tailieunhanh - Báo cáo hóa học: " Multihop relaying and multiple antenna techniques: performance trade-offs in cellular systems"

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: Multihop relaying and multiple antenna techniques: performance trade-offs in cellular systems | Jacobson and Krzymien EURASIP Journal on Wireless Communications and Networking 2011 2011 65 EURASIP Journal op . http content 2011 1 65 Wireless Communications and Networking a SpringerOpen Journal RESEARCH Open Access Multihop relaying and multiple antenna techniques performance trade-offs in cellular systems Kevin R Jacobson1 2 and Witold A Krzymien1 2 Abstract Two very important and active areas of wireless research are multihop relaying and multiple antenna techniques. Wireless multihop relaying can increase the aggregate network data capacity and improve coverage of cellular systems by reducing path loss mitigating shadowing and enabling spatial reuse. In particular multihop relaying can improve the throughput for mobiles suffering from poor signal to interference and noise ratio at the edge of a cell and reduce cell size to increase spectral efficiency. On the other hand multiple antenna techniques can take advantage of scattering in the wireless channel to achieve higher capacity on individual links. Multiple antennas can provide impressive capacity gains but the greatest gains occur in high scattering environments with high signal to interference and noise ratio which are not typical characteristics of cellular systems. Emerging standards for fourth generation cellular systems include both multihop relaying and multiple antenna techniques so it is necessary to study how these two work jointly in a realistic cellular system. In this paper we look at the joint application of these two techniques in a cellular system and analyze the fundamental tradeoff between them. In order to obtain meaningful results system performance is evaluated using realistic propagation models. Keywords MIMO transmission Multiple antennas Multihop relaying Cross-layer design 4G cellular networks LTE-Advanced I Introduction The key goals for future broadband cellular systems are reliable data transmission up to 1 Gb s at high spectral efficiency good coverage