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: Research Article A Novel Quantize-and-Forward Cooperative System: Channel Estimation and M-PSK Detection Performance | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2010 Article ID 415438 11 pages doi 2010 415438 Research Article A Novel Quantize-and-Forward Cooperative System Channel Estimation and M-PSK Detection Performance Iancu Avram Nico Aerts Dieter Duyck and Marc Moeneclaey Department of Telecommunications and Information Processing Faculty of Engineering Ghent University 9000 Gent Belgium Correspondence should be addressed to Iancu Avram Received 26 January 2010 Revised 16 May 2010 Accepted 4 July 2010 Academic Editor Carles Anton-Haro Copyright 2010 Iancu Avram et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. A method to improve the reliability of data transmission between two terminals without using multiple antennas is cooperative communication where spatial diversity is introduced by the presence of a relay terminal. The Quantize and Forward QF protocol is suitable to implement in resource constraint relays because of its low complexity. In prior studies of the QF protocol all channel parameters are assumed to be perfectly known at the destination while in reality these need to be estimated. This paper proposes a novel quantization scheme in which the relay compensates for the rotation caused by the source-relay channel before quantizing the phase of the received M-PSK data symbols. In doing so channel estimation at the destination is greatly simplified without significantly increasing the complexity of the relay terminals. Further the destination applies the expectation maximization EM algorithm to improve the estimates of the source-destination and relay-destination channels. The resulting performance is shown to be close to that of a system with known channel parameters. 1. Introduction As wireless communication .
