本論文共分為三個部分來討論寬頻無線通訊系統之系統設計與效能評估，第一個部分我們討論干擾的來源以及其干擾對系統效能的影響。在IEEE802.16m上行/下行控制通道中我們提出了領航訊號型式，如正方型領航訊號、直線型領航訊號；接著在通道路徑上，考慮一個行動台與多個基地台之間的干擾狀況，其中行動台對應於一個服務基地台，其他基地台對於行動台將會產生不同的干擾狀況，因此我們設計不同干擾權重的領航訊號給其他干擾的基地台使用，最後模擬得知設計後的干擾影響將低於一般無使用此設計的情況。第二個部分提出在IEEE 802.16m Resource Block裡放置領航訊號於不同位置時，同時去估測這些領航訊號的通道頻率響應，並使用這些領航訊號估測出來的通道頻率響應經由線性內插法去估測出Resource Block中其他位置的通道頻率響應。在通道頻率響應的估測中，我們使用了最小平方差以及最小均方差兩種演算法，並提出一個2x2 MIMO OFDM的系統架構模擬速度3km/hr、120km/hr、350km/hr下的位元錯誤率以及分析系統效能。第三個部分在新世代無線通訊系統有著高傳輸速度與高頻寬等優點下，針對基地台在其涵蓋範圍內，如何建立基地台之間的協調合作機制以提高頻寬使用效率；同時也探討當基地台在其涵蓋範圍內存在Femto cells或是Repeaters時，整體的系統架構，通道模型，信號的傳送及接收，Repeater的基本特性等。最後利用模擬方法以比較系統有無存在Femto cells或是Repeaters時其系統通信量及頻寬的使用情況比較。

In this dissertation it consists of three parts to discuss System design and performance evaluation for broadband wireless communication system.
In the first part we discuss the sources of interferences and their effect on the system performance in the transmission of pilot signals in the uplink and downlink (UL/DL) control channels. Square and line type pilot patterns are considered. Then in communication paths between an MS and various BSs, including a desired path between the MS and the desired BS and many interference paths between the MS and other BSs, then when we assign different weight to each interference pilot type the resulting system interference will be lower than the interference induced in the system in which a common and equal weight is assigned to all pilots.
In the second part of this dissertation it involves the estimation of channel impulse response; we first insert various types of pilots at pre-determined locations of the physical Resource Block in IEEE 802.16m to estimate the channel impulse responses at these locations and then use certain linear interpolation techniques to find the channel impulse responses at other locations. In the channel impulse response estimation both the Least Square (LS) and the Minimum Mean Square Error (MMSE) algorithms are considered. Various pilot structures have been proposed for 2x2 MIMO OFDM systems and the system performances in terms of bit error rate (BER) have been simulated and evaluated  from the estimated channel impulse responses when an mobile user moves at speeds of 3 km/hr, 120 km/hr and 350 km/hr.
In the last part of this dissertation we consider in the next generation wireless communication system in the implementation of coordination scheme among base stations to improve the system bandwidth utilization efficiency; simultaneously we also consider the situation when it includes Femto cells or Repeaters in the base station coverage areas. We discuss the basic characteristics of Femto cells and Repeaters; explore the possible overall system structures and the possible channel models. With simulation evaluations we find the system capacity, bandwidth utilization when Femto cells are deployed or Repaeters are installed and compare these system performances with those systems without Femto cells or Repeaters included.

