Research Interests 

Wireless communication

Applied machine learning

Massive MIMO

Cooperative communication

Intelligent reflecting surface
Terahertz communication

 Selected Publications

- Journal Papers (Selected)

[Submitted/In preparation]  

[P-7] A. Matemu and K. Lee*, "Spatial Modulation and Generalized Spatial Modulation for Dynamic Metasurface Antenna," submitted to IEEE Transactions on Wireless Communications.  

[P-6] S. F. Kimaryo and K. Lee*, "Uplink and Downlink Capacity Maximization of a P2P DMA-Based Communication System," submitted to IEEE Transactions on Wireless Communications. (Under Major Revision)

[P-5] M. Munawar and K. Lee*, "Dual-Polarized IRS-Aided Multiuser MIMO Network: Power Minimization and User Grouping Strategy," submitted to IEEE Transactions on Wireless Communications. 

[P-4] A. Matemu, D.H. Kim, and K. Lee*, "IRS-Aided Joint Inter-path and Intra-path Multiplexing for Terahertz Communication," submitted to IEEE Transactions on Wireless Communications.  

[P-3] S. F. Kimaryo, E. E. Bahingayi, and K. Lee*, Joint active/passive beamforming optimization via RWMMSE and Gradient Projection for Downlink IRS-aided MU-MISO Systems," submitted to IEEE Systems Journal. (The conference version won the Best Paper Award at ICTC, 2023.)

[P-2] M. Munawar and K. Lee*, "Power Optimization of Dual-Polarized IRS-assisted Wireless Networks under Spectral Efficiency Constraints,"  submitted to IEEE Transactions on Wireless Communications. 

[P-1] N. H. Tu and K. Lee*, "Multihop MIMO Full-Duplex Relay Networks with Short-Packet URLLCs," submitted to IEEE Systems Journal. (The conference version won the Outstanding Student Paper Award at ICCAS, 2023.)

[Published/Accepted]

[50] N. N. Dao, N. H. Tu, D. T. Hoang, T. H. Nguyen, L. V. Nguyen, K. Lee*, L. Park, W. Na, and S. Cho*, "A Review on New Technologies in 3GPP Standards for 5G Access and Beyond," to appear in Computer Networks.2024.

[49] N. H. Tu and K. Lee*, "IRS-Assisted Coordinated Direct and Multi-Antenna Relay Transmission for MIMO SWIPT Systems," to appear in IEEE Systems Journal, 2024.  

[48] M. Munawar and K. Lee*, "Dual-Polarized IRS-Assisted MIMO Network,"  to appear in IEEE Transactions on Wireless Communications, 2024.

[47] T. V. Le, K. Lee, and N. C. Luong, "Bitmask Dynamic Programming for User Scheduling in Multi-user MIMO mmWave Systems" IEEE Communications Letters, vol. 27,  no. 12, pp. 3365-3369, Dec. 2023.  

[46] N. H. Tu, D. T. Hoang, and K. Lee*, "Short-Packet URLLCs for MIMO Underlay Cognitive Multihop Relaying with Imperfect CSI," IEEE Access, vol. 11, pp. 81672-81689, Aug. 2023.   

[45] S. F. Kimaryo and K. Lee*, "Low-complexity IRS beamforming based on sphere decoding and tabu search," Journal of Communications and Networks, vol. 25, no. 3, pp. 299-311, June, 2023. 

[44] S. F. Kimaryo and K. Lee*, "Downlink Beamforming for Dynamic Metasurface Antennas," IEEE Transactions on Wireless Communications, vol. 22, no. 7, pp. 4745-4755, July 2023. 

[43] M. Munawar and K. Lee*, "Low-Complexity Adaptive Selection Beamforming for IRS-Assisted Single-User Wireless Networks," IEEE Transactions on Vehicular Technology, vol. 72, no. 4, pp. 5458-5462, Apr. 2023. 

