Yong-Up Jang

Learn More
A two-way relay channel (TWRC) in which two terminals <i>T</i> <sub>1</sub> and <i>T</i> <sub>2</sub> exchange orthogonal frequency division multiplexing (OFDM) signals with the help of an amplify-and-forward (AF) relay <i>T</i> <sub>3</sub> is considered here, and an efficient technique for allocating powers to <i>N</i> parallel tones of OFDM is developed.(More)
This paper considers a multiuser two-way relay channel (MU-TWRC) in which a base-station and a selected mobile-station (MS) among K number of MSs exchange messages during two time slots with the help of a half-duplex amplify-andforward relay. We analyze the performances of a MU-TWRC. The closed-form expressions of the lower bound of the average rates are(More)
This paper proposes a block diagonalization (BD) method, which nullifies the multiuser interference and, hence, increases the sum capacity in a multiuser multiple-input multipleoutput (MU-MIMO) downlink system. The proposed BD scheme employs all users' receive processing as well as channel information. In addition, this paper proposes three adaptive mode(More)
Presented in this paper is a study of the capacity evaluation of various multiuser MIMO schemes in cellular environments. The throughputs per user of the generalized zero-forcing with rank adaptation and vector perturbation schemes are compared with the capacity bound of the Gaussian MIMO broadcast channel, obtained by dirty paper coding under proportional(More)
This paper describes the design of a timedivision duplexing frame with a variety of pilots for multiuser multiple-input–multiple-output orthogonal frequency-division multiple access (MU-MIMO OFDMA) systems, where the base station and users are equipped with four and two transmitting and receiving antennas, respectively. In addition, a simplified scheduling(More)
Digital signage (DS) has become a phraseology for recent technology, is gaining massive acceptance to the technology-dependent world. Though the development of DS includes the essence of advertisement purposes, the fusion strategy makes it promising for communication technology. This paper demonstrates a Symbiotic Digital Signage (SDS) system in which one(More)
We introduce a multiuser (MU) scheduling method for amplify-and-forward (AF) relay systems, which opportunistically selects both the transmission mode, i.e., either oneor two-hop transmission, and the desired user. A closed-form expression for the average achievable rates is derived under two transmissions with MU scheduling, and its asymptotic solution is(More)
A limited feedback-based transmit beamforming technique for multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) is investigated in time-varying channels. The performance of the system is significantly degraded by outdated feedback information even when the channel varies slowly. To compensate for the impairment in(More)
This correspondence considers a hybrid cognitive radio (H-CR) where the primary transmitter (PT) transmits message to the primary receiver (PR) whenever traffic occurs by allowing interference level <i>I</i> from the secondary transmitter (ST) to the PR, and the ST transmits messages to the secondary receiver (SR) by controlling the transmitting power based(More)