Investigations on OptimumReferenceSignal Structure forSingle-CarrierFDMA RadioAccess

Thispaperpresents theoptimumreference signal (RS) structure forsingle-carrier (SC)-FDMAradioaccessusing discrete Fourier transform (DFT)-spread OFDM tosatisfy the requirements intheEvolved UTRA uplink. Thesimulation results showsthattheoptimumfastFourier transform (FFT)block length, i.e., datablocklength, isapproximately 66.7- 133.3gsec, corresponding totheFFTlength of1024-2048points assuming thesampling frequency of15.36Mega samples persecond. Moreover, itisshownthatanRSstructure thatcomprises twoRS blocks contained within theduration ofa1-msec sub-frame isthe mostpromising candidate basedon superior userthroughput underlowmobility conditions suchasless thanapproximately 120 km/handonahighdegree ofcommonality ofradio parameters suchas thatinthedownlink, considering thefairly low applicability of 16QAM modulation underextremely high mobility conditions suchas350km/h. IndexTerms- Evolved UTRA,single-carrier FDMA,optimum reference signal structure, FFTblocklength