Enhanced Radio Access Technologies for Next Generation Mobile Communication phần 5 ppt

FUNDAMENTALS OF SINGLE-CARRIER CDMA TECHNOLOGIES 117

R = 3

/4 and additional redundancy is transmitted with the second transmission. The

following puncturing matrices are used (1 represents that the bit at that position is

transmitted and 0 represents that it is not transmitted):

(51) P1 =

⎡

⎣

111111

100000

000100

⎤

⎦, P2 =

⎡

⎣

000000

011110

110011

⎤

⎦

For CC, the same packet with puncturing matrix P1 is transmitted until a positive

acknowledge (ACK) is received. For IR, the puncturing matrix P1 is used for the

first transmission and P2 for the second transmission and the order repeated for

further transmissions. Code combining is employed if the same packet is trans￾mitted more than once. For reference, the throughput obtained with coherent rake

combining is also plotted; the throughput degrades drastically when the number L

of paths increases. With the increase in L, the frequency-selectivity of the channel

gets stronger and the orthogonality distortion is severer. Hence, the throughput

decreases with the increase in L. However, with MMSE-FDE, the throughput is

almost insensitive to L. This is because MMSE-FDE can partially restore the code

orthogonality which is distorted due to the frequency selectivity of the channel

and obtain the frequency diversity gain. For L = 1, the throughput is lower with

MMSE-FDE compared to rake combining, due to the GI insertion loss. However

in broadband channels characterized by time- and frequency-selective fading, the

MMSE-FDE has a better performance.

REFERENCES

[1] F. Adachi, M. Sawahashi, and H. Suda, “Wideband DS-CDMA for next generation mobile

communications systems,” IEEE Commun. Mag., Vol. 36, No. 9, pp. 56–69, Sept. 1998.

[2] Y. Kim, et al., “Beyond 3G: vision, requirements, and enabling technologies,” IEEE Commun.

Mag., Vol. 41, No. 3, pp.120–124, Mar. 2003.

[3] M. Helard, R. Le Gouable, J-F. Helard and J-Y. Baudais, “Multicarrier CDMA techniques for

future wideband wireless networks,” Ann. Telecommun., vol. 56, pp. 260–274, 2001.

[4] S. Hara and R. Prasad, “Overview of multicarrier CDMA,” IEEE Commun. Mag., Vol. 35,

pp. 126–144, Dec. 1997.

[5] B. Sklar, “Rayleigh fading channels in mobile digital communication systems part 1: characteri￾zation,” IEEE Commun. Mag., pp. 90–100, July 1997.

[6] F. Adachi and T. Sao, “Joint antenna diversity and frequency-domain equalization for multi-rate

MC-CDMA,” IEICE Trans. Commun., Vol. E86-B, No. 11, pp. 3217–3224, Nov. 2003.

[7] F. Adachi, D. Garg, S. Takaoka, and K. Takeda, “Broadband CDMA techniques,” IEEE Wireless

Communications Magazine, Vol. 12, No. 2, pp. 8–18, Apr. 2005.

[8] F. Adachi and K. Takeda, “Bit error rate analysis of DS-CDMA with joint frequency-domain

equalization and antenna diversity combining,” IEICE Trans. Commun., Vol. E87-B, pp.

2991–3002, Oct. 2004.

[9] F. Adachi, T. Sao, and T. Itagaki, “Performance of multicode DS-CDMA using frequency domain

equalization in a frequency selective fading channel,” Electronics Letters, Vol. 39, pp. 239–241,

Jan. 2003.

118 CHAPTER 3

[10] D. Falconer, S. L. Ariyavistakul, A. Benyamin-Seeyar, and B. Eidson, “Frequency domain equal￾ization for single-carrier broadband wireless systems,” IEEE Commun. Mag., Vol. 40, pp. 58–66,

Apr. 2002.

[11] N. Benvenuto and S. Tomasin, “On the comparison between OFDM and single carrier modulation

with a DFE using a frequency-domain feedforward filter,” IEEE Trans. Commun., Vol. 50, No.

