... both in-band and out-of-band. In-band distortion results in an error per-formance degradation, while out-of-band radiationreduces spectral efficiency. Filtering methods can reduceout-of-band radiation, ... (l, m) cos−2πlmN and s (l, m) sin−2πlmN.Given l and m, since both c (l, m)ands(l, m)areconstants, the characteristic functions ofˆXl· c (l, m) and Xl· s (l, m)are ... Graphical comparisonFigures 2 and 3 represent the comparison between theestimated (upper) and theoretical (lower) PDs ofm ∈{0,N4,2N4,3N4}for the QPSK and the 16-QAM case,Yoo et al....