TABLE OF CONTENTS
CHINESE ABSTRACT...........................................I
ENGLISH ABSTRACT..........................................II
TABLE OF CONTENTS.........................................IV
LIST OF FIGURES.........................................VIII
LIST OF TABLES............................................XI
CHAPTER 1 INTRODUCTION.....................................1
1.1 Study Motivation.......................................1
1.1.1 Inter-cell interference management in DL/UL PHY control for IEEE802.16m....................................1
1.1.2 Pilot-assisted channel estimation for multi-input multi-output (MIMO) 2x2 OFDM system........................2
1.1.3 Performance analysis with coordination among base stations for next generation communication system..........3
1.2 Organization...........................................3
CHAPTER 2 INTER-CELL INTERFERENCE MANAGEMENT IN DL/UL PHY CONTROL FOR IEEE802.16m....................................6
2.1 Introduction...........................................6
2.2 Interference Types.....................................7
2.3 PHY Control for Interference Management................8
2.3.1 DL/UL control channel for interference management...11
2.4 Interference Reducing Pilot...........................13
2.4.1 Types of interference reducing pilots...............13
2.4.2 Interference reducing pilot pattern versus interference weight.......................................14
2.4.3 Pilots assignment in TDD/FDD........................16
2.5 Simulation............................................19
2.5.1 Simulation for 7 BSs with Frequency Reuse Factor 1..19
2.5.2 Simulation for 19 BSs with Frequency Reuse Factor 19........................................................23
2.6 Summary...............................................27
CHAPTER 3 PILOT-ASSISTED CHANNEL ESTIMATION FOR MULTI-INPUT MULTI-OUTPUT (MIMO) 2x2 OFDM SYSTEM.......................28
3.1 Introduction..........................................28
3.2 System Model..........................................29
3.2.1 Arrangement of pilots...............................30
3.2.2 Interpolation method................................32
3.2.3 Channel estimation..................................33
3.3 Simulation............................................36
3.4 Summary...............................................40
CHAPTER 4 PERFORMANCE ANALYSIS WITH COORDINATION AMONG BASE STATIONS FOR NEXT GENERATION COMMUNICATION SYSTEM.........42
4.1 Introduction..........................................42
4.2 User’s Environment Cases.............................45
4.3 System Performance of Base Station....................46
4.3.1 Analysis of communication environment...............47
4.3.2 Analysis of base station bandwidth usage............49
4.4 Analysis When Certain BS-Complemented Apparatus Are Indoor Installed..........................................54
4.4.1 Repeater............................................54
4.4.1.1 Analysis of repeater..............................55
4.4.1.2 Performance analysis in coordination environment when repeaters are installed..............................56
4.4.2 Femto cell..........................................59
4.4.2.1 Analysis of femto cell............................59
4.4.2.2 Performance analysis when coordination is implemented in femto cells................................61
4.5 Summary...............................................64
CHAPTER 5 CONCLUSIONS AND FUTURE WORKS....................66
REFERENCES................................................69

LIST OF FIGURES
Figure 1.1 Organization of this dissertation………………………..………………………5
Figure 2.1 (a) Control channel structure for TDD……………………..…………………..9
Figure 2.1 (b) Control channel structure for FDD…………………………..………….....10
Figure 2.2 DL flow control for interference management………………………………..10
Figure 2.3 UL flow control for interference management………………………………..11
Figure 2.4 Cell managing information in the DL control channel………………………..12
Figure 2.5 Cell managing information in the UL control channel………………………..12
Figure 2.6 Square type pilots…..…………………………………………………………13
Figure 2.7 Line type pilots…………………..……………………………………………14
Figure 2.8 Interference weight assignments for square type pilot pattern………………..15
