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462 results on '"Park, Sung-Ik"'

104. Noise reduction for channel estimation based on pilot-block averaging in DVB-T receivers

Author

Lee, You-Seok, Kim, Hyoung-Nam, Park, Sung Ik, and Lee, Soo In

Subjects
Noise control -- Analysis, Frequency estimation -- Methods, Business, Electronics and electrical industries, Engineering and manufacturing industries
Abstract

This paper proposes a noise-reduction method to improve the channel-estimation performance in Digital Video Broadcasting-Terrestrial (D VB- T) receivers. In D VB- T, the channel estimation is carried out through two processes of pilot signal estimation and channel coefficient interpolation and thus the performance of the channel estimation is seriously affected by the accuracy of the interpolation. Since the accuracy of the interpolation depends on signal-to-noise ratio, it is important to reduce noise existing at the reference coefficients for the interpolation. To achieve the reduction of noise, we use pilot-insertion type approximation in four consecutive OFDM symbols, which construct one block with the same channel coefficients at the same pilot positions. Considering the fade rate of channels, we average the estimated reference channel coefficients corresponding to the same subcarriers in two or more blocks. Computer simulation shows that the proposed method improves the estimation performance by more than 1 dB in terms of the symbol error rate obtained after equalization. Index Terms--Channel estimation, orthogonal frequency division multiplexing (OFDM), DVB-T, Interpolation.

Published
2006

105. Robust decision-feedback equalization with a noncausal filter for ATSC DTV receivers

Author

Kim, Hyoung-Nam, Lee, You-Seok, and Park, Sung Ik

Subjects
Feedback control systems -- Analysis, Business, Electronics and electrical industries, Engineering and manufacturing industries
Abstract

A robust decision-feedback equalization method for A TSC DTV receivers is presented. Under severe channels, such as O-dB ghost or a distributed transmission environment, decision-feedback equalizers (DFEs), which have been commonly used in ATSC DTV receivers, suffer from error propagation. To improve the robustness to the error propagation, we incorporate a channel-matched filter (CMF) and an intelligent slicer (IS). The use of the CMF prior to the DFE makes severe channels manageable in the DFE. The IS, a trellis decoder with a trace-back depth of 1, enhances a correct-decision probability in the DFE, especially under low SNR conditions. Adoption of the CMF and the IS clearly enhances the robustness of the DFE but may degrade the output SNR due to unwanted pre-ghosts caused by channel-matched filtering. We employ a noncausal all-pass filter operating in reversed time to preserve the robustness acquired by the CMF and the IS without the degradation of the output SNR. The noncausal filter changes an input channel with pre-ghosts into an approximately minimum-phase channel without pre-ghosts. Simulation results show that the proposed equalization scheme achieves the more stable convergence and the higher SNRs than the existing DFEs. Index Terms--DTV, noncausal filter, decision-feedback equalizer, DFE.

Published
2006

106. Frequency-domain equalization for distributed terrestrial DTV transmission environments

Author

Son, Sang-Won, Kim, Ji-Hyun, Lee, You-Seok, Kim, Hyoung-Nam, and Park, Sung Ik

Subjects
Digital television -- Usage, Equalizers (Electronics) -- Usage, Data communications -- Analysis, Digital television, Business, Electronics and electrical industries, Engineering and manufacturing industries
Abstract

The 8-VSB modulation, the transmission standard for the terrestrial digital television (DTV) of the Advanced Television Systems Committee (ATSC), suffers from multipath fading because it conveys information on the amplitude. To solve this problem, decision feedback equalizers (DFEs) have been commonly used in the terrestrial DTV receivers. However, under severe channels, such as a 0-dB ghost channel or a distributed transmission environment, the DFEs have shown unstable convergence due to the error propagation caused by decision errors. Instead of unstable time-domain DFE schemes, by proposing a frequency-domain direct-inversion equalization method, we achieve stable equalization and low symbol error rates. To secure the existence of a channel inverse, channel-matched filtering and noncausal filtering are carried out before equalization. Simulation results show that the proposed method performs much better than the existing DFE schemes in terms of both the stability and the symbol error rates. Index Terms--DTV, channel equalization, noncausal filter, frequency-domain equalization.

