Wireless Communications and Networking

Wireless  research in the Faculty of Engineering at the Chinese University of Hong Kong (CUHK) covers a wide range of areas  including cellular systems, adaptive transmission and reception, diversity combining techniques, multiple input multiple output (MIMO) technologies, spread spectrum methods, RF/microwave engineering and IC design, Low-temperature Co-fired Ceramic technology (LTCC) / antenna design,  ultra wideband (UWB) technologies, media access control (MAC) protocols, mobility management and control algorithms, wireless LAN/Mesh,  and ad-hoc/ sensor networking and RFID systems.

 

Prof. T.S.P. Yum has performed research on different topics in wireless communications, including channel assignment in cellular systems [1], [2]. More recently, he is interested in energy conservation methods for wireless sensor networks, and anti-collision techniques for RFID systems.

Prof. W.S. Wong has considered the control of systems with finite communication bandwidth [3], [4]. He has also considered power control problems in wireless systems, and congestion control problems in communication networks. He is also interested in wireless resource allocation, MAC algorithm for sensor networks, and UWB systems.

Prof. K.L. Wu (Dept. of Electronic Engineering) focuses on LTCC technology for RF/microwave integrated module[13], Electromagnetic numerical modeling in various aspects, and EM modal analysis for various guided wave structure for various high performance microwave sub-system, such as filters and diplexers in space, wireless and RFID applications. He has made significant contributions in the areas of EM modeling, microwave/ antenna engineering, Finite Element and Finite Difference Methods in Electromagnetics Scattering and Computational Electromagnetics [14].

Prof T.M. Lok has considered receiver design for spread spectrum communication systems. He has proposed novel receivers in direct sequence code division multiple access (CDMA) systems [5] as well as multicarrier CDMA systems. He is also interested in adaptive transmission, resources allocation for multiuser communication systems, and wireless ad hoc networks.

Prof S.C. Liew is an expert in high-speed switching and the networking area. He began to venture into wireless networking in 2002, first working on TCP over wireless networks and then on MAC/PHY layers of IEEE 802.11 wireless LAN and ad hoc networks. He and his students won two best-paper awards in IEEE conferences in 2004 ([6] and [7]).

Prof. D.M. Chiu is an expert in networking protocol and control. He recently started working on wireless networking research. So far, the contribution is in ad hoc multi-hop routing to optimize the capacity [10,11]. He is also working on new routing and forwarding approaches (e.g. Bloom filter based) to better support mobility in the Internet, and cross layer traffic controls based on SoftMAC.

Prof. W.C. Lau joined the Information Engineering (IE) Department in Sep. 2005 after working for Qualcomm and Bell Labs. He has been an active contributor to IETF and 3GPP2 mobility management protocols and standards. Prior to that, his research focus was on traffic management[8] and security in high-speed networks[12]. His current research interests include P2P mobile ad-hoc networks, wireless mesh, and RFID systems.

Prof. K.K.M. Cheng's (Dept. of Electronic Engineering) research interests include RFIC design, Transceiver design, Linearization Technique and Microwave Passive Circuit [15,16].

Prof. Y.J. Zhang joined the IE Department in Jan. 2005 after finishing her PhD in 2004. She has been working on cross MAC-PHY layer resource allocation for wireless networks[17]. She is also interested in MIMO-OFDM systems, wireless OFDM [18] and 802.11 networks.

Prof. C.S. Chen joined the IE Department in Sep. 2005 after finishing his PhD in 2005. He is interested in multiple access control, power control, resource allocation optimization, and traffic scheduling and control [19,20].

Prof. O.C. Yue joined the IE Department in August 2003 after spending 26 years in wireless networking research and development in the US. He has worked on 3G systems and wireless LAN [9]. He has major contributions in establishing the Mobile Technologies Centre at CUHK and is now a scientific consultant to the HKSAR Government. He is interested in performance analysis and sensor networks.

Prof. Y.T. Zhang (Dept. of Electronic Engineering), Director of Joint Research Centre for Biomedical Engineering, is interested in wireless body sensor networks and wireless medical devices for m-healthcare [21, 22].

Our professors are also internationally active. They serve on editorial boards of many major international journals including IEEE Transactions on Communications, IEEE Journal on Selected Area of Communications, IEEE Transactions on Multimedia, IEEE Transactions on Vehicular Technology, IEEE Transactions on Automatic Control, and Communications in Information and Systems. They also serve in the program committees of major international conferences including IEEE Infocom, ICC, Globecom, WCNC and VTC.

