naa a22 4500 510798330 CHVBK 20180411083344.0 cr unu---uuuuu 180411e20131001xx s 000 0 eng 10.1007/s11277-013-1151-7 doi (NATIONALLICENCE)springer-10.1007/s11277-013-1151-7 Soft Decision Error Assisted Layered Multiuser Detectors for MIMO 2D Spread MC DS-CDMAs [Elektronische Daten] [Hoang-Yang Lu, Ching-Jer Hung, Jong-Chih Chien] In this paper, we present two layered multiuser detectors (MUDs) for MIMO frequency-time-domain (FT-domain) multi-carrier (MC) direct sequence code division multiple access (DS-CDMA) systems with an antenna array at the base station. We assume that multiple users are active and individually utilize multiple transmit antennas in the MC DS-CDMA system. The users are organized into groups, and each user is assigned a unique Time-domain (T-domain) signature code. Moreover, users in the same group share a unique F-domain signature code. As a result, they can exploit the T-domain and F-domain signature codes to spread their multiple symbols in parallel, and then transmit the FT-domain spread signals from the corresponding multiple antennas over the fading channels to the base station. However, because of the non-ideal channel effect and/or the use of non-orthogonal signature codes, the FT-domain spread MC DS-CDMA system is affected by multiple access interference (MAI) in the same way as CDMA-like systems. To mitigate the effects of MAI and improve the system's performance, we propose two layered MUDs that exploit the layered soft decision errors. Specifically, in a trade-off between the performance and the computational complexity, only the soft decision errors of one user/one group are used in the proposed layered MUDs. The results of simulations and a complexity analysis demonstrate that the proposed layered MUDs outperform existing approaches and the computational complexity is modest. The Author(s), 2013 Layered detector nationallicence Multi-carrier direct sequence code division multiple access nationallicence Multiple input multiple output nationallicence Soft decision error nationallicence Lu Hoang-Yang Department of Electrical Engineering, National Taiwan Ocean University, Keelung, Taiwan, Republic of China aut Hung Ching-Jer Department of Electrical Engineering, Kun-Shan University, Tainan, Taiwan, Republic of China aut Chien Jong-Chih Department of Information Management, Kainan University, Taoyuan, Taiwan, Republic of China aut Wireless Personal Communications Springer US; http://www.springer-ny.com 72/4(2013-10-01), 2305-2320 0929-6212 72:4<2305 2013 72 11277 https://doi.org/10.1007/s11277-013-1151-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11277-013-1151-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Lu Hoang-Yang Department of Electrical Engineering, National Taiwan Ocean University, Keelung, Taiwan, Republic of China aut NATIONALLICENCE 700 1- Hung Ching-Jer Department of Electrical Engineering, Kun-Shan University, Tainan, Taiwan, Republic of China aut NATIONALLICENCE 700 1- Chien Jong-Chih Department of Information Management, Kainan University, Taoyuan, Taiwan, Republic of China aut NATIONALLICENCE 773 0- Wireless Personal Communications Springer US; http://www.springer-ny.com 72/4(2013-10-01), 2305-2320 0929-6212 72:4<2305 2013 72 11277 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer