tailieunhanh - Báo cáo hóa học: " Research Article Zero-Forcing and Minimum Mean-Square Error Multiuser Detection in Generalized Multicarrier DS-CDMA Systems for Cognitive Radio"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Zero-Forcing and Minimum Mean-Square Error Multiuser Detection in Generalized Multicarrier DS-CDMA Systems for Cognitive Radio | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2008 Article ID541410 13 pages doi 2008 541410 Research Article Zero-Forcing and Minimum Mean-Square Error Multiuser Detection in Generalized Multicarrier DS-CDMA Systems for Cognitive Radio Lie-Liang Yang1 and Li-Chun Wang2 1 School of Electronics and Computer Science University of Southampton SO171BJ UK 2 Department of Communications Engineering National Chiao Tung University Hsinchu 300 Taiwan Correspondence should be addressed to Lie-Liang Yang lly@ Received 30 April 2007 Revised 15 September 2007 Accepted 17 November 2007 Recommended by Luc Vandendorpe In wireless communications multicarrier direct-sequence code-division multiple access MC DS-CDMA constitutes one of the highly flexible multiple access schemes. MC DS-CDMA employs a high number of degrees-of-freedom which are beneficial to design and reconfiguration for communications in dynamic communications environments such as in the cognitive radios. In this contribution we consider the multiuser detection MUD in MC DS-CDMA which motivates lowcomplexity high flexibility and robustness so that the MUD schemes are suitable for deployment in dynamic communications environments. Specifically a range of low-complexity MUDs are derived based on the zero-forcing ZF minimum mean-square error MMSE and interference cancellation IC principles. The bit-error rate BER performance of the MC DS-CDMA aided by the proposed MUDs is investigated by simulation approaches. Our study shows that in addition to the advantages provided by a general ZF MMSE or IC-assisted MUD the proposed MUD schemes can be implemented using modular structures where most modules are independent of each other. Due to the independent modular structure in the proposed MUDs one module may be reconfigured without yielding impact on the others. Therefore the MC DS-CDMA in conjunction with the proposed MUDs constitutes one of the promising