FREQUENCY DOMAIN EQUALIZATION TECHNIQUES FOR MULTICODE DS-CDMA IN FREQUENCY SELECTIVE RAYLEIGH FADING CHANNEL
Main Article Content
Abstract
Orthogonal multicode direct sequence code division multiple access (DS-CDMA) has the flexibility in offering high data rate services. However, in a frequency-selective fading channel, the bit error rate (BER) performance is severely degraded since the orthogonality among spreading codes is partially lost. In this paper, frequency-domain equalization (FDE) and space antenna diversity combining are applied to orthogonal multicode DS-CDMA in order to restore the code orthogonality and improve the BER performance of the system. Two methods of FDE are considered, the first method based on fast Fourier transform (FFT), while the second method based on circulant matrices. Moreover, a channel interleaving method, called chip interleaving is used to improve the performance of multicode DS-CDMA system.
Article Details
Section
How to Cite
References
D. Falconer, S.L. Ariyavisitakul, A. Benyamin-Seeyar, and B. Eidson, “Frequency Domain Equalization for Single-Carrier Broadband Wireless Systems”, White paper
http://www.sce.carleton.ca./ bbw/papers/Ariyavisita kul.pdf., 2002
D. Falconer, S. L. Ariyavisitakul, A. Benyamin-Seeyar, and B. Edison, “Frequency Domain Equalization for Single-Carrier Broadband Wireless Systems,” IEEE Communication Magazine, vol.40, no.4, pp.58-66, April 2002.
D. Garg, and F. Adachi, “Performance of DS-CDMA with Chip Interleaving and Frequency Domain Equalization in a Fading Channel,” IEE Proc. Commun., vol.152, no.6, pp.757-764, Dec. 2005.
D. Garg, and F. Adachi, “Chip Interleaved Turbo Codes for DS-CDMA in a Rayleigh Fading Channel with Diversity Reception,” IEE Electron, Lett., vol.38, no.13, pp.642-644, June 2002.
F. Adachi, T. Sao, and T. Itagaki, “Performance of Multicode DS-CDMA using Frequency Domain Equalization in Frequency-Selective Fading Channel,” Electronic Letter, vol.39, no.2, pp.239-241, Jan. 2003.
F. Adachi, D. Garg, S. Takaoka, and K. Takeda, “Broadband CDMA Techniques,” IEEE Wireless Communication, vol.12, no.2, pp.8-18, April 2005.
H. Hourani, "An Overview of Diversity Techniques in Wireless Communication Systems", Postgraduate Course in Radio Communications (2004/2005), Helsinki University of Technology.
www.comlab.hut.fi/opetus/ 333/2004_2005_slides/Diversity_text.pdf.
K. Takeda, and F. Adachi, “Bit Error Rate Analysis of DS-CDMA with Joint Frequency Domain Equalization and Antenna Diversity Combining,” IEICE Trans. Commun., vol. E87-B, no.10, pp.2991-3002, Oct. 2004.
T. Itagaki, and F. Adachi, “Jiont Frequency-Domain Equalization and Antenna Diversity Combining for Orthognal Multicode DS-CDMA Signal Transmissions in a Frequency-Selective Fading Channel,” IEICE Trans. Commun., vol. E87-B, no.7, pp.1954-1963, July 2004.
Y. YANG, "Frequency-Domain Equalization for Space-Time Block Coded Transmissions over Frequency-Selective Fading Channels", Msc. thesis in Electrical and Computer Engineering National University of Singapore, 2003.