IMT Advanced incorporates two 4G standards, they are 3GPP LTE-Advanced (also known as LTE Release 10), which is the evolved version of LTE, and WiMAX 2.0 (based on IEEE 802.16m), which is upgraded from Mobile WiMAX (based on IEEE 802.16e).
These two emerging 4G standards both employ OFDMA as the downlink transmission scheme. However, in an OFDMA downlink system, as adjacent cells use the same frequency, inter-cell interference (ICI) may degrade the bit rate at cell edge. Inter-cell interference coordination (ICIC) is considered as a promising technology for alleviating this ICI and thus improving the cell edge data rate. In sum, ICIC is aimed to provide a more homogeneous throughput to users located in different regions of the network.
In this dissertation, we have studied ICI mitigation schemes in OFDMA systems and especially, we concentrate on the downlink side. The scope of our research encompasses ICIC schemes in cellular homogeneous networks as well as inter-layer interference coordination (ILIC) schemes in cellular heterogeneous networks (HetNets). It is worth noting that ILIC is also a kind of ICIC. There are three main contributions in our works.
Firstly, the performance of two widely accepted ICIC schemes, namely partial frequency reuse (PFR) and soft frequency reuse (SFR), have been evaluated and compared based on the signal strength difference based (SSD-based) user classification method, which is adopted in the LTE standard. Compared with the universal frequency reuse system, our simulation results show that both PFR and SFR schemes provide a significant cell edge throughput gain; however, a loss in total cell throughput usually comes up. Furthermore, based on a well defined data-rate fairness criterion, we show that PFR achieves a higher system capacity when compared to SFR. The second contribution is to present a hybrid ICI mitigation scheme, which makes use of both PFR and soft handover. The basic idea of this hybrid scheme is to dynamically select between a PFR scheme and a soft handover scheme to provide better signal quality for cell edge users. Compared with the standard PFR scheme, computer simulations show that approximately one quarter of cell edge users can get improvements in signal quality as well as link spectral efficiency from using the proposed hybrid scheme. We also observe that by using our approach, there is a significant cell edge throughput gain over the standard PFR scheme. Furthermore, considering the data rate fairness among users, we show that our method achieves higher overall system capacity as compared with the standard partial frequency reuse scheme. The final contribution of this dissertation is the development of an ILIC scheme that enables to deal with inter-layer interference in a co-channel macro-pico HetNet that carrying out (pico)cell range expansion (CRE) technique. The idea of the proposed method is to coordinate frequency and power resources among macrocells and picocells with a set of resource allocation rules. Simulation results show that the proposed method can bring a significant increase in overall system capacity as well as reduce the user outage rate in the system, especially when aggressive CRE is applied.
Next generation mobile communication systems make mobile broadband a reality,
improving transmission bit rate at cell edges will become a pressing problem. In the short term for cellular homogeneous deployments, ICIC strategies could serve to achieve more uniform user experience while maintain acceptable system capacity. It is worthy to note that static ICIC schemes are attractive for operators since the complexity of their deployment is very low. In the long term, a combination of ICIC/ILIC and CoMP could potentially employ to further enhance the system performance not only for cellular homogeneous networks, but also for cellular HetNets. However, while ICIC techniques are primary designed for static or semi-static operation, CoMP techniques target more dynamic coordination [17]. As a result, the backhaul requirements, both in terms of throughput and latency become the top challenge issue for CoMP implementation. Note that the exact requirements depend on different downlink CoMP technologies being considered (e.g., CS/CB, DCS or JT). In addition, excessive (uplink) feedback overhead introduced by CoMP could also be a problem. Therefore, there will be a subject of designing effective CoMP or hybrid CoMP/ICIC schemes that take practical limitations as well as uplink overhead into account for future research.
References
[1] Cisco, “Cisco Visual Networking Index: Global Mobile Data Traffic Forecast Update, 2011-2016,” Cisco White Paper, Feb. 2012.
[2] IEEE 802.16e-2005, “Part 16: Air Interface for Fixed Broadband Wireless Access Systems, Amendment for physical and MAC layers for combined fixed and mobile operation in licensed bands,” 2005.
[3] Recommendation ITU-R M.1645, “Framework and Overall Objectives of the Future Development of IMT-2000 and Systems Beyond IMT-2000,” ITU-R Radio Assembly, June 2003.
[4] IEEE 802.16m-2011, “IEEE Standard for Local and Metropolitan Area Networks Part 16: Air Interface for Broadband Wireless Access Systems Amendment 3: Advanced Air Interface,” May 2011.
[5] 3GPP TS 36.201 V8.3.0, “Evolved Universal Terrestrial Radio Access (E-UTRA);
LTE Physical Layer - General Description,” Mar. 2009.
