tailieunhanh - Báo cáo hóa học: " Differential Space-Time Coding Scheme Using Star Quadrature Amplitude Modulation Method"

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: Differential Space-Time Coding Scheme Using Star Quadrature Amplitude Modulation Method | Hindawi Publishing Corporation EURASIP Journal on Applied Signal Processing Volume 2006 Article ID 89849 Pages 1-12 DOI ASP 2006 89849 Differential Space-Time Coding Scheme Using Star Quadrature Amplitude Modulation Method Xiangbin Yu 1 DaZhuan Xu 1 2 and Guangguo Bi2 1 Information and Communication Engineering Postdoctoral Research Station Nanjing University of Aeronautics and Astronautics Nanjing 210016 China 2 National Mobile Communications Research Laboratory Southeast University Nanjing 210096 China Received 5 July 2005 Revised 11 January 2006 Accepted 13 January 2006 Recommended for Publication by Richard Barton Differential space-time coding DSTC has received much interest as it obviates the requirement of the channel state information at the receiver while maintaining the desired properties of space-time coding techniques. In this paper by introducing star quadrature amplitude modulation star QAM method two kinds of multiple amplitudes DSTC schemes are proposed. One is based on differential unitary space-time coding DUSTC scheme and the other is based on differential orthogonal space-time coding DOSTC scheme. Corresponding bit-error-rate BER performance and coding-gain analysis are given respectively. The proposed schemes can avoid the performance loss of conventional DSTC schemes based on phase-shift keying PSK modulation in high spectrum efficiency via multiple amplitudes modulation. Compared with conventional PSK-based DSTC schemes the developed schemes have higher spectrum efficiency via carrying information not only on phases but also on amplitudes and have higher coding gain. Moreover the first scheme can implement low-complexity differential modulation and different code rates and be applied to any number of transmit antennas while the second scheme has simple decoder and high code rate in the case of 3 and 4 antennas. The simulation results show that our schemes have lower BER when compared with conventional DUSTC and DOSTC schemes. .