naa a22 4500 510798950 CHVBK 20180411083346.0 cr unu---uuuuu 180411e20130901xx s 000 0 eng 10.1007/s11277-013-1085-0 doi (NATIONALLICENCE)springer-10.1007/s11277-013-1085-0 Differential Quadrature Amplitude Modulation and Relay Selection with Detect-and-Forward Cooperative Relaying [Elektronische Daten] [Yang Gao, Jianhua Ge, Weijie Cong] In this paper, we consider a cooperative communication system with differential modulation and relay-selection (DM-RS) in multi-relay networks, where the best relay is selected to forward the source node's signal to the destination node with detect-and-forward (DetF) protocol. Unlike the conventional DM-RS-DetF scheme using phase shift keying (PSK), we propose a DM-RS-DetF scheme with quadrature amplitude modulation (QAM). Since the differential PSK scheme cannot be applied to the QAM constellations directly, we firstly develop the modulation and demodulation methods for the differential QAM scheme. Then, we derive a closed-form approximation and an upper bound of the symbol error rate for the DQAM-RS-DetF scheme over independent Rayleigh fading channels, by using the approximated signal-to-noise ratio of the equivalent relay link. Simulations results verify the validity of the analytical results and further show that when the modulation order $$M>8$$ in Rayleigh fading channels, the DQAM-RS-DetF scheme outperforms the DPSK-RS-DetF scheme. Springer Science+Business Media New York, 2013 Cooperative communication nationallicence Differential modulation nationallicence Detect-and-forward nationallicence Relay selection nationallicence Gao Yang State Key Laboratory of Integrated Service Networks, Xidian University, Xi'an, China aut Ge Jianhua State Key Laboratory of Integrated Service Networks, Xidian University, Xi'an, China aut Cong Weijie School of Science, Xi'an University of Posts and Telecommunications, Xi'an, China aut Wireless Personal Communications Springer US; http://www.springer-ny.com 72/2(2013-09-01), 1399-1414 0929-6212 72:2<1399 2013 72 11277 https://doi.org/10.1007/s11277-013-1085-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11277-013-1085-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Gao Yang State Key Laboratory of Integrated Service Networks, Xidian University, Xi'an, China aut NATIONALLICENCE 700 1- Ge Jianhua State Key Laboratory of Integrated Service Networks, Xidian University, Xi'an, China aut NATIONALLICENCE 700 1- Cong Weijie School of Science, Xi'an University of Posts and Telecommunications, Xi'an, China aut NATIONALLICENCE 773 0- Wireless Personal Communications Springer US; http://www.springer-ny.com 72/2(2013-09-01), 1399-1414 0929-6212 72:2<1399 2013 72 11277 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer