM) systems is proposed for a case where channel estimation is needed symbol by symbol. In the proposed scheme, channel estimation and phase noise suppression are performed iteratively via the expectation-maximization (EM) algorithm. The proposed algorithm mitigates the performance degradation due to phase noise effectively while providing an accurate channel estimate with comparativel

In this letter, we propose an iterative detection scheme in the presence of residual frequency offset (RFO) for orthogonal frequency-division multiplexing systems using an approximate application of the space-alternating generalized expectation-maximization (SAGE) algorithm. In the proposed scheme, the expectation step intends to divide the received signal into the desired signal and the interference signal. In the maximization step, the desired signal is used to estimate required parameters (i.

In this letter, we propose an efficient detection scheme for space-time block coded (STBC) orthogonal frequency-division multiplexing (OFDM) with insufficient cyclic prefix (CP). The proposed scheme employs successive interference cancellation (SIC) and cyclic prefix reconstruction (CPR) concepts. Simulation results present that the proposed scheme outperforms the conventional scheme for STBC OFDM systems.

In this paper, we consider the iterative channel estimation and decoding algorithms for quadrature amplitude modulation (QAM) modulated orthogonal frequency division multiplexing (OFDM) signals. We first describe the optimal sequence estimation based on the expectation-maximization (EM) algorithm. Using some approximations, we propose a sub-optimal iterative channel estimation and decoding algorithm, which is shown to have reduced computational complexity. The bit error rate (BER) performances o

In this paper, we propose an iterative detection
\nscheme in the presence of residual frequency offset (RFO) for
\northogonal frequency-division multiplexing (OFDM) system
\nusing the space-alternating generalized expectation-maximization
\n(SAGE) algorithm. In the proposed algorithm, the expectation
\nstep intends to remove the inter-carrier interferences (ICI) due to
\nRFO in the received signals. Then, the maximization step is
\nutilized to estimate the required pa