Figure 2.9 Interference weight assignments for line type pilot pattern…………………...16
Figure 2.10 Pilot assignments in TDD segments…………………………………………17
Figure 2.11 Pilot assignments in TDD subframes………………………………………...17
Figure 2.12 Pilot type assignments in FDD multiplexing………………………………...18
Figure 2.13 Pilot type assignments for DL and UL subframes in FDD multiplexing…….18
Figure 2.14 Cell - edge interference………………..……………………………………..19
Figure 2.15 Orthogonal pilot pattern assignments for cell 1 and cell 2 when the MS is located at the cell edge……………………………………………………19
Figure 2.16 Interference introduced from neighboring BSs to the serving BS………..…21
Figure 2.17 The MS uses the same frequency to communicate with all cluster’s BSs…...25
Figure 3.1 System structure…………………………………………………………….....30
Figure 3.2 Pilots Allocation………………………………………………………..……...31
Figure 3.3 LS & MMSE simulation result in 3km/hr………………………………….….38
Figure 3.4 LS & MMSE simulation result in 120km/hr…..………………..……..………39
Figure 3.5 LS & MMSE simulation result in 350km/hr…………………………………..40
Figure 4.1 A UE is covered within multiple base stations………………………………..43
Figure 4.2 Users environment be depicted with patterns.………………………………...46
Figure 4.3 System simulation functional block diagram………………………………….47
Figure 4.4 UEs reception statistics: Coordination scheme is implemented………………48
Figure 4.5 UEs reception statistics: Coordination scheme is not implemented…………..49
Figure 4.6 Bandwidth usage with coordination scheme implemented……………………50
Figure 4.7 Bandwidth usage without coordination scheme implemented.………………..51
Figure 4.8 Statistics of services.………………………………………………...………...53
Figure 4.9 Statistics of throughputs.…………………….………………………………...53
Figure 4.10 Repeater set up and its important parameters [37, 38]……………….....……55
Figure 4.11 Output SNR of indoor antenna……………………………………………….56
Figure 4.12 Repeaters installed environment………………..……………………………57
Figure 4.13 Users Service Quantity with and without the Installation of Repeaters……58
Figure 4.14 Throughputs with and without Installation of Repeaters………………….…58
Figure 4.15 Femto cell environments……………………………………………………..59
Figure 4.16 SNR vs. Distance in femto cell………………………………………………61
Figure 4.17 Users Connected in the DL/UL in the Base Stations and Femto Cells with and without the Deployment of Femto Cell…………………………………......63
Figure 4.18 Overall Throughputs in the Base Stations and Femto Cells with and without Deployment of Femto Cell……………………………………………….....63
Figure 4.16 System capacities with or without coordination scheme and with or without the installation of femto cells………………………………………………65

LIST OF TABLES
Table 2.1 Simulation parameters for frequency reuse factor 1…………………...………20
Table 2.2 Pilot type assignments for BSs………………………………………………....22
Table 2.3 Resulting interference levels with and without using interference reducing pilots for BSs………………………………………………………………...............23
Table 2.4 Simulation parameters for frequency reuse factor 19………………………….24
Table 2.5 Pilots assignments for different clusters…………………………………..........26
Table 2.6 Resulting interference levels with and without using interference reducing pilots for BSs…………………………………………………………………...……27
Table 3.1 Simulation Parameters…..……………………………………………………...37
Table 4.1 LTE Parameters………………………………………………………………...48
Table 4.2 Statistics of Service and Throughput…………………………………………..52
Table 4.3 Users Service Quality and Throughput when Repeaters Installed……………..57
Table 4.4 Parameters of Femto Cell [37]……………………………………………………60
Table 4.5 Users Connection Statuses when Femto Cells Implemented………………..…62
Table 4.6 Users Connection Statuses when No Femto Cells Implemented………………62

[1].	Y. G. Jan, Y. H. Lee, M. H. Chuang, H. W. Tseng, W. C. Lee, W. C. Tseng, S. T. Sheu, P. K. Liao, P. Cheng, Y. T. Hsieh, P. A. Ting, “Inter-Cell Interference Management in DL/UL control,“ IEEE 802.16 Broadband Wireless Access Working Group, C80216m-08_443r3, May 2008.
[2].	Z. Li, A. Bacioccola, S. Maheshwari, A. Boariu, Y. Saifullah, X. Qi, X. Wang, “Proposed Text from IEEE C80216m-08/224r2 for Downlink Control Structure in P802.16m SDD,” IEEE 802.16 Broadband Wireless Access Working Group, C80216m-08_017r1, Apr. 2008.
