Wireless Communications

MIMO Communication

Training Signal Design and Channel Estimation for MIMO

• Song Noh, Kyungsik Seo, Youngchul Sung, David Love, Junse Lee* and Heejung Yu*, "Joint direct and indirect channel estimation for RIS-assisted millimeter-wave systems based on array signal processing," IEEE Transactions on Wireless Communications, vol. 22, no. 11, pp. 8378 - 8391, Nov. 2023

• Song Noh, Junse Lee, Gilwon Lee, Kyungsik Seo, Youngchul Sung and Heejung Yu*, "Channel Estimation Techniques for RIS-Assisted Communication: Millimeter-Wave and Sub-THz Systems ," IEEE Vehicular Technology Magazine, vol. 17, no. 2, pp. 64 - 73, Jun. 2022

• Song Noh, Heejung Yu, and Youngchul Sung*, "Training signal design for sparse channel estimation in intelligent reflecting surface-assisted millimeter-wave communication," IEEE  Transactions on Wireless Communications, vol. 21, no. 4, pp. 2399 - 2413, Apr. 2022

• Song Noh, Jiho Song, and Youngchul Sung*, "Fast beam search and refinement for millimeter-wave massive MIMO based on two-level phased arrays," IEEE Transactions on Wireless Communications, vol. 19, no. 10, pp. 6737 - 6751, Oct. 2020

• Junyeong Seo, Youngchul Sung*, Gilwon Lee, and Donggun Kim, "Training beam sequence design for millimeter-wave MIMO systems: A POMDP framework," IEEE Transactions on Signal Processing, vol. 64, no. 5, pp. 1228 - 1242, Mar. 2016.

• Jungho So, Donggun Kim, Yuni Lee, and Youngchul Sung*, "Pilot signal design for massive MIMO systems: A received signal-to-noise-ratio-based approach," IEEE Signal Processing Letters, vol. 52, no. 5, pp. 549 - 553, May 2015.

• Song Noh, Youngchul Sung*, and Michael Zoltowski, "A new precoder design for blind channel estimation for MIMO-OFDM systems," IEEE Transactions on Wireless Communications, vol. 13, no. 12, pp. 7011 - 7024, Dec. 2014

• Song Noh, Michael Zoltowski, Youngchul Sung*, and David Love, "Pilot beam pattern design for channel estimation in massive MIMO systems," IEEE Journal of Selected Topics in Signal Processing, vol. 8, no. 5, pp. 787 - 801, Oct. 2014.

• Youngchul Sung, Tae Sung, Brian M. Sadler, and Lang Tong, "Training for MIMO communications," in Space-Time Wireless Systems: From Array Processing to MIMO Communications, edited by H. Bolcskei, D. Gesbert, C. Papadias, and A. J. van der Veen, Cambridge University Press, 2006.

MIMO Beamformer Design

• Junyeong Seo, Youngchul Sung*, and Hamid Jafarkhani, "A high-diversity transceiver design for MISO broadcast channels," IEEE Transactions on Wireless Communications, vol. 18, no. 5, pp. 2591 - 2606, May 2019

• Jungho So, Youngchul Sung*, and Yong H. Lee, "Tomlinson-Harashima precoding-aided multi-antenna non-orthogonal multiple access," arXiv, Aug. 2018

• Junyeong Seo and Youngchul Sung*, "Beam design and user scheduling for non-orthogonal multiple access with multiple antennas based on Pareto-optimality" IEEE Transactions on Signal Processing, vol. 66, no. 11, pp. 2876 - 2891, Jun. 2018

• Junyeong Seo and Youngchul Sung*, "A new transceiver architecture for multi-user MIMO communication based on mixture of linear and non-linear reception,” SPAWC 2017, Sapporo, Japan, Jul. 2017

• Yongjin Kwon, Jihoon Chung, and Youngchul Sung*, "Hybrid beamformer design for mmWave wideband multi-user MIMO-OFDM systems," Invited Paper to The Special Session of Signal Processing for Millimeter Wave Communication Systems in SPAWC 2017, Sapporo, Japan, Jul. 2017

• Jungho So and Youngchul Sung*, "Improving non-orthogonal multiple access by forming relaying broadcast channels," IEEE Communications Letters, vol. 20, no. 9, pp. 1816 - 1819, Sep. 2016. An extended version is available at arXiv.