[42] E. E. Bahingayi and K. Lee*, "Low-complexity beamforming algorithms for IRS-aided single-user massive MIMO mmWave systems," IEEE Transactions on Wireless Communications, vol. 21, no. 11, pp. 9200-9211, Nov. 2022.

[41] D. T. Hoang and K. Lee*, "Deep learning-aided signal enumeration for lens antenna array," IEEE Access, vol. 10, pp. 123835-123846, Nov. 2022.  

[40] N. T. Nguyen, K. Lee*, and H. Dai, "Hybrid beamforming and adaptive RF chain activation for uplink cell-free millimeter-wave massive MIMO systems," IEEE Transactions on Vehicular Technology, vol. 71, no. 8, pp. 8739-8755, Aug. 2022.

[39] N. T. Nguyen, Q.-D. Vu, K. Lee, and M. Juntti, "Hybrid relay-reflecting intelligent surface-assisted wireless communications," IEEE Transactions on Vehicular Technology, vol. 71, no. 6, pp. 6228-6244, June 2022. 

[38] N. H. Tu and K. Lee*, "Performance analysis and optimization of multihop MIMO relay networks in short-packet communications," IEEE Transactions on Wireless Communications, vol. 21, no. 6, pp. 4549-4562, June 2022. 

[37] T. V. Le and K. Lee*, "Machine learning-aided link performance prediction for coded MIMO systems," IEEE Transactions on Vehicular Technology, vol. 71, no. 3, pp. 3287-3292, Mar. 2022.  

[36] D. T. Hoang and K. Lee*, "Deep learning-aided coherent direction-of-arrival estimation with the FTMR algorithm," IEEE Transactions on Signal Processing, vol. 70, pp. 1118-1130, Jan. 2022. 

[35] A. N. N. Doan, E. E. Bahingayi, and K. Lee*, "Hybrid combining based on selective activation of double constant phase shifters," IEEE Access, vol. 9, pp. 142012-142019, Nov. 2021.   

[35] N. T. Nguyen, K. Lee*, and H. Dai, "Application of deep learning to sphere decoding for large MIMO systems," IEEE Transactions on Wireless Communications, vol. 20, no. 10, pp. 6787-6803, Oct. 2021. 

[33] Q. V. Pham, N. T. Nguyen, T. Huynh-The, L. B. Le, K. Lee, and W. J. Hwang,  "Intelligent radio signal processing: a survey," IEEE Access, vol. 9, pp. 83818-83850, June 2021. 

[32] G. M. Gadiel, N. T. Nguyen, and K. Lee*, "Dynamic unequal-subarray hybrid beamforming architecture for massive MIMO systems," IEEE Transactions on Vehicular Technology,vol. 70, no. 4, pp. 3469-3478, April 2021.  

[31] N. T. Nguyen and K. Lee*, "Deep learning-aided tabu search detection for large MIMO systems," IEEE Transactions on Wireless Communications, vol. 19, no. 6, pp. 4262-4275, June 2020.  

[29] D. Weon and K. Lee*, "Learning-aided deep path prediction for sphere decoding in large MIMO systems," IEEE Access, vol. 8, no. 1, pp. 70870-70877, Apr. 2020.

[28] E. E. Bahingayi and K. Lee*, "Low-complexity incremental search-aided hybrid precoding and combining for massive MIMO systems," IEEE Access, vol. 8, no. 1, pp. 66867-66877, Apr. 2020. (The conference version won the Best Paper Award at IEEE WCNC, 2020.)

[27] E. E. Bahingayi and K. Lee*, "Hybrid combining based on constant phase shifters and active/Inactive switches," IEEE Transactions on Vehicular Technology, vol. 69, no. 4, pp. 4058-4068, Apr. 2020.  

[26] N. T. Nguyen and K. Lee*, "Unequally sub-connected architecture for hybrid beamforming in massive MIMO systems," IEEE Transactions on Wireless Communications, vol. 19, no. 2, pp. 1127-1140, Feb. 2020. 

