tailieunhanh - Báo cáo hóa học: " Quality of service implications of power control and multiuser detection-based cross-layer design"

Quality of service implications of power control and multiuser detection-based cross-layer design | Korger et al. EURASIP Journal on Wireless Communications and Networking 2011 2011 9 http content 2011 1 9 o EURASIP Journal on Wireless Communications and Networking a SpringerOpen Journal RESEARCH Open Access Quality of service implications of power control and multiuser detection-based cross-layer design Ulrike Korger1 Christian Hartmann1 Katsutoshi Kusume2 and Joerg Widmer3 Abstract In order to allow for dense spatial reuse in wireless ad hoc networks multiple access interference must be dealt with. This calls for advanced physical layer techniques such as multiuser detection MUD or power control. However these techniques can only be efficiently applied to ad hoc networks when they are part of a joint physical layer PHY and Medium Access Control MAC cross-layer design CLD . In order to better understand both the potential but also the limits of handling interference by means of MUD and power control respectively in this article we provide a comprehensive comparison between MUD-based and power control-based CLDs. We study the behavior of both approaches in terms of throughput delay as well as fairness in scenarios with high and low user densities respectively. To provide more detailed insight in the interaction between MAC and PHY we separate for each approach the throughput results into gains achieved solely by the MAC layer and by the PHY layer respectively. These results highlight among other aspects some fundamental disadvantage of power control in distributed environments. We conclude that multiuser-based approaches are significantly more beneficial in ad hoc scenarios than power control-based schemes. Introduction Dense ad hoc networks typically suffer from multiple access interference MAI . A well known approach to battle this interference is to block users in the vicinity of a communication pair . by applying an RTS CTS signaling as in the IEEE protocol which however obviously limits the spatial reuse significantly. When