6, pp. 947–955, June 2002.

[12] A. M. Chan and G. W. Wornell, “A class of block-iterative equalizers for intersymbol interference

channels: fixed channel results,” IEEE Trans. Commun., Vol. 49, No. 11, pp. 1966–1976, Nov.

2001.

[13] N. Benvenuto and S. Tomasin, “Block iterative DFE for single carrier modulation,” IEE

Electronics Letters, Vol. 38, No. 19, pp. 1144–1145, Sept. 2002.

[14] S. Tomasin and N. Benvenuto, “A reduced complexity block iterative DFE for dispersive wireless

applications,” Proc. 60th IEEE Veh. Technol. Conf. 2004 Fall, Los Angels, U.S.A., 26–29 Sept.

2004.

[15] K. Takeda, K. Ishihara, and F. Adachi, “Downlink DS-CDMA transmission with joint MMSE

equalization and ICI cancellation,” Proc. 63rd IEEE Veh. Technol. Conf. 2006-Spring, Melbourne,

Australia, 7–10 May 2006.

[16] R. T. Derryberry, S. D. Gray, D. M. Ionescu, G. Mandyam, and B. Raghothaman, “Transmit

diversity in 3G CDMA systems,” IEEE Commun. Mag., Vol. 40, pp. 68–75, Apr. 2002.

[17] S. Alamouti, “A simple transmit diversity technique for wireless communications”, IEEE Journal

on Selected Areas in Commun., Vol. 16, No. 8, pp. 1451–1458, Oct. 1998.

[18] E. G. Larsson and P. Stoica, Space–time block coding for wireless communications, Cambridge

Univ. Press, Cambridge, UK, 2003.

[19] D. Garg and F. Adachi, “Performance improvement with space-time transmit diversity using

minimum mean square error combining equalization in MC-CDMA,” IEICE Trans. Commun.,

pp. 849–857, Mar. 2004.

[20] N. Al-Dhahir, “Single-carrier frequency-domain equalization for space-time block-coded transmis￾sions over frequency-selective fading channels,” IEEE Commun., Lett., Vol. 5, No. 7, pp. 304–306,

July 2001.

[21] F. W. Vook, T. A. Thomas, and K. L. Baum, “Cyclic-prefix CDMA with antenna diversity,”

Proc. 55th IEEE Veh. Technol. Conf. 2002-Spring, pp. 1002–1006, May 2002.

[22] K. Takeda, T. Itagaki, and F. Adachi, “Application of space-time transmit diversity to single-carrier

transmission with frequency-domain equalization and receive antenna diversity in a frequency￾selective fading channel,” IEE Proceedings Communications, Vol. 151, No. 6, pp. 627–632, Dec.

2004.

[23] W. Su, X. G. Xia, and K. J. R. Liu, “A systematic design of high-rate complex orthogonal

space-time block codes,” IEEE Commun. Lett., Vol. 8, No. 6, pp. 380–382, June 2004.

[24] F. Adachi, “Wireless past and future-evolving mobile communications systems,” IEICE Trans.

Fundamentals, Vol.E84-A, pp.55–60, Jan. 2001.

[25] G. J. Foschini and M. J. Gans, “On limits of wireless communications in a fading environment

when using multiple antennas”, Wireless Personal Communications, Kluwer, Vol. 6, No. 3, pp.

311–335, 1998.

[26] G. J. Foschini, “Layered space-time architecture for wireless communication in a fading

environment when using multi-element antennas,” Bell Lab. Tech. Journal, Vol. 1, No. 2, pp.

41–59, 1996.

[27] T. Matsumoto, J. Ylitalo, and M. Juntti, “Overview and recent challenges of MIMO system,”

IEEE Vehicular Technology Society News, pp. 4–9, May 2003.

[28] J. G. Proakis, Digital Communications, 4th edition, McGraw-Hill, 2001.