[25] N. T. Nguyen and K. Lee*, "Groupwise neighbor examination for tabu search detection in large MIMO systems," IEEE Transactions on Vehicular Technology, vol. 69, no. 1, pp. 1136-1140, Jan. 2020.

[24] N. T. Nguyen, K. Lee*, and H. Dai, "QR-decomposition-aided tabu search detection for large MIMO systems," IEEE Transactions on Vehicular Technology, vol. 68, no. 5, pp. 4857-4870, May 2019.

[23] T. Q. Tran, S. Sugiura, and K. Lee*, "Ordering- and partitioning-aided sphere decoding for generalized spatial modulation," IEEE Transactions on Vehicular Technology, vol. 67, no. 10, pp. 10087-10091, Oct. 2018.

[22] N. T. Nguyen and K. Lee*, "Coverage and cell-edge sum-rate analysis of mmWave massive MIMO systems with ORP schemes and MMSE receivers," IEEE Transactions on Signal Processing, vol. 66, no. 20, pp. 5349-5363, Oct., 2018.  

[21] T. V. H. Nguyen, S. Sugiura, and K. Lee*, "Low-complexity sphere search-based adaptive spatial modulation," IEEE Transactions on Vehicular Technology, vol. 67, no. 8, pp. 7836-7840, Aug., 2018.

[20] T. V. Le and K. Lee*, "Adaptive perturbation-aided opportunistic beamforming," IEEE Communications Letters. vol. 22, no. 8, pp. 1660-1663, Aug., 2018. 

[19] R. Nakai, M. Oiwa, K. Lee,  and S. Sugiura*, “Generalized buffer-state-based relay selection with collaborative beamforming,” IEEE Transactions on Vehicular Technology, vol. 67, no. 2, pp. 1245-1257, Feb., 2018.

[18] N. T. Nguyen and K. Lee*, "Cell coverage extension with orthogonal random precoding for massive MIMO systems," IEEE Access, vol.5, Apr. 2017. 

[17] K. Pham and K. Lee*, “Non-cooperative interference alignment for multicell multiuser MIMO uplink channels,” IET Communications, vol. 11, no. 5, pp. 648-654, Apr. 2017.

[16] K. Pham and K. Lee*, “Interference alignment for multicell multiuser uplink channels,” IEEE Transactions on Vehicular Technology, vol. 65, no. 7, pp. 5146-5159, July, 2016.

[15] K. S. Gyamfi, J.-H. Baek and K. Lee*, "Lattice reduction aided tabu search with a channel-dependent stopping criterion for MIMO systems," Electronics Letters, vol. 51, no. 24, pp. 2062-2064, Nov. 2015.

[14] D.-L. Le, J.-H. Baek, and K. Lee*, “Selective cooperative decoding based on a hard-decision-aided log-likelihood ratio approximation,” IET Communications, vol. 9, no. 24, pp. 1754-1762, Sep. 2015.

[13] K. Pham and K. Lee*, “Low-complexity SIC detection algorithms for multiple-input multiple-output systems,” IEEE Transactions on Signal Processing, vol. 63, no. 17, pp. 425-4633, Sep. 2015. 

[12] K. Lee, "Doubly ordered sphere decoding for spatial modulation," IEEE Communications Letters, vol. 19, no.5, pp. 795-798, May. 2015.

[11] K. Lee, "Novel decoding algorithms for decode-and-forward cooperative beamforming systems," IET Communications, vol. 8, no. 17, pp. 3012-3018, Nov. 2014.

[10] K. Lee, “Uplink interference alignment for two-cell MIMO interference channels,” IEEE Transactions on Vehicular Technology, vol. 62, no. 4, pp. 1861-1865, May 2013.

 [9]  K. Lee and L. Hanzo, “Resource-efficient wireless relaying protocols,” IEEE Wireless Communications Magazine, vol 17, no. 2, pp. 66-76, Apr., 2010.