• Donggun Kim, Gilwon Lee, and Youngchul Sung*, "Two-stage beamformer design for massive MIMO downlink by trace quotient formulation," IEEE Transactions on Communications, vol. 63, no. 6, pp. 2200 - 2211, Jun. 2015

• Masahiro Yukawa*, Youngchul Sung and Gilwon Lee, "Dual-domain adaptive beamformer under linearly and quadratically constrained minimum variance," IEEE Transactions on Signal Processing, vol. 61, no. 11, pp. 2874 - 2886, Jun. 2013

• Gilwon Lee, Juho Park, Youngchul Sung* and Junyeong Seo, "A new approach to beamformer design for massive MIMO systems based on k-regularity," International Workshop on Emerging Technologies for LTE-Advanced and Beyond 4G in conjunction with IEEE Globecom 2012, Anaheim, CA, Dec. 2012

User Scheduling for Multi-User MIMO 

• Junyeong Seo and Youngchul Sung*, "Beam design and user scheduling for non-orthogonal multiple access with multiple antennas based on Pareto-optimality," IEEE Transactions on Signal Processing, vol. 66, no. 11, pp. 2876 - 2891, Jun. 2018

• Gilwon Lee and Youngchul Sung*, "A new approach to user scheduling in massive multi-user MIMO broadcast channels," IEEE Transactions on Communications, vol. 66, no. 4, pp. 1481 – 1495, Apr. 2018 

• Gilwon Lee and Youngchul Sung, "MAC scheduler for mmWave massive MIMO," in MmWave Massive MIMO: A Paradigm for 5G, edited by Shahid Mumtaz and Jonathan Rodriquez, Elsevier, Longdon, UK, Nov. 2016

• Gilwon Lee, Youngchul Sung*, and Marios Kountouris, "On the performance of random beamforming in sparse millimeter wave channels," IEEE Journal of Selected Topics in Signal Processing, vol. 10, no. 3, pp. 560 - 575, Apr. 2016

• Gilwon Lee, Youngchul Sung*, and Junyeong Seo, "Randomly-directional beamforming in mm-wave multi-user MISO downlink," IEEE Transactions on Wireless Communications, vol. 15, no. 2, pp. 1086 - 1100, Feb. 2016

• Gilwon Lee, Youngchul Sung*, Jungho So, and Junyeong Seo, "Research trends in realizing massive MIMO for 5G (in Korean),” Special Issue on 5G and Beyond, The Magazine of the IEIE, Oct. 2015

• Gilwon Lee, Youngchul Sung*, and Marios Kountouris, "On the performance of randomly directional beamforming between line-of-sight and rich scattering channels,” Invited Paper to The Special Session of Signal Processing for Millimeter Wave Communication Systems in SPAWC 2015, Stockholm, Sweden, Jun. 2015

• Gilwon Lee and Youngchul Sung*, "Asymptotically optimal simple user scheduling for massive MIMO downlink with two-stage beamforming," Proc. of SPAWC 2014, Toronto, CA, Jun. 2014

MIMO Interference Channels

• Junse Lee, Heejung Yu and Youngchul Sung*, "Beam tracking for interference alignment in time-varying MIMO interference channels: A conjugate gradient based approach," IEEE Transactions on Vehicular Technology, vol. 63, no. 6, pp. 958 - 964, Feb. 2014.

• Heejung Yu, Juho Park, Youngchul Sung*, and Yong H. Lee "Research trend in interference alignment in multi-user interference channels (a survey article in Korean)," The Magazine of the IEEK, vol. 40, pp. 348 - 360, Apr. 2013.

• Juho Park and Youngchul Sung*, "On the Pareto-optimal beam structure and design for multi-user MIMO interference channels," IEEE Transactions on Signal Processing, vol. 61, no. 23, pp. 5932 - 5946, Dec. 2013.

• Juho Park, Gilwon Lee, Youngchul Sung*, and Masahiro Yukawa, "Coordinate beamforming with relaxed zero forcing: The sequential orthogonal projection combining method and rate control," IEEE Transactions on Signal Processing, vol. 61, no. 12, pp. 3100 - 3112, Jun. 2013.

• Juho Park, Youngchul Sung*, Donggun Kim and H. Vincent Poor, "Outage probability and outage-based robust beamforming for MIMO interference channels with imperfect channel state information," IEEE Transactions on Wireless Communications, vol. 11, no. 10, pp. 3561 - 3573, Oct. 2012.   A technical report related to the paper regarding series expansion of Gaussian quadratic forms is also available.

• Youngchul Sung*, Juho Park, and Donggun Kim, "Trends and advances in MISO/MIMO technologies (in Korean)," KICS Information and Communications Magazine, Aug. 2012.