Published
2006

107. Layered Division Multiplexing with Distributed Multiple-Input Single-Output Schemes

Author

Universitat Politècnica de València. Departamento de Comunicaciones - Departament de Comunicacions, Universitat Politècnica de València. Instituto Universitario de Telecomunicación y Aplicaciones Multimedia - Institut Universitari de Telecomunicacions i Aplicacions Multimèdia, European Regional Development Fund, Electronics and Telecommunications Research Institute, Corea, Ministry of Science, ICT and Future Planning, Corea del Sur, Ministerio de Economía y Competitividad, Garro, Eduardo, Barjau, Carlos, Gomez-Barquero, David, Kim, Jeongchang, Park, Sung-Ik, Hur, Namho, Universitat Politècnica de València. Departamento de Comunicaciones - Departament de Comunicacions, Universitat Politècnica de València. Instituto Universitario de Telecomunicación y Aplicaciones Multimedia - Institut Universitari de Telecomunicacions i Aplicacions Multimèdia, European Regional Development Fund, Electronics and Telecommunications Research Institute, Corea, Ministry of Science, ICT and Future Planning, Corea del Sur, Ministerio de Economía y Competitividad, Garro, Eduardo, Barjau, Carlos, Gomez-Barquero, David, Kim, Jeongchang, Park, Sung-Ik, and Hur, Namho

Abstract

"© 2019 IEEE. Personal use of this material is permitted. Permissíon from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertisíng or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.", [EN] Single frequency networks (SFNs) provides an increased spectral efficiency compared to the traditional multiple frequency networks. However, some coverage areas in SFN can be affected by destructive interferences. In order to reduce these situations, distributed multiple-input single-output (MISO) schemes have been adopted in the new digital terrestrial television standards, Alamouti in DVB-T2 and transmit diversity code filter sets in ATSC 3.0. On the other hand, layered division multiplexing (LDM), a non-orthogonal multiple access technology, has been adopted in ATSC 3.0 due to its spectral efficiency increase compared to time or frequency division multiplexing. The LDM signal is formed by a power superposition of two independent signals, which are designed for different reception conditions (mobile and fixed-rooftop). The combination of distributed MISO and LDM techniques has not been evaluated yet. In this paper, the joint transmission of LDM with distributed MISO is analyzed in terms of complexity and the joint performance is evaluated by means of physical layer simulations.

Published
2019

108. Multi‐antenna diversity gain in terrestrial broadcasting receivers on vehicles: A coverage probability perspective.

Author

Ahn, Sungjun, Lee, Jae‐young, Lim, Bo‐Mi, Kwon, Hae‐Chan, Hur, Namho, and Park, Sung‐Ik

Subjects
RADIO frequency, BROADCASTING industry, PROBABILITY theory, TELECOMMUNICATION satellites, NANOSATELLITES, SPACE-time block codes
Abstract

This paper theoretically and empirically explores the reliability gain that can be obtained by installing multiple antennas in on‐vehicle broadcasting receivers. Analytical derivations reveal that maximal‐ratio‐combining‐based diversity allows a multi‐antenna receiver (MR) to achieve significantly better coverage probability than a single‐antenna receiver (SR). In particular, the notable MR gains for low‐power reception and high‐throughput services are highlighted. We also discuss various aspects of mobile MRs, including geometric coverage, volume of the users served, and impact of receiver velocity. To examine the feasibility of MRs in the real world, extensive field experiments were conducted, particularly with on‐air ATSC 3.0 broadcast transmissions. Relying on the celebrated erroneous second ratio criterion, MRs with two and four antennas were verified to achieve notable reliability gains over SRs in practice. Furthermore, our results also prove that layered‐division multiplexing can cope better with receiver mobility than traditional time‐division multiplexing when multiple services are intended in the same radio frequency channel. [ABSTRACT FROM AUTHOR]

Published
2021
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118. Mobile Testing of ATSC 3.0 MISO in SFN

Author

Lim, Bo-mi, primary, Kwon, Sunhyoung, additional, Ahn, Sungjun, additional, Park, Sung Ik, additional, Lee, Jae-young, additional, Hur, Namho, additional, Kim, Heung Mook, additional, and Kim, Jeongchang, additional

