tailieunhanh - Báo cáo hóa học: "Research Article Duplex Schemes in Multiple Antenna Two-Hop Relaying"

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 Duplex Schemes in Multiple Antenna Two-Hop Relaying | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2008 Article ID 128592 14 pages doi 2008 128592 Research Article Duplex Schemes in Multiple Antenna Two-Hop Relaying Timo Unger and Anja Klein Fachgebiet Kommunikationstechnik Institut fur Nachrichtentechnik Technische Universitiit Darmstadt Merkstrasse 25 64283 Darmstadt Germany Correspondence should be addressed to Timo Unger Received 31 July 2007 Accepted 20 January 2008 Recommended by Thomas Kaiser A novel scheme for two-hop relaying defined as space division duplex SDD relaying is proposed. In SDD relaying multiple antenna beamforming techniques are applied at the intermediate relay station RS in order to separate downlink and uplink signals of a bi-directional two-hop communication between two nodes namely S1 and S2. For conventional amplify-and-forward two-hop relaying there appears a loss in spectral efficiency due to the fact that the RS cannot receive and transmit simultaneously on the same channel resource. In SDD relaying this loss in spectral efficiency is circumvented by giving up the strict separation of downlink and uplink signals by either time division duplex or frequency division duplex. Two novel concepts for the derivation of the linear beamforming filters at the RS are proposed they can be designed either by a three-step or a one-step concept. In SDD relaying receive signals at S1 are interfered by transmit signals of S1 and receive signals at S2 are interfered by transmit signals of S2. An efficient method in order to combat this kind of interference is proposed in this paper. Furthermore it is shown how the overall spectral efficiency of SDD relaying can be improved if the channels from S1 and S2 to the RS have different qualities. Copyright 2008 T. Unger and A. Klein. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in .