[6] 3GPP TR 25.913 V7.0.0, “Requirements for Evolved UTRA (E-UTRA) and Evolved UTRAN (E-UTRAN),” June 2005.
[7] 3GPP TR 25.913 V7.0.0, “Requirements for Evolved UTRA (E-UTRA) and Evolved UTRAN (E-UTRAN),” June 2005.
[8] 3GPP TR 36.913 V8.0.1, “Requirements for further advancements for Evolved Universal Terrestrial Radio Access (E-UTRA),” Mar. 2009.
[9] Siemens, “Interference mitigation – Considerations and Results on Frequency Reuse,”
3GPP R1-050738, 3GPP TSG RAN WG1 Meeting #42, September 2005.
[10] M. Sternad, T. Ottosson, A. Ahlen, A. Svensson, “Attaining both coverage and high spectral efficiency with adaptive OFDM downlinks,” in Proc. IEEE 58th Veh. Technol.
Conf., vol. 4, pp. 2486-2490, Oct. 2003.
[11] Huawei, “Soft Frequency Reuse Scheme for UTRAN LTE,” 3GPP R1-050507, 3GPP TSG RAN WG1 Meeting #41, May 2005.
[12] Bin Fan, Yu Qian, Kan Zheng, Wenbo Wang, “A Dynamic Resource Allocation Scheme Based on Soft Frequency Reuse for OFDMA Systems,” in Proc. Int. Symp.
Microwave, Antenna, Propagation and EMT Tech. for Wireless Commu., pp. 1-4, Aug.
2007.
[13] Alcatel, “Interference Coordination in new OFDM DL air interface,” 3GPP R1-050407, 3GPP TSG RAN WG1 Meeting #41, May 2005.
[14] Harri Holma and Antti Toskala, LTE for UMTS – OFDMA and SC-FDMA Based Radio Access, John Wiley & Sons, 2009.
[15] 3GPP TR 36.814 V9.0.0, “Further advancements for E-UTRA physical layer aspects,”
Mar. 2010.
[16] 3GPP TR 36.819 V11.0.0, “Coordinated multi-point operation for LTE physical layer aspects,” Dec. 2011.
[17] Daewon Lee, Hanbyul Seo, Bruno Clerckx, Eric Hardouin, David Mazzarese, Satoshi Nagata, Krishna Sayana, “Coordinated Multipoint Transmission and Reception in LTE-Advanced: Deployment Scenarios and Operational Challenges,” IEEE Commun.
Mag., vol. 50, no. 2, pp. 148-155, Feb. 2012.
[18] Xu Xiaodong, Chen Xin, Li Jingya, “Handover Mechanism in Coordinated Multi-Point Transmission/Reception System,” ZTE Communications, no. 1, pp. 31-35, Mar. 2010.
[19] D. Astély, E. Dahlman, A. Furuskär, Y. Jading, M. Lindström, and S. Parkvall, “LTE:
the evolution of mobile broadband,” IEEE Commun. Mag., vol. 47, no. 4, pp. 44-51, April 2009.
[20] CMCC, “New Work Item Proposal: Enhanced ICIC for non-CA based deployments of heterogeneous networks for LTE,” 3GPP RP-100383, 3GPP TSG RAN Meeting #47, Mar. 2010.
[21] A. Damnjanovic, J. Montojo, Y. Wei, T. Ji, T. Luo, M. Vajapeyam, T. Yoo, O. Song, and D. Malladi, “A survey on 3GPP heterogeneous networks,” IEEE Wireless Commun., vol. 18, no. 3, pp. 10–21, June 2011.
[22] Lopez-Perez and X. Chu, “Inter-cell interference coordination for expanded region picocells in heterogeneous networks,” in Proc. IEEE Int. Conf. Computer Commun.
Networks (ICCCN), pp. 1-6, Aug. 2011.
[23] Qualcomm, “Importance of Serving Cell Selection in Heterogeneous Networks,”
3GPP R1-100701, 3GPP TSG RAN WG1 Meeting #59, Jan. 2010.
[24] A. Khandekar, N. Bhushan, Ji Tingfang, and V. Vanghi, “LTE-Advanced:
Heterogeneous networks,” in Proc. 2010 European Wireless Conference, pp. 978-982,
April 2010.
[25] Lopez-Perez, D. Guvenc, I. de la Roche, G. Kountouris, M. Quek, T.Q.S., Jie Zhang,
“Enhanced intercell interference coordination challenges in heterogeneous networks,”
IEEE Wireless Commun., vol. 18, no. 3, pp. 22-30, June 2011.
[26] Texas Instruments, “Performance of Inter-Cell Interference Mitigation with Semi-Static Frequency Planning for EUTRA Downlink,” 3GPP R1-060368, 3GPP TSG RAN WG1 Meeting #44, Feb. 2006.