Published
2019
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126. Multipath and Impulsive Noise Interference Testing Performance Comparison Between Broadcast Systems: ISDB-TB and ATSC 3.0

Author

Oliveira, George Henrique Maranhao Garcia de, primary, Barros, Uira Moreno Rosario e, additional, Chaves, Leonardo, additional, Ferraresso, Gabriel, additional, Pacheco, Leandro, additional, Omi, Julio, additional, Lee, Jae-Young, additional, Park, Sung-Ik, additional, Akamine, Cristiano, additional, Rabaca, Ricardo Seriacopi, additional, Santiago, Natalia Silva, additional, Leonel, Carlos Felipe Celestino, additional, Santana, Matheus Andrade, additional, Varela, Victor Gabriel Rizzi, additional, Vaz, Rodrigo Admir, additional, Ferraz, Eric da Silva, additional, and Oliveira, Rodrigo Ribeiro de, additional

Published
2019
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130. Layered-Division-Multiplexing for High Spectrum Efficiency and Service Flexibility in Next Generation ATSC 3.0 Broadcast System

Author

Zhang, Liang, primary, Wu, Yiyan, additional, Li, Wei, additional, Rong, Bo, additional, Salehian, Khalil, additional, Lafleche, Sebastien, additional, Wang, Xianbin, additional, Park, Sung Ik, additional, Kim, Heung Mook, additional, Lee, Jae-young, additional, Hur, Namho, additional, Angueira, Pablo, additional, and Montalban, Jon, additional

Published
2019
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131. Coverage Study of ATSC 3.0 Under Strong Co-Channel Interference Environments

Author

Li, Wei, primary, Wu, Yiyan, additional, Lafleche, Sebastien, additional, Salehian, Khalil, additional, Zhang, Liang, additional, Florea, Adrian, additional, Park, Sung-Ik, additional, Lee, Jae-Young, additional, Kim, Heung-Mook, additional, Hur, Namho, additional, Regueiro, Cristina, additional, Montalban, Jon, additional, and Angueira, Pablo, additional

Published
2019
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134. Cooperation Between LDM-Based Terrestrial Broadcast and Broadband Unicast: On Scalable Video Streaming Applications.

Author

Ahn, Sungjun, Park, Sung-Ik, Lee, Jae-Young, Hur, Namho, and Kang, Joonhyuk

Subjects
*STREAMING video & television, *INTER-carrier interference, *VIDEO coding, *STATIC VAR compensators, *SYSTEMS design, *COOPERATION
Abstract

This article investigates the reliability gain of broadcast (BC)/broadband (BB) cooperation for mobile scalable video streaming. A specific form of BC-BB cooperation is introduced, which is referred to as cooperative casting. The proposed system primarily utilizes a BC transmission for streaming, while BB backup transmissions are requested whenever the BC signal is not decodable. For BC deliveries in this system, a cross-layer collaboration between scalable video coding (SVC) and layered-division multiplexing is used to improve spectral efficiency by coupling their hierarchical structures. In this end, in tandem with designing the uplink requesting rules based on channel status, delivery performance of the cooperative casting is analytically evaluated in a probabilistic framework. The system design and analyses presented in this article focus on the service continuity in a mobile and time-varying channel, where the physical aspects, such as delayed unicast response and inter-carrier interference, are carefully taken into account. Compared to the standalone network transmissions, the cooperative casting is numerically verified to better prevent the delivery failures in high-speed mobile channels, especially when the SVC layer-combined (full-scale video) service is intended. Furthermore, it is also shown that relaxing the criteria for the BB stream requesting can reduce delivery failures substantially, while it increases transmission redundancy. [ABSTRACT FROM AUTHOR]

Published
2021
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135. Large-Scale Network Analysis on NOMA-Aided Broadcast/Unicast Joint Transmission Scenarios Considering Content Popularity.