[3].	S. Vrzic, M.-H. Fong, R. Novak, J. Yuan, D. Yu, S.-Y. Kim, A. Tee, K. Sivanesan, “Proposed SDD Text on Downlink Control Structure,“ IEEE 802.16 Broadband Wireless Access Working Group, C80216mDL_ctrl-08_023, Apr. 2008.
[4].	R. Kang, Y. Liu, Y. Guan, Z. Lu,”Proposed Text from IEEE C80216m-08/224r2 for Downlink Control Structure in P802.16m SDD,” IEEE 802.16 Broadband Wireless Access Working Group, C80216mDL_ctrl-08_024, Apr. 2008.
[5].	F. Wang, B. Mondal, M. Cudak, A. Ghosh, T. Thomas, F. Vook ,”Proposal on SDD Text on Downlink Control Structure,” IEEE 802.16 Broadband Wireless Access Working Group, C80216mDL_ctrl-08_025, Apr. 2008.
[6].	C. Sun, W. Wang, L. Yang, “Proposed SDD Text of DL Control Structure based on IEEE C80216m-08/225r3,” IEEE 802.16 Broadband Wireless Access Working Group, C80216m-08_027, Apr. 2008.
[7].	Y. Yuk, H. Cho, J. Kim, K. Ryu, ” Proposed Text for 16m SDD on Downlink Control Structure,” IEEE 802.16 Broadband Wireless Access Working Group, C80216m-08_032r1, Apr. 2008.
[8].	J. B. Park, Y. J. Sang, S.-L. Kim, K. S. Kim, “Adaptive Inter-Cell Interference Management for Downlink FH-OFDMA Systems,” 10th International Conference on Advanced Communication Technology, Vol. 2, pp. 1040 – 1044, Feb. 2008
[9].	Y. Chen, K. H. Teo, S. Kishore, J. Zhang, “Inter-Cell Interference Management in WiMAX Downlinks by A Stackelberg Game between BSs,” IEEE International Conference on Communications, pp. 3442 – 3446, May 2008
[10].	A. Benjebbour, M. Shirakabe, Y. Ohwatari, J. Hagiwara, and T. Ohya, “Evaluation of user throughput for MU-MIMO coordinated wireless networks,” IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications, pp. 1 – 5, Sept. 2008
[11].	R.B. Moreira, F. Cavalcanti, “An hierarchical approach for inter-cell scheduling in interference-limited cellular networks,” IEEE 9th Workshop on Signal Processing Advances in Wireless Communications, pp. 376 – 380, July 2008
[12].	H.-S. Kim, J. S. Song, Y. S. Shin, “Inter-cell Interference Coordination for Uplink Non-real-time Data in CDMA Systems,” 10th International Conference on Advanced Communication Technology, Vol. 1, pp. 777 – 780, Feb. 2008
[13].	E. Karami, “Tracking Performance of Least Squares MIMO Channel Estimation Algorithm,” IEEE Communications Transactions on, vol. 55, pp. 2201-2209, Nov. 2007.
[14].	H. Zamiri-Jafarian, S. Pasupathy, “Robust and Improved Channel Estimation Algorithm for MIMO-OFDM Systems,” IEEE Wireless Communications Transactions on, vol. 6, pp. 2106-2113, Aug. 2007.
[15].	A. Sezgin, E.A. Jorswieck, E. Costa, “LDC in MIMO Ricean Channels: Optimal Transmit Strategy with MMSE Detection,” IEEE Transactions on Signal Processing, [see also IEEE Transactions on Acoustics, Speech, and Signal Processing], vol. 56, pp.313-328, Jan. 2008.
[16].	A. Medles, D. T. M. Slock, “Achieving the Optimal Diversity-Versus-Multiplexing Tradeoff for MIMO Flat Channels With QAM Space–Time Spreading and DFE Equalization,” IEEE Transactions on Information Theory, vol. 52, pp. 5312-5323, Dec. 2006.