• Yeongseok Oh, Heejung Yu, Yong H. Lee* and Youngchul Sung, "A nonlinear transceiver architecture for overloaded MIMO interference channels," IEEE Transactions on Communications, vol. 60, no. 4, pp. 946 - 951, Apr. 2012.

• Heejung Yu, Youngchul Sung*, Haksoo Kim and Yong H. Lee, "Beam tracking for interference alignment in slowly-fading MIMO interference channels: A perturbations approach under a linear framework," IEEE Transactions on Signal Processing, vol. 60, no. 4, pp. 1910 - 1926, Apr. 2012.

• Gilown Lee, Juho Park, Youngchul Sung* and Masahiro Yukawa, "Coordinated beamforming with relaxed zero forcing," in Proc. of the 2011 International Conference on Wireless Communications and Signal Processing (WCSP), an invited paper to the special session "Interference Management Techniques in Wireless Networks," Nov. 2011.

• Heejung Yu and Youngchul Sung*, "Least squares approach to joint beam design for interference alignment in multiuser multi-input multi-output interference channels," IEEE Transactions on Signal Processing, vol. 58, no. 9, pp. 4960 - 4966, Sep. 2010. 

Filter-and-Forward Relays

• Donggun Kim, Youngchul Sung*, and Jihoon Chung, "Filter-and-forward relay design for MIMO-OFDM systems," IEEE Transactions on Communications, vol. 62, no. 7, pp. 2329 - 2339, Jul. 2014.

• Donggun Kim, Junyeong Seo and Youngchul Sung*, "Filter-and-forward transparent relay design for OFDM systems," IEEE Transactions on Vehicular Technology, vol. 62, no. 9, pp. 4392-4407, Nov. 2013.

• Yingbo Yua*, Daniel W. Bliss, Saeed Gazor, Yue Rong, and Youngchul Sung, "Guest Editorial: Theories and methods for advanced wireless relays - Issue II" IEEE Journal on Selected Areas in Communications, vol. 31, no. 8, pp. 1361 - 1367, Aug. 2013

• Yingbo Yua*, Daniel W. Bliss, Saeed Gazor, Yue Rong, and Youngchul Sung, "Guest Editorial: Theories and methods for advanced wireless relays - Issue I," IEEE Journal on Selected Areas in Communications, vol. 30, no. 8, pp. 1297 - 1303, Sep. 2012

• Cheolsoon Kim, Youngchul Sung* and Yong H. Lee, "A joint time-invariant filtering approach to the linear Gaussian relay problem," IEEE Transactions on Signal Processing , vol. 60, no. 8, pp. 4360 - 4375, Aug. 2012. Matlab code.

• Youngchul Sung* and Cheolsoon Kim, "The capacity for the linear time-invariant Gaussian relay channel," Sep. 2011. Available at ArXiv. (This paper presents the capacity of  a noncausal LTI Gaussian relay channel.) An improved version which provides causal achievability of the rate in the previous paper in arXiv.

Code-Division Multiple Access

• Youngchul Sung*, Yirang Lim, Lang Tong and Alle-Jan van der Veen, "Signal processing advances for 3G CDMA: From rake receivers to blind techniques," IEEE Communications Magazine, vol. 47, no. 1, pp. 48 - 54, Jan. 2009

• Youngchul Sung, participation in 3G WCDMA Basestation Modem Design and System Optimization,  at the Corporate R & D Center, Qualcomm, Inc., San Diego, CA, USA, 2005 - 2007

• Youngchul Sung, Lang Tong* and Ananthram Swami, "Blind channel estimation for space-time coded WCDMA," EURASIP Journal on Wireless Communications and Networking, vol. 2004, no. 2, pp. 322 - 334, Dec. 2004

• Youngchul Sung and Lang Tong*, "Tracking of fast-fading channels in long code WCDMA," IEEE Transactions on Signal Processing, vol. 52, no. 3, pp. 786 - 795, Mar. 2004

• Lang Tong*, Alle-Jan van der Veen, Patrick Dewilde and Youngchul Sung, "Blind decorrelating rake receiver for long code WCDMA," IEEE Transactions on Signal Processing, vol. 51, no. 6, pp. 1642 - 1655, Jun. 2003

• Youngchul Sung and Juyul Lee, "System simulation of wireless communication systems using HP-ADS," 1999 Hewlett-Packard Workshop, Seould, Korea, 1999.

• Youngchul Sung, participation in Wireless Local Loop (WLL) Project based on Wideband CDMA (WCDMA), Dept. of Digital Communications, LG Information and Communications, ltd., 1997 - 1999