 [8]  K. Lee and L. Hanzo, “Optimal decoding for hard-decision forwarding aided cooperative spatial multiplexing systems,” IEEE Transactions on Wireless Communications, vol. 8, no. 9, Sep. 2009. (The conference version won the Best Paper Award at IEEE ICC, 2009.)

 [7]  S.-H. Won, K. Lee, and L. Hanzo, “Initial code acquisition in the cooperative non-coherent MIMO DS-CDMA downlink,” IEEE Transactions on Vehicular Technology, vol. 58, no. 3, pp. 1387-1395, Mar. 2009.

 [6]  K. Lee and L. Hanzo, “MIMO-assisted hard versus soft decoding-and-forwarding for network coding aided relaying systems,” IEEE Transactions on Wireless Communications, vol. 8, no. 1, pp. 376-385, Jan. 2009.

 [5]  K. Lee and J. Chun, “ML symbol detection based on the shortest path algorithm for MIMO systems,” IEEE Transactions on Signal Processing, vol. 55, no. 11, pp. 5477-5484, Nov. 2007.

 [4]  K. Lee, J. Chun, and L. Hanzo, “Optimal lattice-reduction aided successive interference cancellation for MIMO systems,” IEEE Transactions on Wireless Communications, vol. 6, no. 7, pp. 2438-2443, July 2007.

 [3]  I. Kim, K. Lee, and J. Chun, “A MIMO antenna structure that combines transmit beamforming and spatial multiplexing,” IEEE Transactions on Wireless Communications, vol. 6, no. 3, pp. 775-779, Mar. 2007.

 [2]  K. Lee and J. Chun, “Symbol detection in V-BLAST architectures under channel estimation errors,” IEEE Transactions on Wireless Communications, vol. 6, no. 2, pp. 593-597, Feb. 2007.

 [1]  K. Lee and J. Chun, “Frequency offset estimation for MIMO and OFDM systems using orthogonal training sequences,” IEEE Transactions on Vehicular Technology, vol. 56, no. 1, pp. 146-156, Jan. 2007.

- International Conference Papers

[20] N. H. Tu and K. Lee*, “Performance Analysis and Deep-Learning-Based Real-Time Evaluation for Multihop MIMO Full-Duplex Relay Networks with Short-Packet URLLCs,“ International Conference on Contro, Automation and Systems (ICCAS), Oct, 2023. (Outstanding Student Paper Award) 

[19]  S. F. Kimaryo, E. E. Bahingayi, and K. Lee*,  “Active and passive beamforming based on RWMMSE and Gradient Projection for IRS-aided MU-MISO Systems,“ International Conference on Information and Communication Technology Convergence (ICTC), Oct. 2023. (Best Paper Award)

[18]  N. H. Tu, D. T. Hoang, and K. Lee*,  “Performance Analysis and Machine-Learning-Based Real-Time Evaluation for MIMO CR Multihop Relaying with Imperfect CSI in Short-Packet URLLCs," International Conference on Information and Communication Technology Convergence (ICTC), Oct. 2023

[17]  D. T. Hoang and K .Lee, “Coherent Signal Enumeration based on Deep Learning and the FTMR Algorithm,“ IEEE International Conference on Communications, May 2022.

[16]  N. T Nguyen, Q. D Vu, K .Lee, and M. Juntti, “Spectral Efficiency Optimization for Hybrid Relay-Reflecting Intelligent Surface,“ IEEE International Conference on Communications Workshops (ICC Workshops), June 2021.

[15]  E. E. Bahingayi and K .Lee, “Energy-efficient Hybrid Combining Based on Active/Inactive Switches,“ International Conference on Electric-Vehicle, SmartGrid and Information Technology (ICESI), Sep. 2020.

[14] E. E. Bahingayi and K. Lee, “Low-complexity hybrid precoding and combining scheme based on array response vectors,” IEEE Wireless Communications and Networking Conference (WCNC), Seoul, South Korea, May 2020. (Best Paper Award)

[12] K. Pham and K. Lee, “An interference alignment scheme for symmetric multicell multiuser channels,” IEEE Vehicular Technology Conference, May 2014.

