양현종 교수

We consider the K-cell multiple-input multiple-output (MIMO) interfering multiple-access channel (IMAC) with time-invariant channel coefficients, where each cell consists of a base station (BS) with M antennas and N users having L antennas each. In this paper, we propose two opportunistic interference alignment (OIA) techniques utilizing multiple transmit antennas at each user: antenna selection-based OIA and singular value decomposition (SVD)-based OIA. Their performance is analyzed in terms of

The non-binary code (NBC) or the lattice code (LC) has been the only possible channel code with the pulse amplitude modulation (PAM) signaling of modulation size greater than two for the physical layer network coding (PNC) over a decode-and-forward (DF) relaying channel. A major drawback with the NBC or LC however is its high computational complexity. In this letter, we present new modified high-order PAMs that enable us to use the computationally efficient binary channel coding under the PNC ov

A multiple-input multiple-output two-way relay channel consisting of two communication nodes and a full-duplex relay node in which no direct link exists between the two communication nodes is considered. We propose an achievable scheme that employs horizontally encoded lattice codes combined with generalized singular value decomposition-based precoding for the first phase. The second phase of the proposed scheme follows the fundamentals of the previous scheme, which uses vertically encoded struc

In this paper, we propose an opportunistic downlink interference alignment (ODIA) for interference-limited cellular downlink, which intelligently combines user scheduling and downlink IA techniques. The proposed ODIA not only efficiently reduces the effect of inter-cell interference from other-cell base stations (BSs) but also eliminates intra-cell interference among spatial streams in the same cell. We show that the minimum number of users required to achieve a target degrees-of-freedom can be

For the multiple-input multiple-output interfering multiple-access channels (IMACs), opportunistic interference alignment (OIA) using the singular value decomposition (SVD)-based beamforming at each user fundamentally reduces the user scaling condition required to achieve any target DoF, compared to that for the single-input multiple-output IMAC. In this paper, we tackle two practical challenges of the existing SVD-based OIA: 1) the need of full feedforward of the selected users' beamforming wei

We derive a new sum-rate lower bound of the multiuser multi-input multi-output (MU-MIMO) cellular two-way relay channel (cTWRC) which is composed of a base station (BS) and a relay station (RS), both with multiple antennas, and non-cooperative mobile stations (MSs), each with a single antenna. In the first phase, we show that network coding based on decode-and-forward relaying can be generalized to arbitrary input cardinality through proposed lattice code-aided linear precoding, despite the fact

Deploying relay stations improves the signal-to- interference and noise ratio (SINR) by making a Pico cell environment. Nonetheless, a critical problem associated with deploying RS is additional resource consumption, which reduces the actual transmission rate. Two-way relaying schemes that use physical layer network coding (PNC) reduce the additional resource consumption and thereby improve the transmission rate. In this paper we propose a novel two-way relaying scheme for coded multiple-input m

We introduce an opportunistic downlink interference alignment (ODIA) for interference-limited cellular downlink, which intelligently combines user scheduling and downlink IA techniques. The proposed ODIA not only efficiently reduces the effect of inter-cell interference from other-cell base stations (BSs) but also eliminates intra-cell interference among spatial streams in the same cell. We show that compared to the existing downlink IA schemes, the minimum number of users required to achieve a

It is well known that relay stations improve the link performance between the base and mobile stations and thereby improve the total system throughput. Nonetheless, the additional resource consumption to deploy the relay station reduces the system throughput significantly. The zero-forcing (ZF)-based two-phase relaying scheme that requires only two phases to communicate a frame was suggested for the system where a single mobile station is considered. The performance bottle-necks of the conventio

A multiple-input multiple-output two-way relay channel consisting of two communication nodes and a full-duplex relay node is considered, assuming that no direct link exists between the two communication nodes. We propose an achievable scheme using lattice codes combined with generalized singular value decomposition-based precoding for the first phase and vertically encoded structural bining for the second phase. We show that the proposed scheme achieves the cut-set bound asymptotically as the si

In this paper, we focus on improving the accuracy of frequency offset estimation for an orthogonal frequency-division multiplexing (OFDM) system under the conditions of the joint impairments in both carrier frequency offset (CFO) and in-phase/quadrature (I/Q) imbalance. To propose a robust CFO estimation scheme and to benchmark its performance, the performance of the conventional frequency estimation algorithm in the presence of I/Q imbalance is analyzed, and some modifications to the convention

Journal Article Deep-Learning Based Autofocus Score Prediction of Scanning Electron Microscope Get access Huisoo Kim, Huisoo Kim Egovid Inc., UNIST-gil 50, Ulsan 44919, Korea Search for other works by this author on: Oxford Academic Google Scholar Moohyun Oh, Moohyun Oh Egovid Inc., UNIST-gil 50, Ulsan 44919, Korea Search for other works by this author on: Oxford Academic Google Scholar Heerang Lee, Heerang Lee Egovid Inc., UNIST-gil 50, Ulsan 44919, Korea Search for other works by this author o

We consider a new opportunistic interference alignment (OIA) for the K-cell multiple-input multiple-output (MIMO) interfering multiple-access channel (IMAC) with time-invariant channel coefficients, where each cell consists of a base station (BS) with M antennas and N mobile stations (MSs) having L antennas each. In this paper, we propose three OIA techniques: antenna selection-based OIA, singular value decomposition (SVD)-based OIA, and vector-quantized (codebook-based) OIA. Then, their perform

Deep-learning has come into its own in analyzing scanning electron microscope (SEM) images As the image analysis part is becoming autonomous with the aid of deep-learning, the main challenge in the use of SEMs is to get high quality images by deftly controlling SEM parameters such as brightness, contrast, focus, and etc. While the other studies attempt to use deep-learning as a classifier or analyzer for images, our previous work To automate the SEM control, the most crucial part is to accuratel

Lattice-reduction-aided precoding (LRP) provides near-capacity rates with the use of low-complexity linear receivers for coded multiple-input multiple-output (MIMO) systems. However, a large amount of feedback in the feedback for an integer or binary precoding matrix has been a bottleneck in its implementation. In this paper, we propose a codebook-based LRP scheme for limited-feedback coded MIMO systems. The proposed LRP scheme follows the fundamentals of the previous LRP scheme that employed mu