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 Medium Access in Spread-Spectrum Ad Hoc Networks with Multiuser Detection | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2009 Article ID 156247 14 pages doi 2009 156247 Research Article Medium Access in Spread-Spectrum Ad Hoc Networks with Multiuser Detection Katsutoshi Kusume 1 Robert Vilzmann 2 Andreas Muller 2 Christian Hartmann 2 and Gerhard Bauch1 1 DOCOMO Euro-Labs Landsberger Strafie 312 80687 Munich Germany 2 Institute of Communication Networks Munich University of Technology Arcisstrafie 21 80290 Munich Germany Correspondence should be addressed to Katsutoshi Kusume kusume@ Received 15 February 2008 Revised 6 June 2008 Accepted 22 July 2008 Recommended by Shinsuke Hara Conventional medium access control protocols are designed to avoid simultaneous transmissions based on a simple collision model in the underlying physical layer. Recently strong physical layer capabilities enabled by multiuser detection techniques have been studied in connection with simple medium access control protocols for example slotted ALOHA. We think that neither of these extreme approaches is optimum particularly in general scenarios where network nodes with different signal processing capabilities coexist. Instead of dealing with interferences in either of the two layers alone both medium access control and physical layer functionalities should be designed to cooperate and complement each other. We discuss several key aspects for designing such a protocol especially with an emphasis on iterative multiuser detection which can provide a good tradeoff between performance and complexity. We propose a new protocol called MUD-MAC which satisfies these key aspects. We analyze its throughput bound and also perform numerical simulations. The simulation results show excellent throughput improvements. It is also demonstrated that the MUD-MAC protocol provides certain fairness among network nodes with different signal processing capabilities. Copyright 2009 Katsutoshi Kusume et al. This is an open .