[11] K. Lee and L. Hanzo, “Iterative detection and decoding for hard-decision forwarding aided cooperative spatial multiplexing,” IEEE International Conference on Communications, Dresden, Germany, June 2009. (Best Paper Award)

[10] K. Lee and L. Hanzo, “Multiple antenna assisted hard versus soft decoding-and- forwarding for network coding aided relaying systems,” IEEE Global Communications Conference, New Orleans, LA, Nov 2008.

 [9]  S.-H..Won, K. Lee, and L. Hanzo, “Serial search based code acquisition in the cooperative MIMO aided DS-CDMA downlink,” IEEE International Conference on Communications, Beijing, China., May 2008.

 [8]  H. Yang, K. Lee, and J. Chun, “Zero-forcing based 2-phase relaying,” IEEE International Conference on Communications, Glasgow, U.K., June 2007.

 [7]  K. Lee, J. Chun, and L. Hanzo, “Interference cancellation assisted lattice-reduction aided detection for MIMO systems,” The 9th International Symposium on Spread Spectrum Techniques and Applications, Manaus, Brazil, Aug. 2006.

 [6]  K. Lee and J. Chun “Carrier frequency recovery in MIMO and OFDM Systems using orthogonal training sequences, ” IEEE Vehicular Technology Conference, LA, CA, Oct. 2004.

 [5]  K. Lee and J. Chun, “On the beamforming weight of the MIMO/SDMA system under channel uncertainty,” IEEE Vehicular Technology Conference, Milan, Italy, May 2004.

 [4]  M. Suk, S. Cho, K. Lee, and J. Chun, “A new calibration algorithm for cellular CDMA antenna arrays,” IEEE Vehicular Technology Conference, Vancouver, British Columbia, Canada, Sept. 2002.

 [3]  K. Lee and J. Chun, “On the interference nulling operation of the V-BLAST under channel estimation errors,” IEEE Vehicular Technology Conference, Vancouver, British Columbia, Canada, Sept. 2002.

 [2]  K. Lee and J. Chun, “A new nulling method in the V-BLAST under uncertain channel information,” IEEE Sensors Conference, Orlando, FL, June 2002.

 [1]  D. G. Kong, K. Lee, J. Chun, P. Choi, J. C. Yun , S. J. Lee, and J. H. Lee, “Performance of coherent adaptation algorithms for the WCDMA smart antenna system in Rayleigh flat-fading channel,” SPIE Annual Meeting, San Diego, CA, July 2001.

- Patents (KR, US, EU) :

[21] K.-C. Lee and K. Pham, "Method for uplink interference alignment in mobile communication system," K.R. Patent 10-1585999, 2016. 01. 11.

[20] K.-C. Lee, "Apparatus and method for optimal and suboptimal computation of log likelihood ratio of cooperative beam forming system,"  K.R. Patent 10-1559344, 2015.10.05.

[19] K.-C. Lee and K. Pham, "Apparatus and method for optimal and suboptimal successive interference cancellation receiver with high efficiency," K.R. Patent 10-1553242, 2015.09.09. 

[18] K.-C. Lee, "Method for uplink interference alignment in mobile communication system," K.R. Patent 1014176610000, 2014.07.02. 

[17] K.-C. Lee, S.-O. Kwon, and N.-H. Lee, "Method and apparatus for transmitting and receiving inter-cell interference information in communication system," U.S. Patent 8565785, 2013.10.22. 

[16] K.-C. Lee, "Apparatus and method for cooperative relaying based on beamforming in a mobile communication system," U.S. Patent 08559484, 2013.10.15. 

[15] N.-H. Lee, S.-O. Kwon, J.-I. Kim, H.-S. Youm, and K.-C. Lee, "Inter-cell interference coordination method and apparatus for wireless communication system," U.S. Patent 08412256, 2013.04.02. 