[17].	Y. Liang, H. Luo, R. Liu, Chongguang Yan, “RLS Channel Estimation and Data Detection in Space-Time Coded MIMO-OFDM Systems,” ChinaCom First International Conference on Communications and Networking, pp.1-5, Apr. 2007.
[18].	T. Koike, “Optimum-Weighted RLS Channel Estimation for Time-Varying Fast Fading MIMO Channels”, IEEE International Conference on Communications, pp. 5015-5020, Aug. 2007.
[19].	M.A. Saeed, B.M. Ali, M. Ismail, S. Khatun, N.K. Noordin, “Time-domain RLS-based channel estimation for MIMO OFDM systems,” IEEE International Conference on Telecommunications and Malaysia International Conference on Communications, pp. 520-525, Feb. 2008.
[20].	M. Juntti, K. Hooli, K. Kiiskila, J. Ylioinas, “Space-Time Equalizers for MIMO High Speed WCDMA Downlinks,” IEEE Transactions on Wireless Communications, vol. 6, pp. 2582-2592, July 2007.
[21].	R. Visoz, N. Gresset, A.O. Berthet, “Advanced Transceiver Architectures for Downlink MIMO CDMA Evolution,” IEEE Transactions on Wireless Communications, vol. 6, pp. 3016-3027, Aug. 2007.
[22].	P.C.F. Eggers, T.W.C. Brown, K. Olesen, G.F. Pedersen, “Assessment of Capacity Support and Scattering in Experimental High Speed Vehicle to Vehicle MIMO Links,” IEEE 65th Vehicular Technology Conference, pp. 466-470, May 2007.
[23].	L.-C. Wang, C.-W. Chiu, C.-J. Yeh, W.-H. Sheen, “Coverage Performance Analysis of OFDM-Based Spatial Multiplexing Systems,” IEEE 65th Vehicular Technology Conference, pp.2334-2338, May 2007.
[24].	K. Acolatse, Y. Bar-Ness, D. Kim, “A Novel MIMO SC-DS-CDMA HARQ scheme for Frequency Selective and Time Varying Channels,” IEEE Ninth International Symposium on Spread Spectrum Techniques and Applications, pp. 297-301, Aug. 2006.
[25].	Z. Tong, B. Li, and M. Liu, “ A Novel Downlink Coordination Scheme for CoMP SU-MIMO,” International Conference on Network Computing and Information Security (NCIS), vol.1, pp.121-125, May 2011.
[26].	G. Liu, J. Zhang, D. Jiang, L. Lei, Q. Wang, F. Qin, “Downlink Interference Coordination and Mitigation for future LTE-Advanced System,” Asia-Pacific Conference on Communications, 2009. APCC 2009, pp. 225 – 229, Oct. 2009
[27].	M. Rahman, H. Yanikomeroglu, and W. Wong, “Interference Avoidance with Dynamic Inter-Cell Coordination for Downlink LTE System,” IEEE Wireless Communications and Networking Conference, 2009. WCNC 2009. pp. 1-6, May 2009.
[28].	S. Brueck, J. Giese, L. Zhao, A. Dekorsy, “On MAC Layer Throughput Enhancements in LTE-A by Downlink Macro Diversity,” IEEE International Conference ON Communications Workshops, 2009. ICC Workshops 2009. , pp. 1-5, Aug. 2009.
[29].	G. J. Foschini and M. J. Gans, “On limits of wireless communications in a fading environment when using multiple antennas,” Wireless Personal Communications, Vol. 6, pp. 311–335, Feb. 1998.
[30].	IEEE 802.16m Evaluation Methodology Document (EMD), IEEE 02.16m-08/004r5, Jan. 2009.