Author

Ahn, Sungjun, Park, Sung-Ik, Lee, Jae-Young, Hur, Namho, Wu, Yiyan, Zhang, Liang, Li, Wei, and Kim, Jeongchang

Subjects
*STOCHASTIC geometry, *POPULARITY, *NUMERICAL calculations, *BROADCASTING industry, *ACCESS control
Abstract

This paper analyzes reliability and quality gains that can be achieved by a broadcast-unicast convergent platform operating in non-orthogonal multiple access (NOMA)-based cellular networks. The analysis is addressed in network scope, dealing with randomly distributed users and base stations (BSs) within a stochastic geometry framework. Additionally a well-known Zipf-distribution popularity model on user demands is also taken into account, which effectively reflects a broadcasting gain from reducing redundant resource expense toward the users demanding same contents. Based on the stochastic modeling, closed-form delivery success probabilities and the consequent transmission rates are analytically derived, where the derivations are obtained separately for the networks with different access control strategies. Furthermore, the optimal broadcast content selection strategy maximizing the transmission rates is proposed. By means of numerical calculations, NOMA is shown to achieve substantial gain at broadcast/unicast joint transmission compared to the conventional orthogonal multiple access (OMA) network, particularly for the service configuration with popular contents having lower target service rates than less popular contents as long as the number of broadcast programs is restricted to be equal to the number of unicast services in a single frame. [ABSTRACT FROM AUTHOR]

Published
2020
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136. Using Non-Orthogonal Multiplexing in 5G-MBMS to Achieve Broadband-Broadcast Convergence With High Spectral Efficiency.

Author

Zhang, Liang, Li, Wei, Wu, Yiyan, Xue, Yu, Sousa, Elvino, Park, Sung-Ik, Lee, Jae-Young, Hur, Namho, and Kim, Heung-Mook

Subjects
MULTICASTING (Computer networks), MULTIPLEXING, LONG-Term Evolution (Telecommunications), SPECTRUM allocation, RESOURCE allocation, DELIVERY of goods, COMPUTER simulation
Abstract

The development of 5G system provides a unique opportunity to implement a unified wireless transmission platform that can simultaneous deliver unicast, multicast and broadcast services using the same spectrum and the same infrastructure. This can be achieved by developing a more capable point-to-multipoint transmission (PTM) system component, also called 5G Multimedia Broadcast Multicast Services (5G-MBMS). A properly designed 5G-MBMS could achieve the convergence of terrestrial mobile broadband and TV broadcasting systems.By inherently allowing dynamic spectrum allocation among different types of services, this converged system could offer significant higher spectrum utilization. In this paper, the power-based non-orthogonal multiplexing (P-NOM) technology is proposed in addition to the existing orthogonal time-division-multiplexing (TDM) scheme. Significant capacity gains could be achieved by using P-NOM in a 5G-MBMS system for delivering different types of broadcast services, and for delivering mixed unicast and broadcast services. The capacity benefits of a 5G-MBMS with P-NOM is demonstrated by both theoretical analysis and computer simulations. A key finding is that using a two-layer P-NOM can essentially deliver a broadcast service on top of a unicast network, each achieving nearly full capacity. Next, a complexity analysis will reveal that implementing P-NOM in a 5G-MBMS system does not require significant additional complexity at consumer devices. Finally, it will be shown that, different from the non-orthogonal-multiple-access (NOMA) technologies, using P-NOM in 5G-MBMS system requires little or no change to the existing radio resource allocation mechanisms in LTE and 5G, when one power layer is used for broadcast services delivery. [ABSTRACT FROM AUTHOR]

Published
2020
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143. Field Testing of LDM and SHVC Broadcast in ATSC 3.0

Author

Lee, Jae-Young, primary, Park, Sung Ik, additional, Kwon, Sunhyoung, additional, Lim, Bo-Mi, additional, Ahn, Sungjun, additional, Hur, Namho, additional, Mook Kim, Heung, additional, Jeon, Sungho, additional, and Gomcz-Barquero, David, additional

Published
2018
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147. ATSC 3.0 Physical Layer Modulation and Coding Performance Analysis

Author

Park, Sung-Ik, primary, Lee, Jae-Young, additional, Kwon, Sunhyoung, additional, Lim, Bo-Mi, additional, Ahn, Sungjun, additional, Kim, Heung Mook, additional, Jeon, Sungho, additional, Lee, Jaekwon, additional, Simon, Michael, additional, Aitken, Mark, additional, Gage, Kevin, additional, Wu, Yiyan, additional, Zhang, Liang, additional, Li, Wei, additional, and Kim, Jeongchang, additional

Published
2018
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