正交分頻多工傳輸技術已被下一代之無線通訊系統採納
。 然而在正交分頻多工系統中，如何消除跨細胞干擾以增強系統表現仍然為一項重要的研究議題。
針對這個議題，幾種解決方案如扇形細胞結構、部分頻譜重複利用結構、及分散式天線系統等均在文獻中有諸多討論。
在此論文中我們以特別的方式結合幾種不同的方案，並建構出一種新的細胞架構。
此架構之關鍵為將分散式天線放置於六邊形細胞之各角落，各分散式天線使用特定之頻帶以服務扇形區之用戶。
模擬結果顯示我們建議的細胞架構能減少功率消耗並提升60%的系統容量，同時中斷率亦在負載0.72時保持0.1。

The orthogonal frequency division multiple access (OFDMA) has been adopted as the
transmission scheme for the next generation wireless communication systems. How-
ever, in the OFDMA systems, how to eliminate the inter-cell interference is still a key
issue to enhance the system performance. In the literature, several solutions have been
proposed, e.g. the sectored cell structure, partial frequency reuse (PFR) scheme and
distributed antenna system (DAS). In this thesis, we combine all these techniques in
a very skillful way and build a new cell architecture. The key idea here is to put a
distributed antenna at each vertex of the hexagonal cell and each antenna is responsi-
ble for serving a sectored area using a part of frequency band. The simulation results
show that the proposed cell architecture can raise the system capacity by 60% while
maintain the outage by 0.1 at loading 0.72 with a lower power consumption.

[1] H. Fujii and H. Yoshino, “Theoretical capacity and outage rate of OFDMA cellular system with fractional frequency reuse," in IEEE Vehicular Technology Conference, May. 2008, pp. 1676-1680.
[2] E. Oh, M.-G. Cho, S. Han, C. Woo, and D. Hong, “Performance analysis of reuse-
partitioning-based subchannelized OFDMA uplink systems in multicell environments," IEEE Trans. on Vehicular Technology, vol. 57, no. 4, Jul. 2008.
[3] C.-S. Chiu and C.-C. Huang, “Combined partial reuse and soft handover in
OFDMA downlink transmission," in IEEE Vehicular Technology Conference, May.
2008, pp. 1707-1711.
[4] J. G. Andrews, W. Choi and R. W. H. JR., “Overcoming interference in spatial
multiplexing MIMO cellular networks," IEEE Wireless Communications, vol. 14,
pp. 95-104, 2007.
[5] W. Choi and J. Andrews, “Downlink performance and capacity of distributed an-
tenna systems in a multicell environment," IEEE Transaction on Wireless Com-
munications, vol. 6, no. 1, pp. 69-73, Jan. 2007.
[6] N. Sei¯, A. Wolfgang, and T. Ottosson, “Downlink performance and capacity of
distributed antenna systems based on realistic channel model," in Smart Antennas,
Feb. 2008, pp. 249-253.
[7] L. Li, G. Li, F. Zhou, and M. Wu, “Downlink performance evaluation of central-
ized and distributed antenna systems in multicell multiuser spatial multiplexing
environment," Oct. 2008, pp. 1-4.
[8] W. Stallings, Wireless Communication and Networks, 2nd ed. Prentice Hall, 2001.
[9] A. A. M. Saleh, A. J. Rustako, and R. S. Roman, “Distributed antennas for indoor
radio communications," IEEE Trans. on Communications, vol. 35, pp. 1245-1251,
Dec. 1987.
[10] S. Venkatesan, A. Lozano, and R. Valenzuela, “Network MIMO: Overcoming inter-
cell interference in indoor wireless systems," in Signals, Systems and Computers,
Nov. 2007, pp. 83-87.
[11] M. K. Karakayali, G. J. Foschini, and R. A. Valenzuela, “Network coordination
for spectrally e±cient communications in cellular systems," IEEE Wireless Com-
munications, vol. 13, pp. 56-61, Aug. 2006.
[12] Y. Akaiwa and H. Andoh, “Channel segregation-a self-organized dynamic channel allocation method: Application to TDMA/FDMA microcellular system," vol. 11,
pp. 949-953, Aug. 1993.
[13] E. Dahlman, S. Parkval, J. SkÄold, and P. Beming, 3G evolution: HSPA and LTE for mobile broadband, 1st ed. Academic Press, July 2007.
[14] T. Keller and L. Hanzo, “Adaptive multicarrier modulation: A convenient frame-
work for time-frequency processing in wireless communications," Proceedings of the
IEEE, vol. 88, pp. 611-640, May. 2000.
[15] M. Morelli, C.-C. J. Kuo, and M.-O. Pun, “Synchronization techniques for orthog-
onal frequency division multiple access (OFDMA): A tutorial review," Proceedings
of the IEEE, vol. 95, pp. 1394-1427, July 2007.
[16] H.-H. Chen, The Next Generation CDMA Technologies, 1st ed. Wiley, 2007.
[17] W. Roh and A. Paulraj, “Outage performance of the distributed antenna systems
in a composite fading channel," in IEEE Vehicular Technology Conference, vol. 3,
Sept. 2002, pp. 1520-1524.
[18] Y. Shen, Y. Tang, T. Kong, and S. Shao, “Optimal antenna location for STBC-
OFDM downlink with distributed transmit antennas in linear cells," IEEE Com-
munications Letters, vol. 11, pp. 387-389, May. 2007.
[19] I. Tou¯k and R. Knopp, “Wideband channel allocation in distributed antenna
systems," in IEEE Vehicular Technology Conference, Sep. 2006.
[20] L. Yang, X. Wang, Z. Li, and W. Wu, “A new reuse partitioning scheme for
distributed antenna cellular systems," in IEEE Information Theory Workshop,
Oct. 2006, pp. 668-672.
[21] G. L. Stuber, Principles of Mobile Communication, 2nd ed. Kluwer Academic,
2001.