[27] Ericsson, “Downlink Inter-Cell Interference Co-ordination/Avoidance – Evaluation of Frequency Reuse,” 3GPP R1-061374, 3GPP TSG RAN WG1 Meeting #45, May 2006.
[28] Yikang Xiang, Jijun Luo, C. Gorg, “Performance Impact of User Grouping on
[31] 3GPP TSG RAN WG1, “LS on additional RSRP trigger for ICIC,” 3GPP R1-083272, 3GPP TSG RAN WG1 Meeting #54, Aug. 2008.
[32] Motorola, “CoMP Operation and Evaluation,” 3GPP R1-091935, 3GPP TSG RAN WG1 Meeting #57, May 2009.
[33] S.-E. Elayoubi, O. Ben Haddada, B. Fourestie, “Performance evaluation of frequency planning schemes in OFDMA-based networks,” IEEE Trans. on Wireless Communications, vol. 7, no. 5, pp. 1623-1633, May 2008..
[34] R. Y. Chang, Zhifeng Tao, Jinyun Zhang, C.-C.J. Kuo, “A Graph Approach to Dynamic Fractional Frequency Reuse (FFR) in Multi-Cell OFDMA Networks,” in Proc. IEEE Int. Conf. Commun. (ICC’09), June 2009.
[35] K. Doppler, C. Wijting, K. Valkealahti, “Interference Aware Scheduling for Soft Frequency Reuse,” in Proc. IEEE 69th Veh. Technol. Conf., April 2009.
[36] Farooq Khan, LTE for 4G Mobile Broadband: Air Interface Technologies and Performance, Cambridge, 2009.
[37] Siemens, “Interference Mitigation by Partial Frequency Reuse,” 3GPP R1-060135, 3GPP TSG RAN WG1 Ad Hoc Meeting on LTE, Jan. 2006.
[38] Stefania Sesia, Issam Toufik, Matthew Baker, LTE - The UMTS Long Term Evolution:
From Theory to Practice, John Wiley, Sept. 2011.
[39] H. Jia, Z. Zhang, G. Yu, P. Cheng, S. Li, “On the Performance of IEEE 802.16 OFDMA System Under Different Frequency Reuse and Subcarrier Permutation Patterns”, in Proc. IEEE Int. Conf. Commun., pp. 5720-5725, June 2007,
[40] Texas Instruments, “Inter-Cell Interference Mitigation for EUTRA”, 3GPP R1-051059, 3GPP TSG RAN WG1 Meeting #42bis, October 2005.
[41] Shannon, C.E., “Collected Papers,” Edit by Sloane & Wyner, IEEE Press, 1993.
[42] P. Mogensen, Wei Na, I.Z. Kovacs, F. Frederiksen, A. Pokhariyal, K.I. Pedersen, T.
Kolding, K. Hugl, M. Kuusela, “LTE Capacity Compared to the Shannon Bound,” in Proc. IEEE 65th Veh. Technol. Conf., pp. 1234-1238, April 2007.
[43] Qualcomm Europe, “Description and simulations of interference management technique for OFDMA based E-UTRA downlink evaluation,” 3GPP R1-050896, 3GPP TSG RAN WG1 Meeting #42, Sept. 2005.
[44] 3GPP TR 25.814 v7.1.0, “Physical Layer Aspects for Evolved UTRA”, Sept. 2006.
[45] Orange, China Mobile, KPN, NTT DoCoMo, Sprint, T-Mobile, Vodafone, Telecom Italia, “Inter-Cell Interference Mitigation for EUTRA”, 3GPP R1-070674, 3GPP TSG RAN WG1 Meeting #48, Feb. 2007.
[46] Huawei, “Power Allocation among eNBs in Close-Loop Downlink CoMP Transmission with CA”, 3GPP R1-091268, 3GPP TSG RAN WG1 Meeting #56bis, Mar. 2009.
[47] NTT DoCoMo, “Investigation on Coordinated Multipoint Transmission Schemes in LTE-Advanced Downlink,” 3GPP R1-090314, 3GPP TSG RAN WG1 Meeting #55bis, Jan. 2009.
[48] A.J. Viterbi, AM. Viterbi, KS. Gihousen, E. Zehavi, “Soft handoff extends CDMA cell coverage and increase reverse link capacity,” IEEE J. Sel. Areas Commun., vol. 12, pp.
1281-1288, Oct. 1994.
[49] H. Holma and A. Toskala, WCDMA for UMTS, 3rd edition, Wiley, 2002.
[50] Renshui Zhu, Xing Zhang, Wenbo Wang, “Scheduling Based Controllable
Interference Coordination in OFDMA Systems,” in Proc. First Internation Conference on Communications and Networking, pp. 1-5, Oct. 2006.