[14] C.-W. Yoo, Y.-S. Choi, J.-H. Lee,  J.-H. Chun, K.-C. Lee, and Y.-S. Kim, "Apparatus and method for receiving transmitted signal in multiple antenna system," K.R. Patent 1012443030000, 2013.03.11. 

[13] Y.-H. Jung, Y.-S. Kim, H.-J. Yang, K.-C. Lee, and J.-H. Chun, "Apparatus and method for relaying in a wireless communication system," U.S. Patent 08126033, 2012.02.28. 

[12] E.-S. Kim, J.-H. Lee, J.-H. Chung, H.-J. Kim, J.-H. Chun, K.-C. Lee, and I.-H. Kim, "Apparatus and method for grouping antennas of Tx in MIMO system which considers a spatial multiplexing and beamforming," K.R. Patent 1009815540000, 2010.09.03. 

[11] Y.-H. Jung, Y.-S. Kim, H.-J. Yang, K.-C. Lee, and J.-H. Chun, "Apparatus and method for relaying in broadband wireless communication system," K.R. Patent 1009736710000, 2010.07.28. 

[10] C.-W. Yoo, E.-S. Kim, J.-H. Lee,  J.-H. Chun, K.-C. Lee, and Y.-S. Kim, "Apparatus and method for transmitting an uplink signal in a mobile communication system using an OFDMA scheme," U.S. Patent 07706351, 2010.04.27. 

 [9]  C.-W. Yoo, E.-S. Kim, J.-H. Lee,  J.-H. Chun,   K.-C. Lee, and Y.-S. Kim , "Apparatus and method for transmitting uplink signal in mobile communication system using an orthogonal frequency division multiple access scheme," K.R. Patent 1009187470000, 2009.09.16. 

 [8]  E.-S. Kim, J.-H. Lee, J.-H. Chung, H.-J. Kim, J.-H. Chun, K.-C. Lee, and I.-H. Kim, "Method for grouping transmission antennas in mobile communication system including multiple transmission/reception antennas," U.S. Patent 07483719, 2009.01.27. 

 [7]  E.-S. Kim, J.-H. Lee, J.-H. Chung, H.-J. Kim, J.-H. Chun, K.-C. Lee, and I.-H. Kim, "Method for assigning channels based on spatial division multiplexing in an orthogonal frequency division multiplexing system with multiple antennas," U.S. Patent 07319685, 2008.01.15. 

 [6]  B.-J. Jeong, J.-Y. Ahn, K.-C. Lee, and J.-H. Chun, "Method of maximum likelihood detection using lattice reduction in multi-input multi-output system," K.R. Patent 1007897540000, 2007.12.21. 

 [5]  C.-W. Yoo, E.-S. Kim, J.-H. Lee,  J.-H. Chun, K.-C. Lee, and Y.-S. Kim , "Apparatus and method for precoding an uplink signal in a mobile communication system using an OFDMA scheme," E.U. Patent 01816815, 2007.08.08. 

 [4]  E.-S. Kim, J.-H. Lee, J.-H. Chung, H.-J. Kim, J.-H. Chun, K.-C. Lee, and I.-H. Kim, "Method for channel estimation with spatial division multiplexing in an orthogonal frequency division multiplexing system with multiple antennas," E.U. Patent 01742405, 2007.01.10. 

 [3]  J.-H. Kwun, C.-S. Hwang, K.-C. Lee, and J.-H. Chun, "Apparatus and method for detecting a signal in a multiple-input multiple-output mobile communication system," E.U. Patent 01677437, 2006.07.05. 

[2]  K.-C. Lee, J.-H. Chun, J.-H. Chung, and S.-H. Nam, "Beamforming method for a MIMO space division multilplexing system," E.U. Patent 01598955, 2005.11.23.

 [1]  E.-S. Kim, J.-H. Lee, J.-H. Chung, H.-J. Kim, J.-H. Chun, K.-C. Lee, and I.-H. Kim, "Method for assigning channels based on spatial division multiplexing in an orthogonal frequency division multiplexing system with multiple antennas," E.U. Patent 01542419, 2005.06.15.