EVM Calculation

The error vector magnitude represents theEuclidian distance between the ideal symbolcoordinate and the actual recorded symbol.
EVM is a way to measure and quantify the performance of a comunication system. A comlex signal sent by an ideal transmitter or received by a receiver would have all constellation points precisely at the ideal locations, however various imperfections in the implementation (such as carrier leakage, low image rejection ratio, phase noise etc.) cause the actual constellation points to deviate from the ideal locations. Informally, EVM is a measure of how far the points are from the ideal locations.

EVM calculation:
EVM ≈ 100%*Sphi(f)*π/180 ........Error vector magnitude due to phase noise.