tailieunhanh - Báo cáo hóa học: " Frequency-domain equalization for OFDMA-based multiuser MIMO systems with improper modulation schemes"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : Frequency-domain equalization for OFDMA-based multiuser MIMO systems with improper modulation schemes | Xiao et al. EURASIP Journal on Advances in Signal Processing 2011 2011 73 http content 2011 1 73 o EURASIP Journal on Advances in Signal Processing a SpringerOpen Journal RESEARCH Open Access Frequency-domain equalization for OFDMA-based multiuser MIMO systems with improper modulation schemes Pei Xiao1 Zihuai Lin2 5 Anthony Fagan3 Colin Cowan4 Branka Vucetic2 and Yi Wu5 Abstract In this paper we propose a novel transceiver structure for orthogonal frequency division multiple access-based uplink multiuser multiple-input multiple-output systems. The numerical results show that the proposed frequencydomain equalization schemes significantly outperform conventional linear minimum mean square error-based equalizers in terms of bit error rate performance with moderate increase in computational complexity. Keywords OFDMA multiple-input multiple-output MIMO frequency-domain equalization 1 Introduction Multiple-input multiple-output MIMO techniques in combination with orthogonal frequency division multiple access OFDMA have been commonly used by most of the 4G air-interfaces . WiMAX long-term evolution IEEE Wireless broadband etc. In the IEEE mobile WiMAX standard OFDMA has been adopted for both downlink and uplink transmission 1 2 . In 3GPP LTE single carrier SC frequency division multiple access FDMA is used for uplink transmission whereas the OFDMA signaling format is exploited for downlink transmission 3 . There are also some proposals on using OFDMA for uplink transmission in the LTE advanced LTE-A standard in which both SC-FDMA and OFDMA can be considered for uplink transmission. This paper investigates receiver algorithms for the uplink of OFDMA-based multi-user MIMO systems. Frequency-domain equalization FDE is commonly used for OFDMA. This includes frequency domain linear equalization FD-LE 4 decision feedback equalization DFE 5 6 and the more recent turbo equalization TE 7 8 . FD-LE is analogous to time-domain LE. A .