 

Selected Publications:

1. Zhang M, Yum TSP, “Comparisons of channel-assignment strategies in cellular mobile telephone systems,” IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 38 (4): 211-215 NOV 1989.
2. Zhang M, Yum TSP, “The nonuniform compact pattern allocation algorithm for cellular mobile systems,” IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 40 (2): 387-391 MAY 1991.
3. Wong WS, Brockett RW, “Systems with finite communication bandwidth constraints - I: State estimation problems,” IEEE TRANSACTIONS ON AUTOMATIC CONTROL 42 (9): 1294-1299 SEP 1997.
4. Wong WS, Brockett RW, “Systems with finite communication bandwidth constraints - II: Stabilization with limited information feedback,” IEEE TRANSACTIONS ON AUTOMATIC CONTROL 44 (5): 1049-1053 MAY 1999.
5. Wong TF, Lok TM, Lehnert JS, et al., “A linear receiver for direct-sequence spread-spectrum multiple-access systems with antenna arrays and blind adaptation,” IEEE TRANSACTIONS ON INFORMATION THEORY 44 (2): 659-676 MAR 1998.
6. P. C. Ng and S. C. Liew, “Offered Load Control in IEEE 802.11 Multi-hop Ad-hoc Networks,” The 1st IEEE International Conference on Mobile Ad-hoc and Sensor System, Oct 2004. (Won best paper award)
7. P. C. Ng and S. C. Liew, “Re-routing Instability in IEEE 802.11 Multi-hop Ad-hoc Networks, ” The 4th IEEE International Workshop on Wireless Local Network, Nov 2004. (Won best paper award)
8. W.C. Lau, S.Q. Li, "Statistical Multiplexing and Buffer Sharing in Multimedia High-Speed Networks: A Frequency Domain Perspective," in IEEE/ACM Transactions on Networking, Vol. 5, No. 3, June 1997, pp. 382-396.
9. A DeSimone, MC Chuah, OC Yue, “Throughput Performance of Transport-Layer Protocols over Wireless LANs” IEEE GLOBECOM, NEW YORK,1993.
10. Y. Gao, D.M. Chiu and J.C.S. Lui , “The fundamental role of hop distance in IEEE802.11 multi-hop ad-hoc wireless networks,”  IEEE ICNP 2005, Boston, November 2005.
11. Y. Gao, D.M. Chiu, J.C.S. Lui, “Determining the End-to-end Throughput Capacity in Multi-Hop Networks: Methodolgy and Applications,” to appear in ACM Sigmetrics/ Performance, 2006.
12. Y. Kim, W.C. Lau, M.C. Chuah and H. J. Chao, "PacketScore -- a distributed proactive defense against DDOS attacks," Proc. of IEEE Infocom, March 2004.
13. K.L. Wu, “Low Temperature Co-fired Ceramic (LTCC) Technology in RF and Microwave Engineering”, Wiley Encyclopedia of RF and Microwave Engineering , in press.
14. K.L. Wu, G. Y. Delisle, D.-G. Fang and M. Lecours, “Coupled finite element and boundary element methods in electromagnetic scattering problem”, Chapter 3 of Finite Element and Finite Difference Methods in Electromagnetic Scattering, Science Publishing Company., 1990.
15. F.L. Wong, K.K.M. Cheng, "A Novel Approach to the Design and Implementation of Dual-Band, Compact, Planar, 90° Branch-Line Coupler",  IEEE Trans. Microwave Theory and Techniques, Nov 2004.
16. C. W. Fan, and K. K. M. Cheng, “Theoretical and experimental study of amplifier linearization based on harmonic and baseband signal injection technique,” IEEE Trans. Microwave Theory and Techniques, Vol. 50, No. 7, pp. 1801-1806, July 2002.
17. Y.J. Zhang and K.B. Letaief, “Cross layer adaptive resource management for wireless packet networks with OFDM signaling,” to appear in IEEE Transactions on Wireless Communications.
18. Y.J. Zhang and K.B. Letaief, “An efficient resource allocation scheme for spatial multiuser access in MIMO/OFDM systems,” IEEE Transactions on Communications, vol. 53, No. 1, pp. 107-116, Jan. 2005.
19. C. S. Chen, W. S. Wong, "Bandwidth allocation for wireless multimedia systems with most regular sequences," IEEE Transactions on Wireless Communications, vol. 4, no. 2, pp. 635-645, Mar. 2005.
20. H. Zhang, C. S. Chen, W. S. Wong, "Distributed power control for time-varying systems: performance and convergence analysis," IEEE Transactions on Vehicular Technology, vol. 54, no. 5, Sep. 2005.
21. R.S.H. Istepanian, E. Jovanov, and Y.T. Zhang, “Beyond seamless mobility and global  wireless health-care connectivity,” IEEE Transactions on Information Technology in Biomedicine, Vol.8, No. 4, pp405-414, December 2004.
22. C.C.Y. Poon, S.D. Bao, and Y.T. Zhang, “A novel biometrics method to secure wireless body area sensor networks for telemedicine and mobile healthcare,” IEEE Communication Magazine (special issue on telemedicine), April, 2006.