An analytical approach to the calculation of EVM in clipped OFDM signals

One of the greatest drawbacks of OFDM communication systems is the high peak-to-average power ratio (PAPR) caused by various degrees of coherent summation in the signal generation using IFFT. Theoretical analysis of information capacities of such systems is difficult due to inaccuracies of models using mathematically unjustified assumptions about Gaussianity of distributions. The error-vector magnitude (EVM) of the signal after clipping is addressed. The EVM is calculated with no underlying model, and it is shown how it can be expressed as a power series of the number of tones. Thus it is concluded that although clipping should be minimized, the extent of minimization is channel and scenario dependent.