[31].	R. Srinivasan, J. Zhuang, L. Jalloul, R. Novak, J. Park, “IEEE 802.16m Evaluation Methodology Document,” IEEE 802.16 Broadband Wireless Access Working Group, 80216m-08_003r7(SDD), Jan. 15, 2009.
[32].	V. Erceg, K. V. S. Hari, M. S. Smith, D.S. Baum, and P. Soma, “Channel Models for Fixed Wireless Applications,” IEEE 802.16 Broadband Wireless Access Working Group, C802.16.3c-01/29r4, June 2003.
[33].	A. F. Molisch, H. Asplund, R. Heddergott, M. Steinbauer, and T. Zwick, “The COST259 directional channel model – I. overview and methodology,” IEEE Trans. Wireless Communication, Vol. 5, pp. 3421–3433, 2006.
[34].	M. Steinbauer, A. F. Molisch, and E. Bonek, “The double-directional radio channel,” IEEE Antennas and Propagation Magazine, pp. 51–63, Aug. 2001. 
[35].	W. Stallings, “Wireless communications and networks,” Prentice-Hall, 2002.
[36].	COST Action 231, ”Digital Mobile Radio Towards Future Generation systems, Final report,” Tech., Rep., European Communities, EUR 18957, 1999
[37].	Rel.9 3GPP TR 36.814 “Further advancements for E-UTRA physical layer aspects,” Mar. 2010.
[38].	Coiler, “WiMAX Band Selective Repeater- BR-2600,” http://www.coiler.com.tw
[39].	D. Chu, "Polyphase codes with good periodic correlation properties," IEEE Transactions on Information Theory, pp. 531-532, July 1972.
[40].	S. Beyme, C. Leung, “Efficient computation of DFT of Zadoff-Chu sequences,” Electronics Letters , vol.45, no.9, pp.461-463, April 23 2009.
[41].	B.M. Popovic, “Efficient DFT of Zadoff-Chu sequences,” Electronics Letters , vol.46, no.7, pp.502 -503, April 1 2010.
[42].	F. Khan, “LTE for 4G Mobile Broadband: Air Interface Technologies and Performance,” 1st Ed., Cambridge University Press, 2009.
[43].	C.-J. Ran, Z.-L. Deng, X. Wang, ”Two average weighted measurement fusion Kalman filtering algorithms in sensor networks,” Intelligent Control and Automation, 2008. WCICA 2008. 7th World Congress on, pp. 2374-2391, 2008.
[44].	R. Olfati-Saber, X. Wang ; , ”Kalman-Consensus Filter : Optimality, stability, and performance,” Decision and Control, 2009 held jointly with the 2009 28th Chinese Control Conference. CDC/CCC 2009. Proceedings of the 48th IEEE Conference on, pp. 7036-7042, 2009.
[45].	L. Wang, T, Liang, ”Kalman Filter Channel Estimation Based on Comb-Type Pilot in Time-Varying Channel,”  Wireless Communications, Networking and Mobile Computing, 2006. WiCOM 2006.International Conference on, pp. 1-3, 2006.
[46].	J. Sterba, D. Kocur, “Pilot symbol aided channel estimation for OFDM system in frequency selective Rayleigh fading channel,” Radioelektronika, 2009, 19th International conference, pp. 77-80, April 2009.
[47].	G. Auer, “Channel estimation in two dimensions for OFDM systems with multiple transmit antennas,” Global Telecommunications Conference, GLOBECOM ’03 IEEE, pp.322-326, Dec. 2003.
[48].	Z. Taheri, M. Ardebilipour, M. A. Mohammadi, “Channel estimation in time and frequency domain in OFDM systems,” Wireless Networks and Information Systems, WNIS ’09 International conference on, pp. 209-212, Dec. 2009.
[49].	S. Colieri, M. Ergen, A. Puri, A. Bahai, “A study of channel estimation in OFDM systems,” Vehicular Technology Conference, VTC 2002 IEEE 56th, vol. 2, pp. 894-898, 2002.