tailieunhanh - Báo cáo hóa học: " Frequency domain equalization space-time block-coded CDMA transmission system"

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: Frequency domain equalization space-time block-coded CDMA transmission system | Medina and Sampaio-Neto EURASIP Journal on Wireless Communications and Networking 2011 2011 80 http content 2011 1 80 EURASIP Journal on Wireless Communications and Networking a springeropen Journal RESEARCH Open Access Frequency domain equalization space-time block-coded CDMA transmission system César Augusto Medina and Raimundo Sampaio-Neto Abstract In this work we propose a space-time block-coded STBF CDMA transmission system suitable for use with frequency domain equalization FDE algorithms. We illustrate the FDE by implementing the maximal ratio combining the zero forcing and the minimum mean squared error single user detection algorithms. A diversity gain analysis is developed and some interesting results are pointed out. It is shown through computer simulations that the proposed transmission system exhibits good performance in terms of bit error rate when compared to previously proposed STBC CDMA transmission systems. Keywords frequency domain equalization FDE space-time block-codes STBC single carrier CDMA transmission systems multicarrier CDMA transmission systems 1 Introduction Space-time block-codes STBC schemes have emerged as a powerful transmit diversity technique to combat fading in wireless communications. One of the most successful space-time coding scheme was first proposed by Alamouti 1 for the case of two transmit and multiple receive antennas. Further developments for more than two transmit antennas were later reported on 2 3 and it was shown that the Alamouti s scheme is the only existing complex orthogonal design with full rate full diversity and minimal delay. STBC was applied for direct-sequence code division multiple access DS-CDMA transmission system in 4 5 . All the aforementioned systems 1 5 assume flat-fading channels and suffer performance degradation in frequency-selective channels. Some STBC schemes to deal with frequency selectivity have been proposed for orthogonal frequency division multiplexing OFDM 6 .