[51] NTT DoCoMo, NEC, SHARP, “Intra-Node B Macro Diversity Using Simultaneous Transmission with Soft-combining in Evolved UTRA Downlink”, 3GPP R1-050700, 3GPP TSG RAN WG1 Meeting #42, September 2005
[52] Jian Huang, P. Xiao, Xiaojun Jing, “A downlink ICIC method based on region in the LTE-Advanced system,” 2010 IEEE PIMRC Workshops, pp. 420-423, Sept. 2010.
[53] ASB, Alcatel-Lucent, “DL Pico/Macro HetNet Performance: Cell Selection,” 3GPP R1-101873, 3GPP TSG RAN WG1 Meeting #60bis, April 2010.
[54] Tongwei Qu, Dengkun Xiao, Dongkai Yang, Wei Jin, Yuan He, “Cell selection analysis in outdoor heterogeneous networks,” in Proc. 2010 IEEE ICACTE, pp.
V5-554 – V5-557, Aug. 2010.
[55] Alcatel, “Comparison of efficiency of DL Interference Coordination schemes and view on measurements on intra-frequency neighbor cells,” 3GPP R1-062365, 3GPP TSG RAN WG1 Meeting #46, Aug. 2006.
[56] Alcatel-Lucent Shanghai Bell, Alcatel-Lucent, “Interference analysis for Type I and Type II Relay,” 3GPP R1-092154, 3GPP TSG RAN WG1 Meeting #57, May 2009.
[57] Samsung, “Cell Range Expansion Performance Evaluation,” 3GPP R1-105408, 3GPP TSG RAN WG1 Meeting #62bis, Oct. 2010.
[58] 3GPP TR 36.942 V8.3.0, “E-UTRA Radio Frequency (RF) System Scenarios,” Sept.
2010.
[59] Nokia Siemens Networks, Nokia, “Initial Results and Assumptions for LTE-Advanced Heterogeneous Scenarios,” 3GPP R1-093329, 3GPP TSG RAN WG1 Meeting #58, Aug. 2009.
[60] Nokia Siemens Networks, Nokia, “Downlink CCH performance aspects for co-channel deployed macro and HeNBs,” 3GPP R1-100350, 3GPP TSG RAN WG1 Meeting #59bis, Jan. 2010.
Vita
Che-Sheng Chiu was born in Chiayi, Taiwan, R.O.C., in 1975. He received his B.S.
degree in Applied Mathematics from National Chiao Tung University, Hsinchu, Taiwan, in 1997. He pursued his M.S. and Ph.D. in the Department of Communication Engineering under the supervision of Professor Chia-Chi Huang in National Chiao Tung University, and was graduated in 1999 and 2012, respectively.
Since 2000, he has been with Telecommunication Laboratories, Chunghwa Telecom Company, working on 3GPP LTE and LTE-Advanced standardization. His research interests include radio network resource management, mobile network system-level performance evaluation, and cross-layer optimization for high-speed wireless networks.
Author’s Publications (2006~2012)
A. Journal Papers
1. C.-S. Chiu and C.-C. Huang, “Performance Comparison between Two Inter-Cell Interference Coordination Schemes for OFDMA Downlink Systems,” International Journal of Electrical Engineering, vol. 18, no. 1, pp. 19-26, Feb. 2011.
2. C.-S. Chiu and C.-C. Huang, “A Hybrid Inter-Cell Interference Mitigation Scheme for an OFDMA Downlink System,” IEICE Transaction on Communications, vol.
E93-B, no. 1, pp. 73-81, Jan. 2010.
B. Conference Papers
3. C.-S. Chiu and C.-C. Huang, “An Interference Coordination Scheme for Picocell Range Expansion in Heterogeneous Networks”, in Proc. IEEE Vehicular Technology Conference 2012 (VTC2012-Spring), May 2012.
4. C.-S. Chiu and C.-C. Huang, “Combined Partial Reuse and Soft Handover in OFDMA Downlink Transmission”, in Proc. IEEE Vehicular Technology Conference 2008 (VTC2008-Spring), May 2008.
5. C.-S. Chiu and C.-C. Huang, “Improving Inter-Sector Handover User Throughput by Using Partial Reuse and Softer Handover in 3GPP LTE Downlink”, in Proc. The 14th International Conference on Advanced Communication Technology (ICACT2008), Feb. 2008.
6. C.-S. Chiu and C.-C. Huang, “A Study on Fast Sector Selection with Frequency Coordination in E-UTRA Downlink,” in Proc. The 4th IEEE VTS Asia Pacific Wireless Communications Symposium, Aug. 2007.
7. C.-S. Chiu and C.-C. Huang, “On Inter-Sector Macro Diversity for 3GPP LTE Downlink,” in Proc. 2006 National Symposium on Telecommunications, Dec. 2006.