A NovelDynamicStepsize PowerControl Algorithm forUMTS
W-Cdma Systems · 2006
Powercontrol isan essential mechanism forwideband codedivision multiple access(W-CDMA)systems.In our earlier work[1], a combined power control anda greedy ratepacking (GRP)allocation schemeemployingconventional fixed stepsize power control (FSPC)is discussed andevaluated. Inthis paper,we extend the algorithm toapply anovel dynamic stepsize power control (DSPC)algorithm toimprove systemperformance. Thedynamic stepsize (DS)isdetermined bythedifferencebetween thetarget SIR*andthereceived SIR.A larger stepsize isapplied whenthedifference between thereceived SIR andthetarget SIR*islarge toenhancetracking ability, andvice versatoreduce granularnoise.Simulation results showtheeffectiveness oftheproposed DSPCalgorithm, witharound 2% gain ofthroughput, 6.5%averagepower consumption saving and0.5dBstandard deviation (STD)reduction ofthereceived SIR,whencompared withtheFSPCscheme.